Control Of DC Variable Frequency Speed Regulation System Based On DSP

With the continuous highlight of energy issues, the underground transportation issue of the coal which is one of the major energy in China has become the focus of attention. As one of the main downhole transportation, the transport system efficiency of the electric locomotive is directly related to the coal mine production efficiency. Motor drive system which is the core of the mine electric locomotive determines the performance of the electric locomotive directly.Taking the Brushless DC Motor (Brushless DC Motor) which has some advantages such as the simple structure, high reliability, high efficiency, convenient maintenance and good speed regulating performance, etc. as the research object, the mathematical model of brushless dc motor drive system is established after analyzing the working principle of the Brushless DC Motor in this paper and then the electric locomotive drive system in the process of starting torque pulsation phenomenon is analyzed on the basis of the structure principle and the operation characteristics of the Brushless DC Motor,. In order to improve the performance of the drive system, the double closed-loop control scheme that speed loop as the outer ring and the current loop as the inner ring is adopted.Taken the American TI company’s motor control microprocessor TMS320F28335as the core, based on improving control system operating characteristics of the brushless dc motor, the characteristics of the control system such as simple structure, easy operation and high stability can be assured. Combined with the on-chip function of the DSP TMS320F28335and its hardware of pin build brushless dc motor variable frequency speed regulation system and software process, the without position sensor test of the zero electric potential method is chosed to confirm the signal of the rotor position. With the inverter control of the three-phase bridge driver IR2130, the power tube oscillation of the rotor position can be restrained and the loss of power switch be reduced. Due to the over-current and under-voltage protection function of the power switch device driver chips IR2310, the circuit is protected simultaneously.As the traditional brush motor replaced by the brushless dc motor through the use of electronic commutation, the way to get the position signal of the rotor turns into the requirement for the brushless dc motor to commutation correctly. Through the comparision, the electric potential zero test is chosed to test the position signal of the rotor to keep the motor’s normal operation. With the use of MATLAB/SIMULINK software platform developed by the company named Mathworks, the simulation model of the brushless dc motor with double closed-loop control system is built and then the simulation results is got, through which the feasibility of the speed control system of the brushless dc based on DSP is verified,an well as the stable speed control, the reliable operation and the better controllability.