The Control System Research Of Bldcm Based On DSP

Brushless DC motor is a new type of motor which is developed on base of DC motor due to the advancement of the power electronics,motor control technology,microprocessor and the appearance of new type of permanent magnet materials. Because this type of motor not only have the merit of the AC induction motor for simple structure, reliable operation and easy upholding but also have the merit of the DC motor for high performance and easy control. The research and application of it has draw lots of attention of the researchers in this field in resent years. This paper proposes a control system on the basis of back-EMF method.The brushless DC motor control system is a novel speed-variable system. It offers excellent characteristics of operation, control and economy, and shows great developing potentiality. The design use Brushless DC motor as an object, completing the design of high performance control system of BLDC based on DSP. The system has the characteristic of digital motor control, Via assembled DSP and analogue circuit accomplishing the digital control of motor.The hardware of the system use the TMS320LF2407A as the microprocessor;the converters is made of the IPM to form the bridge circuit and the drive circuit is made of the optocouple. This control system designs electric current, voltage signal gather the circuit. In order to avoid the direct shoot of the bridge the design also consider the protection of it and the protection circuit is offered in the design. Many EMC method is adopted throughout the design of hardware.The software design mainly come from back-EMF method. The systems software includes initialized module and running module. Sensorless DC motor running module complete DC motor start and has sensorless DC motor close-loop control. Sensorless DC motor close-loop control module include reversing control, current loop regulating, the positive and negative rotational speed controls with speed ring etc. The structure of the software of the whole design is made of the main program. subprogram and interrupt program .Main program finish the initiation of the chip and variable of the program. The interrupt program and subprogram finished the tasks of A/D transform, the scan of the keyboard, digital PI control, the converting of the phase and PWM generating etc.