空间矢量简化算法在三相PWM电压型整流器中的应用

Application of simplified space-vector modulation algorithm to three-phase voltage source PWM rectifier

为了避免常规空间矢量控制方法复杂的反正切函数、正弦函数和平方根运算,提出了应用于三相电压型脉宽调制整流器的空间矢量简化算法.该方法根据两相笛卡儿坐标系上的电压空间矢量,直接确定电压空间矢量所在扇区,从而计算出当前的开关状态及控制占空比.避免了传统控制策略中关于反正切正弦查表等繁杂工作,简化了运算过程.此外推导出了适用于此三相整流系统的建模和控制环设计.通过实验验证了此简化算法和控制环设计的有效性.将此简化算法应用于三相PWM整流电路,得到对称连续正弦的输入电流实验波形,实现了单位功率因数整流.

A simplified algorithm was proposed for space-vector modulation （SVM） of three-phase voltage source pulse width modulation （PWM） rectifier. It avoids calculation of arc tangent, square root, and polar coordinate. In this algorithm, the working sector was determined by the voltage commands in Cartesian coordinates. Then the duty cycles of space voltage vectors were calculated directly in each sector, so that the PWM control could be more efficient. The method avoids the look-up tables of sine and/or arctangent and complex calculations needed in the conventional methods. In addition, transfer function of the proposed rectifier was deduced and could be used for controlling the loop design of the system. The experimental results verified the validity of the algorithm and the control loop design. The system has the advantages including unity input power factor and greatly reduced harmonic distortion due to nearly sinusoidal input line current attainable with controlled rectifiers.