Air-conditioning control system for railroad vehicle

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Solution Overview

Problem

Existing railroad-vehicle air-conditioning control systems face difficulties in detecting and addressing abnormalities in controllers and temperature sensors, as well as communication issues between controllers and higher-level monitor devices, which can disrupt normal air-conditioning operations.

Innovation Solution

The system employs a redundant configuration with multiple controllers and inverters, allowing each controller to transmit invalidation commands to the inverters, enabling self-correction and continued normal operation even when abnormalities occur in controllers, temperature sensors, or communication with the monitor device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If redundant configuration with multiple controllers is employed, then system reliability is improved, but abnormality detection capability deteriorates because controllers cannot detect abnormalities in themselves or their sensors

Engineering Contradiction:
Improvesystem reliabilityVSAvoidabnormality detection capability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The controller performs self-diagnosis by monitoring its own operation status and sensor readings. When the controller detects an abnormality in itself or in temperature sensors, it automatically invalidates its own commands and switches to standby mode, allowing the standby controller to take over. This self-service mechanism enables the controller to detect and respond to its own abnormalities without external assistance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements feedback mechanisms where the controller continuously monitors its own operation status and sensor data. This internal feedback loop allows the controller to detect abnormalities in real-time, such as when temperature sensor readings become invalid or when the controller itself malfunctions, and automatically trigger the abnormality response protocol.

Inventive Principle:
Principle #23Feedback

2Duration of action of stationary object

If redundant configuration is implemented, then continuity of operation is improved, but device complexity increases due to multiple controllers and inverters

Engineering Contradiction:
Improvecontinuity of operationVSAvoiddevice complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The system merges the functionality of active and standby controllers into a unified control architecture. Both controllers share the same control logic and access the same inverter resources, with the standby controller continuously monitoring the active controller's status. This merging approach ensures seamless failover while avoiding complete duplication of independent control systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The controller roles are dynamic rather than static. The system continuously evaluates the operational status of both controllers and can switch roles automatically when abnormalities are detected. This dynamic role assignment ensures that the system always has a functional controller managing operations, maintaining continuity without requiring complex permanent dual-control configurations.

Inventive Principle:
Principle #15Dynamics

3Loss of time

If automatic abnormality response is implemented, then response time is improved, but control system complexity increases

Engineering Contradiction:
Improveresponse timeVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by pre-configuring the standby controller with identical control logic and parameters before any abnormality occurs. The standby controller is continuously prepared to take over immediately, with all necessary control data and inversioner connection parameters already in place. This preliminary preparation eliminates delays that would occur during abnormality response setup.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The controller automatically executes the abnormality response protocol without external intervention. When an abnormality is detected, the controller itself invalidates its commands, switches to standby mode, and triggers the takeover sequence - all self-service actions that eliminate response delays while using built-in control logic rather than external control systems.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3967567B1Air-conditioning control system for railroad vehicle
Publication Date: 2023.07.12 MITSUBISHI ELECTRIC CORP
  • EP3967567B1 patent drawingFigure 1
  • EP3967567B1 patent drawingFigure 2A~2D
  • EP3967567B1 patent drawingFigure 3~4

AI summary

An air-conditioning control system (1) includes a first inverter (I1) that drives a first driving target (3A) in accordance with commands received via a first communication network (10), a second inverter (12) that drives a second driving target (3B) in accordance with commands received via the first communication network (10), a first controller (C1) that is capable of controlling the first inverter (I1) and the second inverter (12) by transmitting commands via the first communication network (10), and a second controller (C2) that is capable of controlling the first inverter (I1) and the second inverter (12) by transmitting commands via the first communication network (10). Each of the first controller (C1) and the second controller (C2) is capable of transmitting, to the first inverter (I1) and the second inverter (12) via the first communication network (10), an invalidation command for invalidating the commands therefrom.