Simulated Experiment Research On The High Power Stepless Speed Control System With The Combination Of Mechanics And Electronics

With the continuous development of our country’s economy,high power motor is more and more widely applied in industrial production,mainly used to drive heavy loads,such as large mechanical equipments,fans and pumps.The electricity consumption accounts for about 65% of the whole industrial system,and often there are speed requirements during the operation of high-power motors.At present,the variable frequency speed control technology is accepted by many enterprises for its excellent performance.However,due to the high cost of inverter and the low efficiency of variable frequency speed control technology in low frequency,the application of variable frequency speed control technology is seriously hindered and causeing energy waste.To this end,the team proposed a hingh power stepless speed control system with the combination of mechanics and electronics,taking the system as the research object,aiming at the low efficiency and energy waste in the control process,through simulation experiment research on the dynamic characteristics and energy saving effect.Firstly,the structure,basic principle and working process of the hingh power stepless speed control system with the combination of mechanics and electronics are introduced,and the advantages of the system compared with other high-power motor’s stepless speed regulation technology are introduced.The factors that affect the energy saving of the speed control system are analyzed in detail,including the soft-start,the power matching of the two motor,the system efficiency and the mechanical characteristics of the load.Then,through the scheme design and equipment selection,based on the similarity principle of complex system,a simulation experiment bench of the hingh power stepless speed control system with the combination of mechanics and electronics is built,and the function and simulation working condition of the experiment bench are analyzed.The whole speed control system simulation experiment bench is divided into transmission system,simulation load system,power motor drive system,bench control system and data measurement and acquisition system.It lays the foundation for the experiment research on the dynamic characteristics and energy saving effect of the speed control system.Secondly,the dynamic characteristics of the speed control system are experimented.The characteristics of stepless speed regulation,soft-start,speed and torque output,matching of two motor power and output current of large power three-phase asynchronous motor are researched.The results show that the dynamic speed control system can realize the stepless speed regulation of the large range of load and the soft-start of the high power motor;And it can realize small torque input large torque output in the range of speed regulation;The power matching relationship between the two motors is obtained,which provides guidance for the motor type selection of the speed control system.Finally,taking constant torque load and two times rate load type as engineering background,the transmission efficiency of speed control system under different load conditions is experimentally researched.Combined with the system cost,the system is comprehensively evaluated.The results show that in the condition of constant torque load,the problems of early system cost and energy saving should be considered;The system has good energy saving effect and great energy saving potential under the condition of two square rate load.