There is provided an electrical assembly for use in a power transmission network. The electrical assembly includes a converter including terminals for connection to an electrical network, where the first terminal is a DC terminal. The assembly also includes a DC power transmission medium connected to the DC terminal, and a circuit interruption device including switching element(s) and an energy absorption element, each switching element being switchable to divert a flow of current in the DC power transmission medium through the energy absorption element in order to reduce the flow of current in the DC power transmission medium; The assembly also includes a converter control unit programmed to operate the converter to control a DC voltage at the DC terminal in a leakage current reduction mode to control a voltage across the energy absorption element.

A system for stabilizing an alternating voltage grid has an inverter, which can be connected to the alternating voltage grid, and is configured to exchange reactive power with the alternating voltage grid. The system further has an inductor arrangement with variable inductor coils, which can be connected to the alternating voltage grid, and a control device, which is configured to control a reactive power in the alternating voltage grid by use of the inverter and by use of the inductor arrangement.

The invention relates to a method for controlling injection and absorption of reactive power in a wind power plant (WPP). In addition to wind turbine generators (WTG), the wind power plant comprises reactive power regulating devices, such as MSU and STATCOM devices. The reactive power regulating devices are controlled by wind power plant controller so that the combined amount of reactive power produced by the wind turbine generators and the reactive power regulating devices satisfies a desired amount of reactive power. In case of communication fault between the power plant controller and one of the reactive power regulating devices, the power plant controller is reconfigured so as to compensate the capability of the reactive power regulating device to inject or absorb the amount of reactive power.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

A control unit for an active filter for reducing resonance in an electric system is provided. The electric system comprises a power source distributing an alternating current to an AC conductor connected to a power consuming unit for distributing the AC to the power consuming unit. The active filter comprises a DC power source and a DC conductor connecting the DC power source to the AC conductor. The control unit comprises: a voltage measurement unit adapter to create a voltage signal on the basis of a measured voltage; a computing unit adapted to compute, using a biquadratic filter, a first compensating current on the basis of the voltage signal for reducing resonance in the electric system and a switching system placed between the DC power source and the DC conductor for creating the calculated first compensating current.

A method and system for locally controlling delivery of electrical power along a distribution feeder. For a feeder segment in the distribution feeder the method includes: obtaining an actual voltage magnitude at an upstream node and at a downstream node of the feeder segment, and a real power value at the upstream node; setting a target voltage phasor at the downstream node as a value when a power flow across the feeder segment is maintained, and when equal reactive power is injected at the upstream and downstream nodes that consumes all the reactive power in the feeder segment; and adjusting operation of the at least one controllable reactive power resource so that the actual voltage magnitude at the downstream node moves towards a target voltage magnitude of the target voltage phasor.

Systems and methods of the present disclosure involve passive, hybrid, and active filtering configurations to mitigate current harmonics for various electrical loads. One hybrid filtering configuration is medium voltage (MV) active filtering using a DC-DC converter and a multi-level inverter, and low voltage (LV) passive filtering. Another hybrid filtering configuration is MV passive filtering and LV active filtering using a two-level inverter. An active filtering configuration includes both MV and LV active filtering. The present disclosure also features power distribution unit (PDU) transformers electrically coupled to respective power supplies on the LV side of an electrical system. Each PDU transformer includes primary coils in a delta configuration and secondary coils in a wye configuration. The secondary coils are in series with respective leakage inductance coils. The secondary coils and the leakage inductance coils are integrated together into a single unit or module.

A power control system for managing energy transfer includes a shared electrical bus including an electrical energy generating source, an electrical energy storage device, and an electrical load, each connected to the shared electrical bus; and a controller operable to execute a plurality of instructions stored in a non-transitory memory on the controller to: receive a command corresponding to a desired operation of the power control system, generate a plurality of control commands as a function of a signal received from at least one sensor, and generate a log storing the present operating state for each of the electrical energy generating source, the electrical energy storage device, and the electrical load over a predefined duration, and wherein the at least one input corresponding to the past operating state of the power control system is the log.

Provided is an active power filter-based modular multilevel converter, relating to the field of power electronics. According to the converter, an active power filter circuit is provided between upper and lower arms of each phase in a modular multilevel converter. The active power filter circuit includes two switch power devices, two submodules, a capacitor, and an inductor. The upper and lower bridge-arms are connected in series by means of two submodules, the two switch power devices are connected in series and then connected in parallel to ends of intermediate submodules which are connected in series, and the capacitor and the inductor are connected in series and then connected in parallel to two ends of the switch power device connected to the lower bridge-arm. The defect of large capacitance of submodule in conventional modular multilevel topology is overcome.

Disclosed herein are systems for maintaining protection of electric power delivery systems in the event of a control power failure or other anomaly. A reliable power module conditions electric power from multiple independent sources and provides electrical operational power to electric power delivery system protective loads. The reliable power module includes a power storage device for providing operational power even upon loss of all control power sources. The power storage may be sufficient to ride through expected losses such as a time to start up backup generation. The power storage may be sufficient to power a trip coil. Thus, electric power system protection is maintained even upon loss of control power.