| As the global energy consumption and environment pollution become more and more serious,the solar power,a renewable and non-polluting energy source,has become one of the effective ways for humans to solve the energy crisis.However,the utilization rate of photovoltaic(PV)system is still insufficient.Therefore,it is very important to focus on a research associated with the maximum power point tracking(MPPT)of solar energy for improving the efficiency of PV systems.Brushless DC motor(BLDCM),a leader of motor field in the 21st century,has been widely used in many areas.Nevertheless,in a certain extent,its position sensor still limits its application.It is also great urgency to study the sensorless control method for BLDCM.In this study,a sensorless control system of BLDCM which combined the PV system with motor system is investigated based on solar MPPT.It possesses a very broad application prospect.The work associated with the system is described as follows.Firstly,the basic principle of PV array and BLDCM is introduced.In the aspect of PV array,the physical structure,working principle and mathematical model of PV array are introduced in detail,and the model of PV array is built in Matlab/Simulink environment.Then,in order to verify the correctness of the model,the output characteristics of the model are simulated and analyzed.In the aspect of BLDCM,the system composition,operation principle and mathematical model of the BLDCM are introduced in details.Next,the implementation principle of the perturbation and observation(P&O)algorithm in the MPPT algorithm and the Back Electromotive Force(Back-EMF)zero-crossing detection in the position control of BLDCM are carefully introduced.Meanwhile,for the purpose of verifying the performance of these two algorithms,the MPPT system based on P&O algorithm and the position control system of BLDCM based on the Back-EMF zero-crossing detection are designed and the simulation structure diagram of the two systems is introduced in details.The simulation results certify the correctness and effectiveness of the two algorithms.Then,a sensorless control system of BLDCM based on solar MPPT is designed.The hardware and software-design of the system are described in details.In the design of hardware,the control system based on TMS320F28035 digital signal processor,MPPT system based on Buck converter and BLDCM drive system based on three-phase full-bridge inverter circuit are demonstrated.In the design of software,the P&O algorithm,starting program of BLDCM,position closed loop program of BLDCM and speed detection program are described.Finally,in order to verify the performance of the system,a series of experiments are given.The experimental results proved that the hardware and software design of the system are correct in this research and the sensorless control of BLDCM could be achieved by the Back-EMF zero-crossing detection algorithm. |
