Generator Rotor Winding Detection via Transient Magnetic Pulse

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Solution Overview

Problem

Current methods for inspecting rotor windings in large generators have low detection accuracy and risk damage due to the use of probes, which are not suitable for detailed, non-destructive testing, especially in high-value equipment.

Innovation Solution

A device comprising a central processing unit, sequential logic circuit, high-voltage full-cycle pulse matching generator, pulse signal coupling feedback acquisition circuit, data acquisition system, and waveform data analysis system, which applies a transient bidirectional rotating magnetic field pulse to the rotor windings, allowing for non-destructive, accurate assessment of subtle changes and health status of each coil.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If probes are used for detailed inspection of rotor windings, then detection precision is improved, but the rotor windings may be damaged

Engineering Contradiction:
Improvedetection accuracyVSAvoidwinding damage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical probe-based inspection with a non-contact electromagnetic detection system. The system uses a portable detector that generates electromagnetic signals to interact with rotor windings, eliminating the need for physical contact and thus preventing mechanical damage while maintaining detection capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electromagnetic fields as an intermediary medium between the detector and rotor windings. The electromagnetic signals serve as a mediator to probe the winding condition without direct physical contact, allowing detailed inspection while avoiding damage to the expensive rotor components

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If periodic inspection is performed on rotor windings, then maintenance scheduling is simplified, but faults occurring between inspections cannot be detected

Engineering Contradiction:
Improveinspection schedulingVSAvoidcontinuous operation safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The portable detection system enables operators to perform inspections independently without requiring generator disassembly or specialized workshop facilities. The system can be deployed directly at the generator location, allowing frequent or continuous monitoring that enhances reliability while maintaining operational simplicity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system enables inspections to be conducted before faults develop into critical failures by detecting subtle changes in electromagnetic characteristics. This preliminary detection capability allows maintenance to be scheduled proactively based on actual winding condition rather than fixed time intervals

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If generator disassembly is performed for winding inspection, then detailed internal examination is enabled, but production downtime increases

Engineering Contradiction:
Improvewinding inspection detailVSAvoidproduction downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces mechanical disassembly with electromagnetic field-based detection that can penetrate and inspect windings through the intact generator structure. This substitution allows detailed internal examination without physical access, eliminating production downtime while maintaining inspection thoroughness

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The portable detection system is designed to work with the generator in its operational state, serving multiple functions including insulation assessment, winding integrity checking, and fault localization without requiring different inspection modes or disassembly procedures

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables precise, non-destructive testing of generator rotor windings, accurately identifying fault points and reflecting electromagnetic characteristics, thus ensuring safe and reliable operation without damaging the equipment.

Implementation Method 1

a high-voltage full-cycle pulse matching generator, a pulse signal coupling feedback acquisition circuit, which applies a waveform to a generator rotor and collects a waveform reflected by the generator rotor

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP3825707B1Generator rotor winding state detection device and method
Publication Date: 2024.04.24 SHANDONG GUTE ELECTRIC CO LTD
  • EP3825707B1 patent drawingFigure 1~2
  • EP3825707B1 patent drawingFigure 3~4
  • EP3825707B1 patent drawingFigure 5~6

AI summary

A device for inspecting the rotor windings of a generator includes a sequential logic circuit that generates a full-cycle pulse. A high-voltage full-cycle pulse matching generator couples the full-cycle pulse generated by the sequential logic circuit to form a corresponding transient bidirectional rotating magnetic field pulse. The transient bidirectional rotating magnetic field pulse is transmitted to two ends and a large shaft of the generator rotor winding through an impedance-matched connecting line. The transient bidirectional rotating magnetic field pulse generates a resonance effect with each large coil in the rotor. The pulse signal coupling feedback acquisition circuit couples all waveforms reflected by the generator rotor to form a magnetic field waveform, and the magnetic field waveform is transmitted to a data acquisition system by an operational amplifier. A central processing unit transmits a digital information stream to an upper computer. The present detection device can perform a non-destructive test on the condition of each large coil of one or multiple pole pairs of rotors of a large generator in a case of a single-end wiring measurement.