间接电流控制可调功率因数电流型PWM变流器

Indirect Current Control Adjustable Power Factor Current Source PWM Converter

电流型PWM变流器(PWM-CSC)因其良好的功率因数和直流电流源特性,可望在某些场合取代产生大量谐波的二极管或晶闸管相控整流装置,但是,PWM-CSC本身的强耦合非线性特性,使得变流器常采用复杂的直接电流控制策略,实现功率因数可调和能量回馈非常困难。提出一种基于dq坐标系的间接电流控制方法,该方法将变流器的直流输出作为网侧电流有功分量的给定值,通过此给定值和tg?的乘积调节无功电流的大小,然后利用PWM-CSC交流侧电流的离散方程,求出当前变流器的控制量,间接控制变流器的网侧电流,从而控制了变流器的有功功率和无功功率,实现了变流器的可调功率因数和能量回馈。论文最后对变流器的稳定运行范围进行了讨论,得出变流器提供的无功功率受有功功率限制的结论。

Current source PWM converter （PWM-CSC） are expected to replace diode and thyristor phase-control rectifier that bring in rich harmonics in some occasions, advantages include perfect power factor and dc current source performance. However, due to inherent nonlinear and compact couple characteristics, the converter is usually controlled by complex direct current control strategies, these methods are very difficult in realizing power factor regulation and energy feedback. This paper proposed an indirect current control technique based on dq coordinate. In the proposed technique, dc output of the conyerter is used as active current reference value of the network current, reactive current of the network is regulated by the produce of the active current reference value and tgφ, then the ac-link current disperse equations of PWM-CSC are used to find instant control variable that control network current of the converter indirectly. Consequently, active power and reactive power of the converter are controlled, and adjustable power factor and energy feedback are obtained. This paper discussed the steady operation-range of the converter, and the conclusion that the reactive power is limited by the actual active power is drawn.