Speed Control of BLDC Motor with Direct Torque Control

Abstract

Brushless DC (BLDC) engine drives are consistently picking up prevalence in movement
control applications. In this way, it is important to have an ease, yet compelling BLDC
engine Speed/Torque controller. This paper displays a novel idea for computerized control of
Trapezoidal BLDC engine, and methodologies an immediate torque control (DTC) system for
BLDC engines with non-sinusoidal back electromotive power (EMF) utilizing a six switch
inverter consistent torque area. By properly selecting the inverter voltage from a simple look
up table at a predefined sampling time, the desired quasi-square wave current is obtained.
Therefore, a much faster torque response is achieved compare to conventional method. In
addition, for effective torque control, a novel switching pattern incorporating the look up
table is designed and implemented for a six switch inverter to produce the desired torque
characteristics as a result it is possible to achieve BLDC motor speed control using DTC. A
theoretical concept is developed and the validity and effectiveness of the proposed DTC
scheme are verified through the simulation and experimental results.