IGBT模块直接串联电压均衡驱动控制技术

高压绝缘栅双极型晶体管(IGBT)模块直接串联技术是实现柔性直流输电、高压直流断路器等高压大功率控制设备的一个重要基础,其中最难解决的是串联IGBT模块之间的电压均衡问题。文中分析了电压不平衡的机制,得出了实现电压均衡的关键在于解决断态电压不平衡和关断电压不平衡问题,门极侧均衡控制方法是较好的解决手段。对基于有源电压控制技术的驱动设计和基于延时补偿的控制策略进行了探讨,并分别采用在有源区对关断波形进行跟随控制和补偿IGBT器件间关断延时的方法,有效实现了串联器件的电压均衡。最后,通过6只3 300V/1 200AIGBT模块直接串联的阀段脉冲和基于该阀段的三相换流阀运行测试,对这两种方法进行了验证,所述方法获得了较好的电压均衡效果。

Driving Control Technology of Voltage Balance for IGBT Modules Connected in Series

The connection of high voltage insulated gate bipolar transistors(IGBTs)in series is a key issue in the high voltage and power self-commuted coverter application, such as the voltage source converter based high voltage direct current(VSC-HVDC)transmission, the HVDC circuit breaker and other high voltage and high power control equipments. The bottleneck for the operation of high power IGBTs connected in series is balancing their voltage. The mechanism of unbalanced voltage of IGBTs connected in series is analyzed. It is concluded that the key to implementing voltage balance is to solve the off state voltage unbalance and turn-off transient voltage unbalance. The gate level side voltage balance control technique could be a good solution. The gate driver design based on the active voltage control(AVC)technology and the time-delay compensation control strategy are discussed. Through the driving control of turn-off voltage waveform tracked in the active area and the time-delay compensation between the IGBT modules during turn-off transient, the voltage balancing of the devices connected in series is effectively realized. A pulse experimental platform with six 3 300 V/1 200 A IGBT modules directly connected in series and a three-phase converter valve based on this valve arm are set up to verify the two methods. The experimental results show that the practical value of the methods proposed is its beneficial effect on voltage balancing. This work is supported by Jiangsu Provincial Natural Science Foundation of China(No. BK20140118).