级联型逆变器的一种新型SVPWM方法

在有高性能调速要求的场合需要矢量控制、直接转矩控制等电机控制方法,级联型逆变器应用电压空间矢量脉宽调制(SVPWM)技术可以实现对电机的高性能控制.随着电平数的增加,电压空间矢量数急剧增多,又存在着冗余开关状态,造成SVPWM算法过于复杂,难以应用于实际系统.本文提出了一种基于两电平SVPWM算法的新型多电平SVPWM方法,并通过Matlab 6.1的系统仿真验证了其正确性和有效性.

A Novel Technique of SVPWM Based on Cascaded H-Bridge Multi-Level Inverter

Multi-level inverters play an important role in the field of high voltage high-power frequency conversion. Pulse width modulation (PWM) technique of multi-level inverters is customarily divided into two categories. One is the carrier-based PWM and the other is the space vector PWM (SVPWM). At times, method of vector control or direct torque control is necessarily to obtain good dynamic and steady state performance of motor drive, in which the carrier-based PWM technique can not be applied. However, the SVPWM technique can integrate the method of vector control or direct control with multi-level inverters. Multi-level SVPWM technique is paid more attention recently. Due to the large number of voltage space vectors and redundant switching states, there is a problem of computational complexity in multi-level inverters, and so the utilization of multi-level inverters with the SVPWM method can not be realized. To resolve the problem, a novel SVPWM technique is proposed, and it is further analyzed in detail. Multi-level inverters are considered as a combination of two-level inverters. Based on conventional two-level SVPWM, the proposed SVPWM technique can be applied to the cascaded H-bridge multi-level inverters conveniently. Simulation verification of theoretical predictions by Matlab6.1 is presented to confirm the capability of the novel technique.