Electric Motor Parameter Detection via Test Pulse

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Solution Overview

Problem

There is a need for an automated method to determine electric motor parameters reliably and efficiently, especially for energy-efficient motors, to prevent user errors that can lead to motor damage, without requiring complex hardware or sensors.

Innovation Solution

The method involves automatically determining motor inductance and resistance using a test pulse generated by switching semiconductor switches in stator windings, with phases defined for precise parameter detection, and utilizing existing measuring devices to record motor voltage and current gradient, allowing for parameter determination without special sensors or complex frequency converters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If automated parameter determination is implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveparameter determination reliabilityVSAvoidhardware complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The motor parameters are determined automatically by the control unit using existing measuring devices and semiconductor switches. The system performs self-diagnosis by utilizing its own components (semiconductor switches, measuring devices) to detect parameters like inductance and resistance without requiring external specialized equipment or sensors.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Existing components in the motor control system are made multi-functional. The semiconductor switches not only control motor operation but also serve to generate test pulses for parameter determination. The measuring devices not only monitor normal operation but also detect parameters during the detection phase, eliminating the need for separate specialized equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If sensorless parameter determination is used, then device complexity is reduced, but measurement precision may be affected

Engineering Contradiction:
Improvesensor requirementVSAvoidparameter detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

Physical sensors are replaced by an electrical measurement method. Instead of using mechanical or physical sensors to detect motor parameters, the system uses electrical test pulses and measures the resulting current and voltage responses through existing measuring devices, achieving parameter detection without additional sensing hardware.

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

Solution Approach 2:

Test pulses serve as intermediaries to indirectly determine motor parameters. Rather than directly measuring parameters like inductance and resistance, the system applies test pulses through semiconductor switches and measures the electrical responses (current, voltage, power) to calculate these parameters mathematically, achieving precise detection without direct physical contact or specialized sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If manual parameterization is used, then device complexity is reduced, but user errors can occur leading to motor damage

Engineering Contradiction:
Improveautomation levelVSAvoidoperation safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system implements automatic feedback by continuously determining motor parameters and using this information for safe operation control. The control unit receives feedback from the measuring devices about actual motor conditions and adjusts operation accordingly, preventing user errors and ensuring reliable motor protection without requiring manual parameter input.

Inventive Principle:
Principle #23Feedback

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 enables precise and reliable automatic parameter determination of electric motors, ensuring safe operation by detecting heating and demagnetization issues without sensors, and can be implemented on simple hardware, reducing the risk of motor damage and improving operational safety.

Implementation Method 1

a test pulse is output in at least one stator winding of the electric motor along the alignment direction of the rotor. The test pulse is generated, for example, by switching at least two semiconductor switches once

Methodology Applied
Scientific EffectElectrical Induction: Electromagnetic Induction

Implementation Method 2

utilizing existing measuring devices to record motor voltage and current gradient, allowing for parameter determination without special sensors or complex frequency converters

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 3

a motor inductance of the electric motor is determined in the start phase and/or the end phase

Methodology Applied
Scientific EffectElectrical Induction: Electromagnetic Induction

Data Source

PatentEP3602772B1Method of operation for an electric motor, and soft starter
Publication Date: 2022.03.09 SIEMENS AG
  • EP3602772B1 patent drawingFigure 1
  • EP3602772B1 patent drawingFigure 2
  • EP3602772B1 patent drawingFigure 3

AI summary

The invention relates to a method (100) for operating an electric motor (10), in particular a permanently excited synchronous motor, comprising the steps of: a) establishing an orientation (25) of the rotor (14) in relation to the stator (12) of the electric motor (10) in which the magnetic north poles (22) and magnetic south poles (24) of said rotor and stator are opposite one another; b) generating a test pulse (30) in a stator winding (15) of the electric motor (10) along the orientation (25) of the rotor (14) in relation to the stator (12); c) ascertaining a motor inductance (37) in a starting phase (42) and/or end phase (51) of a detection window (40), and/or d) ascertaining a motor resistance (31) in an amplitude phase (44) situated between the starting phase (42) and the end phase (51); wherein a motor voltage (34) is at a maximum (36) in the starting phase (42) and/or in the end phase (51).