In this Paper, a speed control system for a Brushless DC (BLDC) motor is to be analysed and enhanced to increase the efficiency of the motor. The objective is to keep the magnetic field between stator and rotor always perpendicular in order to generate the maximum torque with the minimum consumption of energy. The first step taken in this paper is the analysis of the model of a BLDC motor. By using the set of parameters given from a book (Analysis of Electric Machinery), a dynamic model is programmed in Matlab to perform all the experiments required. PI controller is implemented in order the speed tracking to be achieved. The manipulated variable is the input voltage and the controlled variable is the speed.