基于H4结构逆变器在不同调制方式下的性能比较

针对传统双极性调制和单极性调制方式在效率、总谐波失真THD(total harmonic distortion)以及电磁干扰等方面的问题,提出上慢下快调制方式和半周期工频半周期高频调制方式2种新控制策略。上慢下快调制方式在较高电压和电流上升率的工况下,对于驱动电路以及主电路中的杂散电感、电容的电磁干扰影响,能够有效抑制。半周期工频半周期高频调制方式在调制波(正弦波)过零点处无SPWM突变,有效改善输出电压过零点振荡的问题。在Matlab/Simulink仿真平台验证了4种调制方式的可行性。最后通过实验研究,结合效率、THD这2个参数进行对比分析,比较4种调制方式的性能,通过实验数据得出所提控制策略较传统调制方式在效率、总谐波含量以及电磁干扰等方面均有改善,证明了所提控制策略的可行性与有效性。

Performance Comparison of Inverter Based on H4 Structure in Different Modulation Modes

In view of the problems of the traditional bipolar modulation and unipolar modulation in terms of efficiency, total harmonic distortion (THD) and electromagnetic interference, two novel control strategies are proposed, i.e., modulation mode of slow upside and quickly downside, and that of half-cycle power frequency and half-cycle high frequency. The electromagnetic interference of stray inductance and capacitance in the driving circuit and main circuit can be effectively suppressed in the former mode under the operating condition of high voltage and current-rising-rate. There is no SPWM mutation at the zero-crossing point of the modulation wave (sinusoidal wave) in the latter mode, which can effectively improve the problem of oscillations at the zero-crossing point of the output voltage. The feasibility of four modulation modes is tested on the Matlab/Simulink simulation platform. Finally, through an experimental study, the performance was compared in four modulation modes by combining the comparison and analysis of efficiency and THD. The experimental data shows that compared with the traditional modulation modes, the proposed control strategy improves the efficiency, total harmonic content and electromagnetic interference, which proves the feasibility and effectiveness of the novel control strategy.