Traction Converter Power Mode Detection for Safe AC/DC Switching

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Solution Overview

Problem

Existing rail vehicle traction systems face safety risks due to manual operation errors in switching between AC and DC power supply modes, leading to potential circuit burns and operational hazards.

Innovation Solution

An apparatus and method for automatically detecting power supply modes and controlling traction converter operation modes using a voltage detection circuit and transmission control unit, which includes transformers, voltage sensors, and a digital signal processing module to determine and adjust the traction converter's operation based on grid voltage signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual operation is used to switch between AC and DC power supply modes, then the driver can control the operation mode, but manual operation errors may occur causing circuit damage and safety risks

Engineering Contradiction:
Improvemanual control capabilityVSAvoidoperation safety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs automatic self-detection of power supply mode and self-control of operation mode switching. The detection circuit automatically identifies AC or DC power supply mode, and the control unit automatically adjusts the traction converter operation mode without requiring manual driver intervention, thereby eliminating manual operation errors while maintaining operational simplicity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical operation system with an automatic electrical detection and control system. The voltage detection circuit and control unit substitute for the driver's manual decision-making and switching actions, using electrical signals to automatically determine power supply mode and control circuit breakers accordingly

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If automatic detection and control system is implemented, then operation safety is improved and manual errors are eliminated, but device complexity increases due to additional detection circuits and control units

Engineering Contradiction:
Improveoperation safetyVSAvoidcontrol system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit performs multiple functions: it controls circuit breaker switching, detects power supply mode, determines operation mode, and manages traction converter control. By consolidating these functions into a single multi-functional control unit, the system achieves high reliability without proportionally increasing overall system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The voltage detection circuit serves as an intermediary component that bridges the power supply system and the control unit. It automatically extracts power supply mode information from the electrical signals and transmits it to the control unit, simplifying the control logic while enhancing safety through automatic detection

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If the traction converter operates in incorrect mode mismatching the power supply mode, then the system can continue running, but circuit burnup and operational hazards occur

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidcircuit damage risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system takes preliminary protective action by detecting the power supply mode before the traction converter operates. The control unit pre-configures the appropriate operation mode and closes the corresponding circuit breaker based on detected AC or DC power supply mode, preventing incorrect mode operation and potential circuit damage before they can occur

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system implements continuous feedback control where the voltage detection circuit constantly monitors the power supply mode, and the control unit continuously adjusts the traction converter operation mode based on this feedback. This closed-loop control ensures the operation mode always matches the power supply mode, preventing circuit damage while maintaining continuous operation

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 enhances rail vehicle safety by eliminating manual operation errors, ensuring the traction converter operates in the correct mode, thereby preventing circuit damage and ensuring safe operation.

Implementation Method 1

the first voltage detection circuit includes a transformer, and the first voltage detection circuit is configured to perform step-down processing on the grid voltage through the transformer

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the second voltage detection circuit includes a voltage sensor, and the second voltage detection circuit is configured to collect the grid voltage through the voltage sensor

Methodology Applied
Scientific EffectElectrostatic sensing: Electric Field

Implementation Method 3

The filter capacitor is connected in parallel with the current-limiting resistor

Methodology Applied
Scientific EffectCapacitance filtering: Capacitance

Data Source

PatentEP4167412B1Control device and method for traction converter
Publication Date: 2026.01.28 ZHUZHOU CSR TIMES ELECTRIC CO LTD
  • EP4167412B1 patent drawingFigure 1
  • EP4167412B1 patent drawingFigure 2
  • EP4167412B1 patent drawingFigure 3

AI summary

A control device and a control method for a traction converter. The control device comprises a voltage measurement circuit and a transmission control unit. The voltage measurement circuit is used for measuring a power grid voltage and outputting a voltage signal. The transmission control unit is used for determining a power supply mode of a line according to the voltage signal, obtaining, by means of calculation, the power grid voltage according to the voltage signal, and controlling an operation mode of a main circuit of the traction converter according to the power supply mode and the power grid voltage. The control device can automatically detect a power supply mode and control an operation mode of a main circuit of a traction converter, thereby avoiding the risk of human misoperation, and improving the running safety of a rail vehicle.