A redundant energy supply circuit and control method for sub-modules of a multilevel converter

Abstract

The invention discloses a redundant energy supply circuit and a control method for sub-modules of a multilevel converter. The multilevel converter sub-module includes at least one power semiconductor unit, a sub-module capacitor C M , bypass switch K B , power board and control board. The redundant energy supply circuit is composed of a first resistor R1, a second resistor R2, a connection module and a voltage conversion circuit. After the failure of the power supply board, the solution of the present invention realizes the charging of the energy storage capacitor of the bypass switch and the power supply of the control board by using the equalizing resistor voltage division and the voltage conversion circuit, so as to ensure the reliable closing of the bypass switch after the failure of the power supply board. and sub-module status to avoid system shutdown and operation with faults when the status of the bypass switch is unknown, improving the security and reliability of the system. The scheme of the invention utilizes the energy of sub-module voltage equalizing resistance loops without additional system loss, improves system operation economy, has simple and reliable structure, is practicable, and has low cost.

Description

technical field [0001] The invention discloses a redundant energy supply circuit and a control method for a sub-module of a multilevel converter, and relates to the field of flexible AC and DC power transmission, in particular to the energy acquisition technology of a power unit module. Background technique [0002] Cascaded multilevel converters are widely used in UHV AC and DC transmission, reactive power compensation, DC distribution network and other power, rail transit and new energy occasions. In order to ensure the safe and stable operation of the cascaded multi-level converters, the sub-modules of the multi-level converters all require the design of a fault bypass function. When a fault occurs inside the sub-module, the bypass function will bypass the faulty module to avoid The failure expands, maintains the system to continue to operate, and avoids economic losses. [0003] However, the power board, as the energy source for all control and protection functions in t...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is: the sub-module of the multi-level converter cannot perform bypass after the failure of the power board, resulting in system outage, and the possible faulty operation under the unknown state of the bypass. A multi-level converter is proposed. Level converter sub-module redundant energy supply circuit and control method

Images