基于虚拟同步电机技术的混合储能平抑微网频率波动策略研究

Research on strategy of micro-grid frequency control in hybrid energy storage system based on virtual synchronous generator technology

由锂电池和超级电容器组成的混合储能系统(HESS)具有响应快速、短时吞吐功率能力强的优点,可以很好地作为电网的分布式储能设备补偿电网频率波动。提出在储能单元体系优化匹配下,基于荷电状态(SOC)反馈的自学习平滑储能控制策略,自主归纳更新混合储能的控制规则,利用虚拟同步电机(VSG)技术来解决可再生能源功率波动引起的电网频率偏移问题。最后,在Matlab/Simulink中建立了光储微网模型。通过仿真验证了配置混合储能单元的VSG能有效模拟出同步电机的转动惯量与一次调频特性,提高了并网系统的稳定性。

The Hybrid Energy Storage System(HESS)consisting of battery and super capacitor has the advantages of fast response and high power capacity,which can well act as distributed energy storage equipment to compensate power grid frequency fluctuation.This paper puts forward a self-learning smooth energy storage control strategy based on State-of-Charge(SOC)feedback under energy storage unit system optimal matching,which automatically concludes and updates the control rule of hybrid energy storage and makes use of Virtual Synchronous Generator(VSG)to solve the problem of grid frequency offset caused by power fluctuation of renewable energy.Finally,a photovoltaic-storagemicrogrid model is established in Matlab/Simulink.Simulation results show that the proposed HESS based VSG can effectively simulate the rotational inertia and the primary frequency modulation characteristics of SG,which improves the stability of the connected grid.