用于电流输出型电压源逆变器的三相四线桥保护拓扑及参数选择方法

A bridge-type protection topology for 3-phase 4-wire current output inverters and its parameter selection method

通过引入无源元件和开关器件的非理想模型,并考虑杂散参数影响,建立了逆变桥的实际模型,对逆变桥正常工作条件下开关器件开关过程进行详细分析,在此基础上推导出逆变桥桥臂电路中冲击尖峰电流的发生机理和危害,提出了一种由无源元件组成的逆变桥桥臂保护拓扑电路。通过对这种逆变桥桥臂保护电路的深入分析和实验研究,证明这种电路可有效地降低功率器件在开关过程中的冲击尖峰电流、电流变化率和电压变化率,可防止开关器件出现误触发以有效保护功率器件。并给出了桥臂保护电路拓扑的参数选择方法。

The inverter＇s actual model was built with the consideration of passive devices＇ un-ideal models and the impact of distributed impedance.The causes and potential damages of pulsed current during the switching transition process of the current source inverter bridge in normal operation state was analyzed in detail.A LCRD bridge protection circuit was presented.Detailed analysis as well as experiments based on this bridge protection topology fully validated that the topology could effectively decrease the pulsed current,current transition rate and voltage transition rate in the switching process,and could also protect power devices from inappropriate triggers and possible damage.In addition,the parameter selection method was also given for establishing the bridge protection circuit.