Research On The Control Strategy Of Static Frequency Conversion Starting Of Pumped Storage Unit Based On Speedgoat

At present,pumped-storage power plants are the most commonly used energy storage method for power systems.Its rapid development has greatly improved the regulation capabilities of the power system,enabling the power system to cope with today’s increasingly complex power consumption conditions.The core function of a pumped storage power station is peak shaving and valley filling,which can relieve the pressure of thermal power generation and save surplus electricity.In order to achieve the function of peak regulation and valley filling,the pumped storage unit needs to switch between generator operating conditions and motor operating conditions.As the pumped storage unit is an excited synchronous motor with large capacity and large inertia,how to start the pumped storage unit smoothly and quickly has always been the core problem to be solved by the pumped storage power station.This article deeply analyzes the working principle of the thyristor static frequency converter,and studies the corresponding static frequency conversion starting control strategy.Use Speedgoat real-time simulation equipment to build a corresponding HIL simulation experiment platform,and verify the correctness of the adopted control strategy through offline simulation results and HIL experiment results.Firstly,the basic principle of the static variable frequency starting control strategy is introduced,mainly focusing on the stator magnetic potential distribution and the two commutation modes of operation.And for the problems often encountered in the process of control strategy design,such as the switching of two commutation methods,the selection of the commutation lead angle,etc.,solutions are proposed.On this basis,combined with the corresponding mathematical relationship,the operating characteristics of the pumped storage unit are analyzed.Secondly,this article used position sensorless detection technology to detect the rotor position in each stage of the starting process,and improved the rotor position detection method above 5HZ.Then,the corresponding rotor position detection simulation model was built on the Matlab/Simulink simulation platform,and the effectiveness of the rotor position detection method was verified by the simulation results;this article also combines the sequence control logic and control strategy of the starting process to build the corresponding control strategy simulation model,and analyzes the motor running state and the speed increase curve during the full starting process,through which the adopted control strategy was simulated and verified.Finally,the 7-order mathematical model and the 5-order mathematical model of the excitation synchronous motor are analyzed and derived.According to the principle of the mathematical model of the fifth order synchronous motor,the corresponding simulation model of the fifth order synchronous motor was built on the Matlab/Simulink simulation platform.Combined with the external characteristics of the real unit,the parameters of the motor were corrected and the offline simulation test was carried out.The HIL experiment platform was designed and built by using real-time simulator Speedgoat and SFC controller provided by Nanruijibao.The control performance of the SFC controller was tested by HIL experiment,and the correctness of the synchronous motor model was verified.The results of HIL experiment were compared with the control strategy adopted in this paper to further verify the correctness and feasibility of the control strategy adopted in this paper.