Multi-System Power Converter Pre-Charging Circuit

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Solution Overview

Problem

Conventional multi-system power converter arrangements for rail vehicles require significant installation space and maintenance due to separate pre-charging circuits for AC and DC networks, necessitating the removal of the entire converter to replace pre-charging resistors.

Innovation Solution

A multi-system power converter arrangement that uses a single pre-charging circuit with a switching group to couple a shared pre-charging resistor to both AC and DC networks, eliminating the need for separate resistors and reducing maintenance costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate pre-charging circuits with separate pre-charging resistors are provided for AC and DC networks, then the intermediate circuit can be precharged from both networks, but the installation work and space required increase significantly

Engineering Contradiction:
Improvepre-charging capabilityVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The pre-charging circuit is designed to serve dual purposes: it can pre-charge the intermediate circuit from both AC and DC networks using a single pre-charging resistor. The switching group enables the circuit to be coupled to either network type, making the pre-charging infrastructure universal rather than requiring separate dedicated circuits for each network type.

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

Solution Approach 2:

Separate pre-charging circuits for AC and DC networks are merged into a single unified pre-charging circuit. The switching group acts as a coupling mechanism that allows one pre-charging resistor to be connected to either the AC network or the DC network, combining what were previously two distinct functions into one shared resource.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If separate pre-charging circuits with separate pre-charging resistors are provided for AC and DC networks, then the intermediate circuit can be precharged from both networks, but the maintenance and repair work required increase significantly

Engineering Contradiction:
Improvepre-charging capabilityVSAvoidmaintenance effort
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The pre-charging circuit is designed to serve dual purposes: it can pre-charge the intermediate circuit from both AC and DC networks using a single pre-charging resistor. The switching group enables the circuit to be coupled to either network type, making the pre-charging infrastructure universal rather than requiring separate dedicated circuits for each network type.

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

Solution Approach 2:

Separate pre-charging circuits for AC and DC networks are merged into a single unified pre-charging circuit. The switching group acts as a coupling mechanism that allows one pre-charging resistor to be connected to either the AC network or the DC network, combining what were previously two distinct functions into one shared resource.

Inventive Principle:
Principle #5Merging (Combining)

3Area of stationary object

If a single pre-charging resistor is shared between AC and DC networks, then production costs and space requirements are reduced, but the switching group must be used to couple the resistor to the appropriate network

Engineering Contradiction:
Improveinstallation spaceVSAvoidswitching group configuration
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The pre-charging circuit is designed to serve dual purposes: it can pre-charge the intermediate circuit from both AC and DC networks using a single pre-charging resistor. The switching group enables the circuit to be coupled to either network type, making the pre-charging infrastructure universal rather than requiring separate dedicated circuits for each network type.

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

Solution Approach 2:

The switching group acts as an intermediary element that mediates between the single pre-charging resistor and the two different network types (AC and DC). It provides the necessary coupling mechanism that allows one resistor to interface with both network types without requiring direct permanent connections to both.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of repair

If a single pre-charging resistor is shared between AC and DC networks, then production costs and maintenance efforts are reduced, but the switching group must be used to couple the resistor to the appropriate network

Engineering Contradiction:
Improvemaintenance effortVSAvoidswitching group configuration
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The pre-charging circuit is designed to serve dual purposes: it can pre-charge the intermediate circuit from both AC and DC networks using a single pre-charging resistor. The switching group enables the circuit to be coupled to either network type, making the pre-charging infrastructure universal rather than requiring separate dedicated circuits for each network type.

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

Solution Approach 2:

The switching group acts as an intermediary element that mediates between the single pre-charging resistor and the two different network types (AC and DC). It provides the necessary coupling mechanism that allows one resistor to interface with both network types without requiring direct permanent connections to both.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design reduces production costs, space requirements, and maintenance efforts by allowing a single pre-charging resistor to be used for both AC and DC operations, improving the reliability of the converter arrangement.

Implementation Method 1

an ohmic pre-charging resistor is provided to limit the current during pre-charging

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3019366B1Precharge circuit for a multi-system power converter arrangement
Publication Date: 2019.01.02 SIEMENS MOBILITY GMBH
  • EP3019366B1 patent drawingFigure 1
  • EP3019366B1 patent drawingFigure 2

AI summary

The invention relates to a multi-system power converter arrangement (1) for supplying a rail vehicle electrical drive motor (17, 18) from either an alternating current network (2) or from a direct current network (3). Said multi-system power converter arrangement (1) comprises a direct current intermediate circuit (4) that connects a network-side power converter (13, 15) to a load-side power converter (14, 16), as well as a pre-charge switching circuit (53), which comprises at least one pre-charge resistor (45, 47), for pre-charging said direct current intermediate circuit (4). Using a switching assembly, said pre-charge resistor (45, 47) can be optionally coupled to the alternating current network (2) or to the direct current network (3) for the purpose of pre-charging said direct current intermediate circuit (4).