电压控制型并网逆变器瞬时功率降阶控制方法

Order-reduced Control Method of Instantaneous Power for Voltage-controlled Grid-connected Inverter

电压控制型并网逆变器由于其特有的优点,如便于孤岛运行、可脱离锁相环、有利于提高电网稳定性等,受到越来越广泛的关注。针对电压控制型并网逆变器瞬时功率控制需求,文中提出了时间常数与功率幅度可自由调节的有功惯量支持控制与下垂控制。所提算法采用前馈与零极点消除的方式,将原有二阶有功控制系统降阶为一阶系统,从而有效改善了功率控制的动态响应,且由于前馈的引入,有效提高了系统的控制自由度,使得功率调节时间与功率-频率调节幅度可独立设计。实验结果表明所提控制方法可以实现具有良好动态性能的惯量支持及下垂控制。

The voltage-controlled grid-connected inverter has received more and more attention due to its unique advantages,such as easy island operation,being able to break away from the phase-locked loop,and helping to improve the stability of power grid.Aiming to meet the demand of instantaneous power control for voltage-controlled grid-connected inverters,this paper proposes the active inertia support control and the droop control,the time constants and amplitudes of which can be independently adjusted.The feedforward control method and zero-pole cancellation technique are used to reduce the original second-order active power control system to a first-order system.Consequently,the dynamic performance of the power control is improved.Moreover,the introduction of the feed-forward method improves the control freedom of the system and makes the power regulation time and adjusted power-frequency amplitude can be independently designed.The experimental results show that the proposed control method can achieve inertia support and droop control with good dynamic performance.