The Research Of Power System With Wind Power And Energy Storage System Load Frequency Control

Frequency is an important index to measure the power quality.With the large-scale of wind power connected to power system,not only the frequency response inertia of the whole power system is reduced,but also the difficulty of system frequency control is increased due to its intermittency and unpredictability.Energy storage system(ESS)has the characteristics of fast response and flexible control.It can play an important role in load frequency control(LFC)of power system.In this paper,a coordinate control strategy for ESS and the sliding mode load frequency controller(SM LFC)is proposed to optimize the load frequency for the interconnected power system with wind power and ESS.The main content of this paper include,Firstly,the background and significance of this research topic are reviewed.The research status of interconnected power system load frequency control and energy storage system are introduced.The LFC model,mathematical model of wind turbine and ESS are given.Secondly,a multi-area interconnected power system load frequency control model with wind turbine and ESS is established.Meanwhile,the time delay of control channel in ESS and traditional generator are considered.In order to improve the robustness of the power system,a SM LFC is designed.And a coordinate control strategy for SM LFC and ESS is proposed to optimize the load frequency.The simulation results based on MATLAB/Simulink verify the effectiveness of the proposed strategy.Third,a control strategy of battery energy storage system(BESS)combined with automatic generation control(AGC)system to optimize load frequency is proposed for the interconnected power system with wind power.Through the filtering method,the high frequency component of the AGC signal is allocated to the BESS and the low frequency component is allocated to conventional generator units.Meanwhile,in order to improve accuracy of load frequency control,disturbance observer and SM LFC are designed.And the high frequency component of the observation value is used as a control signal of the BESS.The effectiveness of the control strategy is verified by the RTDS platform.Finally,a multiple complementary system composed of conventional generator,wind turbine,supercapacitor and BESS is built.In the proposed coordinate strategy,different frequency devices make response according to the zone of ACE.In order to improve the response speed of the conventional generator,an adaptive SM LFC is designed.Through MATLAB platform analysis,the proposed strategy not only fully utilize the advantage of hybrid energy storage system(HESS),but also reduces the system frequency deviation.