Insulation Parameter Assessment via Multi-Frequency Immitance
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Solution Overview
Problem
Existing methods for detecting insulation parameters of electrical insulation in power supply equipment are limited by inaccurate assessments due to reliance on single factors, lengthy measurement processes, and high material requirements, leading to error-prone diagnostics and inefficiencies in mobility and measurement accuracy.
Innovation Solution
A method involving complex impedance or admittance measurements at two different frequencies to determine four insulation parameters, including capacitance, loss resistance, and polarization components, allowing for a more comprehensive and accurate assessment of insulation conditions using a polarization equivalent circuit diagram.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If VLF measurement technique is used to reduce reactive power requirement, then power consumption is reduced, but measurement precision is limited to only two insulation parameters
Solution Approach 1:
The patent segments the measurement process into multiple frequency steps, measuring insulation parameters at different frequencies (including VLF and higher frequencies) to obtain both capacitance and loss resistance values. This segmentation allows comprehensive insulation assessment while maintaining the low power consumption advantage of VLF measurements.
2Measurement precision
If operating-frequency measurements are used to simulate actual operating conditions, then measurement accuracy is improved, but device size and cost increase due to high power requirements
Solution Approach 1:
The patent employs periodic measurements at multiple frequencies including the operating frequency. By performing measurements at VLF and operating frequency in sequence rather than simultaneously, the system achieves comprehensive insulation assessment without requiring continuous high power output, thus reducing device size and cost while maintaining measurement accuracy.
3Ease of operation
If single-factor loss factor measurement is used to simplify assessment, then measurement process is simplified, but diagnostic reliability decreases due to error-prone single-factor assessment
Solution Approach 1:
The patent transitions from single-factor loss factor measurement to multi-dimensional parameter assessment by measuring both capacitance and loss resistance at multiple frequencies. This dimensional expansion provides a more comprehensive and reliable insulation condition assessment while maintaining ease of operation through automated multi-frequency measurement sequences.
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 approach enables extended diagnostic capabilities with shorter measurement times and higher accuracy, providing detailed insights into polarization processes and insulation status, combining the advantages of existing methods while overcoming their limitations.
Implementation Method 1
complex immitance measurements at two different frequencies to determine four insulation parameters
Implementation Method 2
parallel insulation capacitance Ciso
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a method for determining the insulation parameters of an electrical insulation (4) of a power supply device (2) which has a first and a second electrical conductor (3, 5) that are electrically insulated from each other by means of the electrical insulation (4). In this method, two first real immitance components of a first complex immitance lying between the first and the second conductor (3, 5) are determined by means of a first measurement performed on the power supply device (2) at a first frequency (f1), and at least two second real immitance components of a second complex immitance are determined by means of a second measurement performed on the power supply device (2) at a second frequency (f2) different from the first frequency (f1).Furthermore, four first insulation parameters of the electrical insulation (4) are determined on the basis of the two first real immitance components and the two second real immitance components according to a polarization equivalent circuit in the form of a parallel insulation capacitance, a parallel insulation loss resistance, a first polarization resistance and a first polarization capacitance, wherein according to the polarization equivalent circuit the insulation capacitance, the insulation loss resistance and the series connection of the first polarization resistance and the first polarization capacitance are connected in parallel to each other.