基于最优开关角的逆变器谐波优化研究

为了更好地抑制谐波和提高输出电压波形质量,在对逆变器进行深入分析与研究的基础上,提出一种新型最优开关角调制方法应用于SPWM逆变器。该方法仅对调制脉冲波的起点进行优化,而脉冲宽度依然随着正弦规律变化,在建立优化数学模型时加入滤波环节模型,目标是使滤波输出电压波形的THD最小,同时基于实际非理想情况考虑系统对开关角的灵敏度。在多个约束条件下求解非线性超越方程的最优解,并在不同开关频率、调制度和负载阻值下与一般SPWM调制方法对比优化效果,找到优化效果的最佳条件。最后,通过仿真和硬件实验验证所提方法的正确性。

Research on Harmonic Optimization of Inverter Based on Optimum Switching Angles

In order to restrain harmonic and improve the quality of the output voltage waveform, an new optimum switching angles modulation method based on in-depth analysis and research on the inverter is proposed in this paper. In this method only the starting point of the modulation pulse waves are optimized, and the width of pulse waves still change as the sine law. The model of filter is taken into consideration while the mathematical model of optimization is set up, in order to minimize the THD of output voltage waveform. At the same time, the sensitivity between the system and the switching angles is considered based on the non-ideal actual situation. The optimal solution of nonlinear transcendental equation is solved under several constraint conditions, and the optimization effects are compared with general SPWM modulation method under different switching frequency, modulation and load resistance. Finally, the reliability of the proposed method is validated through the simulations and experiments.