反电势过高造成逆变失败故障一例分析

Analysis of Inverter Failure which Led by Over Back Electromotive Force

逆变失败是晶闸管整流电路应用中非常严重的故障,其危害相当大,常常导致设备元器件损坏。因为此类故障很难查找原因,所以常常困扰很多电气工作者,为加深对这一故障的了解,通过实际发生的一例由于反电势过高造成的逆变失败的例子,再通过波形分析,使读者了解此逆变失败的原因及过程中各个晶闸管的动作状态。虽然例举的是交交变频而不是典型直流调速系统,但其主电路是由3个三相全控桥组成,而且其控制原理也是以直流调速为基础的,所以对分析直流调速系统及类似的整流电路也有很好的借鉴作用。

Inverter failure is the serious fault in the thyristor rectifying circuit, which leads to great damages to the equipments. It is very difficult to find the reason so it also puzzles electricians normally. A practical fault case of over reversepotential leads to inverter failure was set. Through the analysis of wave, it is explained that the thyristor＇ s working state during the inverter failure and reason. The example is cycloconverter not typical DC driving system, but the main circuit including 3 three phases bridge rectifying circuit, and the control theory also is based on the DC driving system, so it will helps electricians to understand the DC driving system and other similar course very well.