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EP0616418A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Circuit and method for driving variable reluctance motor

Assignee: Fanuc Corp
•
Filing: 1993-09-30
•
Granted: —
•
Expires: 2013-09-30
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Abstract

Abstract A variable reluctance motor is driven by a circuit comprising a common switching element, and switching elements which correspond to the phases. The total value (total current it) of the currents flowing through the phase coils is found. In accordance with the difference between the total value and a current command icmd, and its sign (positive or negative), the duty ratio of the PWM signal for turning the common switching element on and off is calculated. Further, based on which phase is excited according to the electrical angle of the rotor, and on the sign of the difference, the turn on/off of the switching element corresponding to each phase is controlled. In this way, a current loop is controlled to permit the detected total current it to follow up the current command icmd. Therefore, even when the excited phases are switched over, the current is always controlled to suppress the torque ripple. <IMAGE>

Inventors

  • 👤 Tetsuro Room S-7 Fanuc Haitsufuji Sakano
  • 👤 Kohei Fanuc Dai-3 Vira-Karamatsu Arimoto

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-31 11:36
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/08; H02P25/098

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 83 words
A driving method for driving a variable-reluctance motor by means of a driver circuit composed of switching devices one more in number than the phases of the motor, comprising the steps of; mounting a current detector in a position such that a total current equal to the sum of currents flowing through individual coils of the motor can be detected, and executing a current loop process such that the total current detected by means of said current detector follows up a current command.
Claim 2
Dependent Claim 326 words
A driver circuit for a variable-reluctance motor, comprising: a rectifier circuit; a common series circuit including a common switching device for PWM operation and a diode, one end of said common switching device being connected to a positive terminal of said rectifier circuit, and the cathode and anode of said diode being connected to the other end of said common switching device and a negative terminal of said rectifier circuit, respectively; a series circuit including switching devices for alternatively exciting the coils for the individual phases and diodes, one end of each said switching device being connected to the negative terminal of said rectifier circuit, the other end being connected to the anode of each corresponding diode, and the cathode of each said diode being connected to the positive terminal of said rectifier circuit, the junction of the switching device of the series circuit for each phase and the corresponding diode being connected to one end of each corresponding exciting coil of the reluctance motor, the other end of each said exciting coil being connected to the junction of the switching device and the diode of said common series circuit, a current detector being mounted in a position such that a total current equal to the sum of currents flowing through the individual coils of the motor can be detected, between the junction of the switching device and the diode of said common series circuit and the respective other ends of said individual exciting coils; and a control circuit for receiving a current value transmitted from said current detector, a command current value, a main voltage value delivered from said rectifier circuit, and a detected value of the rotor electrical angle of the reluctance motor, computing the duty ratio of a pulse width modulation signal for switching the switching device of said common series circuit, and outputting a signal for controlling the switching operation of the switching device in the series circuit for each said phase.
Claim 3
Dependent Claim 19 words
A driver circuit for a variable-reluctance motor according to claim 1, wherein each said switching device is a transistor.
Claim 4
Dependent Claim 46 words
A driver circuit for a variable-reluctance motor according to claim 2, wherein said current detector is located between a common junction of the respective other ends of said individual exciting coils and the junction of the switching device and the diode of said common series circuit.

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