摘要
以每相5个功率单元串联的结构为例,研究串联式多电平高压变频器功率单元故障时的处理方法,着重分析中性点漂移技术。通过数理分析,推导出中性点漂移算法/模型,计算相位角变化值和线电压值。而后分别对各种故障类型进行分析,运用所得算法计算出相位角变化值和线电压值。该算法通过调整各相功率单元电压的相位角,使输出到电动机的三相线电压仍然维持平衡,从而让变频器能够以最优输出载荷继续运行。最后利用Simulink仿真验证了算法/模型的正确性,并最终得出结论可以将该计算方法推广到实践中解决实际问题。
5-power modules in series of each phase was taben as an example to analyze the neutral point drifting technology and research the treatment of module failure of modules in series high-voltage transducer.According to the mathematical analysis,neutral point drifting formulas were deduced to calculate phase angles and line voltage.After theoretical analyzing on specific module failures,phase angles and line voltage are calculated by formulas.The method adjusts the phase angle to keep three-phase line voltages symmetrical and make the transducer output the largest effective power when broken modules are bypassed and phase voltages are not unsymmetrical.Compared simulation results simulate by Simulink with theoretical values,the mathematical model is verified.At this point,the model and formulas can be widely popularized to solve the practical issues.
出处
《电气传动》
北大核心
2010年第12期12-16,共5页
Electric Drive
关键词
中性点漂移
单元串联式
高压变频器
功率单元
neutral point drifting
modules in series
high-voltage transducer
power module