Coordinated Control Of Active Power Of Wind Farm Cluster Based On Safety Constraints

Wind power technology is one of the effective ways to solve the serious problem of global energy shortage.Therefore,it is an inevitable trend to vigorously develop wind power technology.However,due to the poor stability of the power system caused by the large-scale grid connection of wind power,the frequency of the FM is high,and even the frequency of the event,in order to ensure that the frequency fluctuation under high wind power permeability meets the security constraints of(+0.2Hz)grid-connected in China,this paper considers the large-scale energy storage power station to participate in frequency modulation,and conducts in-depth theoretical and simulation research on wind farm cluster active power control and wind-fire storage cooperative frequency modulation.The main work of the paper is as follows:Firstly,based on the actual data and output power characteristics of the wind farm cluster,the complementarity and stability of the wind farm cluster are analyzed.It can be seen that the wind farm cluster can track the dispatching task of the dispatching center and participate in the grid frequency adjustment.At the same time,the research premise of this paper is taken out.It is necessary to meet the safety constraints of grid-connected frequencies,and select the two parts of wind farm active power adjustment and cluster-level multi-source coordination gridconnected control for in-depth analysis and research.Secondly,a large-scale energy storage power station is introduced in the system coordination layer,and the auxiliary wind power system participates in frequency adjustment to share the frequency modulation task of the thermal power unit.In order to fully utilize the frequency modulation potential of wind power,thermal power and energy storage,a frequency divider is introduced to determine the corresponding frequency modulation range and frequency modulation sequence.In the secondary frequency modulation,the safety problem of the system involved in frequency modulation is considered firstly,and the limit value of the state of charge of the energy storage system is set.The traditional regional control demand allocation strategy(ARR)is allocated to each frequency modulation unit and the output order of the unit is determined.The secondary frequency modulation improves the stability of the system frequency by the cooperation of the primary and secondary frequency modulation capacities.In order to verify the frequency modulation effect of the wind-fire storage cooperative frequency modulation strategy,the simulation verification was carried out on the MATLAB platform,and the multi-source coordinated frequency modulation method and the traditional thermal power unit frequency modulation method were compared and analyzed.The results show that the multi-source coordinated frequency modulation method improves the stability of the system frequency.Finally,an in-depth study on the primary frequency control strategy of wind farm clusters is carried out.Taking the wind farm as the research object,the active power control strategy based on the fuzzy gain PI control scheme is selected to form the closed loop frequency adjustment.Simulation on the MATLAB platform,in the case of step load and classic load,the comparative analysis simulation results show that the closed-loop frequency modulation scheme based on fuzzy gain PI control is superior to the traditional open-loop frequency modulation scheme in terms of rapid response to frequency events and recovery performance.