虚拟同步发电机自适应转动惯量策略研究

虚拟同步发电机(VSG)可在系统发生功率扰动时减小系统频率变化率和频率偏差,然而固定的转动惯量参数无法保证功率和频率的调节性能,不能使系统发生扰动时的系统频率响应兼具稳定性和快速性。因此,在离网和并网模式两种工况下提出了转动惯量自适应控制策略。首先,介绍了虚拟同步机的工作原理并分析了不同转动惯量对VSG输出频率的影响;其次,依据转子加速区和减速区的概念提出了自适应转动惯量控制策略,并利用李雅普诺夫稳定性理论证明了该算法的稳定性,给出了关键控制参数的取值原则;最后通过Simulink验证了该算法的有效性。

Study on Adaptive Inertia Strategy of Virtual Synchronous Generator

Virtual synchronous generator (VSG) can reduce the system frequency change rate and frequency deviation when the system power disturbance occurs. However, the fixed moment of inertia parameter cannot guarantee the regulating performance of power and frequency, and cannot make the system frequency fast response when disturbance occurs. Aiming at the above problems, an adaptive control strategy of moment of inertia is proposed under off grid and grid connected conditions. Firstly, the working principle of virtual synchronous machine is introduced and the influence of different moment of inertia on VSG output frequency is analyzed. Secondly, according to the concept of rotor acceleration zone and rotor deceleration zone, an adaptive control strategy of moment of inertia is proposed, and the stability of the algorithm is proved by Lyapunov stability theory. The principle of the key parameters is given. Finally, the validity of the algorithm is verified by Simulink.