Electronic Circuit Breaker Dual-Microcomputer Tripping Control

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Solution Overview

Problem

Existing electronic circuit breakers with a single microcomputer control unit face increased processing time and memory usage due to varied overcurrent time-limit characteristics and display control functions, leading to insufficient power supply when currents are low, and potential erroneous tripping signals during power instability.

Innovation Solution

The implementation of a dual-microcomputer system where one microcomputer handles A/D conversion and calculation, and the other manages time-limit characteristics, sharing processing loads and reducing memory usage, with a tripping device driven by instantaneous and time-limit signals to open the switching contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single microcomputer control unit is used, then device complexity is reduced, but processing time increases and memory usage increases

Engineering Contradiction:
Improvecontrol unit structureVSAvoidprocessing time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The single microcomputer control unit is segmented into two separate microcomputers: a first microcomputer handling A/D conversion and calculation, and a second microcomputer handling time-limit characteristics and display control. This division reduces the processing burden on each unit, thereby reducing overall processing time while maintaining structural complexity at an acceptable level.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single microcomputer control unit is used, then device complexity is reduced, but memory usage increases

Engineering Contradiction:
Improvecontrol unit structureVSAvoidmemory usage
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The memory requirements are segmented between two microcomputers, each with its own memory space. The first microcomputer stores A/D conversion results and calculation data, while the second microcomputer stores time-limit characteristics and display control data. This distribution reduces the peak memory usage requirement compared to a single microcomputer that must store all data simultaneously.

Inventive Principle:
Principle #1Segmentation

3Loss of time

If processing load is increased to reduce processing time, then processing time is reduced, but power consumption increases leading to insufficient power supply when currents are low

Engineering Contradiction:
Improveprocessing timeVSAvoidpower consumption
Core Design Contradiction:
Loss of timeVSUse of energy by moving object

Solution Approach 1:

The processing load is segmented between two microcomputers, each executing only the functions required for its specific task. This reduces the overall computational burden compared to a single microcomputer performing all functions, thereby reducing power consumption while maintaining reduced processing time. The distributed architecture allows for more efficient power management.

Inventive Principle:
Principle #1Segmentation

4Productivity

If power supply is increased to support higher processing loads, then processing capability is improved, but operational reliability decreases due to potential erroneous tripping signals during power instability

Engineering Contradiction:
Improveprocessing capabilityVSAvoidoperational reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control functions are segmented into two independent microcomputers with separate processing paths. This segmentation creates redundancy and independence in critical functions, so that power fluctuations affecting one microcomputer do not necessarily cause erroneous tripping signals. The distributed architecture improves operational reliability by isolating potential failure points.

Inventive Principle:
Principle #1Segmentation

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 configuration reduces processing time and memory usage, prevents erroneous tripping, and ensures stable operation by sharing A/D conversion and calculation units between microcomputers, while maintaining efficient power management and operational reliability.

Implementation Method 1

Reference signs 21, 22, and 23 are current transformers that detect load currents flowing in the electric paths 111, 112, and 113

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3591779B1Electronic circuit breaker
Publication Date: 2023.08.30 MITSUBISHI ELECTRIC CORP
  • EP3591779B1 patent drawingFigure 1
  • EP3591779B1 patent drawingFigure 2
  • EP3591779B1 patent drawingFigure 3

AI summary

The present invention includes a first microcomputer (50a) to which an output signal of a current detecting device that detects a current in an electric path is inputted, and a second microcomputer (50b) that acquires information on current flowing through the electric path from the first microcomputer. The first microcomputer (50a) outputs an instantaneous tripping signal, and the second microcomputer (50b) outputs a time-limit tripping signal. The reset outputs of reset circuits (14a, 14b) are connected to reset terminals of the respective microcomputers (50a, 50b) and input terminals of an undervoltage operation prohibiting circuit.