一种改进SVPWM算法在三相逆变器中的应用

Application of improved SVPWM algorithm in three-phase inverter

为解决传统空间矢量调制(SVPWM)算法带来繁琐坐标变换和复杂计算量的问题,从理论上推导和分析了传统SVPWM算法的控制机理,研究了三相空间矢量调制的内在规律,提出了一种改进的基于abc坐标系的无扇区SVPWM算法。该算法采用更加快速简便的方式实现了传统SVPWM功能,利用三相电压的内在关系,推导出了各相SVPWM算法的调制时间函数,无需进行复杂坐标变换和扇区判断,降低了SVPWM算法计算量;接着将改进SVPWM算法运用于245 k VA地铁辅助逆变器中,实现了三相电压的精确闭环控制。理论和实验结果表明:该算法无需复杂运算,具有快速、简洁等优点,应用在三相逆变器中具有实用性和可行性。

In order to solve thecoordinate transformation and complex calculationof traditional SVPWM algorithm,the mechanism of SVPWM algorithm was deduced and analyzed; the inherent law of three-phase space vector modulation was studied and a modified non-sector algorithm based on abc coordinates was proposed. The proposed modulation algorithm was used to fulfill the traditional SVPWM function. By using the internalrelationship of the three-phase voltage,the modulation time function of SVPWM algorithm was deduced,and the computational complexity of SVPWM algorithm was reduced without complex coordinate transformation and sector judgment. The modified SVPWM algorithm was then applied to the 245 kVA subway auxiliary inverter to realize the accurate closed-loop control of the three-phase voltage. The theory and experiment show that the algorithm does not require complex calculation,and has the advantages of quickness and simplicity,as well as practicality and feasibility in the three-phase inverter.