| 摘要 |
The problem of efficiently starting a motor (16) which is used to start an engine (12) during engine start is solved with a motor control unit (30) which includes a resolver (34) having a primary winding (34P) coupled to an oscillator (36). The resolver (34) includes two single-phase secondary windings (34S1, 34S2) which are placed in space-quadrature to each other and which develop signals proportional to the sine and cosine of the angular position of the rotor for the motor (16). The sine wave and the cosine wave are transferred to a phase conversion circuit (46) which develops three sinusoidal signals 120 DEG out of phase with respect to each other. Each of the three developed sinusoidal signals is supplied to a respective multiplier circuit (51-53) which also receives a current command. The output of each multiplier (51-53) is a sinusoidal current command signal. The command signal is applied as one input to a current control loop (60-62) which also receives an actual phase current signal developed by a current sensor (32A-32C) for each of the three phases. The output of each loop is a control signal to an inverter (26) which powers the motor (16).
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