一种应用于三相PWM整流器的空间矢量脉宽调制优化算法及谐波计算

摘要

为解决传统空间矢量脉宽调制(SVPWM)技术步骤烦琐、计算量大及占用微处理器资源多等不足,提出一种在复平面坐标系下,利用三相电压幅值及其简单四则运算即可得到各相占空比的优化SVPWM算法,极大地减小了计算量并简化了计算过程.在此基础上,针对电压型PWM整流器(VSR)网侧存在电压谐波庞杂且不易抑制等问题,采用傅里叶分析推导出在载波比和调制度变化时,仍可定量计算输出相电压各次谐波的表达式,并通过三相VSR双闭环矢量控制模型验证了该优化算法有效性,得出相应的谐波电压分布规律,为网侧滤波器的设计提供了依据和指导.%In order to solve the problems of the traditional SVPWM,such as cumbersome steps,large amount of computation,and too much resource occupied of microprocessor,has been proposed an optimized SVPWM algorithm,which can be used to obtain the duty cycle of each phase by the three phase voltage amplitude and their simple four-arithmetic operations in the complex plane coordinate system,greatly reducing the amount of calculation and simplify the calculation process.Based on this,as the voltage harmonic were complex and not easy to suppress in the AC side of VSR,was used the Fourier analysis to derive the expression of each harmonic of the output phase voltage under arbitrary carrier wave ratio and modulation parameters.Finally,the effectiveness of the optimization algorithm was verified based on the VSR double closed loop vector control model,and analyzed the corresponding harmonic voltage distribution rules,which provides the basis and guidance for the design of the filter.