自然采样SPWM逆变电源的谐波分析及抑制策略

在借鉴国内外相关研究的基础上，对电太源型自然采样正弦脉宽调制（SPWM）逆变器输出电压、电流的谐波及其产生规律进行了较为详尽的分析，并从工程实际出发给出了3种谐波抑制策略：选择合适的载波频率，以消除低次和某些奇次谐波；精确实现先定的载波频率，以避免异步调制中出现的偶次谐波；注入适当的谐波分量，以在不加大输出谐波含量的情况下提高电压利用率。最后，把以上谐波抑制策略应用于35kVA客车空调逆变电源，并给出了实验结果。

ANALYSIS AND RESTRAINT OF HARMONICS FOR INVERTING POWER SUPPLIES USING NATURAL SAMPLING SPWM

In the SPWM inverters, harmonic content of nonsinusoidal voltage and current can not only cause harmonic loss of the load, but also affect the control performance of the whole system to a certain extent. Therefore, using for reference of relative studies home and abroad, a detailed analysis on harmonics in output voltage and current of voltage source IGBT SPWM inverters and their production law is carried out.Simultaneously,The relevant strategies for restraining harmonics are presented in this paper. They are:selecting appropriate frequency of carrier wave to eliminate harmonics of low order and those of a certain odd order; accurately implementing the selected frequency of carrier wave to avoid harmonics of even order which arises only in asynchronous modulation; and injecting proper harmonics into the inverter to improve the utilization ratio of the voltage when output harmonic content is not increased. The above mentioned strategies for restraining harmonics are applied to 35 kVA inverting power supplies for air conditioners of passenger cars. Experimental results show that the presented methods are feasible.