A power flow control subsystem having multiple configurations is described. The subsystem is three-way configurable: as a transportable configuration, as a deployable configuration, and as a transmission line configuration. The transportable configuration includes a collection of impedance injection modules and at least one bypass module carried on a wheeled vehicle such as a trailer. The deployable configuration is an assembly of the collection of impedance injection modules and at least one bypass module, operable to perform power flow operations. The transmission line configuration includes connection of a deployable configuration to a phase of a high voltage transmission line for performing power flow control. The deployable configuration may be open or closed frame. The deployable configurations may be mounted on one or more wheeled vehicles in a mobile subsystem, or semi-permanently mounted at a ground site.

In an impedance injection module in which multiple converter units are placed in series to realize a high level of impedance injection, switches, preferably vacuum interrupters, are connected to short the input and the output terminals of each individual unit. Unlike the fault-protecting switch across the entire module, these switches at the individual converter unit level serve several purposes, overload and surge protection of a unit, insertion loss minimization of an idle unit when the required impedance injection is small, and electrically removing a defective injection unit from the power flow to increase the overall reliability of the impedance injection module in the face of the failure of one unit or a few units. For more rapid response, particularly in response to faults, the vacuum interrupter at the unit level may be accompanied by an SCR switch in parallel with it.

A charging system for a vehicle is provided. The charging system is for charging an energy storage system of the vehicle using grid power. The grid power may be an external three-phase AC. The charging system may use field weakening techniques to reduce a peak line-line voltage detected at input terminals of conversion circuitry when a need is determined.

An intelligent impedance injection module is for use with transmission lines in a power grid. The intelligent impedance injection module has a plurality of transformer-less impedance injector units and a controller. The controller changes injector gain of the impedance injector units to compensate for current swings in a transmission line.

A power conversion device includes: a power converter connected to an electrical storage device that stores direct current power, the power converter being capable of converting the direct current power stored in the electrical storage device to alternating current power and outputting the alternating current power to a power system and to a customer load; and a control unit to control the power converter on a basis of a first active power command value and a first reactive power command value provided from an external controller, of a power consumption of the customer load, of a current root-mean-square value of a power flow current supplied to the power system, and a current upper limit that is set on a basis of a rated current of a molded case circuit breaker connected between the power converter and the power system.

Management of an electrical power transmission network is obtained by providing at each subscriber premises a power correction system for applying a switched reactor for voltage correction across the input voltage and a sensing system defined by a pair of meters one at the supply and the second downstream of the voltage correction for detecting variations in power factor. The system includes an arrangement for balancing loads between a first phase on a first BUS and a second phase on a second BUS by calculating a required correction current by adding load currents from the first and second phases. In addition an arrangement is provided when a load is switched on and off power is supplied by or supplied to a battery for a short time and this power is reduced over a time period substantially matching or greater than said natural time constant of the power supply system.

A system architecture and method for enabling hierarchical intelligent control with appropriate-speed communication and coordination of control using intelligent distributed impedance/voltage injection modules, local intelligence centers, other actuator devices and miscellaneous FACTS coupled actuator devices is disclosed. Information transfer to a supervisory utility control is enabled for responding to integral power system disturbances, system modelling and optimization. By extending the control and communication capability to the edge of the HV power grid, control of the distribution network through FACTS based Demand response units is also enabled. Hence an integrated and hierarchical total power system control is established with distributed impedance/voltage injection modules, local intelligence centers, connected other actuator devices, miscellaneous FACTS coupled devices and utility supervisory all networked at appropriate speeds allowing optimization of the total power system from generation to distribution.

A system architecture and method for enabling hierarchical intelligent control with appropriate-speed communication and coordination of control using intelligent distributed impedance/voltage injection modules, local intelligence centers, other actuator devices and miscellaneous FACTS coupled actuator devices is disclosed. Information transfer to a supervisory utility control is enabled for responding to integral power system disturbances, system modelling and optimization. By extending the control and communication capability to the edge of the HV power grid, control of the distribution network through FACTS based Demand response units is also enabled. Hence an integrated and hierarchical total power system control is established with distributed impedance/voltage injection modules, local intelligence centers, connected other actuator devices, miscellaneous FACTS coupled devices and utility supervisory all networked at appropriate speeds allowing optimization of the total power system from generation to distribution.

A power flow control subsystem having multiple configurations is described. The subsystem is three-way configurable: as a transportable configuration, as a deployable configuration, and as a transmission line configuration. The transportable configuration includes a collection of impedance injection modules and at least one bypass module carried on a wheeled vehicle such as a trailer. The deployable configuration is an assembly of the collection of impedance injection modules and at least one bypass module, operable to perform power flow operations. The transmission line configuration includes connection of a deployable configuration to a phase of a high voltage transmission line for performing power flow control. The deployable configuration may be open or closed frame. The deployable configurations may be mounted on one or more wheeled vehicles in a mobile subsystem, or semi-permanently mounted at a ground site.

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.