Research On Optimization Of Double Motor Energy Feedback AC Dynamometer System

Power dynamometer system is a new motor test system used for motor power and load test.On one hand,it is easy to save energy.On the other hand,it greatly improves the dynamic performance and stability of the dynamometer system.It is an ideal substitute for the traditional motor test system.On the basis of the analysis of the different power dynamometer characteristics,this paper optimizes the design of a double motor energy feedback AC dynamometer system,the paper choosed the common DC bus as the energy feed scheme of this system.The squirrel cage asynchronous electric machine with the advantages of simple structure and reliable operation is used as the dynamometer,and the test will be produced.The energy feedback to the DC bus supply motor test is used to achieve the purpose of high efficiency and energy saving.It has high application value.At the same time,the voltage fluctuation of DC bus is caused by the sudden increase of load.The influence of DC bus voltage fluctuation on inverter output and motor performance is studied in this paper.The improved control method improves the anti disturbance ability and stability of the system.Through the analysis and research of the traditional frequency difference control method of asynchronous motor,in view of its miscellaneous and poor precision,this paper established an improved frequency difference algorithm which is easier to calculate by analyzing the relationship between the T-circuit and the transfer rate of the double machine to the towing system.At the same time,a double closed loop control strategy of torque speed is proposed for the improved algorithm.The PID controller is used to control the speed closed loop,and the fuzzy self-tuning PID controller is used as the torque outer loop regulator,and the fuzzy rules are found,and the fuzzy rule table and the number of membership functions are constantly revised,thus the faster torque response speed is obtained.It effectively improved the dynamic performance of the system.The simulation model of the test system was built with the Simulink toolbox of Matlab.The two working states of the test system,namely,constant torque control torque and constant torque regulation speed state,were simulated respectively.The reliability and efficiency of the frequency difference loading scheme was verified by comparing the loading capacity of the system to the other similar systems..On the basis of theoretical analysis and simulation research,the double motor energy feedback AC dynamometer system is perfected,and the feasibility of the optimized scheme of the double motor energy feedback AC dynamometer system is further verified through the experiment.