Converter Loss Estimation Across Motor Winding Variants
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Solution Overview
Problem
Current methods for determining losses in converter-fed electric motors are inefficient and require significant effort, especially when comparing different motors with varying numbers of windings and wire cross sections.
Innovation Solution
A method that calculates the losses of a first motor with a pulse width modulated converter and applies the characteristic function to determine the losses of a second motor, using the intermediate circuit voltage and number of windings, allowing for quick and inexpensive calculations without additional effort, and enabling loss determination in motors with similar designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If loss determination is performed for each motor individually through measurement, then measurement precision is improved, but loss of time and productivity deteriorate due to repeated measurements
Solution Approach 1:
The patent creates a characteristic function model from the first motor's measured data that can be copied and applied to calculate losses for the second motor. Instead of measuring each motor individually, the loss characteristics are copied through the characteristic function that relates losses to operating parameters, significantly reducing determination time while maintaining accuracy.
Solution Approach 2:
The patent performs preliminary measurement and characterization on a reference motor (first motor) to establish the characteristic function. This preliminary action allows subsequent loss determinations for other motors (second motor) to be made through calculation rather than repeated measurement, improving efficiency.
2Measurement precision
If detailed measurement and calculation procedures are applied to each motor, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent develops a universal characteristic function that can be applied across different motors within the same series. This single function serves multiple purposes: characterizing loss behavior, enabling calculations for different motor configurations, and providing a standardized approach. The universality reduces procedural complexity while maintaining precision.
Solution Approach 2:
The patent utilizes parameter changes (number of windings, wire cross-section) as the key differentiating factors between motors. By focusing on these specific parameters and their relationship to losses through the characteristic function, the determination procedure becomes simpler while maintaining accuracy, as only these parameters need to be adjusted in calculations between different motors.
3Adaptability or versatility
If conventional loss determination methods are used for motors with different winding configurations, then adaptability deteriorates, but manufacturing precision requirements increase
Solution Approach 1:
The patent explicitly accounts for parameter changes in winding configurations (number of windings w1, w2 and wire cross-sections A1, A2) within the characteristic function framework. The method adapts to different motor configurations by adjusting for these parameters in the loss calculation, maintaining both adaptability and manufacturing precision through standardized relationships.
Solution Approach 2:
The characteristic function serves as a universal tool that can determine losses across multiple motor types within a series. The function is designed to handle different winding configurations through standardized parameter relationships, making the determination method adaptable to various motors while maintaining consistent precision requirements.
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 method simplifies the determination of converter-related losses across motors with different winding configurations, allowing for efficient loss calculation and application in ongoing operations, improving energy efficiency and motor control.
Implementation Method 1
a three-phase electric motor, in particular a synchronous motor, fed by a pulse-width modulated converter
Implementation Method 2
in the Fourier spectrum of the supply voltage of the first motor, in particular which is detected
Data Source
AI summary
The invention relates to a method for determining losses, wherein, in a first method step, the losses P HL_1 of the first drive are determined according to (I), wherein (II) applies, wherein i and j number the frequencies fij, in particular the non-disappearing frequencies fij, in the Fourier spectrum of the supply voltage of the first motor, in particular which is detected, wherein (III) applies, wherein g i,j (m) is a standardised output voltage of the converter at the particular frequency f ij , wherein the standardised output voltage g i,j (m) is determined from U i,j = U DC • g i,j (m), wherein in a second method step the losses P HL_2 of the second drive are determined according to (IV).