Research On Output Characteristics Of Wind Energy Suction Pump With Low Speed And Large Displacement

Hydraulic pump is the power source of the hydraulic wind power generation system,its output characteristics affect the power generation efficiency and quality of the wind turbine directly.Aiming at the development situation of large displacement hydraulic pump at home and abroad,this thesis designs a kind of large displacement wind energy suction pump which is suitable for low speed operating condition,the theoretical analysis and simulation of output characteristic and constant pressure variable control method of the designed wind energy suction pump are also carried out in main part of the thesis,the main contents and achievements are as follows:(1)A kind of low speed and large displacement wind energy pump with double cylindrical cam driving multi-row hydraulic cylinder and using reversing valve flow distribution is designed,and the parameterized structure design is also used in hydraulic cylinder,cylindrical cam,flow valve and accumulator.The conclusion is that the pressure impact in commutation process can be relieved by increasing throttle groove at valve core.(2)Combined with motion law of the wind energy suction pump,by building mathematical model of the single chamber and total pump flow,the main factors influencing the flow characteristics of single chamber are obtained,and the influence of the arrangement of the main hydraulic cylinder on the flow fluctuation is studied,then the conclusion that the double row staggered arrangement structure can reduce the flow pulsation of the pump is revealed.Based on the compressibility of oil,a mathematical model of single chamber and pump is constructed by means of lumped parameter method,and obtain that the dead volume,internal leakage and flow pulsation are the main factors affecting the pressure change of the wind power suction pump.(3)According to the structure characteristics of the wind energy suction pump,the force analysis and the torque characteristics of the main moving parts are studied,and the overturning force of the cylindrical cam can be cancelled out by setting even several cylinders in motion,then the torque characteristics of the wind energy suction pump under the turbulent wind speed are studied by the method of theoretical calculation and simulation,and the results show that the resistance moment of the wind energy suction pump has the same fluctuation law of output flow.(4)In the maximum wind energy capture area,the main and auxiliary hydraulic cylinders can realize the equal proportion adjustment of the input torque and displacement of the wind energy suction pump at the same time,so as to achieve the purpose of constant pressure control of the wind energy suction pump,and verify the feasibility of the method by simulation.In the rated power area,the influence of the accumulator configuration on the output pressure of the wind energy pump is studied.The research shows that the configuration of double accumulators can effectively suppress the pressure fluctuations caused by wind speed changes.