虚拟同步发电机惯量及阻尼协同自适应控制研究

Research on Synergistical Adaptive Control of Inertia and Damping of Virtual Synchronous Generator

采用虚拟同步发电机(virtualsynchronousgenerator,VSG)控制的并网逆变器,当电网工况发生突变时,系统输出的功率和频率会出现超调和振荡。考虑到实际工程应用中,难以实现对角频率变化率的测量,为了提高并网逆变器的动态性能,经过对VSG的功角特性曲线和输出频率振荡曲线的分析,得到并网逆变器输入、输出功率差值与角频率变化率的对应关系,并依据参考功率与实际输出功率的差值,提出一种改进型的惯量及阻尼协同自适应控制策略。并通过仿真结果对其可行性和优越性进行了验证。

Virtual synchronous generator(VSG)controlled grid-connected inverters may experience power and frequency overshoot and oscillations during sudden changes in grid conditions.Considering that it is difficult to measure the angular frequency change rate in practical engineering applications,in order to improve the dynamic performance of grid-connected inverters,the corresponding relationship between the input and output power difference of grid-connected inverters and the angular frequency change rate is obtained by analyzing the power angle characteristic curve and output frequency oscillation curve of VSG.An improved inertia and damping cooperative adaptive control strategy is proposed.The simulation results verify the feasibility and superiority of the proposed control strategy.