Research On Constant Motor Speed Control Of Hydraulic Energy Storage Power System Based On Fuzzy Adaptive PID

As a kind of renewable and clean energy,wind energy has made a great contribution to the sustainable development of energy and environment in the world.Compared with the traditional mechanical gear wind turbine,the hydraulic energy storage type wind turbine can use the hydraulic energy storage system to store the wind energy absorbed by the wind turbine,so as to eliminate the impact of output power fluctuation caused by the randomness and intermittence of wind speed on the grid.Because the hydraulic energy storage system is directly installed on the high pressure lines,the energy loss in the process of wind energy storage is reduced,and the utilization rate of wind energy is improved;at the same time,multi hydraulic energy storage type wind turbines can share a set of energy storage system,which effectively reduces the manufacturing cost of the energy storage system.When the energy storage system releases the stored hydraulic energy to drive the hydraulic motor to rotate and drive the synchronous generator to generate power,the change of motor speed has a great influence on the frequency and quality of the electric al energy.Because of the real-time load change of the synchronous generator driven by the motor,the motor speed overshoot is too large when using the traditional PID control,and the output power frequency can not meet the requirements.In this paper,the hydraulic energy storage power system in the hydraulic energy storage type wind turbine is taken as the research object,using fuzzy adaptive PID to control the speed of the hydraulic motor to improve the constant motor speed control performance and the output power quality,providing theoretical and technical reference for the application and promotion of the hydraulic energy storage wind power technology.Firstly,the paper introduces the working principle,three working modes and advantages of the hydraulic energy storage type wind turbine.Based on the analysis of the ideal gas equation of hydraulic accumulator,the flow equation of the hydraulic energy storage power system,the torque balance equation of the hydraulic motor and the generator,and the control equation of the synchronous generator,the mathematical model of the main components of the hydraulic energy storage power system is established.In order to improve the constant motor speed control performance,the fuzzy adaptive PID control is used instead of the traditional PID control.The basic control principle,fuzziness,the basis of making fuzzy rules and the anti fuzziness process of fuzzy adaptive PID control are described.Secondly,the simulation model of hydraulic energy storage power system is built in MATLAB/Simulink,and the influence of PID control parameters on motor speed control performance is analyzed.According to the obtained laws,the fuzzy rules of motor speed control and the fuzzy adaptive PID controller are designed.Under the condition of generator load step change,the control performance of fuzzy adaptive PID and traditional PID is compared and analyzed.At the same time,the online adjustment and correction process of system error,error change and PID control parameter correction in fuzzy adaptive PID control is analyzed,which provides the basis for further optimization of the fuzzy rules.Finally,the principle design and main components lectotype of the fuzzy adaptive PID control test-bed for the motor speed of hydraulic energy storage power system are completed,and the control system design is carried out in the Links-RT hardware-in-the-loop measurement and control system,which provides the experimental platform for the subsequent experimental research.