GB1247104A - Ac poly-phase variable speed brushless and commutatorless electric machine - Google Patents

Abstract

1247104 Electric motors; core constructions TOYO DENKI SEIZO K K 17 April 1969 [19 April 1968 19 July 1968 28 Oct 1968] 19572/69 Heading H2A A polyphase brushless synchronous machine comprises a cyclo-converter 2, Fig.1, connected to the armature windings U, V, W, and connectable to a polyphase supply, a rotor position sensing device, a signal generator 13 producing output signals representative of line current and of the difference between the desired and actual speeds of the machine, and a logic control device supplied from the signal generator and the rotor position sensor to produce control signals for the converter. The rotor position sensing device comprises a light bulb and three photo-transistors arranged to produce 180 degree outputs in each transistor, these outputs being converted to 120 degree signals in a further signal generator 8. The outputs of the two signal generators 8, 13 are fed to a gate signal generator 14 controlling the cyclo-converter to produce various operating modes of the machine, e.g. bi-directional motoring and generating modes. The machine shown in Fig.10 has interdigitated rotor poles 4a, 4b, magnetized by a D.C. energized winding 7a, 7b, mounted on the stator. In a modification, Fig.11 (not shown), the rotor and stator cores are both substantially E-shaped in axial cross-section, the rotor having three axially displaced poles S-N-S, and the D.C. energized winding is located between the limbs of the stator core.