基于虚拟同步机的风-光-储并网系统自适应功频控制策略

Adaptive Power Frequency Control Strategy for Wind-Photovoltaics-Storage Grid Connected System Based on Virtual Synchronizer Generator

风-光-储系统通过虚拟同步发电机(virtual synchronous generator,VSG)并网时,其运行工况变化将引起系统功频波动。针对这一问题,提出一种VSG自适应惯量阻尼功频控制策略。首先,建立VSG的数学模型及功率小信号模型,分析虚拟参数变化对系统稳定性的影响;然后,依据系统受扰时的功角曲线分析惯量阻尼的动态特性,设计了一种分段线性调整函数,并给出参数选取原则;最后,在Matlab/simulink平台中搭建仿真模型验证。结果表明,在工况变化情况下,采用VSG自适应控制的风光储并网系统功频响应得到了改善,相比传统VSG控制具有更好的动态调节性能。

Operating condition changes can cause system power frequency fluctuations when the wind/photovoltaics/storage system using virtual synchronous generator control technology is connected to the grid for operation.In allusion to this problem,an adaptive inertia-damping power frequency control strategy based on a virtual synchronous generator(VSG)was established.Firstly,the VSG mathematical model and Small signal model were established to analyze the impact of the model’s virtual parameter changes on system stability.Secondly,a segmented-linear adjustment function was designed and parameter selection principles were given based on the principle of inertia damping dynamic characteristics analyzed by the power angle characteristic curve when the system is disturbed.Finally,the simulation model was built on the Matlab/Simulink platform.The results show that the power and frequency response of wind-photovoltaics-storage grid-connected system are improved by using VSG adaptive control strategy in the case of operating condition changes,and this control strategy has better transient performance compared to traditional VSG control technology.