An electric power conversion device includes a power conversion unit and a converter control unit. The power conversion unit includes three arms connected to an AC circuit. The converter control unit includes a phase DC voltage control unit, a negative sequence current command value calculation unit, an output current control unit, a circulating current control unit, a voltage command value calculation unit, and a gate signal generation unit, and imbalance of cell DC capacitor voltages among phases due to grid imbalance is controlled by circulating current and negative sequence current.

Electric power conversion device

Research on methods of measuring extinction angle and measures to suppress repetitive commutation failures through equivalent DC input resistance

The invention discloses a direct current deicing device based on a voltage source type converter and a control method of the direct current deicing device. The direct current deicing device comprises a connection reactor, a modularization multi-level converter, a smoothing reactor, a deicing disconnecting link, a deicing bus and a deicing alternating current circuit. The alternating current side of the modularization multi-level converter is connected to the alternating current side bus through the connection reactor, an isolating disconnecting link and a breaker. The direct current side of the modularization multi-level converter is connected with the deicing alternating current circuit through the smoothing reactor, the deicing disconnecting link and the deicing bus. According to the direct current deicing device, a special transformer is not needed, the feature that a full-H bridge module can output three kinds of module voltages, namely the positive module voltage, the zero module voltage and the negative module voltage is fully utilized, the voltage and the current at the direct current side of the modularization multi-level converter can be continuously adjusted between the rated value and zero. The requirement for deicing of multiple power transmission lines with different lengths and different specific resistances can be met with one set of deicing device, and in all operation conditions, the alternating current power quality can be ensured. The control method of the direct current deicing device is easy and convenient to carry out.

Direct-current de-icing device based on voltage source type converter and control method therefor

An electric power conversion device (100) that is provided with a first arm (4) and a second arm (5) that are each provided with converter cells. The converter cells that constitute the first arm (4) are first converter cells (10) that have a full-bridge configuration and that have an energy storage element (20) and semiconductor switching elements (21s, 22s, 23s, 24s), and the converter cells that constitute the second arm (5) are second converter cells (15) that have a half-bridge configuration, that have an energy storage element (20) and semiconductor switching elements (41s, 42s, 51s, 52s), and that suppress short-circuit current between direct-current terminals.

Electric power conversion device and electric power system

Commutation failure prediction method based on characteristic of accumulated energy in inverter

Improved predictive calculation-based extinction angle control for HVDC

The utility model relates to a DC deicing device based on a voltage source converter. The DC deicing device comprises a connecting reactor, a modularized multi-level converter, a smoothing reactor, a deicing switch, a deicing bus and a deicing AC circuit, wherein the AC side of the modularized multi-level converter is connected to the AC side bus through the connecting reactor, an isolating switch and a circuit breaker, and the DC side of the modularized multi-level converter is connected to the deicing AC circuit through the smoothing reactor, the deicing switch and the deicing bus. According to the DC deicing device, a special transformer is not required, the characteristic that a full H bridge module can output positive, zero and negative module voltages is fully utilized, voltage and current of the DC side of the modularized multi-level converter are continuously adjustable between rated values and zero, deicing requirements of a plurality of power transmission lines with different lengths and different resistivity can be satisfied by a set of deicing device, and AC electric energy quality can be ensured under all operating conditions. The DC deicing device can be controlled simply and conveniently.

DC deicing device based on voltage source converter

A voltage source converter based DC deicer and its control method are provided. The voltage source converter based DC deicer includes a connecting reactor, a modular multilevel voltage source converter based on a full H-bridge submodule, smoothing reactors, deicing disconnectors, a deicing bus, and a deicing AC line. The AC side of the modular multilevel voltage source converter is connected to an AC side bus through the connecting reactor, an isolation disconnector and a breaker. The DC side of the modular multilevel voltage source converter is connected to the deicing AC line through the smoothing reactors, the deicing disconnectors, and the deicing bus.

Shukai Xu

Papers

Improved predictive calculation-based extinction angle control for HVDC

DC deicing device based on voltage source converter

Direct-current de-icing device based on voltage source type converter and control method therefor

Voltage source converter based direct current deicer and controlling method thereof