POWER DISTRIBUTION SYSTEM
20230155390 · 2023-05-18
Inventors
- Madhu Sudhan Chinthavali (Oak Ridge, TN, US)
- Michael Starke (Oak Ridge, TN, US)
- Radha Krishna Moorthy (Oak Ridge, TN, US)
- Steven Campbell (Oak Ridge, TN, US)
Cpc classification
H02J1/084
ELECTRICITY
H02J3/06
ELECTRICITY
H02J3/46
ELECTRICITY
H02J2203/20
ELECTRICITY
International classification
H02J3/38
ELECTRICITY
Abstract
A hierarchical approach is provided to integrate functions and components into the various systems and subsystems within a distribution network, including standardization of modular and scalable power electronics power blocks with embedded diagnostics and prognostics.
Claims
1. A solid-state power substation (SSPS) comprising: a plurality of smart universal power electronic regulators (SUPERs); a first control system communicatively coupled to the plurality of SUPERs, the first control system associated with one of a node or a hub; wherein, in the case of the first control system being associated with the node, the node includes the plurality of SUPERs connected together to a single point of connection of a power grid, wherein the point of connection includes one or two feeders; wherein, in the case of the first control system being associated with the hub, the hub includes the plurality of SUPERs, wherein a first one of the plurality of SUPERs is connected to a first feeder, wherein a second one of the plurality of SUPERs is connected to a second feeder; and wherein each SUPER includes one or more intelligent power stages (IPSs) and is configured to be operated according to one of a plurality of converter classes, wherein the plurality of converter classes include a DC load interface (DCLI), an AC load interface (ACLI), a DC source interface (DCSI), an AC source interface (ACSI), or a grid interface (GI).
2. The SSPS of claim 1 wherein the point of connection of the power grid includes the first feeder, such that the first one of the plurality of SUPERs is connected to the point of connection of the power grid.
3. The SSPS of claim 1 wherein the first one of the plurality of SUPERs is connected to at least one feeder in addition to the first feeder, and wherein the second one of the plurality of SUPERs is connected to at least one feeder in addition to the second feeder.
4. The SSPS of claim 1 comprising a second plurality of SUPERs and a second control system communicatively coupled to the second plurality of SUPERs.
5. The SSPS of claim 4 wherein: the first control system is provided in the node, such that the node includes the plurality of supers connected together to a single point of connection of the power grid; the second control system is associated with the hub; the hub includes the second control system and the second plurality of SUPERs; a first one of the second plurality of SUPERs is connected to a third feeder; and a second one of the second plurality of SUPERs is connected to a fourth feeder.
6. The SSPS of claim 1 wherein the hub controller is operable to coordinate operation of the second plurality of SUPERs to control power flow between the first feeder and the second feeder.
7. The SSPS of claim 6 wherein the hub controller is operable to control voltage for at least one of the first and second feeders.
8. The SSPS of claim 6 wherein: the first feeder operates at a first voltage and a first frequency; the second feeder operates at a second voltage and a second frequency; and at least one of the first voltage and the first frequency is different respectively from the second voltage and the second frequency.
9. A solid-state power substation (SSPS) comprising: a first plurality of smart universal power electronic regulators (SUPERs), each of the first plurality of SUPERs operable to provide either a load interface to a load or a source interface to a feeder; a second plurality of SUPERs, each of the second plurality of SUPERs operable to provide a load interface to a feeder; a node including the first plurality of SUPERs connected together to a single point of connection of a power grid; a node controller associated with the node, the node controller communicatively coupled to the first plurality of SUPERs of the node, the node controller operable to direct operation of the first plurality of SUPERs to control power for at least one of the load and the feeder; a hub including the second plurality of SUPERs, a first one of the second plurality of SUPERs connected to a first feeder and a second one of the second plurality of SUPERs connected to a second feeder; and a hub controller associated with the hub, the hub controller communicatively coupled to the second plurality of SUPERs of the hub, the hub controller operable to direct operation of the SUPERs to control power flow between the first and second feeders.
10. The SSPS of claim 9 wherein the hub controller and the node controller are provided by a server system remote from the first and second pluralities of SUPERs.
11. The SSPS of claim 9 wherein the SSPS is associated with an SSPC controller operable to direct operation of the node and hub controllers of the SSPS.
12. The SSPS of claim 9 wherein the SSPS controller is communicatively coupled to a domain controller associated with a power transmission substation.
13. The SSPS of claim 9 wherein the first feeder is coupled to the hub, and wherein the single point of connection of the power grid corresponds to the first feeder.
14. A power distribution system comprising: a plurality of smart universal power electronic regulators (SUPERs); a control system communicatively coupled to the plurality of SUPERs; a first one of the plurality of SUPERs connected to and operably coupled to a first feeder, the first one of the plurality of SUPERs configured to control a characteristic of power associated with the first feeder; and each SUPER includes one or more intelligent power stages (IPSs) and is configured to be operated according to one of a plurality of converter classes, wherein the plurality of converter classes include a DC load interface (DCLI), an AC load interface (ACLI), a DC source interface (DCSI), an AC source interface (ACSI), or a grid interface (GI).
15. The power distribution system of claim 14 wherein the first one of the SUPERs is configured to control the characteristic of power received from the first feeder.
16. The power distribution system of claim 14 wherein the first one of the SUPERs is configured to control the characteristic of power provided to the first feeder.
17. The power distribution system of claim 14 wherein the plurality of SUPERs are provided in a node of the power distribution system, wherein the plurality of SUPERS are connected together to a single point of connection of a power grid, wherein the single point includes the first feeder.
18. The power distribution system of claim 14 comprising: a second plurality of SUPERs provided in a hub of the power distribution system, wherein a first one of the second plurality of SUPERs is connected to a second feeder and a second one of the second plurality of SUPERs is connected to a third feeder; and a second control system is communicatively coupled to the second plurality of SUPERs and operable to control power flow between the second and third feeders.
19. The power distribution system of claim 14 wherein the plurality of SUPERs are provided in a hub of the power distribution system, wherein a second one of the plurality of SUPERs is connected to a second feeder, and wherein the control system is operable to control power flow between the first and second feeders.
20. The power distribution system of claim 19 wherein: the second feeder operates at a second voltage and a second frequency; the third feeder operates at a third voltage and a third frequency; and at least one of the second voltage and the second frequency is different respectively from the third voltage and the third frequency.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0117] In one embodiment according to the present disclosure, there are numerous capabilities that PE systems can add to the electric grid beyond a simple conversion of energy. PE systems have been shown to be able to support electric grid nodal voltage through dynamic control of reactive power, power quality improvement through harmonic cancellation, fast responsive control to provide grid resiliency through islanding, and direct and precise management of power. In one embodiment, providing and extracting value from these functions is based on orchestration of system hierarchies of the PE systems and integration into solid state power substations.
[0118] An SSPS in accordance with one embodiment may be classified based on voltage and power: distribution (SSPS up to 34.5 kV), sub-transmission (SSPS up to 138 kV) and transmission (SSPS greater than 138 kV).
[0119] An SSPS framework in accordance with one embodiment defines an architecture and associated layers for SSPS up to 35 kV. This includes linking everything between a grid-edge device to distribution scale solid state substations. While this configuration may not be described in conjunction with sub-transmission and transmission systems directly, the present disclosure is not so limited—the SSPS framework may be potentially applied in other systems including sub transmission and transmission systems powers greater than 35 kV.
