三相有源电力滤波器控制方法的研究

Study on Control Method of Three-phase APF

基于单周控制的三相有源电力滤波器(APF)虽不需谐波检测电路,电路相对简单,但只能同时补偿谐波和无功电流,且要求电源电压无畸变,故有局限性。为此将ip-iq谐波检测法和单周控制方法相结合,利用ip-iq法检测负载电流的谐波和无功分量,以单周控制作为电流跟踪控制方式,推出单周控制方程,基于此的建模和仿真研究结果表明:APF可灵活地补偿非线性负载的谐波和无功电流,且补偿效果良好,有一定可行性。

With the wide application of nonlinear equipment, a great amount of harmonic and reactive currents are generated in power system. Active power filter （APF） is one kind of power electronic devices used to restrain harmonics and compensate reactive power dynamically. It has advantages such as fast response, high control ability and adaptability. So the research on APF is more and more in many countries. One-cycle control （OCC） is a nonlinear control method, its principle is to control the duty-ratio of switch to make the average value of switch variable of the switching converter equal to or proportional to the control reference in each cycle, so that steady-state and dynamicstate errors can be eliminated effectively. Nowadays, OCC has been applied successfully, which displays fast response, excellent power source perturbation rejection and simple control circuit, but it only can compensate harmonics and reactive currents simultaneously. In fact, APF is more used to eliminate harmonics, but compensating harmonics and reactive power simultaneously is in the next place. In order to solve the disadvantages of one-cycle controlled APF, this paper uses an ip-iq method as harmonic currents detecting circuit and one-cycle control as currents tracing control circuit, accordingly, the control function and mathematics model are built. The simulation results verify that this scheme compensates effectively and can provide harmonic current compensation or both harmonic and reactive currents compensation according to requirements of the distorted source voltages flexibly.