Investigation on Direct Torque Control of BLDC Motor Using Various Controllers

Abstract

BLDC Stands for brushless DC Motor. Direct torque control is a type of a vector control. Direct Torque control consist of two control loops one is speed control and other one is torque control. For the purpose of speed control several speed controllers are used in this work such as PI, PID Controller and Fuzzy Controller. PID Controller was used for better speed response, no steady state error but due to the difficulty in tuning of PID parameters and non-linear characteristics of BLDC Motor Fuzzy controller was used. When response was compared both Fuzzy-PID Controller was providing better speed response as compared to individual PID Controller. A simulation study using MATLAB/Simulink introducing Direct Torque Control (DTC) method which is implemented on BLDC motor Using PID Controller. BLDC motor is well known and has been widely used in the industrial area due to the high speed and power density. Electronic commutation is by far more favorable compared to the conventional DC motor which uses brushes and commutators that wears and tears by time. Based on in depth analysis of BLDC mathematical model and the operation of Direct Torque Control system, a simulation model is developed using MATLAB/Simulink. The capability and performance of torque and flux control of the drive system is verified. The conventional PID speed controller is implemented to meet various design specifications like rise time, settling time, peak overshoot and the steady state error of the system. It is difficult to tune the parameters and get satisfied control characteristics by using normal conventional PID controllers. In this work initially PID Controller was used but due to the difficulties regarding the tuning of parameters and it was difficult to get satisfied control characteristics by using normal PID Controller. To overcome these difficulties and to get better speed response advance controller is used called Fuzzy controller. This work was performed on MATLAB/SIMULINK Software.