Auxiliary Winding Harmonic Coupling for AVR Power
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Solution Overview
Problem
Existing generator systems face challenges in providing power to an AVR, including the need for battery charging systems, additional PM alternators increasing costs and complexity, and susceptibility to harmonic interference when using auxiliary windings.
Innovation Solution
A single auxiliary winding on the stator is configured to couple with desired harmonic components while rejecting undesired ones, using a distribution function to optimize coupling with the fundamental and third harmonic components of the magnetic flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pair of auxiliary windings are used to supply power to the AVR, then the AVR can continue operating under fault conditions, but the size of the stator and the complexity of the windings are increased
Solution Approach 1:
The auxiliary winding is segmented into multiple independent coils distributed around the stator perimeter, each capable of providing power to the AVR. This segmentation allows the system to maintain reliability through distributed redundancy while keeping each individual coil simple and the overall stator size compact.
Solution Approach 2:
The auxiliary winding serves multiple functions: it provides power to the AVR under normal operating conditions and continues to provide power under fault conditions. The distributed coils can individually or collectively serve the AVR, eliminating the need for separate dedicated fault-protection windings and reducing overall system complexity.
2Adaptability or versatility
If auxiliary windings are used to provide power to the AVR, then power can be supplied under varying conditions, but the windings are susceptible to coupling to undesirable harmonic components that may interfere with the AVR operation
Solution Approach 1:
Each coil in the auxiliary winding is positioned at a specific location around the stator perimeter, creating local quality variations in the magnetic coupling. This spatial distribution allows selective coupling to fundamental frequency components while minimizing coupling to harmful harmonic components, as different locations experience different harmonic content.
Solution Approach 2:
The patent converts the potentially harmful harmonic components into a beneficial distributed coupling pattern. By distributing coils around the stator, the system naturally filters harmonics through spatial averaging, where harmful localized harmonic effects are transformed into a smooth, stable power supply for the AVR.
3Reliability
If a battery is used to power the AVR, then the AVR can operate independently, but the system requires a battery charging system
Solution Approach 1:
The auxiliary winding provides self-service power to the AVR by directly converting magnetic flux into electrical power without requiring external charging infrastructure. The distributed coils continuously generate power from the generator's magnetic field, making the AVR self-sufficient and eliminating the need for separate battery charging systems while maintaining independent operation capability.
4Power
If a permanent magnet alternator is coupled to the rotor, then power can be provided to the AVR, but a longer rotor shaft is required resulting in additional axial length of the alternator
Solution Approach 1:
The auxiliary winding is merged with the existing stator structure, using the same magnetic flux path and spatial envelope as the main generator windings. This integration eliminates the need for a separate permanent magnet alternator assembly, maintaining the original rotor shaft length and alternator axial dimensions while providing the necessary power to the AVR.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces the size and complexity of the stator, minimizes harmonic interference, and maintains stable power supply to the AVR under varying conditions, including short circuits, without the need for additional components or increased costs.
Implementation Method 1
a single auxiliary winding on a stator that is coupled to desired harmonic components but rejects undesired harmonic components of the voltage generated by the stator
Data Source
Figure 1
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AI summary
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 air gap of the alternator along with selected spatial harmonic components to provide power to an automatic voltage regulator during all operating conditions.