三相电流型PWM整流器的功率因数控制方法

Power Factor Control Method of Three Phase Current Source PWM Rectifier

由于三相电流型PWM整流器需要在交流侧加入LC滤波电路,如果不加入任何功率因数控制,电源电流将超前电源电压。为了有效地控制系统的功率因数,本文提出了一种简单可靠的功率因数控制方法。该方法只需检测网侧电源电压和电源电流,不需要其他任何系统参数,因此具有很高的可靠性。不同于以往的基于静止三相abc坐标系的控制方法,本文将控制算法建立在以电源电压矢量定向的dq同步旋转坐标系上,这使得整个控制系统的实现更加简单。本文提出的功率因数控制算法能够自动调节系统,使其运行在可以达到的最大功率因数运行点。对比分析了采用和未采用功率因数控制时在不同直流侧电流下系统的功率因数特性,证明了该控制能有效提高系统的单位功率因数运行范围。通过仿真并进一步在一台5kVA样机上进行的试验,证明了该方法的有效性和可行性。

Because a LC filter is needed in the ac side of the three phase current source pulse width modulation（PWM）rectifier,the source current will lead the source voltage if without any power factor control.In order to control the power factor effectively,a simple and reliable power factor control method is proposed in this paper.The proposed control method only needs to detect the source voltage and the source current,and any other system parameters are not required,so the whole system has very high reliability.Meanwhile,different from the conventional control in the static abc frame,the proposed method based on the gird voltage vector is built in dq synchronous rotating frame,which makes the implementation easy.What’s more,this power factor control method can make the rectifier reach the achievable power factor.Meanwhile,the power factor of the whole system is measured in different dc side current conditions when without or with power factor compensation,from which we can see that the rectifier’s unity power factor operation area can be improved to a great extent with the proposed power factor control method.All these analyses and the effectiveness of the control method are firstly validated by simulation results,and are verified further in a 5kVA laboratory prototype.