Working condition simulation test circuit and method for cascaded converter sub-module

Abstract

The invention discloses a working condition simulation test circuit and method for a cascaded converter sub-module. The circuit comprises a current generator which is used for generating a current needed by a to-be-tested sub-module; the to-be-tested sub-module which is used for receiving a current signal and outputting a capacitor voltage signal; a voltage controller which is used for receiving the capacitor voltage signal and generating a voltage regulation signal, so that the capacitor voltage of the to-be-tested sub-module is consistent with a reference voltage; a current controller whichis used for receiving the current signal and the voltage regulation signal and generating a control signal of the current generator to control the running state of the current generator; an auxiliarybridge arm which is switched on when the to-be-tested sub-module operates in a cut-off state and matches the current generator to carry out auxiliary adjustment on the output current of the current generator; an auxiliary bridge arm controller which is used for controlling the auxiliary bridge arm; and a converter system model which is used for controlling the to-be-tested sub-module, the currentcontroller and the voltage controller. According to the invention, the test cost is reduced, and the safety is improved.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a working condition simulation test circuit and method of a sub-module of a cascaded converter. Background technique [0002] In recent years, due to its scalability, cascaded converters have been widely used and paid attention to in medium-high voltage and high-power fields. However, with the continuous improvement of the voltage level and capacity of the cascaded converter, the number of sub-modules of the cascaded converter will also become very large, and the reliability of the cascaded converter mainly depends on the sub-modules of the cascaded converter. module reliability. In order to ensure the reliable operation of the cascaded converter system, the verification and testing of its sub-modules becomes very important. [0003] At present, the main modulation method of cascaded converters is nearest level approximation modulation. The operating conditions of cas...

AI Technical Summary

Problems solved by technology

[0010] In view of the problems existing in the above-mentioned prior art, the present invention proposes a working condition simulation test circuit and method of cascaded converter sub-modules, using the auxiliary bridge arm and its corresponding control method, when the sub-module to be tested is cut off, the The auxiliary bridge arm is put into use to compensate for the voltage difference generated when the sub-module to be tested is cut off, and the auxiliary bridge arm is cut off when the sub-module to be tested is put into use, which solves the problem of applying correct voltage and current stress to the sub-module in the traditional method, while testing The system has a large system capacity, a large number of sub-modules, inflexible configuration, and high security requirements during testing.

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