New design methodologies for printed circuit axial field brushless dc motors

摘要: [Abstract] A number of factors are contributing to the increased practical importance printed circuit axial flux brushless direct current (BLDC) machines. The main ones availability low cost power electronic devices and digital controllers as well effective high strength permanent magnets. Advancement multi-layer technology is also an important factor. Existing board motors, found in applications such computer disk drives portable audio-visual equipment, typically rated at a few watts per thousand revolutions minute (krpm). focus this thesis project has been on motors with ratings tens krpm. A significant part devoted development systematic design procedures for stators. In particular those include algorithms which allow performance comparisons several stator coil shapes. A new shape, improved torque capability, developed. BLDC that operate sensorless mode advantages lower cost, better reliability space saving. generalised version previously reported equal inductance method developed allows commutation down zero speed start-up practically no back rotation. Computer efficient numerical models have predict phase inductances eddy-current loss. Sufficiently accurate inductance predictions make possible theoretical assessment under control based equal method. proposed calculation eddy loss designers determine track width beyond becomes excessive. The mathematical model enhanced used assessment, prediction evaluation all validated by specially designed laboratory tests carried out prototype motors.