Relay Point-on-Wave Switching With Automatic Coil Timing Control

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Solution Overview

Problem

Existing switching devices face challenges in consistently and efficiently opening and closing electric power connections due to delays and variability in coil inductance, resistance, and temperature, leading to issues like torque oscillations and reduced lifespan of contacts.

Innovation Solution

A control system that uses a processor to determine a switching profile based on datasets related to the load and protection equipment, adjusting the switching profile to control the armature movement with respect to an electrical waveform, and providing a higher voltage than the rated voltage to minimize inductance variability, along with a constant current source to ensure consistent operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a switching device is used to open and close electric power connections, then power control is achieved, but delays and variability in coil inductance and resistance cause inconsistent switching timing

Engineering Contradiction:
Improveswitching timing consistencyVSAvoidcoil parameter variability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by providing a higher voltage than the rated voltage to the coil to minimize the effect of inductance variability. This voltage override technique compensates for variations in coil inductance and resistance, ensuring consistent switching timing despite manufacturing tolerances and temperature changes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The control system uses feedback by monitoring the actual switching timing and adjusting the voltage applied to the coil accordingly. This closed-loop control ensures that switching occurs at the desired point on the waveform despite variations in coil parameters.

Inventive Principle:
Principle #23Feedback

2Object-generated harmful factors

If point-on-wave switching is implemented to reduce torque oscillations, then load operation smoothness is improved, but switching device coordination becomes more difficult

Engineering Contradiction:
Improvetorque oscillationsVSAvoidswitching coordination
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The control system implements feedback control to monitor the switching timing of multiple switching devices and adjust their operation to achieve coordinated point-on-wave switching. This ensures that switching occurs at optimal moments to minimize torque oscillations while maintaining proper coordination between devices.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts switching timing based on real-time conditions, allowing the switching devices to adapt their operation to achieve coordinated point-on-wave switching that minimizes torque oscillations under varying load conditions.

Inventive Principle:
Principle #15Dynamics

3Productivity

If manual configuration of relay settings is used, then device simplicity is maintained, but configuration time and potential for error increase

Engineering Contradiction:
Improveconfiguration speedVSAvoidautomatic configuration system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The control system implements self-service by automatically detecting the characteristics of connected switching devices and configuring relay settings without manual intervention. The system self-identifies device parameters and optimizes switching profiles, eliminating the need for manual configuration while improving accuracy and speed.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The automatic configuration uses feedback from device detection to dynamically adjust relay settings. The control system monitors device characteristics and automatically configures optimal switching profiles, reducing configuration time and eliminating human error.

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 solution enables more consistent and efficient POW switching operations across various coil resistances and temperatures, reducing torque oscillations and extending the lifespan of switching device components.

Implementation Method 1

A control system may be used to control a current provided to a coil of the switching device based on the switching profile

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

providing a higher voltage than the rated voltage to minimize inductance variability

Methodology Applied
Scientific EffectInductance variability compensation: Inductor

Data Source

PatentEP3799091B1Systems and methods for automatically configuring point-on-wave settings in a relay device
Publication Date: 2023.10.25 ROCKWELL AUTOMATION TECH INC
  • EP3799091B1 patent drawingFigure 1~3
  • EP3799091B1 patent drawingFigure 4
  • EP3799091B1 patent drawingFigure 5

AI summary

A control system may include a processor that may receive a first dataset associated with a type of load device coupled to a relay device. The processor may then receive a second dataset associated with one or more operations of the load device over a period of time. The processor may also determine a switching profile to control moving an armature of the relay device between a first position and a second position based on the first dataset and the second dataset, such that the switching profile comprises a firing angle for moving the armature with respect to an electrical waveform. The processor may then control a current provided to a relay coil of the relay device based on the switching profile.