改进滞环电流控制在光伏并网系统中的应用

Improved Hysteresis Current Control for Grid-Connected PV Power Systems

为减少光伏PV(photovoltaic)并网系统功率开关损耗,提高系统响应速度,同时实现电网电压电流同相运行,提出了光伏并网系统改进滞环电流控制方法。该方法基于空间矢量调制SVM(space vector modula-tion)的概念,结合滞环电流控制方法,通过对电流误差信号及参考电压的矢量关系改进功率器件开关状态,从而使网侧电流响应快速,同时降低系统开关频率,减少功率器件的功耗。该方法软件及硬件电路简单且易于安装,可有效降低装置成本。结果表明,该方法结合了空间矢量技术和滞环电流控制技术的优点,提高光伏系统直流侧电压利用率,并且系统响应速度快,鲁棒性好。

An improved hysteresis current control techqniue for grid-connected photovoltaic （PV） system is proposed in order to reduce the power loss of the switching devices, impove the system response speed and keep the grid current in phase with the grid voltage. The technique is based on space vector modulation （SVM） concept and hysteresis current control method. By improving the switch state of power electronics devices in accordance with the space vector relationship between current error signal and reference voltage signal, fast current response is gained, and system switching frequency and overall power loss are reduced. The mehtod is easy to implement due to its simplicity in both hardware and software configurations, which can reduce the overall cost of PV system. Results show that this method offers merits of both SVM technique and hysteresis control technique, which increases the utilization of DC-link voltage and improves the response speed and robustness of the PV system.