Motor Winding Insulation With Built-In Partial Discharge Detection
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Solution Overview
Problem
Dynamo-electrical machines experience partial discharges due to overvoltages caused by steep-flank switching processes in converter operations, leading to insulation deterioration and potential motor failure, which is difficult to predict and prevent with existing technologies.
Innovation Solution
A stator and/or rotor with a winding system in the grooves of an electromagnetically conductive body, featuring a composite insulation material with particulate, electrically partially conductive layers and a plastic matrix, forming a conductor structure that can detect partial discharges by measuring resistance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional insulation materials (wire enamel, impregnation, groove lining) are used, then the insulation system meets basic dielectric strength requirements, but it cannot detect partial discharges and insulation deterioration occurs unnoticed
Solution Approach 1:
The patent combines the insulation function and detection function into a single integrated slot lining component. The slot lining contains both insulating material and a conductor structure with sensing capability, eliminating the need for separate insulation materials and detection sensors. This merging approach resolves the contradiction by achieving reliable partial discharge detection without increasing overall system complexity.
Solution Approach 2:
The slot lining is designed to perform multiple functions simultaneously: electrical insulation, mechanical support, and partial discharge detection. The conductor structure embedded in the slot lining acts as both part of the insulation system and as a sensing element for detecting insulation deterioration, thereby achieving multi-functionality that resolves the contradiction between reliability improvement and complexity avoidance.
2Productivity
If steep-flank switching processes are used in converter operations, then power conversion efficiency is improved, but voltage overshoots cause partial discharges that deteriorate insulation
Solution Approach 1:
The patent implements a feedback mechanism where the conductor structure continuously monitors the insulation condition by detecting changes in resistance caused by partial discharges. This real-time feedback allows for early detection of insulation deterioration, enabling preventive measures to be taken before complete insulation failure occurs, thus resolving the contradiction between maintaining efficient switching operations and preventing insulation damage.
Solution Approach 2:
The slot lining with embedded conductor structure is installed in advance during manufacturing, creating a built-in monitoring system before the motor enters service. This preliminary action ensures that partial discharge detection capability is already in place, allowing for early detection of insulation issues caused by steep-flank switching without requiring additional retrofitted equipment.
3Measurement precision
If manual inspection methods are used to detect insulation weaknesses, then detection capability is limited, but automated detection systems increase complexity and cost
Solution Approach 1:
The slot lining performs self-diagnosis by continuously monitoring its own insulation condition through the embedded conductor structure. The system detects partial discharges and insulation deterioration automatically without requiring external inspection equipment or manual testing, thereby achieving high measurement precision while avoiding additional system complexity.
Solution Approach 2:
The conductor structure acts as an intermediary element that bridges the insulation material and the detection function. It is embedded within the slot lining itself, serving as both part of the insulation system and as the sensing element, thereby achieving accurate detection without requiring separate complex detection systems.
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
The solution enables direct detection of partial discharges regardless of electrical load, allowing for early identification of insulation weaknesses and preventing motor failure, while also being more cost-effective than existing methods.
Implementation Method 1
forming a conductor structure that can detect partial discharges by measuring resistance changes
Implementation Method 2
an impregnation process is applied (cold dipping, hot dipping, or trickling). This process fills the spaces between the wires, the spaces in front of and behind the slot linings, and the geometric gaps in the winding heads, at least partially, with impregnating resin
Implementation Method 3
the wire enamel, which is applied to the copper wire by the manufacturer (approx. 200 μm) and is a multilayer structure
Data Source
Figure 1
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Figure 5~7
AI summary
The invention relates to a stator (8) and/or rotor (9) of a dynamoelectric machine (1), with a winding system (13) arranged in slots (16) of an electromagnetically conductive body (10), in particular a multiphase winding system (13), which forms winding heads (7) on the end faces of the respective electromagnetically conductive body (10), wherein an insulating material is provided at least partially in the slots (16) and/or in the winding head (7), wherein the insulating material has a conductor carrier (27) which provides a composite material (28) with frequency-dependent resistance behavior in definable sections in order to detect voltage overload, in particular partial discharges in the winding system, especially in the slot and/or winding head area.