在微电网中,双向变流器作为核心组网装置,起到稳定接入点电压,降低网损率和提高功率因数的作用.但是在同步旋转坐标系下,双向变流器是一个强耦合、非线性的系统,因此需要对其进行解耦控制,以保证并网电流能够快速无差地跟踪给定信号.研究双向变流器的解耦控制策略,对其在同步旋转d一q 坐标系下的数学模型进行了推导和分析,在此基础上采用PI 控制和前馈控制相结合的解耦控制方法,将原系统进行线性化解耦,消除了有功与无功电流的耦合,实现系统的解耦控制.实验结果表明,所提解耦控制策略能够降低稳态跟踪误差和总谐波失真,具有较好的控制性能.
Bidirectional converter, as the core network device in the micro-grid, plays important roles in stabilizing accesspoint voltage, decreasing network loss rate and improving the power factor. While in synchronous rotating coordinatesystem, bidirectional converter is a strong coupling and nonlinear system. Therefore it needs to be decoupled control toensure the grid current can track the given signal. The decoupling control strategy of bidirectional converter is studied, andthe mathematical model of synchronous rotating coordinate system is deduced and analyzed. Based on it, the decouplingcontrol method combining PI with feed-forward is presented. The original system is linearized and decoupled, and thecoupling between active current and reactive current is removed, so that the decoupling control of the system can berealized. The experimental results show that the proposed decoupling control strategy can reduce the steady state trackingerror and the total harmonic distortion.