容错型三相并网变换器的建模分析与矢量调制  

Modeling and Modulation of the Fault-tolerant Grid-connected Three-phase PWM Converters

作　　者：郑玮仪 曾志勇[1] 赵荣祥[1] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《中国电机工程学报》2016年第8期2202-2212,共11页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2013CB 035600)~~

摘　　要：对故障后并网型三相脉宽调制(pulse width modulation,PWM)变换器系统建模、矢量调制技术和系统控制策略3个方面进行详细的研究。分析容错后变换器工作原理,建立容错后电力变换器三相静止模型。该模型揭示了故障后电容中性点电压波动的固有原因。利用伏秒平衡原理,推导基于三相静止系下矢量调制方法,该方法无需复杂的三角函数运算,且具有统一的表达公式。利用电流纹波有效值对容错后矢量调制算法进行评估,以便选择电流性能良好的调制算法。为防止中性点电压偏移对系统造成的影响,提出一种基于修正故障相调制波的中性点电压偏移控制方法,保证故障后并网变换器稳定安全运行。实验结果证明,所提方法提高电流品质,实现了故障后并网变换器稳定安全运行。The modeling, modulation and control of the fault-tolerant three-phase PWM converter were investigated. The proposed stationary frame model reveals the effect of faulty phase currents on the capacitor oscillation. Using the volt-second balance principle, two simple pulse width modulation methods were built. Compared with the conventional space vector modulation approach, the proposed method does not require the sector identification and the trigonometric function calculation. In addition, with the proposed space vector modulation（SVM） approach, the model of post-fault operation of PWM converters is similar with that of converters in healthy conditions. The current ripple RMS was used to evaluate the current performance of the SVM method. Using the analytical results, the method introducing the smallest current ripple was selected as the optimized SVM approach. Considering the deviation of the capacitor voltage, a control strategy based on the modulation wave compensation was developed to eliminate the capacitor voltage deviation, guaranteeing the stable fault-tolerant operation of the three-phase PWM converter. Experimental results demonstrate that effectiveness of the proposed strategy.

关 键 词：三相PWM并网变换器 器件故障 容错运行 空间矢量调制 电流纹波 

分 类 号：TM46[电气工程—电器]