Low-voltage circuit breaker short-circuit test system and impedance adaptive correction method thereof

Abstract

The invention discloses a low-voltage circuit breaker short-circuit test system which comprises a voltage signal source and an impact test transformer. The voltage signal source is input into the impact test transformer through a switch cabinet. The impact test transformer is connected with a low-voltage closing protection phase selection cabinet through a voltage conversion device. The low-voltage closing protection phase selection cabinet is connected with a front stage load. The front stage load comprises an inductive load and a resistive load, wherein the inductive load and the resistive load are connected in series. The output end of the front stage load is connected with a test port provided with a tested product. The test port is connected with a change-over switch in change-over connection with a post stage load or a ground line. The invention further discloses an impedance adaptive correction method of the low-voltage circuit breaker short-circuit test system. The correction method uses software to quickly set test parameters and improves the test accuracy through impedance thermal compensation and loop impedance compensation.

Description

technical field [0001] The invention belongs to the technical field of low-voltage circuit breakers, in particular to a low-voltage circuit breaker short-circuit test system and an impedance self-adaptive correction method thereof. Background technique [0002] At present, according to the requirements of national standards GB14048.1-2012 (IEC60971-1:2011) and GB14048.2-2008, low-voltage circuit breaker products need to undergo type tests before they go on the market, including rated operating short-circuit breaking capacity and rated limit short-circuit breaking capacity tests It is especially critical. Therefore, the device required for the short-circuit test must be accurate and reliable. At the same time, for the test station that provides external services, it is very important to provide efficient service quality. It is necessary to quickly and accurately set parameters to allow accurate short-circuit current to pass the test. Taste. However, when conducting short-cir...

AI Technical Summary

Problems solved by technology

However, when conducting short-circuit tests, different customers and products have different parameter requirements. When encountering new test parameters, the traditional method needs to manually calculate the test parameters each time, and it is necessary to manually look up the table to obtain the set impedance combination switch. The data, the traditional method impedance parameter setting such as figure 1 As shown, after each setting of the impedance knife switch combination, a short-circuit test will be carried out. It is necessary to compare the actual measured value with the expected parameter requirements. Repeated adjustments are required to obtain accurate test parameters. The work is cumbersome, and there are various in the circuit. There are oxidation phenomena in the connecting wires and connecting terminals, the inherent impedance of the system loop cannot be ignored, and there is a large error in the numerical value calculated only by theory

After analysis, the traditional method is inefficient, and the main factors that lead to multiple calculations are as follows: ① The inherent impedance of the system loop is not fully considered; ② The temperature compensation of the system impedance is not considered; ③ Manual calculations, table lookups, etc. are not automated

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