5MW储能虚拟同步发电机孤岛启动与同期控制技术

储能虚拟同步发电机既要实现并网和离网工况下的良好运行,又要实现同期并网的无缝切换。通过对传统逆变器多模块并联孤岛运行控制策略分析比较改进,提出一种基于虚拟同步机技术的孤岛并联启动控制策略。该孤岛并联启动控制策略引入同步发电机电气方程、下垂控制和虚拟阻抗分量,通过控制电压环输出电压调节量、系统反馈电压和虚拟阻抗分量计算出系统参考电流。同期控制通过对电网并网点两侧电网角度、幅值和频率的检测调节使并网时刻电压幅值、角度和频率满足误差范围要求,最终实现电压电流平滑过渡,孤岛到并网的无缝切换。最后,建立4机并联5 MW储能虚拟同步发电机并联仿真RTDS模型,利用RTDS仿真验证算法的有效性。

Control Techniques of Islanded Microgrid System Startup and Synchronization for 5 MW Energy Storage Virtual Synchronous Generator

Energy storage virtual synchronous generator(VSG)should not only achieve good operation under grid connected and off grid conditions,but also achieve seamless switching over synchronous grid connection. Based on the analysis and improvement of the multi module parallel island operation control strategy of traditional inverters, a novel parallel startup control strategy based on virtual synchronous machine was proposed. The electrical equation of synchronous generator,drooping control and the virtual impedance component were introduced in the islanding parallel start control strategy. The system reference current was calculated by controlling the voltage loop output voltage regulation,the system feedback voltage and the virtual impedance component. The regulation of voltage amplitude,angle and frequency on both sides of the power grid merge point in the grid time detection was controlled by synchronization control to meet the requirement of error range. The smooth transition of voltage and current,the island seamless switching grid were realized. Finally,to confirm the control technology effectiveness,four parallel 5 MW energy storage VSG RTDS simulation model was established.