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US 6,014,003 AGranted
Method and apparatus for controlling a switched reluctance machine
AssigneeEmerson Electric Co.
InventorAlan P. French
Life of this patent
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AssigneeEmerson Electric Co.
InventorAlan P. French
Estimating the term…
A method and apparatus for controlling the average voltage applied to a phase winding of a reluctance machine during a period of current increase, controlling the current when a desired current is reached, and controlling the voltage applied during a period of current decrease, to improve machine efficiency and thereby reduce acoustical noise produced by the machine, and unwanted vibration. The apparatus comprises circuitry and associated elements which are operable to switch the phase winding into circuits which apply either a positive DC voltage, a zero voltage, or a negative DC voltage, to increase, maintain, or decrease the current in the winding. The timing and the rate of the switching is controlled as a function of the angular position and speed of a rotor of the reluctance machine, the torque output of the machine, and the desired speed or torque. A method is provided whereby a duty cycle corresponding to a specific reluctance machine, as well as to specific operating parameters of the machine at a given rotor position, speed, and torque, is calculated by the controller for applying voltage to the phase winding during the period of current increase to increase the current from at or near zero to a desired peak current. Additionally, a method is provided for calculating a duty cycle for the time at which the phase is de-energized, corresponding to a specific reluctance machine, and to specific operating parameters of the machine at a given rotor position, speed, and torque, as well as a method for changing the duty cycle to drive the current in the winding to zero or near zero. The calculation of the appropriate duty cycle for the specific operating conditions of the reluctance machine controls the net average voltage applied, has been found to reduce abrupt changes in the current. This reduction correlates into reduced abrupt changes in the magnetic flux, resulting in reduced acoustic noise and unwanted vibration.
A method of enhancing the performance of a reluctance machine system, the machine system including a rotor, a phase winding coupled to a voltage bus by power switching devices, the method comprising the steps of:
A method of controlling the energization of a phase winding in a reluctance machine, the machine having a rotor and at least one phase winding, the method comprising the steps of.
A method of enhancing the performance of a reluctance machine system, the machine system including a rotor, a phase winding coupled to a voltage bus by power switching devices, the method comprising the steps of:
Dependencies are inferred from the claim text.