Position Control of Permanent Magnet Brushless DC Motor using PID Controller

Abstract

Growing need of industry for higher productivity is placing new demands on mechanisms connected with electrical motors. This is leading to different problems in work operation due to fast dynamics and instability. The stability of the system is essential to work at desired set targets. The non- linear effects caused by a motor frequently reduce stability, which reduces the controller‟s ability to maintain speed or position at set points. Hence number of the industrial process applications requires position control of DC motor. A brushless DC motor describedas magnet being the rotor and its stationary windings forming the stator. This design provides many advantages over the brush DC motor. Brushless DC (BLDC) motor drives are becoming widely used in various consumerand industrial systems, such as servo motor drives, home appliances, computerperipherals, and automotive applicationsin recent years because of their high efficiency, silent operation, compact form, reliability, and low maintenance. The aim of the thesis is to design a simulation model of Permanent Magnet Brushless DC (PMBLDC) motor and to control its position. In the developed model, the characteristics of the speed, torque, back EMF, voltages as well as currents are effectively monitored and analyzed. The PID controller is used to control the position of a Permanent magnet brushless DC motor by changing the current flow to control the average voltage and thereby the average current. Most useful application is in controlling of CNC machines.