Trackside Variable Frequency Power Modules for Shuttle Trains

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional electrified railways for energy storage require costly onboard power conversion equipment and suffer from significant electrical losses due to the need for rectification and inversion of current, which is inefficient and expensive, especially when interconnecting with the utility grid.

Innovation Solution

The system replaces onboard power conversion equipment with trackside power conversion modules that create variable frequency track segments, allowing trains to operate in direct synchronization with the grid frequency, reducing the need for onboard rectifier/inverter units and minimizing energy losses by using dual 3-level active rectifier/inverter units controlled by an automation system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If onboard power conversion equipment is used in conventional electrified railways, then speed control and power conversion are achieved, but the cost of locomotives increases significantly and electrical losses are significant

Engineering Contradiction:
Improvespeed controlVSAvoidonboard power conversion equipment
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the power conversion function from the locomotive and relocates it to trackside power supply modules. The variable frequency power supply modules are installed at trackside locations, eliminating the need for expensive onboard rectifier/inverter sets in each locomotive. This extraction reduces locomotive cost and complexity while maintaining speed control capability through centralized trackside power conversion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces trackside variable frequency power supply modules as intermediaries between the utility grid and the locomotives. These modules act as mediators that convert utility frequency power to variable frequency power needed for motor control, eliminating the need for onboard power conversion equipment. The intermediary modules centralize the power conversion function and reduce overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If rectifier/inverter units are installed onboard each locomotive for grid interconnection certification, then grid compatibility is achieved, but the equipment cost becomes far more expensive

Engineering Contradiction:
Improvegrid interconnection certificationVSAvoidonboard power conversion equipment
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the grid interconnection certification requirement from the locomotive level and relocates it to the trackside power supply module level. The trackside modules are designed to meet grid interconnection standards, while locomotives receive standardized variable frequency power. This extraction eliminates the need for expensive certified equipment in each locomotive while maintaining grid compatibility through centralized control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The trackside variable frequency power supply modules serve multiple functions: they provide grid interconnection certification, perform power conversion, and control multiple locomotives simultaneously. By consolidating these functions at the trackside level, the system achieves grid compatibility without requiring expensive certified equipment in each locomotive, reducing overall system cost while maintaining reliability.

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

3Ease of operation

If onboard power conversion equipment is used, then power frequency control is achieved, but electrical losses due to rectification and inversion are significant

Engineering Contradiction:
Improvepower frequency controlVSAvoidelectrical losses
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts the power conversion function from distributed onboard units to centralized trackside modules. This consolidation enables more efficient power conversion with reduced electrical losses, as the trackside modules can optimize the rectification and inversion processes centrally rather than having multiple smaller conversion units in each locomotive. The extracted function maintains power frequency control while reducing energy waste.

Inventive Principle:
Principle #2Taking out (Extraction)

4Power

If multiple onboard rectifier/inverter units are deployed, then power conversion capability is sufficient, but the number and capacity of devices required is significantly reduced with trackside modules

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidnumber of power conversion devices
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent merges multiple distributed onboard power conversion units into centralized trackside power supply modules. Instead of having separate rectifier/inverter sets in each locomotive, the system combines these functions into fewer trackside units that serve multiple locomotives. This merging maintains sufficient power conversion capability while significantly reducing the total number of devices required in the system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The trackside variable frequency power supply modules are designed to serve multiple locomotives simultaneously, providing universal power conversion service. Each module can control the frequency and voltage for multiple trains, eliminating the need for dedicated power conversion equipment in each locomotive. This multi-functional approach maintains adequate power conversion capability while reducing device count and system complexity.

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

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 significantly reduces the number and capacity of power conversion devices, achieves energy savings, simplifies maintenance, and stabilizes grid frequency by utilizing the heavy inertia of shuttle trains, thereby enhancing the efficiency and cost-effectiveness of the energy storage system.

Implementation Method 1

a synchronous generator 31b coupled to the drive motor of the shuttle train

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an asynchronous generator 31c coupled to the drive motor of the shuttle train

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The frequency of the electrical power supplied by the asynchronous power supply module is synchronized to the frequency of the electrical power supplied by the synchronous power supply module

Methodology Applied
Scientific EffectFrequency synchronization:

Implementation Method 4

stabilizes grid frequency by utilizing the heavy inertia of shuttle trains

Methodology Applied
Scientific EffectInertia: Inertia

Data Source

PatentEP2699447B1Combined synchronous and asynchronous power supply for electrically powered shuttle trains
Publication Date: 2019.06.05 ADVANCED RAIL ENERGY STORAGE LLC
  • EP2699447B1 patent drawingFigure 1
  • EP2699447B1 patent drawingFigure 2
  • EP2699447B1 patent drawingFigure 3

AI summary

A power supply and control system for electrically powered shuttle-trains incorporates at least one shuttle train (12) having a motor (31b) and a generator (31a). A first plurality of track segments ( 6,8) has associated synchronous power modules (110) exchanging power synchronously with a power grid through a plurality of power supply rail segments (112) connectable to the motor or generator. A second plurality of track segments (214) has associated variable frequency power modules (109) exchanging power through a second plurality of power supply rail segments (114, 116) connectable to the motor or generator, isolation segments (113a, 113b, 113c, 113d) separate adjacent power supply rail segments. A control system (120) interconnected to the variable frequency power modules controls the frequency of each variable frequency power module based on the location of the shuttle train.