Digital current loop control of a brushless DC motor

Servo control of motors has important applications m such areas as robotics, numerically controlled machines and 'fly by wire* aircraft systems. The development of high power high coercivity magnetic alloys, such as samarium cobalt, has led to the advent of the brushless dc machine, which offers a more advantageous alternative to the brush machine. The brushless DC machine eliminates the need for brush contacts, through the use of electronic commutation. It has better thermal characteristics, as the rotor does not carry any current, and the rotor moment of inertia tends to be smaller than an equivalent brush machine. To achieve servo performance with a brushless dc machine requires the control of the motors torque angle. This thesis proposes digital control schemes for torque angle control, presents a simulation of the motor system with the schemes implemented, and concludes that digital schemes are more advantageous than analog control schemes, in the context of torque angle control of a brushless DC system