Power supply method for switched reluctance motor - using oscillatory magnetising-demagnetising current control mode at lower speeds, and conventional control mode at higher speeds

摘要

For a three-phase motor (2) with six double-wound (11) stator and four rotor poles, a DC power source (23) is switched successively to each phase by, e.g., a MOS transistor (12a,12b,12c). A shunt (22) with a current monitor (14) provides one input to a comparator (18), whose other input is set by a controlling computer (17), and whose output serves the oscillatory (1) and conventional (6) mode controllers. A demultiplexer (8), sequentially controlling phase switching (12a,12b,12c) through an interface unit (9), receives instructions from a pre-programmed EPROM memory (3), and via a selector (7), from one mode controller (1,6). In the oscillatory mode, phase current is interrupted after reaching a preset level. After demagnetisation, the cycle is repeated till the input is transferred to the succeeding phase. ADVANTAGE - Lower EM interference and commutation losses than with PWM systems.