Disclosed is state trajectory prediction in an electric power delivery system. Electric power delivery system information is calculated from measurements by intelligent electronic devices (IEDs), and communicated to a state trajectory prediction system. The state trajectory prediction system may be configured to generate a load prediction profile. The load prediction profile may provide a predicted response of a load at a future time. Further, the state trajectory prediction system may be configured to generate a generator prediction profile that provides a predicted response of a generator at a future time. The state trajectory prediction system may generate a state trajectory prediction based, at least in part, on the load prediction profile and the generator prediction profile. The state trajectory prediction may represent a future state of the electric power delivery system.

A method for controlling a power distribution network includes receiving, by an electronic processor, a fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices. The processor identifies a first subset of a plurality of phases associated with the fault indication and a second subset of the plurality of phases not associated with the fault indication. The first and second subsets each include at least one member. The processor identifies an upstream isolation device upstream of the fault. The processor identifies a downstream isolation device downstream of the fault. The processor sends an open command to the downstream isolation device for each phase in the first subset. Responsive to the first isolation device not being the upstream isolation device, the processor sends a close command to the first isolation device for each phase in the first subset.

A micro grid system comprises an adapter, a power controller, and secondary energy source. The adapter is in communication with an electric grid and configured to connect and disconnect a connection between the electric grid and a micro grid. The power controller is in communication with the adapter and configured to receive first AC power from the electric grid via the adapter, obtain grid information, and control the adapter to connect and disconnect the connection between the electric grid and the micro grid. The power controller controls the adapter to disconnect the connection in response to determining that the electric grid is abnormal based on the grid information. The secondary energy source is in communication with the power controller and is configured to generate DC power and to supply the DC power to the power controller.

The present invention deals with microgrids, which represent a new approach to integrate distributed energy resources economically reliably and efficiently. A microgrid can operate in a connected mode if it makes an energetic exchange with a main grid or in an island mode otherwise. In its island operation mode, a microgrid ensures its energy self-sufficiency. However, the availability of resources in this mode is greatly influenced by meteorological factors and the microgrid must satisfy the high requirements on intelligent power management in order to achieve high availability of energy. The present invention provides a multi-agent control system based on the production forecasting and loads shedding for high availability of the microgrid power supply.

A method for managing a microgrid network under a blackout condition. The method may include partitioning the microgrid network into a plurality of clusters. The method may also include determining a virtual inertia value for each of the plurality of clusters. The method may further include classifying the plurality of clusters based on corresponding virtual inertia values. In addition, the method may include performing a black-start operation by employing a Tower of Hanoi concept to restore power to the microgrid network. According to certain embodiments, performance of the black-start operation may take into account the virtual inertial values.

Provided are a ground fault protection method and apparatus for a photovoltaic station output transmission line. A circuit breaker on a photovoltaic side is controlled by a control element. Whether measured zero sequence impedance on the photovoltaic side of a segment line has a large variation before and after an action of power grid side distance protection is determined, the variation of the measured zero sequence impedance is inputted into the control element, in condition that the variation of the measured zero sequence impedance is less than a setting value, a tripping signal is outputted to the circuit breaker on the photovoltaic side to isolate the fault; and in condition that the variation of the measured zero sequence impedance is greater than the setting value, photovoltaic side distance protection is not started.

A photovoltaic power generation system includes a capacitor bridge arm, an inverter bridge arm, and the fault protection apparatus. The capacitor bridge arm includes a positive electrode output port, a negative electrode output port, and a reference output port The inverter bridge arm includes a positive electrode input port, a negative electrode input port, and a reference input port. The positive electrode input port is connected to the positive electrode output port. The negative electrode input port is connected to the negative electrode output port. The reference input port is connected to the reference output port by using the fault protection apparatus. The fault protection apparatus is turned off based on a magnitude value or a variation of a voltage, or a magnitude value or a variation of a current between the reference input port and the positive electrode input port or the negative electrode input port.

A method for characterizing power quality events in an electrical system includes deriving electrical measurement data for at least one first virtual meter in an electrical system from (a) electrical measurement data from or derived from energy-related signals captured by at least one first IED in the electrical system, and (b) electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system. In embodiments, the at least one first IED is installed at a first metering point in the electrical system, the at least one second IED is installed at a second metering point in the electrical system, and the at least one first virtual meter is derived or located at a third metering point in the electrical system. The derived electrical measurement data may be used to generate or update a dynamic tolerance curve associated with the third metering point.

Embodiments of present disclosure relates to a modular interconnection device (MID) and an electrical network system. The MID comprises a modular port assembly, a node, a converter and a local controller. The modular port assembly is configured to transmit alternating current and/or direct current. The node is coupled to an AC source via a first switch and the modular port assembly. The first switch is configured to selectively disconnect the modular interconnection device from the AC source. The converter is coupled to the node via a second switch and coupled to a DC source via a third switch. The converter is configured to convert the AC current into DC current or convert DC current into AC current. The local controller is coupled to the first, second and third switches and configured to control operation of the first, second and third switches.

The disclosure provides a method for monitoring a short-term voltage stability of a power system. The method includes: obtaining a topology and time series of a current power system; inputting the topology and the time series of the current power system into a trained spatial-temporal graph network model, the trained spatial-temporal graph network model being obtained by classification learning on a spatial-temporal graph network model based on a simulation sample dataset; outputting a status of the short-term voltage stability of the power system; and sending an alarm signal in response to outputting an unstable status of the short-term voltage stability of the power system.