常规斩波串级调速系统主要部件逆变器易发生换相失败导致逆变颠覆,其保护机构真空接触器和快速熔断器不能即时动作,造成短时保护空白区.设计增加Crowbar电阻电路,对故障进行暂态分析,建立系统数学模型,利用Simulink软件仿真,制作样机进行试验.实验表明Crowbar电路能在μs级时间内投入主回路,限制故障电流上升,阻止故障进一步扩大.电阻保护的方法是可行的,可适当在实际项目试用推广.%The main components SCR inverter of conventional chopper cascade speed control system are prone to commutation failure to damage the equipment,the protection mechanism of vacuum contactor and the fast fuse cannot instantaneous work,which result in short-term protection blank area. The Crowbar resistance circuit was designed,the fault transient process was analyzed,the mathematical model was established,the model of simulation was established to verify the production of experimental prototype. Experiments show that the Crowbar circuit can be connected to the main circuit in the time of the micro-second level,to limit the fault current rise,and to prevent further expansion of the fault. It may be appropriate to the actual project trial promotion.
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