【摘要】 在给出故障重构和容错控制策略的基础上,重点建立NPC型三电平逆变系统的数学模型,并给出同步旋转坐标系下的等效电路,分析故障前和两类故障容错控制后母线电容电压的波动机理,并给出统一的母线电容电压波动的抑制策略。通过实验对理论推导的母线电容电压波动规律及两类容错控制模式下母线电容电压波动抑制策略进行验证。结果表明,故障和容错控制模式下控制母线电容电压波动的关键在于通过注入零序电压来控制等效并联导纳相等。更多还原

【Abstract】 Based on the fault reconstruction and tolerant control strategy,the model of the NPC three-level inverter is built. Then the equivalent circuit under the synchronous rotating coordinate system is proposed. The mechanism of the fluctuation of the DC link capacitor voltage under both normal mode and two types of fault tolerant control modes are analyzed. A universal mitigation strategy dealing with the DC link capacitor voltage fluctuation is proposed afterwards. Finally,the experiments are carried out to verify the validity of the theoretical analysis of the DC link capacitor voltage fluctuation and its mitigation strategies under the fault tolerant control mode. The results show that the key to control the fluctuation of the DC link capacitor voltage under fault tolerant mode is to balance the equivalent parallel admittances by injecting the zero-sequence voltage.更多还原