Presentation Description: We have discovered a method of electronic brushless commutation for brushless D.C. motors and generators using a prime numbered armature configuration. The prime numbered armature winding circuits (or phases) are sequentially stepped using solid state switches in an open or closed 'feedback' loop requiring only one Pulsed Width Modulated PWM channel to control multiple circuits without Clark/Park transforms. Our synchronous reluctance topology does not require permanent magnets or copper wound rotating field but does require half bridge electronic switches for each circuit. This technology is ideal for large direct driven wind turbines as the cycle or pulse count generated per revolution is a product of the prime numbered circuits and the number of poles. For example: A 3 phase, 4 pole (12 coil) convention synchronous AC generator outputs the equivalent of 12 half cycle pulses per revolution at 120 deg phase angle displacement. Our 4 pole machine comprising '13' (prime number) coils output the equivalent of 52 half cycle pulses per revolution at 6.92 deg phase angle displacement rectified via 13 half bridge switches to produce clean D.C. power with a crest factor of nearly 1 without torque ripple.
A large slow turning wind turbine, 44 pole - 89 coil, generator could output 3,916 pulses per revolution at a phase angle displacement of 0.0919 degrees. Our design is capable leveraging a relatively small number of phases (circuits and half-bridge rectifiers) to generate a very large number of pulses for extremely smooth operation at very slow speeds!
Methodology: Prototype demonstration. I have a 700 lb prototype that demonstrates my concept.
Learning Objectives:
Upon completion, participants will have been exposed to a disruptive paradigm shift in the way power is generated using wind.
Upon completion, participants will understand how d.c. power generation and transmission could lower the levelised cost of clean energy from wind.
Upon completion, participants will see how vertical axis wind turbines can compete effectively with vertical axis machines up to utility scale.
