Electric Motor

Brushless DC (BLDC) motors are one of the electrical drives that are rapidly

gaining popularity, due to their high efficiency, good dynamic response and low

maintenance. In this paper, the modeling and simulation of the BLDC motor was done

using the software package MATLAB/SIMULINK. A speed controller has been designed

successfully for closed loop operation of the BLDC motor so that the motor runs very

closed to the reference speed. The simulated system has a fast response with small

overshoot and zero steady state error.

http://www.eurojournals.com/ejsr_35_2_05.pdf

It is assumed that the BLDC motor is connected to the output of the inverter, while the inverter input terminals are connected to a constant supply voltage, as shown in Fig.1. Another assumption is that there are no power losses in the inverter and the 3-phase motor winding is connected in star.

http://www.eurojournals.com/ejsr_35_2_05.pdf

The control consists of logic circuitry and a power stage to drive the motor. The control’s logic circuitry is

designed to switch current at the optimum timing point. It receives information about the shaft/magnet

location (signals from the Hall devices), and outputs a signal, to turn on a specific power device, to apply

power from the power supply (not shown) to specific windings of the brushless motor.

http://www.motioncontrolonline.org/files/public/BrushlessOperation.pdf

This application note discusses the steps of developing

several controllers for brushless motors. We cover sensored,

sensorless, open loop, and closed loop design.

There is even a controller with independent voltage and

speed controls so you can discover your motor’s characteristics

empirically.

The code in this application note was developed with

the Microchip PIC16F877 PICmicro® Microcontroller, in

conjuction with the In-Circuit Debugger (ICD). This

combination was chosen because the ICD is inexpensive,

and code can be debugged in the prototype hardware

without need for an extra programmer or

emulator. As the design develops, we program the target

http://www.jimfranklin.info/microchipdatasheets/00857a.pdf