Patent ID: 7383110

Claim:
A motor control device having a voltmeter for measuring a power supply voltage (Vb) applied to a three-phase inverter and using the three-phase inverter for operating a brushless DC motor under three-phase drive control, the motor control device comprising: electric power inference means for inferring an electric power (P) consumed by the brushless DC motor, from three parameters including: (a) motor phase currents (I) flowing through at least two phases of three phases of the brushless DC motor, (b) motor phase voltages (V) applied to at least two phases which of the three phases, are the same in phase as the motor phase currents (I) flowing through the two phases, and (c) a motor rotational angle (θ); and power supply current inference means for inferring the value of a power supply current (Ib) supplied to the three-phase inverter, based on both of the power supply voltage (Vb) and the electric power (P).