Rotating Electrical Machine Mode Transition Control

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Solution Overview

Problem

Conventional rotating electric machines with spilled rotor configurations experience decreased availability due to the need to completely flux and re-flux the rotor when switching between operation modes, leading to inefficient transition times.

Innovation Solution

A method for controlling a rotating electric machine with a stator and wound rotor, where the excitation current evolves from a first setpoint to a second setpoint via a strictly positive minimum intermediate setpoint, avoiding complete fluxing, allowing the machine to maintain direct current delivery in generator mode without interruption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the rotor is completely fluxed and re-fluxed when switching between operation modes, then the machine can operate in different modes (motor and generator), but the availability time of the electric machine decreases due to transition delays

Engineering Contradiction:
Improveoperation mode switching capabilityVSAvoidtransition time between modes
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The invention applies preliminary action by maintaining a minimum intermediate excitation current above zero during mode transitions, so the rotor flux is not completely collapsed. This preliminary preservation of flux reduces the time needed to re-establish flux when switching modes, thereby decreasing transition time while maintaining adaptability between motor and generator operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the excitation current parameter from a conventional binary state (zero or high) to a continuous range including a minimum intermediate value. By adjusting the excitation current to evolve from a first setpoint to a second setpoint through a strictly positive minimum intermediate setpoint, the system optimizes transition characteristics and reduces time loss during mode switching

Inventive Principle:
Principle #35Parameter changes

2Speed

If the excitation current is completely switched off during mode transition, then the rotor can be re-fluxed for the new mode, but the response time of the machine decreases

Engineering Contradiction:
Improveresponse timeVSAvoiddirect current delivery continuity
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The invention ensures continuity of useful action by maintaining a strictly positive minimum intermediate excitation current during transitions, preventing complete flux collapse. This continuous presence of excitation current allows the machine to maintain direct current delivery capability throughout the transition, improving response time while preserving reliability of DC output

Inventive Principle:
Principle #20Continuity of useful action

3Loss of time

If the excitation current evolves through a strictly positive minimum intermediate setpoint, then the transition time is reduced and response time is improved, but the control complexity increases

Engineering Contradiction:
Improvemode transition timeVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The invention applies dynamics by making the excitation current evolution dynamic rather than static or binary. The control system dynamically adjusts the excitation current through a defined trajectory from first setpoint to second setpoint via a minimum intermediate setpoint, optimizing transition speed while managing control complexity through a systematic approach

Inventive Principle:
Principle #15Dynamics

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 improves response time and reduces torque generation inefficiencies by defining an intermediate setpoint based on output voltage and rotor speed, enabling faster mode transitions without complete rotor fluxing.

Implementation Method 1

a rotating electric machine with a stator and a wound rotor, the winding rotor being intended to be traversed by an excitement current

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The generator mode can be used in a recovered braking function allowing the electrical machine to provide electrical energy into the battery during a braking phase

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The motor mode can in particular be used in a stop function and automatic restart of the thermal engine according to the circulation conditions

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3747121B1Method for optimising the passage from one operating mode to another for a rotating electrical machine
Publication Date: 2022.02.23 VALEO EQUIP ELECTRIC MOTEUR
  • EP3747121B1 patent drawingFigure 1~2
  • EP3747121B1 patent drawingFigure 3a~3b
  • EP3747121B1 patent drawing

AI summary

The invention mainly relates to a method for controlling a rotating electrical machine (10) for a motor vehicle, comprising a stator (18) and a wound rotor (19), the wound rotor (19) being intended to be traversed by an excitation current, said rotating electrical machine (10) being capable of operating in an alternator mode and in a motor mode, characterised in that when the rotating electrical machine (10) passes from one operating mode to another, said method comprises a step of controlling the rotor (19) so that the excitation current changes from a first setpoint value to a second setpoint value passing through a strictly positive minimum intermediate setpoint value, said intermediate setpoint value corresponding to a minimum excitation current above which the rotating electrical machine (10) delivers a DC current in generator mode and at which and below which the rotating electric machine does not deliver a DC current.