Pulsed DC Injection Rotor Lock for Regenerative Braking

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Solution Overview

Problem

Conventional regenerative braking systems experience high current transients and power dissipation, leading to overheating, and struggle with achieving precise motor stopping positions due to nonlinear stopping behavior and the need for a constant DC power supply.

Innovation Solution

A regenerative electrical braking system incorporating a feedback loop to monitor electromagnetic field energy, utilizing pulsed DC injection rotor locking and dynamic braking techniques, which stores dissipated energy in charge storage elements and eliminates the need for a constant power supply by using kinetic energy to charge storage elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional regenerative braking systems are used, then braking function is achieved, but high current transients and power dissipation occur leading to overheating

Engineering Contradiction:
ImproveoverheatingVSAvoidpower dissipation
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The patent applies periodic pulsed DC injection to the motor windings instead of continuous braking. The controller delivers pulsed DC current at specific intervals during the braking cycle, creating periodic electromagnetic fields that maintain braking force while reducing overall power dissipation and heat generation compared to conventional continuous regenerative braking.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes the electrical parameters by injecting DC current into the motor windings during braking, altering the electromagnetic field characteristics. This parameter change enables the system to achieve braking while reducing current transients and power dissipation, thereby preventing overheating without sacrificing braking effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If conventional regenerative braking systems are used, then braking is achieved, but precise motor stopping position cannot be achieved due to nonlinear stopping behavior

Engineering Contradiction:
Improvemotor stopping positionVSAvoidstopping behavior
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback mechanism where the controller monitors motor speed and braking conditions in real-time, then adjusts the pulsed DC injection timing and duration accordingly. This feedback control enables precise adjustment of the braking process, allowing the motor to stop at accurate positions despite nonlinear stopping behavior.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic braking control by adjusting the pulsed DC injection parameters based on real-time motor speed and load conditions. The controller dynamically modifies the braking torque profile throughout the stopping process, enabling precise position control and improving stopping behavior stability.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If conventional DC injection brakes are used, then braking is achieved, but a constant DC power supply is required

Engineering Contradiction:
Improvepower supply requirementVSAvoidpower supply system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent enables the motor itself to serve as the power source for DC injection during braking. The controller rectifies and stores the motor's generated electrical energy during deceleration, then uses this stored energy to power the pulsed DC injection braking process, eliminating the need for an external constant DC power supply.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent recovers the electrical energy generated by the motor during braking instead of dissipating it as heat. The controller captures this regenerative energy, stores it in capacitors, and reuses it to power the pulsed DC injection braking, thereby eliminating the need for external power supply infrastructure.

Inventive Principle:
Principle #34Discarding and recovering

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 solution reduces the size of the braking resistor, improves nonlinear stopping characteristics, and enables precise motor control, enhancing energy efficiency and compliance while preventing overheating.

Implementation Method 1

a feedback loop to monitor electromagnetic field (EMF) energy generated by the motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

pulsed DC injection rotor locking

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP3832878B1Sequential electrical braking with pulsed DC injection rotor lock mechanism
Publication Date: 2023.04.19 HAMILTON SUNDSTRAND CORP
  • EP3832878B1 patent drawingFigure 1
  • EP3832878B1 patent drawingFigure 2
  • EP3832878B1 patent drawingFigure 3

AI summary

A regenerative braking system includes a motor (102) configured to rotate at a variable rotational speed in response to receiving power from a three-phase power supply, and a regenerative braking circuit (200) in signal communication with the three-phase power supply to control the rotational speed of the motor. A brake controller (206) is in signal communication with the regenerative braking circuit and is configured to selectively operate the regenerative braking circuit in a plurality of different braking modes based on the rotational speed of the motor.