5000A以上断路器显示电流与实际电流差异分析

Analysis of the difference between the display current and the actual current of circuit breaker above 5000A

5 000A以上的断路器通常是每相由多极并联引出双接线端子的结构,针对5 000A以上万能式断路器正常工作时显示电流明显大于实测电流的情况,显示误差通常超过企业规定精度的现象。通过理论分析和实际测试,通过理论分析断路器内部以及连接排之间的互感和自感现象,发现断路器每极阻抗不完全一致,它们之间的负载电流数值不相等,同相不同极上的负载电流之间存在明显的相位角,相位角大约为32°。因为断路器内部和外接负载之间的互感和自感现象,断路器显示电流比实际电流大,它们之间的差值约为5%。

More than 5000 Acircuit breaker is usually each phase by multi-pole structure of parallel double terminal derivation,for above 5000 Auniversal circuit breaker normal work shows the current is significantly greater than the measured current situation,the display difference is usually more than the accuracy of the manufacture gived.In this paper,through the theoretical analysis and the actual test,Through the theoretical analysis of the circuit breaker inside and the connection between the mutual sense and self-inductance phenomenon,it is found that the impedance of each pole of the circuit breaker is not exactly the same,the value of the load current between them is not equal,there is a significant phase angle between the load currents at different poles at the same phase,the phase angle is about 32°.Because of the mutual inductance and self-inductance between the internal and external loads of the circuit breaker,the display is larger than actual current and the difference is about 5%.