ROTOR POSITION DETECTOR OF BRUSHLESS DC MOTOR

摘要

PURPOSE:To accurately detect the rotor position of a motor by adding positive and negative detection outputs obtained from the output clamped with the phase winding voltages of stator windings energized by chopper control as phase voltages. CONSTITUTION:In a position detector 100 for outputting a position detection signal of a rotor 6 of a motor 4, an imaginary neutral point voltage is outputted from an imaginary neutral point circuit 101 inserted in parallel with an inverter 7 to the output terminal of a rectifier 2, and positive and negative detection outputs are fed from a detector 103 connected to the output terminal of a voltage clamping circuit 102 coupled in a star-connection of clamp units connected to the phase stator windings 5. A comparator 105 for adding these positive and negative outputs and comparing the integrated output of an addition integrator 104 for integrating the 90 deg. phase delay to the phase voltage with the neutral point voltage outputs position detection signals U0-W0 of the rotor 6 to a distributor 11.