Insulation Testing Apparatus for Rotary Electric Machines
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Solution Overview
Problem
Conventional insulation testing apparatuses for rotary electric machines face accuracy issues due to floating potentials, leading to erroneous detections and decreased test accuracy, especially when conducting interphase insulation tests.
Innovation Solution
The proposed insulation testing apparatus includes a power unit, switching unit, discharge measurement unit, insulation determination unit, and control unit, which connects all wire rods and the stator core to a terminal, preventing floating potentials and allowing simultaneous inter-phase and ground insulation testing, thereby reducing the number of tests and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional insulation testing is performed with floating potentials, then the testing process is simpler, but the test accuracy deteriorates due to erroneous detections
Solution Approach 1:
The patent applies equipotentiality by connecting all wire rods and the stator core to a common reference potential through the switching unit. This eliminates floating potentials during insulation testing, preventing erroneous discharge detections and improving measurement accuracy without significantly increasing system complexity
Solution Approach 2:
The switching unit acts as an intermediary device that controls the connection state between wire rods, stator core, and reference potential. It mediates the testing process by selectively connecting components to eliminate floating potentials only when needed for accurate measurement, rather than permanently altering the system configuration
2Productivity
If multiple separate insulation tests are conducted for inter-phase and ground insulation, then comprehensive testing is achieved, but the testing time increases
Solution Approach 1:
The patent merges inter-phase insulation testing and ground insulation testing into a single integrated testing operation. By controlling the switching unit to connect all wire rods and stator core to reference potential simultaneously, both types of insulation tests can be performed in one test cycle, halving the required testing time while maintaining comprehensive coverage
Solution Approach 2:
The switching unit provides multi-functionality by serving both inter-phase insulation testing and ground insulation testing purposes. A single testing configuration with the switching unit enabled can perform both test types, making the testing system universal and eliminating the need for separate dedicated test setups
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 configuration enhances test accuracy by preventing discharge induction from non-measurement to measurement portions, reducing the number of tests required, and shortening the testing time while ensuring accurate determination of wire rod quality.
Implementation Method 1
measures an amount of discharge produced between a first member electrically connected to the first terminal and a second member electrically connected to the second terminal
Data Source
AI summary
An insulation testing apparatus includes: a power unit having a first and second terminals; a switching unit switching between an electrical connected and disconnected states between the wire rods of respective phases and the core, and the first and second terminals; a discharge measurement unit measuring an amount of discharge produced between a first and second members electrically connected to the first and the second terminal, respectively; an insulation determination unit determines, based on the amount of discharge, whether the coating of the wire rods satisfies a predetermined quality regulation; and a control unit controlling the switching unit such that all of the wire rods and the core are electrically connected to the first or second terminals, while controlling the switching unit such that none of the wire rods nor the core is insulated with both of the first and second terminals.