A mmc sub-module circuit with DC side fault blocking capability

Abstract

An MMC sub-module circuit with DC side fault blocking capability. It involves the field of power system protection and control. The short-circuit current can be completely blocked, the structure is simple, the required components are few, and the integration degree is high. Consists of two half-bridge sub-modules, power switch one with anti-parallel diodes and diodes. One of the half-bridge sub-modules is connected to the emitter of the first power switch tube with an antiparallel diode, and the other is connected to the collector of the first power switch tube with an antiparallel diode. The cathode of the diode is connected to the collector of the power switch tube 2 with the anti-parallel diode in the half-bridge sub-module connected to the emitter of the power switch tube 1 with the anti-parallel diode, and the anode is connected to the collector of the power switch tube 1 in the other half-bridge sub-module. The emitter connection of the power switch tube three with an antiparallel diode. The product is small in size and high in stability; simple in topology, low in cost and easy to implement; flexible in configuration and low in power consumption; it can disconnect the DC side at any time and respond quickly.

Description

technical field [0001] The invention relates to the field of power system protection and control, in particular to an MMC sub-module circuit with DC side fault blocking capability. Background technique [0002] The output voltage level of the traditional power quality comprehensive compensation device with three-phase half bridge as the main circuit is limited and the compensation ability for negative sequence current is limited, so the final compensation result cannot achieve the required effect, and its switching frequency Higher, greater loss. Sometimes in order to improve the withstand voltage of the system, it is necessary to divide the voltage in series with multiple switching devices, but this will bring problems such as the consistency of the switching devices and the voltage equalization. [0003] An invention patent application published by the State Intellectual Property Office on May 13, 2015 (application number: 201410848005X name: improved structure and isolat...

AI Technical Summary

Problems solved by technology

Its disadvantages are that the required components are diverse, the withstand voltage value is low, the DC circuit breaker has a long response time, the action frequency is high, and the loss of the components is large.

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