Apparatus and method for driving motor

Abstract

Reduce motor vibration and electromagnetic sound by using a current sense resistor without abrupt changes in multiple phase currents. A motor drive device including a plurality of output circuits consisting of upper and lower switching elements connected in series. It also includes: a current detection resistor connected in series with the above-mentioned multiple output circuits and a common connection point, and used to detect the current supplied to the above-mentioned multiple output circuits; allowing a switch in any one of the above-mentioned multiple output circuits an energized phase switching circuit that conducts an element for a period corresponding to a predetermined electrical angle, and causes another switching element among the remaining ones of the plurality of output circuits to perform a switching operation; and generates and outputs a signal for controlling the switching operation Signal, so that: in each period after the above-mentioned period is divided into a plurality of periods, there is a first period in which a plurality of switching elements are turned on, and any of the plurality of switching elements that are turned on in the first period An energization period control unit of a second period in which conduction is continued.

Description

technical field [0001] The present invention relates to motor drive technology, especially the motor drive technology of pulse width modulation (PWM: Pulse Width Modulation). technical background [0002] The PWM driving methods of brushless motors include: triangular wave peak clipping (slice) method and peak current detection method. In the triangular wave peak clipping mode, the coil current flows into the detection resistor, and the difference between the voltage generated in the detection resistor and the torque command voltage is used as the error amplifier (error amplifier) ​​outputting the peak clipping value, and the cutting cycle is fixed by the peak clipping value. The triangular wave, so as to determine the energization period for energizing the coil. In the peak current detection mode, no error amplifier is used, and when the voltage generated by the current detection resistor through which the coil current flows reaches the torque command voltage, the supply o...

AI Technical Summary

Problems solved by technology

Furthermore, it is difficult to mount current detection resistors in integrated circuits. As a result, when the number of current detection resistors increases, the scale of the device increases and the cost increases accordingly.

[0014] Furthermore, since the resistance characteristics generally have deviations, in the case of using current detection resistors corresponding to each phase, the current detection characteristics of each phase will be different.

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