[0120] In one embodiment, a hierarchical approach to integrate advance functions and components into the various systems and subsystems within the distribution network is provided, including standardization of modular and scalable PE power blocks with embedded diagnostics and prognostics. In one embodiment, with strategic integration of intelligent platforms and communication interfaces, PE systems in substations can be used to apply new grid functions and control flexibility to the grid. For instance, interoperability, wide-scale communication, and control, autonomous operations, and cyber security risks may be addressed in accordance with the one impediment. As another example, machine learning or artificial intelligence at the grid edge may provide or facilitate autonomous decision making of systems without resorting to fast communications and controls for a system of tens of thousands of devices.
[0121] One embodiment according to the present invention may include many levels of controllers and embedded intelligence to automate energy flow between sources and loads. These controllers can be hosted in physical platforms in a node, hub, or a solid-state substation or as a “virtual substation” residing in a cloud construct. To enhance grid reliability, resiliency, power quality, economics, and efficiency, the SSPS architecture may be standardized, modular, and scalable. The SSPS architecture may include one or more of different layers, controls, and protections.
[0122] The SSPS system may be based on hierarchical layers, which may include power electronic converters. An SSPS controller may control and coordinate the components (aggregators, such as nodes and hubs) of the system over a geographical area.
[0123] For instance, the SSPS-based system based on hierarchical layers may provide edge nodes that can transform the way the grid operates by establishing coordinated control in a single feeder, or between multiple feeders, and can enhance or maximize the grid support from the edge nodes. Interoperability and vendor agnostic configurations may be supported.
[0124] The SSPS-based system based on hierarchical layers may also provide a universal architecture that can enhance or maximize grid support functions from a single SSPS node, link, or hub by splitting the functions across various converters (e.g., SUPERs) in a multi-port framework. This configuration may also reduce the number of grid-connected nodes compared to conventional systems.
[0125] I. SSPS Aspects
[0126] The system in accordance with one embodiment of the present disclosure may facilitate control or mitigation over several aspects of power distribution.
[0127] For instance, with respect to voltage and frequency regulation, the SSPS may provide active and reactive support for voltage and frequency stabilization. The SSPS may enhance the power quality and prevent flicker. The SSPS may be configured to provide such support via control over apparent and reactive power (PQ), Volt-var control, or power factor control, or a combination thereof for power quality enhancement. The SSPS may provide control for correction of voltage deviations associated with flicker.
[0128] The SSPS can tackle phase imbalance by providing dynamic balance algorithms. The SSPS may be adapted for phase imbalance control by utilizing strategies such as Volt-var control for voltage stabilization or correction of sequence components.
[0129] Quick islanding and resynchronization may also be enabled by the SSPS with respect to islanding that is intentional or unintentional. This operability with respect to the SSPS may enhance safety for maintenance and limit energy delivered to a fault. Additional operability with respect to islanding includes providing reliable, low voltage ride through and fault ride through capabilities for inverter-based generation, black start capability, and ease of islanding resynchronization.
[0130] The SSPS in one embodiment can enable capacity expansion without the need for upgrading existing infrastructure. The DC coupled architecture of the SSPS may enable simplified integration of renewables and energy storage units and expansion. This may reduce the impact of higher penetration of distributed generation on existing utility equipment without requiring significant equipment upgrades.
[0131] The SSPS in one embodiment may provide voltage support and substantially eliminate the need for voltage regulators or capacitor banks in the Power Distribution system. Control algorithms for Volt-var, PQ, PV, or power oscillation damping, or a combination thereof, may be provided. The SPSS may be provided in a system with distributed intelligence for autonomous decision-making capabilities, such as mode changing capabilities for PQ and power factor based on local measurements.
[0132] In one embodiment, the SSPS may support active filtering or power factor correction with respect to harmonics caused by non-linear loads. Active filtering may be provided with respect to dominant harmonics (3rd, 5th, 7th . . . 11th), and a multi-port configuration may help to eliminate the need for diode-based power conversion stages or redundant power conversion stages. The SSPS in this configuration may help to enable loads with active front ends.
[0133] II. Overview
[0134] In
[0135] Utility: Utility level layers may include wide area management systems, such as a DMS controller 162 or an advanced distribution management system (ADMS) controller, which may be based on a DMS controller 162 but with additional functionality. For purposes of disclosure, one or more embodiments are described herein in conjunction with a DMS or DMS controller 162; however, the DMS or DMS controller 162 may be respectively replaced with an ADMS or ADMS controller. The utility level layer may include a utility transmission system 160. The resource management systems within a utility distribution network may correspond to a DMS or an ADMS. The DMS or the ADMS may focus on managing the distribution voltage through control of capacitor banks and other substation equipment. An SSPS, described herein, may take directive from the DMS controller 162 to carry out voltage transformation, electrical isolation, managing power flow, and power system protection for distribution electric grid networks. The SSPS may incorporate and facilitate management of power distribution for assets 150, such as distributed generation (DG) and energy storage (ES), electric vehicle (EV) charging stations, and data centers. As described herein in conjunction with one embodiment, the DMS may form part of a hierarchal systems to sub-divide an optimization problem into different layers, potentially enhancing reliability and resiliency for a variety of applications, including microgrids, nano grids, and even hybrid AC-DC systems.
[0136] The utility level layer may represent the entire electrical network owned by a utility including the larger distribution network. The utility in this case may also operate the overall system through the DMS. For instance, the DMS may coordinate with SSPS controllers 112 to manage the distribution network voltage between a transmission substation 160 and SSPS 110.
[0137] SSPS: An SSPS level layer or SSPS 110 may include power electronics converter systems and an SSPS controller 112, along with other substation equipment for filtering, monitoring, and protection.
[0138] The SSPS 110 may reside within a substation. The SSPS controller 112 may be used to communicate and control devices within the SSPS 110 and coordinate the nodes 120, the hub 130, and free acting SUPERs 140 within the downstream feeders. The SSPS 110 may be configured to manage real and reactive power to support voltage and energy delivery within the substation and interconnected feeders.
[0139] Additional features of the SSPS 110 are depicted in the illustrated embodiments of
[0140] Node: Node level layers or node 120 may include a cluster of building blocks termed as smart universal power electronics regulators (SUPERs) 140 tied together to a single point of connection to one feeder. A node architecture template that can be extended to a variety of distribution scale applications is shown in
TABLE-US-00001 Type: Description: DCSI/ACSI Used for interfacing DC or AC sources in a system. Used for functions like power flow, frequency regulation, black start and voltage translation. Can be a low frequency or hybrid transformer in case of ACSI. DCLI/ACLI Designed to support load functions like power flow control and load transient management in case of EV etc. GI Grid-tied converters used for functions like active harmonic filtering, reactive power compensation, etc.
[0141] As depicted in the illustrated embodiments, the node level layer may include a node controller 122.
