Aspects of the disclosure include a power system comprising at least one three-wire active harmonic filter (AHF) configured to be coupled to, and provide compensation current to, a three-phase load, at least one four-wire AHF configured to be coupled to, and provide compensation current to, the three-phase load, and a controller configured to determine a total compensation current to provide to the three-phase load, the total compensation current including a zero component and a non-zero component, determine an output capacity of the at least one three-wire AHF and the at least one four-wire AHF, calculate a current-compensation ratio based on the output capacity of the at least one three-wire AHF and the at least one four-wire AHF, and control the at least one four-wire AHF to provide at least a portion of the non-zero component of the total compensation current to the three-phase load based on the current-compensation ratio.

A device for reactive power compensation in a high-voltage network contains a phase conductor. A high-voltage connection is provided for each phase of the high-voltage network. Each high-voltage connection is connected to a first high-voltage winding which surrounds a first core portion and to a second high-voltage winding which surrounds the second core portion. The core portions are part of a closed magnetic circuit. The low-voltage ends of each high-voltage winding can be connected to at least one saturation switching branch configured to saturate the core portions and has actuatable power semiconductor switches controlled by a control unit. To manufacture the device inexpensively, each saturation switching branch has a two-pole submodule having a bridge circuit and a DC voltage source so that, depending on the actuation of the power semiconductor switches, the DC voltage source can either be connected in series to the high-voltage winding or can be bridged.

A device for reactive power compensation in a high-voltage network contains a phase conductor. A high-voltage connection is provided for each phase of the high-voltage network. Each high-voltage connection is connected to a first high-voltage winding which surrounds a first core portion and to a second high-voltage winding which surrounds the second core portion. The core portions are part of a closed magnetic circuit. The low-voltage ends of each high-voltage winding can be connected to at least one saturation switching branch configured to saturate the core portions and has actuatable power semiconductor switches controlled by a control unit. To manufacture the device inexpensively, each saturation switching branch has a two-pole submodule having a bridge circuit and a DC voltage source so that, depending on the actuation of the power semiconductor switches, the DC voltage source can either be connected in series to the high-voltage winding or can be bridged.

A method for feeding electrical power into an electrical, three-phase supply network by means of an inverter device, wherein the electrical supply network has a three-phase line voltage with a first, second and third line voltage phase, comprising the steps: feeding the electrical power during normal operation if a fault-free operation has been identified for the electrical supply network, wherein during normal operation a positive sequence voltage and optionally a negative sequence voltage is recorded from the line voltage and a reactive current is specified at least depending on the positive sequence voltage and optionally depending on the negative sequence voltage, and changing to a fault operation if a voltage change in the line voltage meets a predetermined fault criterion, in particular if the voltage change exceeds a predeterminable minimum amount of change or a minimum amount of change gradient, wherein during the fault operation, at least directly after the change, the reactive current is specified depending on a space vector voltage.

A power supply circuit, a compensation circuit and a harmonic distortion compensation method thereof are disclosed. The power supply circuit includes a rectifier and filter module, a main power stage module, a voltage waveform detection module and a compensation module. The rectifier and filter module converts an AC voltage into a DC voltage. The main power stage module receives the DC voltage and provides power to a load. The voltage waveform detection module is configured to detect a waveform of the DC voltage and derive, from the waveform, information about each cycle of the DC voltage. The compensation module is configured to generate a compensation signal based on the information about each cycle of the DC voltage and trigger the main power stage module to perform compensation operation based on the compensation signal. The compensation operation is performed to accomplish total harmonic distortion compensation of the power supply circuit.

A method for operating a motor vehicle comprising at least one first electric machine and at least one second electric machine, which are electrically interconnected to each other, wherein the first electric machine is operated at a first operating point and the second electric machine is operated at a second operating point, wherein the reactive power generated or taken up by the first electric machine at the first operating point is at least partly compensated by the second electric machine operating at the second operating point.

A method for operating a motor vehicle comprising at least one first electric machine and at least one second electric machine, which are electrically interconnected to each other, wherein the first electric machine is operated at a first operating point and the second electric machine is operated at a second operating point, wherein the reactive power generated or taken up by the first electric machine at the first operating point is at least partly compensated by the second electric machine operating at the second operating point.

A power management system includes a first server configured to manage electric vehicle supply equipment in a microgrid and a second server configured to manage power supply and demand balance of a power system. The electric vehicle supply equipment is configured to execute a charging and discharging operation that suppresses a voltage fluctuation of the microgrid by exchanging power between the microgrid and a vehicle, and a reactive power compensation operation that suppresses a voltage fluctuation of the power system by controlling reactive power of the microgrid.

The present disclosure relates to a wireless neutral current sensor (WNCS) for monitoring a neutral cable of a capacitor bank. The WNCS may include a power storage device that provides power to allow the WNCS to send a test signal to a capacitor bank controller (CBC) of the capacitor bank to confirm operation of the WNCS during commissioning. The WNCS may include processing and communication circuitry that, during operation, detects an electrical characteristic on the neutral cable. The processing and communication circuitry may provide a message indicating the electrical characteristic to the CBC.

A system and method of a multi-channel, multi-mode electric vehicle (EV) AC to DC charger has power channels, each power channel contains an AC/DC converter and corresponding DC/DC regulator. Each channel is configured to supply DC power to a channel-connected EV. The charger also has a controllable bridging switch, connected in parallel between the power channels and disposed before or after the DC/DC regulators, and provides an intermediary path between the power channels. It also contains controllable series switches, after the DC/DC regulators to provide a break in a power channel output path. A controller controls the AC/DC converters, DC/DC regulators, bridging and series switches. The charger is multi-mode capable, enabling (a) charging an EV, (b) directing power from one channel's connected end device to another channel's connected end device, (c) injecting real or reactive power back to an AC power source, (d) active AC filtering, and (d) phase balancing.