有源缓冲型逆变器功率解耦技术研究

Research on active buffered inverter power decoupling technology

为实现单级单相升压逆变并能有效抑制直流侧二次纹波电流,提出一种带有源缓冲的电流型逆变器电路拓扑,研究该逆变器的6种电路模态并提出其两模态调制策略和三模态调制策略,设计2种调制策略下的模型预测控制策略,提供主电路参数设计准则。从储能电感电流的最大脉动量与二次纹波含量两方面对2种调制策略进行对比分析,得出了三模态调制策略具有更好纹波抑制效果的结论。对2种调制策略下的逆变器进行仿真分析,仿真结果表明,三模态调制下电路的输出电压总谐波失真率、电感电流相对脉动量与二倍频含量均低于两模态调制下的数据。设计并搭建500VA 48VDC/220V50HzAC有源缓冲型单级单相升压逆变器实验装置,给出了三模态调制下基于模型预测控制的逆变器实验波形,进一步证实了所提研究方案在实现单级升压逆变的同时具有二次纹波抑制能力。

In order to realize a single-stage single-phase boost inverter and effectively suppress the secondary ripple current on the DC side,a current inverter circuit topology with source buffer was proposed.Six circuit modes of the inverter were investigated and two-modal modulation strategies and three-modal modulation strategies were proposed.A model prediction control strategy under the two modulation strategies was designed,and design guidelines for the parameters of the main circuit were provided.The two modulation strategies were compared and analyzed in terms of the maximum pulsation of the storage inductor current and the secondary ripple content.It is concluded that the three-modal modulation strategy has a better ripple suppression effect.The inverter under the two modulation strategies was simulated and analyzed,and the simulation results show that the total harmonic distortion rate of the output voltage,the relative pulsation and dual frequency content of the inductor current under three-mode modulation are lower than those under two-mode modulation.A 500VA 48VDC/220V50HzAC active buffered single-stage single-phase boost inverter experimental setup was designed and constructed,and the experimental waveforms of the inverter based on the model predictive control under the three-mode modulation were given,which further confirms that the proposed research scheme has the ability of secondary ripple suppression while realizing the single-stage boost inverter.