[0142] In one embodiment, a node 120 may be defined as an electrical network that contains SUPERs 140 interconnected to a single point of connection. The node controller 122 may coordinate the SUPERs 140 to inject net real and reactive power to the point of common coupling (PCC) and to perform other local supporting functions within the node 120 (such as improved resiliency control options offered by droop type controls.) This type of system can be represented in the form of a microgrid or nano-grid, such as the one depicted in the template of
[0143] It is noted that the template of
[0144] Hub: A hub level layer or hub 130 may include a cluster of power electronic interfaces (i.e., SUPERs 140), which tie multiple feeders together or from which multiple feeders emanate as shown in
[0145] In one embodiment, a hub 130 may be defined as an electrical network that includes a plurality of SUPERs 140, which interconnect multiple feeders. A hub controller 132 may coordinate the SUPERs 140 to control power flow through the hub 130 and to support voltage along the feeder. The hub controller 132 (or a node 120) may also be responsible for ensuring stability of the converter network within the hub 130. A hub 130 can be used to interconnect two systems with different frequencies and voltages, such as the hub architecture depicted in the illustrated embodiment of
[0146] SUPER: A SUPER level or SUPER 140 may be a primary building block of the nodes 120 and the hubs 130. As discussed herein, a SUPER 140 may be a power conversion entity or PEC with integrated control, protection, communication, and embedded intelligence and decision-making capability. The SUPER 140 may include one or more entities described herein as intelligent power stages (IPSs). An arrangement of a plurality of SUPERs 140, some of which may be configured differently from each other, may provide a common framework for different voltage levels, futuristic loads and sources, and central controller integration. The power requirements for a particular application (e.g., an asset 150) can be met by connecting the SUPERs in series or parallel.
[0147] III. Nodes and Hubs
[0148] Nodes 120 and hubs 130 may provide the backbone of the SSPS architecture and the two can be differentiated based on the power layout and the feeder configuration. That is, the nodes 120 and the hubs 130 can be differentiated based on the number of incoming or outgoing feeders and the point of connection. At the grid edge and at the substation level, nodes 120 and hubs 130 can be linked to form regions that can be coordinated to improve grid resiliency, reliability, power quality and security. As a result, nodes 120 and hubs 130 can be defined as autonomous, intelligent grid-entities capable of power and information exchange and serve as an interface between the grid and the end user. By coordinating multiple downstream SUPERs 140, the nodes 120 and hubs 130 can facilitate realization of various grid functions, including voltage regulation, frequency regulation, phase balancing, and harmonic filtering simultaneously without compromising on the load requirements at the consumer end.
[0149] The SUPERs 140 and IPSs, designated by reference number 146 herein, are modular and scalable building blocks configured to provide different pre-defined functionalities. These fundamental building blocks allow the distribution and segregation of the controls, protection, and intelligence at various levels of the hierarchy ensuring fast decision-making capability and response to transient or abnormal conditions. Additionally, the fundamental blocks are equipped with additional features, such as cyber-physical security, health monitoring to facilitate resilient, and reliable grid tied systems.
[0150] Nodes 120 and hubs 130 may be multiport systems built with SUPERs (e.g., multiple source and load interfaces). This consolidation may increase the grid security by minimizing or reducing the number of power electronics (PE) interfaces in the grid, reduce the number of transactive systems for utility management systems (and therefore reduce computational capability), enable segregation of grid functions, and provide parallel execution of multiple grid functions. As shown in
[0151] The DCSI 123 and the ACSI 126 may be used for interfacing respective DC or AC sources in a system. For example, the DCSI 123 and the ACSI 126 may be configured to control power flow, frequency regulation, black start, and voltage translation. The ACSI 126 may also include a hybrid transformer. As another example, an ACSI 126 or DCSI 123 converter coupled to an energy storage system (ES) may be configured for power flow control battery state of charge control, or charge/discharge rate control, or a combination thereof.
[0152] The DCLI 129 and the ACLI 128 may be configured to support load functions, such as power flow control and load transient management in the case of a load (e.g., an asset 150) in the form of an electric vehicle. The ACLI 128 or DCLI 129 converter configuration vary based on the asset 150 or type of asset coupled to the converter. For instance, a load facing converter coupled to an electric vehicle (EV) may be configured to generate maximum power point tracking or power rate control (ramp rate), or a combination thereof.
[0153] The GI 125 provided is a grid tied converter operable for active harmonic filtering or reactive power compensation, or both. The GI 125 configuration may vary depending on the application and may provide harmonic filtering or reactive power injection.
[0154] As described herein, the SUPERs 140 may be configured according to one or more converter classes defined within the system 100. The converter classes may be used interchangeably to the extent such changes are software-based and do not require physical changes to a SUPER 140. For instance, a load-facing converter may be reconfigured as a grid tied converter based on software changes only in one embodiment. A matrix of fundamental blocks, such as the SUPERs 140 may be used to design a variety of power distribution topologies, including asynchronous ties, interties, and HVDC links.
[0155] IV. Control Architecture
[0156] The SSPS 110 may be represented as a set of systems and the feeders that are connected to a transmission substation 160. To control and coordinate these downstream systems the SSPS controller 112 may be configured in accordance with the controller 300 depicted in the illustrated embodiment of
[0157] The controller 300 in the illustrated embodiment includes a database 350 operable to store information obtained from components of the SSPS 110, such as the node 120, the hub 130, and devices not attached to a hub 130 or node 120. The nodes 120 and the hubs 130 may be grouped together as a node/hub pool 330, and the device is not attached to a hub 130 or a node 120 and may be grouped as an unattached pool 340. Information from these two pools may be stored separately in the database 350.
[0158] The controller 300 may include a processor 310 operable to analyze information obtained from the database 350 and determine objectives and constraints with respect to the components of the SPS 110. The objectives and constraints may be provided from the processor 310 to an optimization processor 320 (which may be integral to the processor 310 or separate therefrom as depicted). The optimization processor may determine price and quantity information with respect to energy and services. This information may be communicated to components of the node/hub pool 330 and devices of the unattached pool 340.
[0159] The SSPS 110 may be represented as a set of systems in the feeders that are connected to a substation 160. Control and coordination of these downstream systems via an SSPS controller 112 may be implemented as a controller 300 described herein. The SSPS controller 112 may either reside in the cloud or push needed calculations (or services) to the cloud such as artificial intelligence (AI) and optimization. The SSPS controller 112 may determine the amount of additional grid services that may be required, and amount of energy based on forecasts. Based on available data, considering the electrical network and electrical system needs, a transactive market for hubs 130, nodes 120, and SUPERs 140 (in the unattached pool 340 or not already residing in a hub 130 or node 120) may be available. This may provide an opportunity for the hubs 130, nodes 120, and SUPERs 140 in the unattached pool 340 to bid and provide services and energy beyond the point of interconnection. Market clearing on needs may establish the target objectives of the hubs 130, nodes 120, and SUPERs 140 for different time intervals. This information may be shared with a DMS controller 162 to be aggregated with other SSPSs 110.
[0160] A multi-level architecture in accordance with one embodiment may facilitate preserving customer privacy, being less dependent on a central system, and provide relatively high plug-and-play capability. Even within such a multi-level architecture, different distributed communication can be utilized, such as those that use a coordinator, or without a coordinator, a ring connection, or random connections.
