三相桥式整流电路谐波的概率分析

Probabilistic analysis on harmonics of three-phase bridge rectifier circuit

为了抑制谐波干扰,对三相桥式全控整流装置的谐波进行分析和预测,得到三相电压对称与不对称条件下谐波的成分、含量及THD.考虑三相电压不对称实际情况.以指数分布表示三相不平衡因子幅值的概率密度函数,建立了一种关于三相桥式全控整流电路的概率模型.利用此模型对整流装置交流侧电流中的特征谐波与非特征谐波的幅值和相角进行了分析,并采用Monte Carlo方法、电路模型抽样方法与所建立概率模型计算结果进行了对比验证,3种方法得到一致的谐波特性对比结果,验证了所建立概率模型的正确性.

In order to suppress the harmonic interference, the harmonics of three-phase full bridge rectifier is analyzed and predicted in this paper. The harmonics orders, magnitudes and THD can be obtained in the conditions of three phase symmetry and asymmetry voltages, respectively. Considering the actual sit- uation of the three phase asymmetry voltage, the probability density function of the three phase unbal- ance factor＇s magnitude is presented by exponential distribution. A new probabilistic model about the three-phase full bridge rectifier circuit is established. By using this model, the magnitude and the phase angle of the current characteristic harmonics and non-characteristic harmonics on AC side are analyzed. Compared the results calculated by probabilistic model with Monte Carlo method and circuit model sam- piing method, the same results of harmonic characteristics are acquired and the validity of the proposed probabilistic model has been verified.