By-pass switch interface circuit of modular multilevel converter (MMC) valve sub-module and implement method thereof

Abstract

The invention discloses a by-pass switch interface circuit of a modular multilevel converter (MMC) valve sub-module and an implement method of the by-pass switch interface circuit. The interface circuit comprises a charging circuit and a trigger circuit, wherein the charging circuit is connected with the trigger circuit. The trigger circuit is connected with a closing coil of a by-pass switch, and an input power supply provides an energy-storage capacitor with power through the charging circuit. The input end of the trigger circuit is connected with the energy-storage capacitor, the output end of the trigger circuit is connected with the closing coil inside the by-pass switch, and the trigger circuit controls the connection and disconnection of the circuit through a thyristor. When a sub-module controller commands the by-pass switch to be turned off, the by-pass switch is closed immediately under the action of the interface circuit, that is a main contact of the by-pass switch is closed immediately, the auxiliary contact turns into normally open state from former normally close state, and a signal that switch is closed successfully is reported back to the sub-module controller. The interface circuit has the advantages that reliable control over the by-pass switch closing by the sub-module controller is realized and power requirement of the input power supply is reduced.

Description

technical field [0001] The invention belongs to the field of power systems, and in particular relates to a bypass switch interface circuit of an MMC valve sub-module and a realization method. Background technique [0002] The modular multilevel flexible DC transmission system is different from the traditional DC transmission system. Its smallest unit is the sub-module that composes the converter valve, and the bypass switch is an indispensable key component of the sub-module. When a sub-module fails, the sub-module controller issues a command to close the bypass switch to bypass the sub-module, thereby eliminating the impact of the fault on the system. If the bypass switch cannot be closed accurately and quickly, it is considered that the faulty sub-module is out of control, and the hazard of the fault may expand, and the system will perform a trip operation, requiring power-off maintenance. Therefore, the reliable operation of the sub-module bypass switch is the guarantee ...

AI Technical Summary

Problems solved by technology

The fast closing of the bypass switch requires a lot of energy, and the power supply method for the control and protection of the sub-module is to obtain energy from the internal capacitor of the sub-module, and the power is usually about tens of watts, which is difficult to meet energy needed

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