基于线性自抗扰控制和虚拟同步发电机控制的并网逆变器频率调节

Frequency regulation of grid-connected inverter based on LADRC and virtual synchronous power generator control

虚拟同步发电机(virtual synchronous generator,VSG)技术通过模拟同步发电机运行原理,在正常情况下能够让并网逆变器自主稳定地参与电网运行。然而,在负载突变以及系统工作模式相互切换的情况下,则会出现频率波动及偏差等问题。为了解决这个问题,提出了一种基于线性自抗扰控制(LADRC)及VSG技术的并网逆变器频率调节方法。通过在VSG有功-频率控制的基础上引入LADRC作为外环频率控制器,实现系统并网及并离网运行模式的切换,减小系统频率波动。最后在Simulink仿真平台中验证了该方法的有效性,仿真结果表明该方法有效地减小了扰动下的系统响应时间和系统超调,改善了系统性能。

The virtual synchronous generator(VSG) technology simulates the operation principle of the synchronous generator, which enables the grid-connected inverter to participate in the grid operation autonomously and stably under normal conditions. However, in the case of sudden load changes and mutual switching of system operating modes, problems such as frequency fluctuations and deviations will occur. To solve this problem, a frequency regulation method of grid connected inverter based on linear active disturbance rejection control(LADRC) and VSG technology is proposed. On the basis of VSG active power-frequency control, LADRC is introduced as the outer-loop frequency controller to realize the switching between grid-connected and off-grid operation modes and reduce the system frequency fluctuation. Finally, the effectiveness of the method is verified in the Simulink simulation platform. The simulation results show that the method can effectively reduce the system response time and system overshoot under disturbance, and improve the system performance.