Research On Three Phase Converter Based On DSP28335

Permanent magnet brushless DC motor(hereinafter referred to as motor)as a new type of motor,because of its high power density,high efficiency,easy heat dissipation,high reliability,good dynamic performance and so on,is widely used in the automotive industry,aviation,automation and other fields.Because of the traditional control method of three-phase converter hard switching technology,the switch tube loss is large,and the system algorithm compatibility is poor.In this paper,the working mode of the previous three-phase converter is improved.The three-phase converter is composed of three groups of DC-DC converters through parallel connection,and the commutation is carried out by detecting the rotor space position,and three groups of DC-DC converters are controlled by the fuzzy PID control strategy respectively.The advantages of the topology in this paper are independent module structure,high compatibility of the algorithm,easy modeling of the model and good symmetry of the output signal.Therefore,the three-phase converter has very important research significance for the efficient operation of the motor.In this paper,the working principle of the motor and the development of the switching power supply are expounded.The main topology of the switching power supply market is investigated in detail,and the traditional topology is improved on this basis.In this project,a converter constructed by three groups of phase shifted full bridge topology is adopted and analyzed with the single-phase structure.It is divided into 12 modes of work in a single working cycle and analyzed the problem of the loss of duty ratio in the soft switching technology and the process of the three-phase converter.Then the parameter design and component selection of each unit are completed.Secondly,the small signal model of the three-phase converter is derived through the BUCK topology structure,and the phase sequence conduction process of the three-phase converter is expounded on the basis of the motor as the load.At the same time,the design process which includes the conventional fuzzy controller,PID controller and fuzzy controller is described based on the model of small model,and the performance of the control algorithm is compared through the MATLAB software.Finally,a prototype of a three-phase converter with the maximum power of 1500 W is built by the DSP28335 control chip which is the main control module in this system,and the validity of the prototype is verified through the experiment.