Research On The Dispatching Strategy Of Pumped-Storage Power Plants For Power Systems With High Proportions Of Wind Power

Wind power output has typical characteristics of random fluctuation and reverse peak regulation.As large-scale wind power is connected to the grid,the pressure of system peak regulation is increasing,and frequent and deep peak regulation of thermal power units has become normal,which greatly increases the total peak regulation cost of the system and reduces the economy of thermal power peak regulation and unit life.The pumped storage power station has the advantages of quick start up and flexible working mode,and can effectively assist the system peak regulation,but its utility has not been fully played at present,and the sequence of calls with other types of units is not clear.Therefore,this article focuses on the optimization of pumped storage operation of power systems with a high percentage of wind power,and studies the dispatching sequence and strategy of joint peak shaving of pumped storage units and thermal power units.The specific research content is as follows:Firstly,analysis of the current call strategy of pumped storage power stations in China.Taking the actual operating data of Zhanghewan Power Station and Shisanling Power Station in North China Power Grid in 2018 as an example,the utilization hours,operation mode and output distribution range of the units in the pumped storage power station are analyzed.Combined with two typical wind power output scenarios,the characteristics and deficiencies of the current pumped storage power station calling method are analyzed in detail.Secondly,a joint optimized scheduling strategy of pumped storage-wind-fire synchronization considering the flexible space of pumped storage is proposed.According to the variation of the storage capacity of the pumped storage power station and the actual call demand,the flexible margin space for pumped storage is introduced,the deep peak shaving cost model of thermal power is established,and the combined pumped storage-wind-fire combined synchronization optimization dispatching strategy is proposed;and the standard 10-unit system is taken as an example to verify the effect of the proposed scheme from three aspects:wind power consumption ratio,number of gensets and peak shaving economy.The results show that,compared with the current strategy of pumped storage,the proposed scheme is beneficial to reduce the number of thermal power deep adjustments,improve the utilization efficiency of pumped storage units,and significantly reduce the total peak shaving cost of the system,and improve the system’s wind power consumption level.Finally,a hierarchical optimization call strategy of combined pumped storage and thermal power peak shaving is proposed.Taking into account the utilization benefit of pumped storage power stations and the economic factors of deep peak shaving of thermal power,a layered optimization scheduling model for combined peak shaving of pumped storage and thermal power is established.Taking an actual regional system as an example for simulation,it analyzes in detail the effects of pumped storage timing pumping calls,pumped storage-thermal power synchronization optimization calls,and the proposed scheme from the perspectives of system peak shaving technology,system peak shaving economy,and solution time.The results show that the adoption of the proposed strategy can greatly increase the utilization rate of pumped storage units,reduce the period and number of deep adjustments of thermal power plants,improve the economy of system peak shaving and thermal power peak shaving,and significantly reduce the abandonment rate,which is also conducive to ensure the benefit of pumped storage power station deployment,the efficiency of model solution is acceptable.At the same time,it is helpful to guarantee the benefit of pumped storage power station,and the efficiency of model solution is also acceptable;however,the target weight of pumped storage in the model to improve the peak and valley volatility of netload is not as large as possible.There is a suitable value(0.7 in the calculation example),which can make the overall effect of the system peak shaving optimal.