Research On Frequency Stability Of Multi-area Microgrid System Based On Distributed Sliding Mode Control

In the power system,the random change of load demand is one of its basic characteristics.The change of load leads to a mismatch between power generation and demand,resulting in a decrease in the quality of power generation.Therefore,the AGC of the power system has two goals: to minimize the frequency deviation in the system and the dynamic deviation of tie line power;to ensure that the steady-state error of these two quantities is zero.Around these two control objectives,the optimization of AGC control has important theoretical and practical significance in the actual power system.SMC has been proven to be an effective control strategy.The advantages of SMC are to overcome system uncertainty,improve system robustness,and have a fast response speed.If SMC is applied to electric power,the anti-disturbance ability of the system can be improved,which can reduce the sensitivity of the system.Therefore,this paper uses the variable structure sliding mode algorithm to control the frequency stability of the power system.First,the principle of sliding mode control algorithm is introduced.At the same time,it elaborates the governor,generator and the mathematical model of the power system in the system.The non-linear components in the power system—GDB and GRC are introduced.Secondly,based on the mathematical model analysis of the above components,a single power system is constructed.Construct a sliding mode control strategy based on neural network nonlinear disturbance observer.The simulation results of the case prove that the proposed control strategy can effectively suppress the deviation of the grid frequency when the load,governor and generator in the power system have nonlinear interference and GRC exists in the system.Thirdly,due to the certain shortcomings of the sliding mode control strategy based on the neural network observer,this paper designs a high-order disturbance observer,which can evaluate the unknown disturbance in real time according to the mathematical state space equation of the power system.In a single power system,simulation analysis proves the effectiveness of the sliding mode control strategy based on high-order disturbance observer.Finally,considering the time delay of the power system,the nonlinear characteristics of the interconnected system,and the jitter phenomenon of sliding mode control,an adaptive sliding mode control strategy based on a high-order disturbance observer is proposed.In the interconnected power system with time delay.The proposed control strategy can suppress the frequency offset in the system,and can reduce the jitter phenomenon of sliding mode control.