A containerized power flow control system is described, for attachment to a power transmission line or substation. The system includes at least one container that is transportable by road, rail, sea or air. A plurality of identical impedance injection modules is operable while mounted in the container, wherein each of the modules is configurable to inject a pre-determined power control waveform into the power line.

A modular power flow control system is described for optimizing power flow control in a multi-phase power transmission system. Identical impedance injection modules are arranged in an mn matrix, where m is the number of series-connected modules inserted into each phase (forming a leg of the installed bank of modules), and n is the number of parallel-connected legs per phase. Each impedance injection module in a phase is configurable to collectively insert a pre-determined (controllable) power control waveform into the phase to which it is attached. The modular flow control system is agile with respect to configurability, reconfigurability, maintenance, size, weight, and cost.

A method which is suitable for a system having a frequency converter and a generator, both of which are connected to a power grid, includes obtaining sub-synchronous components of the grid voltage and determining damping current set points according to the sub-synchronous components to compensate for sub-synchronous resonances of the grid. Damping current set points are determined by receiving the sub-synchronous components of the grid voltage and returning damping current set points as outputs. A variable damping gain is adjusted according to the sub-synchronous frequency of the grid, such that the required compensation level can be adapted to the frequency converter for damping sub-synchronous resonance of the grid.

Each of the first and second switching modules may include first through (n+1)th cooling plates stacked along a vertical direction with respect to the support module; first through nth switches respectively disposed between the first through (n+1)th cooling plates; a first electrode plate disposed on the (n+1)th cooling plate; a first supporting member disposed on the first electrode plate; a first pressing member disposed between the first electrode plate and the first supporting member; a second electrode plate disposed below the first cooling plate; a second supporting member disposed below the second electrode plate; and a second pressing member disposed between the second electrode plate and the second supporting member.

Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.

An apparatus, such as an adjustable frequency drive (AFD), includes an inverter configured to be selectively coupled to a motor in a first mode and an AC line in a second mode and a control circuit configured to operate the inverter as a motor drive in the first mode and as a power compensator in the second mode. The power compensator may provide power factor correction. The control circuit may include a scalar controller configured to control the inverter according to a voltage vs. frequency characteristic determined by a field weakening point reference and the control circuit may vary the field weakening point reference in the second mode. The inverter may have an input coupled to a DC bus and the control circuit may be configured to adjust a frequency of the inverter in the second mode to increase a voltage on the DC bus.

Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.

A modular power flow control system having early detection and reporting of transmission line faults is described. The response time for closing a bypass switch and reporting the fault is less than 200 microseconds for hard faults, longer for soft faults. Reprogramming of distance relays is not required. Transmission line faults are characterized using a fault detection sensor suite, normally including at least a current sensor such as a current transformer and a rate of current change sensor such as a Rogowski coil, and in some embodiments, a temperature sensor. Other embodiments are disclosed.

An apparatus and method for aggregating and supplying energy includes a plurality of power modules for inverting a first type of electrical power, which is supplied to the power modules from multiple sources of power, to a second type of electrical power at an output of the power modules for delivery of the inverted power to a storage device for future use, or to an electrical load, or to a regional or central utility grid. A microcontroller (the power microcontroller) is carried by and incorporated within each of the power modules and each is configured for controlling the power inversion operations. A microcontroller (the control microcontroller) carried by the control module is configured for monitoring voltage levels within the at least one energy storage device and for rebalancing voltage within the energy storage device and for correcting lead and lag power factor. Means for selectively supplying power received from said multiple disparate sources of power to the destination are provided.

Flexible AC transmission system (FACTS) enabling distributed controls is a requirement for power transmission and distribution, to improve line balancing and distribution efficiency. These FACTS devices are electronic circuits that vary in the type of services they provide. All FACTS devices have internal circuitry to handle fault currents. Most of these circuits are unique in design for each manufacturer, which make these FACTS devices non-modular, non-interchangeable, expensive and heavy. One of the most versatile FACTS device is the static synchronous series compensator (SSSC), which is used to inject impedance into the transmission lines to change the power flow characteristics. The addition of integrated fault current handling circuitry makes the SSSC and similar FACTS devices unwieldy, heavy, and not a viable solution for distributed control. What is disclosed are modifications to FACTS devices that move the fault current protection external to the FACTS device and make them modular and re-usable.