基于直接功率控制的AFE变换器研究

AFE Converter Based on Direct Power Control

研究了一种基于直接功率控制(DPC)的有源前端(AFE)变换器,该变换器具有网侧电流正弦、功率因数高、直流电压恒定、动态和稳态性能好、能量可双向流动等优点。首先,建立两相同步旋转坐标系下AFE变换器的功率控制模型,在此基础上外环采用电压平方控制,并采用电压给定值斜率限制,改善启动性能;内环采用功率前馈解耦控制,结合瞬时功率理论,用空间矢量算法取代开关表控制,解决传统DPC中开关频率不固定的问题,实现了对有功功率和无功功率的无耦合独立控制。仿真和实验均验证了该控制策略正确可行。

The active front end （AFE） converter based on direct power control （DPC） is studied, it has the advantages of sinusoidal line current, high power factor, constant DC voltage, dynamic steady-state performance, energy flowing in both directions.Firstly,a two-phase synchronous rotating coordinate system power control model of AFE converter is created.On this basis, outer loop uses voltage square control, and useing the slope of the voltage setpoint limit to im- prove the startup performance;Inner loop uses power feed-forward decoupling control, combined with the instantaneous power theory, using space vector control algorithm to replace the switch table to solve the problem that traditional DPC switching frequency is not fixed, achieved without coupling independent control of active and reactive power. Simulation and experimental results verify the correctness and validity of the control strategy.