BAT ALGORITHM OPTIMIZED FUZZY PD BASED SPEED CONTROLLER FOR BRUSHLESS DIRECT CURRENT MOTOR

Abstract

Brushless Direct Current (BLDC) motors are widely used in servo robotic positioning actuators, traction, fans, and blowers due to their high reliability, high efficiency, low maintenance, and many other advantages. So, speed control of BLDC motor should be done in an optimal way. This project describes about the design of bat algorithm optimized fuzzy proportional derivative controller for speed control of BLDC motor. The error and change in error is given as input to the PD fuzzy logic controller. The speed error is then processed via controller based on the fuzzy rules given to the Fuzzy PD Controller. The fuzzy PD bat optimized controller provide the controlling signal to the switching logic. Based on the switching logic the PWM inverter switches are triggered and converts the DC to AC which is fed to the BLDC motor. Thus it control the dc bus voltage thereby by controlling the speed of the motor. Optimization of PD controllers design is carried out using nature inspired optimization algorithms such as particle swarm, cuckoo search, and bat algorithms. Time domain specifications and performance indices are measured and compared for the PD controller under different operating conditions such as varying set speed and load disturbance conditions. The precise investigation through simulation is performed using MATLAB simulink toolbox. From the simulation test results, it is evident that bat optimized fuzzy proportional derivative controller has superior performance than the other controllers considered. Experimental test results have also been taken and analyzed for the optimal controller identified through simulation.

Existing System

In the existing system, a fuzzy logic controller for the speed control of bidirectional brushless DC motor (BLDC) is used.

Proposed System

The proposed system consists of two loops inner loop and the outer loop. Inner loop is used for synchronizing the inverting gate signal with back electro motive force or rotor position of the motor. The outer loop is used to sense the actual speed of the motor and then it is compared with the reference speed to produce speed error. The position of the rotor is sensed using hall sensor. The error and change in error is given as input to the PD fuzzy logic controller. The speed error is then processed via controller based on the fuzzy rules given to the Fuzzy PD Controller. The input and output scaling factor, antecedent part of the input membership function, and coefficients of the consequent parts of the fuzzy inference system of the fuzzy PD controller are optimized with bat search algorithms. The fuzzy PD bat optimized controller provide the controlling signal to the switching logic. Based on the switching logic the PWM inverter switches are triggered and converts the DC to AC which is fed to the BLDC motor. Thus it control the dc bus voltage thereby by controlling the speed of the motor.

Architecture

Block Diagram of the Proposed System