Modeling Of Permanent Magnet BLDC Motor Using State Space Analysis

Abstract

BLDC motor is one of motor type gaining popularity nowadays. We find that brushless DC (BLDC) motor modelling can be simply implemented using transfer function analysis. But it suffers from certain drawbacks such as transfer function is only defined under zero initial conditions, only applicable to linear time-invariant systems and so on.   To overcome these drawbacks this paper presents a detailed state space modelling of permanent magnet brushless DC motor. In this paper, the motor is designed based on state space model to get information about the state of the system variables. By reading the instantaneous position of the rotor as an output, different variables of the motor can be controlled without the need of any external sensors or position detection techniques. With state space model representation, the motor performance can be analyzed for different  motor parameters.