Auxiliary winding for a generator
AssigneeGenerac Power Systems, Inc.
InventorGraham W. McLean
Life of this patent
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Abstract
An auxiliary winding for use in an engine-driven generator system is disclosed. The auxiliary winding is separate from but resides with the main winding in the stator slots of an alternator in the generator system. The auxiliary winding is configured to utilize the fundamental component of the flux in the airgap of the alternator along with selected spatial harmonic components to provide power to an automatic voltage regulator during all operating conditions.
Claims19
An alternator for a generator system, comprising:
- a rotor having an excitation winding;
- a stator having a plurality of slots, wherein a three-phase main winding and a single-phase auxiliary winding are each wound in the plurality of slots;
- and
- an airgap defined between the stator and the rotor, wherein the auxiliary winding includes a plurality of turns of wire, each turn wound in a first direction in a first slot selected from the plurality of slots of the stator and in a second direction in a second slot selected from the plurality of slots of the stator and wherein:
- each of the plurality of turns of wire are wound in the plurality of slots according to a distribution function;
- the distribution function is defined to couple the auxiliary winding to a fundamental component and a desired spatial harmonic component selected from a plurality of spatial harmonic components of a magnetic flux generated in the airgap, the desired special harmonic component having a magnitude greater than magnitudes of the plurality of spatial harmonic components under a short circuit condition;
- and
- the distribution function is configured to link the auxiliary winding to the desired spatial harmonic component during the short circuit condition.
A method of providing power to an excitation winding on a rotor of an alternator in a generator system, the method comprising the steps of:
- winding each of a three-phase main winding and a single-phase auxiliary winding on a stator of the alternator, the stator being separated from the rotor by an airgap;
- receiving power on the auxiliary winding corresponding to a current conducted by the excitation winding, wherein the auxiliary winding is wound on the stator to couple the auxiliary winding to a fundamental component and a desired spatial harmonic component selected from a plurality of spatial harmonic components of a magnetic flux generated in the airgap of the alternator;
- transmitting the power from the auxiliary winding to an automatic voltage regulator (AVR);
- controlling power from the AVR to the excitation winding as a function of the output voltage of the main winding;
- and
- linking the auxiliary winding to the desired spatial harmonic component during a short circuit condition;
- wherein:
- the desired special harmonic component has a magnitude greater than magnitudes of the plurality of spatial harmonic components under the short circuit condition.
An alternator configured to be driven by an engine in an engine-driven generator system, the alternator comprising:
- a stator, including:
- a plurality of slots,
- a three-phase main winding distributed in the plurality of slots, and
- a single-phase auxiliary winding distributed in the plurality of s according to a distribution function, wherein the distribution function defines a distribution of the auxiliary winding in the slots of the stator in order to couple the auxiliary winding to a fundamental component and a desired spatial harmonic component of a magnetic flux generated in an airgap of the alternator;
- a rotor, rotatably mounted within the stator and driven by the engine, the rotor including an excitation winding configured to conduct a current which establishes the magnetic flux in the airgap;
- and
- an automatic voltage regulator (AVR) controlling the current in the rotor as a function of at least one of a current and a voltage present on the main winding;
- wherein:
- the auxiliary winding is linked to the desired spatial harmonic component during a short circuit condition;
- and
- the desired special harmonic component has a magnitude greater than magnitudes of the plurality of spatial harmonic components under a short circuit condition.
Dependencies are inferred from the claim text.