基于PWM整流器双PFC模型的电机能量回馈系统

用PWM整流器取代通用变频器的二极管整流电路,采用双PWM整流器/逆变器,设计了电机能量回馈系统。通过分析PWM整流器的数学模型,提出了一种基于α-β静止参考坐标系的PWM整流器双功率因数校正变换器(PFC)定频控制策略。在两相静止坐标系中将PWM整流器等效为2个与传统单相PFC类似的电路结构,然后根据电压空间矢量调制理论,分析了开关信号由两相静止坐标系到三相静止坐标系变换的控制策略。实验结果表明,该系统不仅能够将电机机械能转化的电能有效地回馈到电网,而且能够有效抑制注入电网的谐波,实现网侧单位功率因数控制。

Motor energy feedback system based on dual-PFC model of PWM rectifier

A motor energy feedback system is designed with dual PWM rectifier/inverter,instead of the diode rectifier of general inverter.The mathematical model of PWM rectifier is analyzed and a fixed frequency dual-PFC control strategy based on α-β coordinates is proposed for PWM rectifier.The α-axis and β-axis models ale equivalent to two traditional single-phase power factor correction circuits,and the control strategy of switching signal conversion from two-phase to three-phase stationary reference frame are analyzed according to the theory of voltage space vector modulation.The experimental results show that,the electrical energy converted from mechanical energy of motor is effectively fed back to power grid and the harmonics are greatly suppressed to realize the unit power factor control at grid side.This work is supported by the Basic Research Programs of Natural Science Foundation of Shaanxi Province (2006E128)and the Key Discipline Special Foundation of Shaanxi Province.