Electric Machine Type Detection Using Resonance Waveforms

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Solution Overview

Problem

Existing Electric Motor Drives (EMDs) in Motor Drive Systems (MDS) face challenges in determining which type of electric machine they are paired with, as they lack logic circuits or pre-programmed software to identify the correct EM, leading to potential misconfiguration and inefficiencies.

Innovation Solution

A method and system that utilizes a series resonance circuit formed by a capacitor and windings in a three-phase electric machine to monitor resonance characteristics, such as frequency and voltage, to determine the type of electric machine, enabling accurate configuration of control software and detection of inter-phase and inter-turn faults.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the EMD uses a universal hardware design to control multiple EM types, then the adaptability and versatility are improved, but the ability to automatically identify the paired EM type deteriorates

Engineering Contradiction:
ImproveEMD compatibility with multiple EM typesVSAvoidEM type identification information
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The EMD performs self-identification of the paired EM type by autonomously generating resonance signals and analyzing the resulting waveforms. The system uses its own capacitor and inverter circuitry to create excitation signals that elicit characteristic responses from different EM types, enabling the EMD to automatically determine which EM is connected without external intervention or additional sensors.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent applies electrical resonance (analogous to mechanical vibration) by generating sinusoidal excitation signals at varying frequencies and observing the EM's response. Different EM types exhibit distinct resonance characteristics and waveform patterns when subjected to these excitation signals, allowing the EMD to identify the EM type through frequency-domain analysis of the electrical responses.

Inventive Principle:
Principle #18Mechanical vibration

2Device complexity

If the EMD lacks logic circuits or pre-programmed software for EM identification, then the device complexity is reduced, but the measurement precision of EM type detection deteriorates

Engineering Contradiction:
ImproveEMD circuit and software complexityVSAvoidEM type detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces complex logic circuits and pre-programmed identification software with a signal-based approach using the existing inverter and capacitor. Instead of using additional hardware components for identification, the system leverages the natural electrical characteristics and resonance behavior of the EM to generate identifiable response patterns, thereby maintaining low device complexity while achieving accurate EM type detection.

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

3Reliability

If the EMD must be manually configured with specific control software for each EM type, then the ease of operation is reduced, but the reliability of EM-EMD pairing is improved

Engineering Contradiction:
ImproveEM-EMD pairing accuracyVSAvoidEMD configuration process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary EM type identification automatically during the startup or configuration phase by analyzing resonance responses before operational parameters are set. This preliminary detection enables the EMD to pre-configure appropriate control parameters and software settings based on the identified EM type, eliminating the need for manual configuration and ensuring correct pairing from the outset.

Inventive Principle:
Principle #10Preliminary action

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

Facilitates easy and secure identification of the paired electric machine type, allowing for precise control software configuration and fault detection, thereby improving operational efficiency and reducing errors in heavy-duty vehicles.

Implementation Method 1

connecting any two phases of a three-phase electric machine to the EMD such that a series resonance circuit is formed by the capacitor and windings comprised in the three-phase electric machine; monitoring the resonance waveform of the resonance circuit across the terminals of the capacitor

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4708669A1Method and system for determining electric machine type
Publication Date: 2026.03.11 VOLVO PENTA AB
  • EP4708669A1 patent drawingFigure 1~2
  • EP4708669A1 patent drawingFigure 3
  • EP4708669A1 patent drawingFigure 4

AI summary

A method and system for determining a type of electric machine (420) comprised in a propulsion system (400) of a vehicle (700) are provided. An EMD (410) is firstly connected to a voltage source (430) until a capacitor (C1) is charged to a desired voltage level, secondly the EMD (410) is disconnected from the voltage source (430), then any two phases of a three-phase electric machine (420) are connected to the EMD (410) such that a series resonance circuit is formed by the capacitor (C1) and windings comprised in the three-phase electric machine (420). The resonance waveform of the resonance circuit across the terminals of the capacitor (C1) is monitor and the type of the electric machine (420) is determined based on the resonance characteristics of the resonance circuit.