一种SVPWM过调制算法及其在两电平逆变器中的应用

摘要

过调制能够有效地提高逆变器的输出基波电压，传统的空间矢量PWM过调制算法需要经过复杂的实时计算或查表，不易于实现。针对此问题，研究一种过调制算法，不需要经过复杂的运算和查表，易于实现，能够使逆变器从线性调制区平滑地过渡到六阶梯波工作区，并且输出电压谐波含量低。在两电平逆变器矢量控制系统上对过调制算法进行了实验。理论分析和实验结果表明该算法具有输出电压谐波含量低和实现简便的优点，适合应用于矢量控制系统中。%The fundamental voltage of the inverter can be effectively improved with over-modulation. It needs complex real-time calculation or look-up table for traditional SVPWM over-modulation algorithm, which is not easy to implement. A over-modulation algorithm for SVPWM inverters is presented, which was simple and suitable for digital implementation. The inverter transited from the linear operation to the six-step operation smoothly. The harmonic components and the total harmonic distortion of the output volt-age were analyzed. The over-modulation algorithm experiments were carried out on the two-level inverter vector control system. Theoretical analysis and experimental results verify that the algorithm is convenient and feasible, with low THD.