Research And Implementation Of Saving-energy Operation Controller For Asynchronous Motor

Now,three phase induction motor is the most widely used power equipment.It has high efficiency,power factor and good mechanical properties when working near the rated power.But there are three problems in the practical application such as the large starting current,the low work efficiency in light load,and unable to self-eliminate hidden dangers,and cause economic loss.Aiming at the problem of low efficiency in light load of asynchronous motor,this study designs a kind of saving energy control device with soft start,protection and automatic load change.This thesis makes a deep analysis on the mechanical characteristics and the energy consumption structure of the asynchronous motor.On this basis,this paper deeply analyzes the relationship between controllable loss and input voltage of asynchronous motor at light load,and provides a theoretical basis for the control of asynchronous motor.Secondly,this paper deeply studies the optimal operating voltage control strategy with method for controlling stator current.Stator minimum current control optimization algorithm of online search is designed by using the golden section algorithm.The strategy can effectively reduce the search time,but also has the absolute convergence,can make the motor work in the load optimal operating point of matching with the size.In order to verify the effectiveness of the algorithm,the hardware system of the reducing energy-saving controller of asynchronous motor is designed and completed.The main control circuit is based on DSP as the processing unit,ensures the reliability and flexibility of the system while meeting the requirements of the system for real-time and fast.The motor driving circuit is mainly composed of IGBT module,IGBT drive circuit,detection circuit,auxiliary power supply and other auxiliary circuits;system auxiliary power supply design multiple output isolation switch power supply of Bidirectional voltage stabilized current limiting control structure of inductor current feedback as inner loop;the driver of IGBT module design driving circuit of photoelectric isolation which is reasonable,fast and reliable;At the same time,the reasonable design of other auxiliary circuits is also carried out.Finally,the system prototype is tested consisting of various functional and energy saving effects.The experimental data show that the functions of the energy saving controller and the energy saving effect have achieved the goal of design,and verify the feasibility and rationality of the control method of designing.