| 摘要 |
<p>A method of determining the average current drawn by an electric motor, the motor comprising a plurality of phases, the method comprising: driving each phase of the motor with cyclic pulse width modulated drive signals having a first state and a second state, and a duty ratio indicative of the ratio of time spent in the first to second states within a cycle, determining the current flowing through each phase at an instant in the cycle; and determining the average current drawn by the motor over at least one cycle by combining the currents flowing through each phase with the duty ratios for each phase. The method may be embodied in a combination of a motor and a drive circuit for the motor, such as can be used in an Electric Power Assisted Steering system.</p> |
