Speed Regulator for Rotary Electrical Machine Gear Synchronization

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Solution Overview

Problem

Existing speed control systems for rotating electrical machines, particularly in high-power motor vehicle applications, tend to overshoot setpoints due to derivative action in the closed-loop transfer function, leading to instability during gear synchronization.

Innovation Solution

A speed regulator configuration featuring a pure integrator and gain-based feedback loop, ensuring the closed-loop transfer function lacks zeros in the numerator and behaves as a second-order filter with damping equal to 1, preventing overshoot while maintaining fast dynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a PI regulator is used for speed control, then the system can maintain speed, but the closed-loop transfer function contains a zero in the numerator which causes overshoot of the setpoint

Engineering Contradiction:
Improvespeed control stabilityVSAvoidspeed setpoint accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the regulator structure from a standard PI regulator to a modified configuration where the proportional and integral actions are applied to different error signals. Specifically, the proportional gain K is applied to the speed error (ω* - ω) while the integral gain Ki is applied to the torque error (Te* - Te), fundamentally altering the closed-loop transfer function characteristics to eliminate numerator zeros and prevent overshoot

Inventive Principle:
Principle #35Parameter changes

2Speed

If the proportional gain K is increased to improve response speed, then the system reaches setpoint faster, but the overshoot becomes more severe

Engineering Contradiction:
Improveresponse speedVSAvoidsetpoint accuracy
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The patent segments the control actions by applying proportional control to speed error and integral control to torque error separately, rather than combining both gains on a single error signal. This segmentation allows independent optimization of response speed and overshoot prevention, as the proportional term provides fast response while the integral term ensures steady-state accuracy without causing overshoot

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3360709B1Corrector of a speed control system of a rotary electrical machine
Publication Date: 2020.05.27 VALEO EQUIP ELECTRIC MOTEUR
  • EP3360709B1 patent drawingFigure 1~2
  • EP3360709B1 patent drawingFigure 3~4
  • EP3360709B1 patent drawingFigure 5

AI summary

The invention relates mainly to a rotating electrical machine (7) intended to cooperate with a motor vehicle gearbox (1) comprising a plurality of speed ratios (R1-Rn), characterized in that it comprises: - a speed regulator capable of being activated during a synchronization phase between gears of two speed ratios (R1-Rn) during which said rotating electrical machine (7) is driven in speed, - said speed regulator comprising a cascaded integrator with a gain.