Combined Current Transformer Metering System Integration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing transformer and metering systems for electrical power systems are costly to install and maintain, require extensive training for personnel, and are prone to errors due to the separation of current and voltage transformers from the metering devices, leading to potential damage and inaccuracies in billing.

Innovation Solution

A combined current transformer and metering system (TIMS) that encapsulates secondary coils and leads in a single housing with integral instrumentation, providing prewired switching and testing capabilities, allowing for secure and efficient installation and reducing the need for separate components and personnel training.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If separate current transformers, voltage transformers, test switches and meter sockets are used, then the system can be standardized according to existing infrastructure, but the installation cost, complexity and maintenance requirements increase significantly

Engineering Contradiction:
ImprovestandardizationVSAvoidsystem complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines separate components (current transformer, voltage transformer, test switch, meter socket) into a single integrated housing. The current transformer secondary terminals, voltage transformer terminals, and test switch are all housed together with pre-wired connections, eliminating the need for separate installations and reducing system complexity while maintaining manufacturing standards.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If separate components are used with extensive wiring, then flexibility in component selection is maintained, but installation time and potential for wiring errors increase

Engineering Contradiction:
Improvecomponent selection flexibilityVSAvoidinstallation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system comes pre-wired from the current transformer secondary terminals through the voltage transformer to the meter socket. All connections are established during manufacturing, so installation only requires mounting the integrated unit and connecting primary sides, dramatically reducing installation time and eliminating wiring errors.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the secondary circuit is left open during meter changes, then meter replacement is simple, but voltage builds up in the current transformer causing damage or fire

Engineering Contradiction:
Improvemeter replacement simplicityVSAvoidvoltage buildup damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A test switch is integrated into the housing as an intermediary device. Before removing a meter, the test switch is closed to provide an alternative path for secondary current, preventing voltage buildup. The switch acts as a safety mediator between the metering circuit and the current transformer secondary winding.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If multiple separate components are installed in different locations, then each component can be optimized independently, but the overall system accuracy and coordination decrease

Engineering Contradiction:
Improvecomponent optimizationVSAvoidsystem accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

By housing all critical components (current transformer secondary terminals, voltage transformer terminals, test switch) in a single integrated unit with controlled internal wiring, the system maintains component optimization while ensuring consistent electrical relationships and improved measurement accuracy across the entire system.

Inventive Principle:
Principle #5Merging (Combining)

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

The TIMS reduces installation and maintenance costs, minimizes errors, and enhances security by providing a self-contained, prewired system that can be installed quickly, ensuring accurate metering and reducing the risk of voltage buildup and tampering.

Implementation Method 1

An Instrument Current Transformer is a transformer designed to provide a current in its secondary coil proportional to the current flowing in its primary coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2587500B1Transformer instrumentation and metering system
Publication Date: 2020.01.15 MCGRAIL KENNETH WILLIAM
  • EP2587500B1 patent drawingFigure 1A
  • EP2587500B1 patent drawingFigure 1B
  • EP2587500B1 patent drawingFigure 2

AI summary

A combined current transformer and metering system is described, having a securable case, two or more current transformers each having a core and secondary windings connected to a secondary circuit, wherein the transformers are mounted within the case. A wiring harness connects the secondary windings of the transformers with shorting current switches for short circuiting the secondary current circuit, and voltage switches for disconnecting a voltage, wherein both sets of switches are mounted on the case. A process of manufacturing the system is described, wherein the transformer cores are positioned within the case, the wiring is connected between the transformer cores and attachment hardware on an upper deck of the case, and insulation medium is inserted within the case. A base plate is described, having rails to hold the system and having a tab at one end, and apertures for a rod positionable between rails at a second end.