Control system capable of realizing direct current (DC) capacitive voltage balance of H-bridge cascaded STATCOM (static synchronous compensator)

Abstract

The invention discloses a control system capable of realizing direct current (DC) capacitive voltage balance of an H-bridge cascaded STATCOM (static synchronous compensator). The control system comprises an H-bridge unit, an A / D (analog-to-digital) sampling unit, an FPGA (Field Programmable Gate Array) control unit and a main control unit (MCU), wherein, the A / D sampling unit converts the acquired DC capacitive voltage analog signal of the H-bridge unit into a serial data signal and then transmits the serial data signal to the FPGA control unit for data processing; the FPGA control unit performs serial communication with the MCU so as to transmit a sampling value and a modulation signal; and the FPGA control unit comprises a sampling module, a PI (proportional-integral) regulation module, a modulation signal phase-shift module and a communication module. The control system has the beneficial effects that DC capacitive voltage balance control and DC voltage detection of each module are integrated and completed in the FPGA control unit, wherein, the PI regulation module and the modulation signal phase-shift module can jointly realize DC capacitive voltage balance so that the H-bridge cascaded STATCOM can obtain higher modularization degree, thus facilitating use of a multi-module cascade device.

Description

technical field [0001] The invention relates to a control system for realizing H-bridge cascaded STATCOM DC capacitor voltage balance. Background technique [0002] With the continuous application of power electronic devices in high-voltage and high-power occasions, FACTS technologies such as static var generator (STATCOM) and active power filter (APF) have been developed rapidly. The DC side of the bridge inverter unit is independent, and the cascaded inverter structure can realize the series connection of the inverter units to improve the voltage and power level of the inverter output, so the H-bridge cascaded inverter is widely favored. [0003] One of the main disadvantages of the cascaded STATCOM used in high-power applications is that it is difficult to achieve balanced control of the DC capacitor voltage. If the DC voltage deviates, the withstand voltage of the switching device will be too high, resulting in a failure of the main circuit, which seriously affects the r...

AI Technical Summary

Problems solved by technology

The main disadvantage of this method is that the balance of the DC capacitor voltage is achieved through the peripheral circuit, and the use of the transformer increases the cost of the module unit

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