[0161] Optimization of nodes 120 or hubs 130, or a component thereof, within the electric grid may be achieved in a variety of ways in accordance with one or more embodiments described herein. Optimization may be implemented by a respective node controller 122 or a hub controller 132. The optimization approach may target design improvements, improved operational efficiency, and energy management and voltage control in electrical networks. However, the present disclosure is not limited to such optimization approaches. The SSPS 110, node 120, or hub 130 can do more than pure energy and voltage supporting systems for the electric grid. Operational capabilities of an SSPS 110, node 120, or hub 130, or a component thereof, may include the ability to detect and transition electrical networks to islanded networks due to electric grid challenges, provide harmonic attenuation and power quality improvement, coordinate load sharing and formation, and support multiple levels of system protection to name a few. These are operating capabilities of the SSPS 110, node 120, or hub 130 that are provided in both normal and abnormal operating conditions automatically at potentially the cost of not meeting optimized targets. In one embodiment, the amount of capability a resource is to provide at any given instance may be determined based on an established setting instrumented into the SSPS 110, node 120, or hub 130, or a component thereof deployment and not based on current operating conditions within the electric grid. However, this may hamper integration efforts by potentially falsely portraying availability or neglecting a main charge.
[0162] In one embodiment, the hub 130 or node 120 may utilize a SUPER 140 to provide advanced control capabilities and leverage machine learning models for managing operation of the SSPS 110. The hub controller 132 or node controller 122 may be operable to characterize one or more SUPERs 140 of the system and an electrical model of the system, and to direct system needs based on historical data stored in memory (e.g., database 350). Resource characteristics include accurately portraying the SUPER capability considering environmental impacts, weather forecasts, and other parameters, while direct system needs may establish the potential changes in harmonics, system impedance, system voltage and frequency based on historical trends. The node controller 122 or the hub controller 132, via machine learning models, may be operable to generate bidding strategies.
[0163] Controller coordination among components of the system 100, including the SSPS 110, the hubs 130, and the nodes 120 may be achieved in a variety of ways, including mixed integer linear programming or other techniques. The mixed integer linear programming may involve optimization formulation considering economics, such as cost of P and Q, allocation for reserves for dynamic conditions/operations, reserves, downstream nodes/hubs architecture, or available control modes, or a combination thereof. Other possible techniques include hybrid techniques, such as machine learning, training data set generation for different operating conditions, problem formulation based on feeder losses, and system training and testing. Training data set generation for different operating conditions may be based on variables such as grid parameters and hub/node parameters. Problem formulation based on feeder losses may also be based on placement of the nodes/hubs.
[0164] Optimization algorithms implemented by the SSPS controller 112 may be based on swarm intelligence, evolutionary algorithms, neural networks, fuzzy logic, or deterministic, stochastic, or robust methods, or any combination thereof. The optimization may be multi-objective and may consider accepted bids, a need to reduce power quality issues, capture poor forecasting challenges, and other system factors. The output of the optimization algorithm may be a set of prioritized control modes, thresholds, and operating setpoints for a SUPER 140 or a multiple SUPERs 140.
[0165] As discussed herein in conjunction with one or more embodiments, the SUPER architecture may include multiple levels of controls and decision making, which can be coordinated with the hub controller 132 or the node controller 122. The hub controller 132 or the node controller 122 may distribute a set of control modes and priorities to SUPERs 140 such that fast communication between the hub controller 132 or the node controller 122 and SUPERs 140 may not be required. Instead, for example, only local measurements and nearby devices requiring support may drive the control decisions within the SUPER 140. The SUPER controller 142, as described herein and shown in
[0166] The three levels of controls (e.g., SSPS control, hub control/node control node and SUPER control) may utilize timing requirements to keep the system responsive to both abnormal and normal grid conditions. The identified timing requirements for the three layers in accordance with one embodiment is shown in
[0167] In the illustrated embodiment, the hub controller 132/node controller 122 may coordinate with the SUPER controller 142 in the order of minutes based on the changes in the grid or system conditions. The hub controller 132 and/or the node controller 122, within this control loop, may control splitting of reactive and apparent power and grid functions across multiple SUPERs 140 and communicate directives to optimize or enhance operation and coordination of the SUPERs 140.
[0168] The SSPS controller 112 may communicate with the hub controller 132 or the node controller 122 in the order of tens of minutes for transactive control. Within this control loop, the SSPS controller 112 may negotiate with the DMS 162 and negotiate bids with the hub controller 132 and/or the node controller 122.
[0169] The SUPER 140 may be configured to emulate a conventional power converter via one or more IPSs 146 (e.g., multiple subsystems/power stages). The SUPER controller 142 may be operable as the secondary controller while the subsystems (e.g., the IPS controllers 147) are the primary controllers. Based on the type of interface, the SUPER controller 142 may host regulation curves, the PLL, and the outer and the inner control loops. The SUPER 140 may generate AC voltage references (for 1-ph/3-ph DC/AC configurations) or the duty cycles (for DC/DC configurations). The reference or duty cycles, or other signals generated by the SUPER 140, may be relayed through a communication channel (optionally a dedicated communication channel) to the IPSs 146. The IPSs 146 may be equipped with PWM generators to generate gating signals based on the values received from SUPER 140 as shown in
[0170] The transmission of the control signals between the SUPER controller 142 and the IPS controller 147 may be periodic and dependent on the switching frequency of the SUPER 140. The communication link may be an integral part of the control loop of the SUPER 140, and so the quantization and resolution of the control signals through the channel may impact the total harmonic distortion (THD) of the grid/output current. This may be factored into the communication protocol. Additionally, the data transmission time may be a delay in the control loop, and this may be reduced or kept as low as possible (e.g., less than a switching cycle) to enhance the control bandwidth through synchronization. In case of single or multiple IPSs 146 within the SUPER 140, the SUPER 140 may coordinate the synchronization of one or more IPSs146.
[0171] The SUPER 140 may receive setpoints/commands from a hierarchical controller or upper level controller (e.g., a node controller 122, a hub controller 132, or an SPS controller 112) at the grid node through the SUPER agent of the SUPER controller 142. The upper level controller may correspond to the next level of the control hierarchy in the node 120, hub 130, or SSPS 110 with respect to the SUPER 140. The upper level controller may determine the system level objectives, including optimization algorithms for economic operation and various functions, such as voltage and frequency regulation. The upper level controller may be responsible for negotiations with the DMS 162 or other utility level controller. Based on negotiations (direct or indirect) with a further upper level controller (e.g., a DMS 162) and the system configuration, the upper level controller may estimate the P, Q setpoints (i.e., apparent and reactive power setpoints) for the various converters (e.g., SUPERs 140) in the system under normal conditions. The SUPER agent of a SUPER 140 may receive communications from the upper level controller and operate based on the information received in the communication. For instance, the communications may include the P, Q setpoints, and the SUPER 140 may translate the setpoints, regulation curves, and control modes for operation. The timeline of operation of the SUPER 140 and the upper level controller may be based on time constraints such as those described in conjunction with
[0172] Dynamic grid support algorithms can also be provided in SUPER 140 or the preset regulation curves in the SUPER 140 can be changed through the agent framework (e.g., communications between the SUPER controller 142 and an upper level controller).
[0173] The SSPS controller 112, the node controller 122, and the hub controller 132 may all be developed considering a base set of features. These features or components may include data capture in a historian, and data evaluation using various levels of analytics (which could include artificial intelligence), communication interfaces, forecasting, and optimization. A depiction of a controller architecture as utilized in this work is shown in the illustrated embodiment of
[0174] Each of these components may be launched via a central set of code that creates operational threads that operate the respective features in parallel. The threads may interact through the message queuing system 238 (get and set commands to a que) to ensure operational decisions are using the most recent sets of data. The controller 230 may be provided as an integrated aspect of a component described herein (e.g., a node controller 122, a hub controller 132, or an SSPS controller 112) or provided as a system that is distributed (such as in a cloud platform).
