不对称电压空间矢量PWM的研究与仿真

典型的电压空间矢量PWM (VSVPWM )本质上是一种在调制波中加入了零序分量的对称规则采样PWM ,而仿真结果表明 ,在较低的开关频率范围内对称规则采样PWM的总谐波畸变率明显高于不对称规则采样PWM。本文把不对称规则采样PWM与电压空间矢量PWM相结合 ,提出了一种改进的VSVPWM———不对称VSVPWM (AVSVPWM )。仿真结果表明 ,AVSVP WM的总谐波畸变率低于典型VSVPWM ,而基波含量高于典型VSVPWM ,开关频率较低时效果尤为明显。并且AVSVPWM能适用于更低的开关频率。

Study and Simulation of Asymmetrical VSVPWM Technique

The classical voltage space vector PWM(VSVPWM) is a kind of symmetric regular-sampled PWM(SRS-PWM) with zero sequence signal added to its reference voltages, per se. However, simulation results indicate that symmetric regular-sampled PWM has higher THD and lower fundamental component than asymmetric regular-sampled PWM(ARS-PWM) when the switching frequency is low. In this paper, the asymmetric regular sampling method is combined with the VSVPWM, thus, an improved VSVPWM method, asymmetrical VSVPWM(AVSVPWM), is developed. Simulation results show the AVSVPWM can greatly reduce the total harmonic distortion and increase the fundamental component of the output voltage compared with the classical VSVPWM, especially when the switching frequency is in the range of typical GTO switching frequency. Furthermore, the AVSVPWM do not add much calculation and can be real time realized easily.