Motor power factor correction apparatus and method
AssigneeRamu, Inc.
InventorKrishnan Ramu
Life of this patent
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Abstract
A power factor correction system includes a rectifier that rectifies the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions, in a half sinusoid, from a minimum amplitude to a maximum amplitude and back to the minimum amplitude twice in the period of the ac power source. A phase winding of a motor conveys current induced by the voltage waveform, and a regulator regulates the flow of the current conveyed by the phase winding for storage as energy in a storage component.
Claims35
A power factor correction system comprising:
- a first rectifier that rectifies the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions from a minimum amplitude to a maximum amplitude and back to the minimum amplitude, in a half sinusoid, twice in the period of the ac power source;
- a first phase winding of a motor that conveys current induced by the voltage waveform;
- a first storage component;
- a first regulator that regulates the flow of current conveyed by the first phase winding to the first storage component so as to store energy in the first storage component;
- a second phase winding of the motor;
- a second regulator that regulates the discharge of energy stored by the first storage component by conducting current through the second phase winding;
- and
- no circuit path exists for the first storage component to discharge stored energy by conducting current through the first phase winding.
A motor system comprising:
- a motor;
- a rectifier that rectifies the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions from a minimum amplitude to a maximum amplitude and back to the minimum amplitude, in a half sinusoid, twice in the period of the ac power source;
- a power factor correction circuit comprising:
- a first phase winding of the motor that conveys current induced by the voltage waveform;
- a storage component;
- and
- a first regulator that regulates the flow of current conveyed by the first phase winding to the storage component so as to store energy in the storage component;
- a second phase winding of the motor;
- and
- a second regulator that regulates the discharge of energy stored by the storage component by conducting current through the second phase winding, wherein:
- current induced within the first phase winding by the voltage waveform generates torque that is applied to the motor, and
- no circuit path exists for the storage element to discharge stored energy by conducting current through the first phase winding.
The motor system of claim of 25, wherein the stator poles carry generated flux in the same direction.
The motor system of claim of 21, wherein the first phase winding comprises two separate winding portions, for power factor correction, that are wound on diametrically opposite portions of the back iron of a stator of the motor where flux flowing through the stator does not reverse direction.
A power factor correction method comprising:
- rectifying the voltage of an alternating current (ac) power source to produce a voltage waveform that transitions from a minimum amplitude to a maximum amplitude and back to the minimum amplitude, in a half sinusoid, twice in the period of the ac power source;
- applying the voltage waveform to a phase winding of a motor to induce the conveyance of current through the phase winding;
- and
- regulating the flow of current conveyed by the phase winding to a storage component so as to store energy in the storage component and produce a constant voltage potential across the storage component.
A power factor correction device comprising:
- first and second switches;
- a first capacitive element;
- and
- a first unidirectional current element that conducts current unidirectionally, wherein:
- the first and second switches, first capacitive element, and first unidirectional element are coupled such that when coupled with first and second windings of a motor and a full-wave rectified voltage source:
- the full-wave rectified voltage source conducts current through the first winding, when the first switch is in a conductive state,
- the full-wave rectified voltage source conducts current through the first winding, first unidirectional current element, and first capacitive element, so as to store energy in the first capacitive element, when the first switch is in a non-conductive state,
- energy stored by the first capacitive element is discharged by the conduction of current through the second winding, so as to store energy in the second winding, when the second switch is in a conductive state, and
- no circuit path exists for the first capacitive element to discharge stored energy by the conduction of current through the first winding.
Dependencies are inferred from the claim text.