AC-DC-AC变换器的直接谐波计算及其可行性

Direct Harmonic Analysis Method and Feasibility Analysis for AC-DC-AC Converters

为了简化AC-DC-AC变换器复杂的谐波计算过程,采用直接谐波计算对变换器进行了谐波分析。根据谐波向量及其序量特性研究了变换器系统中PWM逆变器的电压电流传递规律,并由此获得整个AC-DC-AC变换器的直接谐波计算方法。该法可由供电端交流电压求得同侧各次谐波电流的向量表达式而勿需交流侧和直流侧的迭代过程。对该算法进行了时域仿真验证,对直接谐波计算的可行性分析证明该法算法简单,步骤明确,尤其适用于干线电压畸变小、变换器多的场合。

A direct harmonic analysis approach for AC-DC-AC conversion system was presented to simplify the com- plicated harmonic calculation process. The characteristic of the vectors and its sequence characteristic were adopted to obtain the voltages and currents transfer rules of the converters in conversion systems, and to get the direct har- monic analysis method of the whole AC-DC-AC. The method can deduce the expressions of ac harmonic currents from ac voltage, and does not require iteration between AC and DC side. The time domain simulation results verify the direct harmonic method, meanwhile, the feasibility analysis is proposed. Being simple and defined, the method is more fit to apply on low-voltage distortion and multi-converters situations.