论文部分内容阅读
1.晶阐管过电压保护 (1)产生过电压的原因 在电路中出现过电压,其值超过晶闸管的阻断电压时,将会使其PN结损坏。过电压是造成晶闸管电路故障的重要原因之一,产生过电压的原因有如下几种: 1)雷击浪涌电压 直击雷和感应雷将在输电线上产生浪涌电压,尽管电网中装有阀形避雷器,但是残余电压仍有可能涌入控制电路并损坏晶闸管。 2)线路谐振产生高压 由于变压器漏电抗和二次侧线圈分布电容的存在,当变压器一次侧接通时,二次侧会产生谐振高电压,其值最大可
1. Crystal tube over-voltage protection (1) The cause of over-voltage occurs in the circuit over-voltage, the value exceeds the thyristor blocking voltage, it will make PN junction damage. Over-voltage is one of the important reasons for the thyristor circuit failure. Overvoltage can be caused by the following types: 1) Lightning surge voltage The lightning surge and induced lightning will generate surge voltage on the transmission line. Although there is a valve Arrester, but the residual voltage may still flow into the control circuit and damage the thyristor. 2) Line Resonance Generates High Voltage Due to the transformer leakage reactance and the distributed capacitance of the secondary winding, when the primary side of the transformer is connected, the secondary side will generate a resonant high voltage, the maximum value of which may be