[0175] For plug-and-play adaptability in accordance with one embodiment, a message queuing system for multiple controllers may be provided. For instance, a Message Queue Telemetry Transport (MQTT) protocol may be adopted between the controllers with a schema that supports registration of SUPERs 140 and sub-systems via a device/system integrator engine 231. This registration process may be conducted autonomously by configuring a specified internet protocol address of the higher-level systems and importing this address into the sub-system or SUPER controller 142. The historian 236 may collect all communicated data external to the controller 230 and developed system data from analytics, optimization, and forecasting. This may be configured in an SQLite structure for reporting.
[0176] In one embodiment, a multiagent system (MAS) may be used to embed intelligence in the system 100, such that a MAS is extended to the SSPS 110 to embed the computational aspects starting from the fundamental building blocks. The MAS architecture may be used for interactions between the different entities (e.g., SUPERs 140, nodes 120, and hubs 130) that have local decision-making capabilities and systems that progressively utilize the addition of new functionalities.
[0177] In addition to the MAS, real-time load and source optimization with price negotiation optimization of the assets in the SSPS 110 may be used to realize multiple combinations of grid functions without substantially compromising the load requirements.
[0178] In the illustrating embodiment of
[0179] V. Protection Architecture
[0180] Like hierarchical control, hierarchical protection may enable resilient and reliable operation of the power distribution system 100. The hierarchal protection configuration of the system 100 is described primarily in conjunction with internal protection of the systems and subsystems (e.g., the nodes 120, the hubs 130, and the SUPERs 140). However, it is to be understood that the present disclosure is not so limited, and that aspects of the protection configuration may be implemented in the SSPS 110.
[0181] The hub controller 132 and/or the node controller 132 may coordinate with the SUPERs 140 and their connection to the grid at the point of connection (POC). Therefore, the hub controller 132 and/or the node controller 122 may provide protection constraints, thresholds, and a finite state machine (FSM) to facilitate functionality, such as initial system startup, back start, grid forming and islanding, and system reconfiguration in the event of loss of one or multiple SUPERs 140 (e.g., fault tolerant operation). These protection thresholds and constraints may be part of the optimization algorithm for the hub 130/node 120 that outputs control setpoints to the SUPERs 140. The hub controller 132 and/or the node controller 122 may also manage or coordinate protection circuitry within the hub 130 and/or the node 120 that include breakers and a grid disconnect switch in an effort to deal with the faults internal to the system 100.
[0182] The SUPERs 140 may include protection circuitry to isolate themselves and their entities in the event of an internal fault and/or based on external grid conditions. In case of grid conditions, the SUPER controller 142 may be programmed with thresholds to respond to over voltage (OV), under voltage (UV), over frequency (OF), under frequency (UF), and over current (OC) conditions at the POC. Additionally, the SUPER controllers 142 may be programmed with ride though settings as mandated by IEEE 1547. The hub controller 132 and/or the node controller 122 can reconfigure these settings of the SUPER controller 142 based on the grid conditions, system configuration, and when needed.
[0183] Internally, the SUPERs 140 may respond to faults and events, such as power stage failure and loss of communication. The SUPERs 140 may also host health-based algorithms, such as active thermal control to enable resilient and reliable operation. Also, the SUPERs 140 may be equipped to auto configure and start and shutdown based on the commands from the hub controller 132 and/or the node controller 122. This type of operation may be achieved via an FSM provided in the SUPER controller 142 or FSM advanced algorithms.
[0184] Like the control architecture, the protection architecture may utilize timing requirements for reliable operation. An example set of timing requirements is depicted in the timing diagram 500 in the illustrated embodiment of
TABLE-US-00002 Function: Frequency: IEEE 1547 functions with the corresponding Based on grid protection thresholds conditions Functions for transactive control - generation Based on request of bids for assets Intelligently operate a power stage within the Periodic Watchdog SUPER 140 (i.e., IPSs with loss in communica- tion to the SUPER) Intelligently operate the SUPER 140 with loss in Periodic Watchdog communication to assets 150 (c.g.. ES, wind turbine, and PV) Operate the SUPER 140 even with loss of Periodic Watchdog communication with the SSPS controller 112 Inherent black start capability to maintain critical With change in system loads in the event of grid/catastrophic failures operating conditions Controller parameter tuning On Startup and change in system conditions Capability to realize dynamic grid functions, such Continuous as voltage and frequency regulation. For instance, the SUPER controller 142 may dynamically choose and vary a converter mode of operation depending on system conditions Anomaly detection (Cyber-attacks, fault condition Continuous etc.) Reliability e.g., lifetime-based and self-awareness Periodic (minutes) control. Examples of such control include managing DER charge/discharge rates based on lifetimes, active thermal/power flow control, and prognostics Adaptive flow rate (air) control Changes in operating conditions (ΔT) Respond to internal SUPER faults with least Periodic impact to the system and degrade gracefully Manage the start-up and shutdown of the SUPER On startup & 140 under normal and catastrophic conditions shutdown Hot swap capability and the associated controls In frequent for system stabilization Auto/self-configure the SUPER 140 based on the On Startup & change load/source attached to it and based on its in system conditions protection circuitry
[0185] Like the controls, the system protection may be hierarchical to isolate the system or the components as quickly as possible in the event of a localized fault or a failure. Thus, the IPS 146 may be configured to respond faster to faults using hybrid signals (i.e., digital and analog). The IPS 146 may disable the PWMs to the semiconductor switches in the event of over voltage (OV), over current (OC) or over temperature (OT) with respect to the power stage. The IPS 146 may be equipped with sensors for fast protection. The SUPER controller 142 may respond to abnormalities in the converter operating conditions (e.g., IPS operating conditions) and may meet the ride through requirements for grid-connected systems. Fault-tolerant operation involving reconfiguration of IPSs 146 may fall under the domain of SUPER protection. The SUPER controller 142, on the other hand, may coordinate the startup/shutdown of the SUPER 140 based on the loads or assets connected to it. The SUPER 140 may internally coordinate the startup/shutdown of the IPSs 146 internal to it. To enable such a coordination, a finite state machine (FSM) of IPS 146, SUPER 140 and the SUPER controller 142 may be coordinated through the communication links existing between them. A SUPER computational node 151 may conduct operation of the FSM, which may communicate with controller 143 via a communication interface 152. An example of such a coordination between the SUPER 140 and IPS 146 is shown in
[0186] The upper-level controller may also enable fault-tolerant (i.e., reconfiguring the system and the grid functions when one converter i.e., SUPER 140 is faulted) operation with respect to the whole system based on the information received from the SUPERs 140 and the measured nodal voltages and currents.
