A two-level voltage source DC circuit breaker synthesis test circuit and method

Abstract

The present invention provides a DC circuit breaker synthetic test circuit and method with a two-level voltage source, including a current source and a two-level voltage source, wherein both the current source and the two-level voltage source are connected in parallel to the DC circuit breaker of the test product Both ends; the present invention uses a two-level voltage source equivalent transient breaking voltage, which can not only ensure sufficient transient breaking voltage and duration during the test, but also provide the DC system voltage that the DC circuit breaker needs to withstand after breaking , the test circuit is simple and has high equivalence; the cooperation between the current source and the two-level voltage source can be equivalent to the current and voltage stress that is more consistent with the actual breaking of the DC circuit breaker, so that the breaking performance of the DC circuit breaker is reliable. Verification, the capacity of the test circuit is small, the structure is simple, and the economy is high.

Description

technical field [0001] The invention belongs to the field of DC circuit breaker testing, and in particular relates to a DC circuit breaker synthetic test circuit and method with two-level voltage sources. Background technique [0002] With the rapid growth of installed capacity of renewable clean energy such as wind energy and solar energy, the multi-terminal DC transmission and distribution technology suitable for large-scale access of intermittent renewable energy has received extensive attention. As an important protection device in the DC system, the DC circuit breaker can quickly clear and isolate faults to ensure the safety and stability of the DC system. In order to ensure that the DC circuit breaker can be reliably broken, the breaking test of the DC circuit breaker plays an important role in the verification of its performance. [0003] The DC circuit breakers mainly used in the DC power grid include hybrid DC circuit breakers and mechanical DC circuit breakers. Al...

AI Technical Summary

Problems solved by technology

If the arrester of the DC circuit breaker is used for the test, the application of voltage stress will become very difficult. For example, the arrester needs to dissipate more than 100MJ energy when the 535kV DC circuit breaker is disconnected. This requires too high requirements for the test power supply. The circuit is difficult to realize, and the small-capacity test circuit will cause the duration of the transient breaking voltage to be too short due to the insufficient energy provided, and the voltage stress equivalent of the test is not enough

In order to solve this contradiction, this method adopts to remove the arrester for breaking test. In this case, how to equivalent the current and voltage stress in the actual breaking situation of the DC circuit breaker is the key. The transient state provided by the arrester when absorbing energy The amplitude and duration of the breaking voltage, as well as the DC system voltage withstood by the DC circuit breaker after the surge arrester operates, all require the test circuit to be applied to the test product in an equivalent manner. The design of this test circuit is difficult, and the related mature design scheme not yet proposed

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