Apparatus and method for controlling brushless DC motor
First Claim
1. An apparatus for controlling a brushless direct current (DC) motor having a rotator, comprising:
- a power converting unit to convert alternating current (AC) power to polyphase AC power and supply the polyphase AC power to the brushless DC motor;
a rotator position/speed detecting unit to detect status information of the rotator of the brushless DC motor;
a terminal voltage detecting unit to detect variations of terminal voltages of the polyphase AC power supplied to the brushless DC motor; and
a control unit to detect phase commutation periods of the polyphase AC power using the status information of the rotator provided from the rotator position/speed detecting unit and terminal voltage variation information of the polyphase AC power provided from the terminal voltage detecting unit, and to control the power converting unit to supply to the brushless DC motor a compensation voltage used to constantly maintain a mean voltage of a non-commutation phase of the polyphase AC power during the detected phase commutation periods.
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Accused Products
Abstract
An apparatus and method for controlling a brushless DC motor, which minimizes a torque ripple thereof, and includes a power converting unit to convert alternating current (AC) power to polyphase AC power and to supply the polyphase AC power to the brushless DC motor. A rotator position/speed detecting unit detects status information of a rotator. A terminal voltage detecting unit detects variations of terminal voltages of the polyphase AC power. A control unit detects phase commutation periods of the polyphase AC power using the status information provided from the rotator position/speed detecting unit and the terminal voltage variation information of the polyphase AC power provided from the terminal voltage detecting unit. The control unit controls the power converting unit to supply a compensation voltage used to constantly maintain a mean voltage of a non-commutation phase of the polyphase AC power during the detected phase commutation periods.
21 Citations
47 Claims
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1. An apparatus for controlling a brushless direct current (DC) motor having a rotator, comprising:
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a power converting unit to convert alternating current (AC) power to polyphase AC power and supply the polyphase AC power to the brushless DC motor;
a rotator position/speed detecting unit to detect status information of the rotator of the brushless DC motor;
a terminal voltage detecting unit to detect variations of terminal voltages of the polyphase AC power supplied to the brushless DC motor; and
a control unit to detect phase commutation periods of the polyphase AC power using the status information of the rotator provided from the rotator position/speed detecting unit and terminal voltage variation information of the polyphase AC power provided from the terminal voltage detecting unit, and to control the power converting unit to supply to the brushless DC motor a compensation voltage used to constantly maintain a mean voltage of a non-commutation phase of the polyphase AC power during the detected phase commutation periods. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of controlling a rotation of a brushless DC motor, the brushless DC motor being supplied with power from a power converting unit to convert AC power to polyphase AC power, comprising:
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driving the brushless DC motor by supplying a non-commutation phase current thereto;
monitoring a starting time of a phase commutation using position information of a rotator;
supplying a compensation voltage to the brushless DC motor to minimize a torque ripple due to the phase commutation when the phase commutation starts; and
detecting an ending time of the phase commutation using information on a time when a trigger of a terminal voltage waveform is generated to stop the supply of the compensation voltage. - View Dependent Claims (10, 11, 12)
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13. An apparatus for controlling a brushless direct current (DC) motor having a rotator, comprising:
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a converting unit to convert alternating current (AC) power to polyphase AC power and to supply the polyphase AC power to the brushless DC motor;
a rotator operation detecting unit to detect operational information of the rotator;
a variation detecting unit to detect variation information of terminal voltages of the polyphase AC power supplied to the brushless DC motor; and
a control unit to detect phase commutation periods of the polyphase AC power using the operational information of the rotator and the variation information of the polyphase AC power supplied to the brushless DC motor and to control a supply of a compensation voltage to the brushless DC motor to maintain a mean voltage of a non-commutation phase of the polyphase AC power during the detected phase commutation periods. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
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42. A method of controlling a brushless DC motor, which is supplied with polyphase AC power, the brushless DC motor having a rotator therein, comprising:
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supplying a non-commutation phase current to the brushless DC motor;
detecting a starting time of a phase commutation using operational information of the rotator and an ending time of the phase commutation using information on a time when a trigger of a terminal voltage waveform is generated to stop the supply of the compensation voltage, a phase commutation period being defined by the starting and an ending times of the phase commutation; and
supplying a compensation voltage to the brushless DC motor to substantially eliminate a torque ripple thereof during the phase commutation period. - View Dependent Claims (43, 44, 45, 46)
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47. An apparatus for controlling a brushless direct current (DC) motor having a rotator, comprising:
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a converting unit to convert alternating current (AC) power to polyphase AC power and to supply the polyphase AC power to the brushless DC motor;
a rotator operation detecting unit to detect operational information of the rotator;
a variation detecting unit to detect variation information of terminal voltages of the polyphase AC power supplied to the brushless DC motor; and
a control unit to detect phase commutation periods of the polyphase AC power using the operational information of the rotator and the variation information of the of the polyphase AC power supplied to the brushless DC motor and to control a supply of a compensation voltage to the brushless DC motor to substantially eliminate a torque ripple thereof.
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Specification