[0187] A list of the control and protection features that can be embedded in a hub 130 and/or a node 120 is provided below. Specifically, the hub controller 132 and/or the node controller 122 may be configured to implement one or more of the following:
TABLE-US-00003 Function: Frequency: Auto/self-configure the hub/node based on the On Startup & change load/source attached to it and based on its in system conditions protection circuitry Anomaly detection Continuous Intelligently operate the hub/node with loss of Periodic watchdog communication to SSPS controller Respond to internal SUPER faults with least Periodic impact to the system and degrade gracefully Manage the start-up and shutdown of the system On startup & under normal and catastrophic conditions shutdown
[0188] VI. Communications
[0189] Communication may be used as a basis for the control and the protection hierarchy, as well as operating within the timing requirements described and shown in conjunction with
[0190] Communication between the SUPER 140 and the IPS 146 and an upper-level controller may facilitate control and the protection hierarchy. The communication speed/channel capacity in bits per second (bps) decreases from IPS to higher level controllers, while the control and protection speed increases from the higher level controllers to the IPS. To meet the interoperability and scalability requirements, the SUPER 140 and IPS 146 are designed with two communication channels and a synchronization channel as shown in
[0191] It is noted that the IPS 146 in one embodiment is optional with respect to the SUPER 140. The IPS 146 in the illustrated embodiment of
[0192] In the illustrated embodiment of
[0193] In one embodiment, the control channel between the SUPER 140 and the IPS 146 may be dedicated to transmitting the AC voltage references and/or the duty ratios from a controller 143 of the SUPER 140 to the IPS controller 147. A data channel (operating at a slower rate than the control channel) may be used for miscellaneous messages including health, status, setpoints, and warnings. The data framework or the messages in the data channel may support a variety of features, such as health monitoring.
[0194] The dedicated control channel may help to provide quality control bandwidth by reducing the update rate to less than a switching cycle in the IPS 146, which otherwise would be impacted as the communication is an integral part of the control loop. The communication and the synchronization channels may be fiber-based links to lower any additional latencies, avoid loss of data packets, and enhance noise immunity. Issues relating to loss of data packets in the control channel may be addressed quickly as loss may adversely impact the PWM/control signals and therefore the output of the SUPER 140. Details on the communication and the synchronization channel may be provided in accordance with the following:
TABLE-US-00004 Synchronization Control Channel Data Channel Channel Purpose Transmit control signal Transmit other Synchronization of one or (i.e., AC voltage messages like health, more IPSs within SUPER references or duty) commands, etc. Direction Unidirectional (SUPER Bidirectional Unidirectional (SUPER to to IPS) IPS) Message size 16-bit/phase ≥16 bits Sync pulse ≤ fs Bit/Baud rate 6.25 Mbps 6.25 Mbps to 100 — kbps Type Half duplex Full duplex — Data occurrence Periodic~μs Periodic~sub Periodic (Hz or kHz) interval seconds/seconds Information <10 μs Sub seconds~seconds — transfer time Peripheral used SCI SCI EPWM
[0195] There may be several message categories associated with the data channel, including the types of messages identified in the table below:
TABLE-US-00005 Message Information Categories: Flow Direction: Messages: Configuration IPS to SUPER Converter class, operation mode, maximum and minimum voltages and power levels Status IPS to SUPER Operation state, input and output precharging, activation General Faults IPS to SUPER OV, UV, OF, UF, OC, OT, precharged failure, loss of communication (data and control) Gate Drive IPS to SUPER Desat, open and short circuit, and gate Faults oxide degradation Health IPS to SUPER Junction temperature, on state Estimates resistance, on state resistance gradient, gate leaking current, capacitance Commands SUPER to IPS Activate, close/open contactor, and clear faults Set Points SUPER to IPS P, Q, Vdc
[0196] The SUPER 140 may be provided with an ethernet based control channel to communicate with the SUPER agent platform. The P and Q reference commands and other commands from the higher-level controller is translated to the SUPER through the SUPER controller 142 and can be transmitted via the ethernet channel in seconds/minutes without impacting the system performance.
[0197] In one embodiment, the SSPS controller 112 may correspond to the highest level of the control hierarchy and hosts the system level objectives including optimization algorithms for economic operation and various functions like voltage, frequency regulation, etc. The SSPS controller 110 may be mainly responsible for negotiations with the DMS 162. Based on the negotiations with the DMS 162 and the system configuration, the SSPS controller 112 may estimate the P, Q setpoints for the various components (e.g., SUPERs 140, nodes 120, or hubs 130) in the system under normal conditions. The hub controller 132 and the node controller 122, which are the next in the hierarchy, may coordinate the downstream SUPERs 140 based on the setpoints from SSPS controller 110. If the SSPS controller 112 is coordinating the SUPER 140 directly, the SUPER 140 may respond to the setpoints from the SSPS controller 112 and generate the AC voltage references/duty ratio, etc., based on the type of converter configuration of the SUPER 140.
[0198] This information may be used by the IPS controllers 147 to generate the PWM for the power stage operation. Thus, the timeline of operation of the controllers in the system may vary widely as depicted in the time diagram 400 in the illustrated embodiment of
[0199] VII. Super
[0200] A SUPER 140 in accordance with one embodiment may be defined as a power conversion system that has one input port, one output port, and an intermediate port to which an asset (e.g., a load or a source) can be connected. The SUPER 140 may form a fundamental building block (FBB) of the system 100, and may itself include building blocks in the form of one or more IPSs 146 (which may also be described as an FBB). Additional modules or building blocks of the SUPER 140 include filter blocks, protection blocks, shielded communication or control interface blocks, and auxiliary power supply units depicted in the illustrated embodiment of
[0201] The SUPER 140 may support functions of a smart inverter, such as responding to system conditions autonomously, continuously modulating system output, continuing to operate within ranges of voltage and frequency, varying power factor, and enhancing the power quality at the POC or at the point of common coupling (PCC).
[0202] In a SUPER 140 in accordance with one embodiment, the interfaces for communication, controls, protection, and filters may be standardized for interoperability and scalability. Additionally, the subcomponents of the SUPER 140 may be optimized to enable hardware reusability that allows a SUPER 140 to be operated in one of the several converter classes described herein. For example, a two stage SUPER 140 designed with a 500˜900 V DC input and 480 V, 60 Hz AC output can be operated as a GI, a DCSI and a DCLI with changes to control and protection algorithms based on grid functions as shown below:
TABLE-US-00006 Control and Grid Startup - Type Configuration functions Direction GI DC/AC Voltage regulation, From grid Reactive power compensation ACSI DC/DC + DC/AC Frequency From DC regulation, Power source/grid flow control, P/Q control DCLI DC/DC + DC/AC Power flow control, From grid Load transient management & Reactive power compensation
[0203] The SUPER 140 may include an integral agent, e.g., a SUPER controller 142 as shown in
[0204] Each converter in the node 120 and/or hub 130 may be represented by a class of PE systems that support a hierarchy of hardware and software systems. The converter as a subsystem has been termed as a SUPER 140 with a computational platform or node (the agent) interfacing with an embedded platform, such as a digital signal processor (or field programmable gate array), that orchestrates control among several switching devices as shown according to the template depicted in the illustrated embodiment of
[0205] In the illustrated embodiments of
[0206] The IPS controller 147 maybe in communication with the SUPER controller 142. The SUPER controller 142 may receive and transmit communications to the IPS controller 147 in order to direct operation of the IPS controller 147. Information communicated from the IPS controller 147 to the SUPER controller 142 may be used as a basis for directing operation of the IPS 146. Such information communicated from the IPS controller 147 may also form the basis for information transmitted from the SUPER controller 142 to an upper-level controller power control system, such as a node controller 122 and/or a hub controller 132.
