| 摘要 |
<p>A motor control system (20) creates a rounding effect on square wave phase currents which results in reduced acoustic noise. The control system (20) includes a voltage sources (30) for providing a DC bus current, and an inverter (40). The inverter (40) has a switching (42) for regulating the DC bus current to a fixed level. The switching circuit (42) also forces consecutive phases of the motor (22) to share the bus current at commutation. Forcing consecutive phases of the motor (22) to share a desired amount of the DC bus current creates a 'rounding' effect on the phase currents, which results in reduced acoustic noise. The preferred inverter (40) has a plurality of transistors, (Q1 - Q6) and a control module (46). The control module (46) selectively engages the transistors (Q1 - Q6) such that each phase of the motor (22) has a phase turn-on point that occurs before a phase turn-off point of a preceding phase. The control module (46) also pulse width modulates the transistors (Q1- Q6) such that the DC bus current is regulated to the fixed level. The result is a motor control system (22) and method that is less expensive and produces less acoustic noise than conventional noise.</p> |