[0207] An alternative embodiment of an IPS is depicted in
[0208] In the illustrated embodiment, agent systems may be used to provide the innerworkings and communication between sub-systems. Examples of agent systems employed within PE systems as computational nodes include energy storage or photovoltaic systems controls. In this configuration, an agent may perform the integration of PE systems to interconnected resources and represent the SUPERS controllers of the integrated systems. A central controller, such as one or more of the hub controller 132, node controller 122, or the SSPS controller 112 may coordinate with the SUPERs 140 through an optimization algorithm. Data from learning programs and forecasting can provide additional information to the optimization formulation.
[0209] A SUPER 140, in one embodiment, may be based on a smart inverter that, while operating autonomously for grid support, may also provide a transactive embedded system. Several control aspects of the SUPER 140 and their corresponding system level affects are listed below. The SUPER 140 may be configured according to one or more of the below listed features. Metrics associated with the features may correspond to economic, reliability, reduced downtime, greater noise immunity, or grid support, or any combination thereof.
TABLE-US-00007 SUPER Features: System level input: 1. Interoperability Easy integration and Standardized interconnects reduction in BOS costs Standardized communication ports Compliance to standards and protocols Protection From factor - Demonstrate scalability for power and voltage 2. Embedded intelligence and decision-making Improved voltage capability with a flexible scalable platform profile at the POC Interoperable/scalable with different embedded controllers (G/L) Flexibility with open-source software De-rated/continuous Respond dynamically to voltage & frequency operation during abnormalities etc. failure events Monitor the point of connection continuously Immediate response to internal and external faults with least impact to the system Converter functioning is not compromised with loss of communication 3. Embedded online health monitoring system - Allows maintenance to Diagnostics/Prognostics be pre-planned Metering to be included - Calculations of P and Prevent the loss of the Q for control and diagnostics inverter from affecting Monitors the health and lifetime of components the overall system including passives in the system Increase lifetime Captures and/or maps faults to their Data for offline learning corresponding signatures algorithms Robust and/or retrievable events and data logging system (Non-real-time/Offline) 4. Cyber-physical security Improved protection Hardware and software mechanisms to secure against power electronics systems cyber threats 5. Self-contained intelligent power stages Decouples parasitics Embedded passives, auxiliary power, sensors, and noise loops processors etc. Additional sensing & processor can be utilized for internal health monitoring of IPS
[0210] Additional functions for controls for the SUPER 140 are provided in the table below.
TABLE-US-00008 Function Type: Description: Functions: Hosted In: Autonomous No communication Low/high voltage ride SUPER and (Operates with architecture needed through IPS static Behavior controlled Frequency ride through SUPER setpoints) by inverter operating Volt-var control (via dynamic parameters reactive power injection) Anti-islanding Parameters defined Ramp-rate controls (for as system default/emergency conditions) commissioning or Provide reactive power (via later fixed power factor) Parameters can be Frequency-Watt adjusted, behavior Volt-Watt activated or Dynamic reactive current deactivated at later injection date via remote or on site changes Impacts the PCC/POC directly Non autonomous Communications Command DER to connect or SUPER operation and control disconnect infrastructure utilized Limit/set real power Direct control of Respond to pricing signals inverter behavior Participate in automatic Control from generator control (AGC) remote operator Provide spinning reserves or commands or bid into market feedback, based on Update static set points for conditions at PCC autonomous functions (fixed power factor, Volt-var curves, voltage ride through, frequency ride through) Intelligent Features Embedded software Intelligently operates the IPS framework and converter even with loss in communication communication Architecture for Inherent black start capability SUPER decision making to maintain critical loads in the Direct control of event of grid failures or inverter behavior catastrophic failures Communication Controller parameter tuning SUPER with another Adaptive algorithms for grid SUPER controller with functions such as frequency respect to any change and voltage regulation. in operating Dynamic selection and varying conditions of the converter mode of operation depending on system conditions Functions internal Anomaly detection (e.g., cyber SUPER and to the SUPER 140 or attacks, fault conditions) IPS the system 100
[0211] Additional functions for protection and maintenance for the SUPER 140 are provided in the table below.
TABLE-US-00009 Function Type: Description: Functions: Hosted In: Intelligent Features - Embedded software Fault Tolerant Capability - SUPER Protection framework and respond to internal and communication external system faults with low Architecture for or least impact to the system decision making and degrade gracefully Direct control of Manage the startup and SUPER and inverter behavior shutdown of the system under IPS Communication normal and catastrophic with another conditions controller with Hot swap capability SUPER respect to any change Auto/self-configure the system SUPER in operating based on the load/source conditions attached to it and based on its Functions internal protection circuitry Intelligent Features - to the SUPER 140 or Reliability (e.g., lifetime based SUPER Maintenance the system 100 and self-awareness control, such as management of DER charge/discharge raids based on lifetimes or active thermal/power flow control Adaptive flow rate (air) control SUPER and IPS Preventative maintenance SUPER and prognostics IPS
[0212] A method of operation for a SUPER controller 142 in accordance with one embodiment is shown in
[0213] A decision tree in accordance with one embodiment of the present disclosure is shown in
[0214] VIII. IPS
[0215] As described herein, the SUPER 140 may include one or more IPSs 146. The IPS 146 may be a self-contained holistic power stage (single or multiple stages) with an input 134, output 136, and intermediate ports (as needed) that can be cascaded or paralleled (such as the configuration depicted in
[0216] The IPS 146 may be configured according to one or more of the below listed features:
TABLE-US-00010 IPS Features SUPER level impact 1. Interoperability Allow for standardized IPSs Standardized electrical ports and communication interface connected to the standardized Enclosure scalability and standardization SUPER to be swapped in and Compliance to standards and protocols out and easily Standardize IPS power ratings and the corresponding form factors 2. Embedded intelligence and decision-making capability Provide sufficient with a flexible scalable platform computation and Interoperable/scalable with different embedded controllers communication capabilities to Monitors the point of connection continuously handle the rapid command Easy transition between control mode required by SUPER implementation, control Immediate response to IPS internal faults with least impact algorithm, and heavy to the SUPER communication and data- logging burden between the SUPER 140 and the IPS 146 Coordinate with more intelligent IPS subcomponents to enable features 3. Embedded online health monitoring system - Provide industry standard Diagnostics/Prognostics module packaging pattern and Embeds temperature sensors in IPS to enhance thermal corresponding thermal monitoring for prognostics monitoring Monitors the health and degradation status of critical Evaluating the IPS level components in IPS health status and conditions to Captures and/or maps faults to their corresponding provide most precise signatures information to the SUPER Robust and/or retrievable events recording and reporting 140. system 4. Cyber-physical security Protect bottom layer Hardware and software mechanisms to secure power components from cyber electronics systems attacks by means of hybrid (analog and digital) configurations 5. Self-contained auxiliary power supply units Provide shutdown during Draws the required power from IPS itself and power the system crash and reduce or contained components minimize electrical interconnection to enhance our maximize plug and play aspects and to simplify manufacturing 6. Integrated minimum passive, intelligent gate driving, Lower the corresponding sensing and protection electrical stresses for Standardized minimum integrated passives components, regardless of Intelligent and robust gate driving scheme normal or fault operating Integrated sensing and protective device conditions Provide reliable switching events and potentially reduce switching losses Isolate the IPS during fault scenarios
[0217] Methods of operation for the SUPER 140 and the IPS 146 in accordance with one embodiment are depicted in
[0218] The SUPER computation platform in the illustrated embodiment is depicted with a controller 143 operable to execute the state machine and a resource integration controller 141 operable to communicate between external components (e.g., an upper level controller) and the controller 143. The state machines executed by the controller 143 and the IPS controller 147 may be closely coupled in order to effect operation in an efficient manner, while enabling the resource integration controller 141 and/or other aspects of the SUPER controller 142 to handle operations that are less time sensitive. A timing diagram of communications between the state machines of the controller 143 in the IPS controller 147 is depicted in illustrating embodiment of
[0219] A health monitoring framework for the IPS 146 in accordance with one embodiment is depicted in
[0220] Health monitoring may predominantly involves the following stages: measurement/estimation, data storage, data processing and additional controls. Estimation may be done at both the SUPER level and the IPS level based on the components present in both. The measurement and estimates from the IPS 146 can be stored and processed locally in the IPS 146 and/or the processing can be done at SUPER level.
[0221] IX. Modular Aspects
[0222] To provide modularity and scalability, SSPS 110 may include several fundamental building blocks, such as SUPERs 140 and IPSs 146. These fundamental building blocks may allow the distribution/segregation of controls, protection, and intelligence at various levels of the hierarchy, enabling fast decision-making capability and response to transient or abnormal conditions. Additionally, the fundamental blocks may be equipped with added features, such as cyber-physical security, health monitoring to facilitate resilient and reliable grid interfaces. The fundamental blocks may be configured together as a multiport system (e.g., scalable and interoperable) and present themselves as a single transactive node to the grid in case of a node/hub/link. This consolidation in turn increases the grid security by reducing or minimizing the number of PE interfaces in the grid.
[0223] The architecture of the SSPS 110 may allow for automation of energy flow between sources and loads, including between assets 150 that operate as sources and loads. In addition to the automated energy management, the SSPS 110 may maintain operation according to power quality requirements and the functionalities stipulated by grid standards such as IEEE 1547 and beyond. For instance, up to twelve grid functions including power management, voltage and frequency regulation, grid forming capability, and black start capability have been identified and can be realized simultaneously via the SSPS 110. The table below identifies functionalities of the SUPERS 140 according to different converter classes and emphasizes segregation capabilities (+ indicates inclusion of a function and − indicates absence).
TABLE-US-00011 ACSI ACLI and and # Function GI DCSI DCLI 1 Power and energy management − + + (PEM) for economic operation 2 Voltage support (PQ, Volt-var, + + + constant Q) 3 Phase balancing − + − 4 Flicker reduction − + − 5 Power factor correction + − + 6 Frequency support (Freq-Watt) − + − 7 Active harmonic filtering + − − 8 Grid forming capability − + − 9 Black start capability − + − 10 Voltage and frequency ride + + + through 11 Cyber security + + +
[0224] A library of building blocks or modular aspects can be used in the SSPS architecture, such as to build the nodes 120 and hubs 130 for various applications. A SUPER library 910 in accordance with one embodiment is depicted in
[0225] As described herein, the SUPERs 140 may be configured as a modular component of the system 100. The SUPERs 140 may be both adaptable and standard and implemented so that interoperability within the system 100 may be provided despite use of differently configured SUPERs 140. The SUPERs may be described as fundamental building blocks (FBBs).
[0226] Interoperability of SUPERs 140 may translate into enabling strategical coordination (e.g., control, communication, and protection coordination) of multiple SUPERs in the system 100. Coordination of multiple SUPERs 140 may call for standardization of interfaces and interconnections. Standardization of communication protocols, messages between the different entities, control coordination, synchronization of the different entities, and timing requirements may be provided in order to satisfy interoperability specifications and to enable coordinated hierarchical control.
[0227] Modular SUPERs 140 that allow scaling with regards to voltage and current may be used to develop grid connected systems that tie to secondary distribution scale feeders. Modular and holistic design (e.g., with controls, protection, synchronization, and communication) may enable plug and play to maintain and service the submodules as required while reducing or minimizing the down time. It is noted that scaling can introduce additional challenges with regards to circulations in the system 100; therefore scaling may be constrained by the availability of the required power and communication interconnections or interfaces and the subcomponents of the SUPERs 140.
[0228] As described herein, the SUPERs 140 may be used to build various PE interfaces of various converter class types, such as DCLI, ACLI, DCSI, ACSI and GI. The SUPERs 140 may utilize a standard construction across the converter class types. For instance, the SUPERs 140 may support a) startup from the DC or AC side based on the current direction or information on assets 150 (e.g., a source or load) connected to the system, b) components selected or optimized to handle the various operating conditions and grid functions, and c) sensing and protection circuitry to isolate and/or connect the systems and the subsystems. A standardized design portion of the SUPERs 140 may enable hardware reusability i.e., a given hardware with a particular configuration can be made to function as a DCSI/DCLI/GI by only changing the software layer, the controller, or the computational platform.
[0229] To enhance the grid reliability, resiliency, and power quality and to reduce the operating and maintenance of systems, the SUPERs 140 may be equipped with features, such as online health monitoring (prognostics/diagnostics), cyber physical security, embedded intelligence and decision-making capability, and control algorithms. These capabilities may be enabled by computational capabilities, storage or data logging units, and advanced sensing provided in the SUPER 140, as described herein.
[0230] X. Optimization
[0231] The system 100 may implement an optimization architecture in accordance with one or more embodiments described herein. An example optimization architecture is depicted in the illustrated embodiment of
[0232] In the illustrated embodiment, the DMS 162 may negotiate a net P and Q for each SSPS 110. The SSPS controller 112 may manage internal resources to beneath the negotiated net P and Q for the respective SSPS 110. This method may be extended to other services of the system 100, such as sequence currents for a phase balancing or harmonic components for active filtering/compensation.
[0233] A timing example of the optimization architecture 1000 in accordance with one embodiment is depicted in
[0234] The optimizer may enable price negotiation of SSPS or customers with respect to the DMS 162 for energy and ancillary surfaces. The architecture 1000 may change traditional paths of customers into active customers, which could consume or generate energy as well as provide ancillary services, such as voltage or frequency regulation, or protection, phase balancing, or power quality improvements, or a combination thereof.
[0235] The optimization architecture 1000 in accordance with one embodiment is shown in further detail in
[0236] The local optimizer may send P and Q values or constraints to components corresponding to the next level below the SSPS controller 112. The local optimizer may transmit such values at an interval that is faster than the interval of the global optimization interval, such as every three minutes. Steps 1004, 1008. The local optimizer may determine the P and Q values for assets below the SPS controller 112 based on state of charge and an updated PV and load forecast period steps 1014, 1012. The hubs 130, the nodes 120, or the unattached SUPERs 140 may operate during the interval for the local optimizer and transmit information, such as state of charge, to be used by the SPS controller 112 to determine global optimization and/or local optimization outputs. Steps 1006, 1014.
[0237] Directional terms, such as “vertical,” “horizontal,” “top,” “bottom,” “upper,” “lower,” “inner,” “inwardly,” “outer” and “outwardly,” are used to assist in describing the invention based on the orientation of the embodiments shown in the illustrations. The use of directional terms should not be interpreted to limit the invention to any specific orientation(s).
[0238] The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.