Magnetic Latching Relays for Automatic Transfer Switches

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Automatic transfer switches (ATS) face challenges with size, cost, and safety due to the need for strong springs and large electromechanical solenoids to manage high fault currents, which can lead to destructive arcing and increased costs.

Innovation Solution

The use of multiple magnetic latching relays with a safety board and control board to manage power switching between two sources, preventing back-feeding by ensuring safe transitions and minimizing arc length through controlled contact opening and closing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If strong springs and large electromechanical solenoids are used to maintain contact closure pressure during large fault currents, then the reliability and safety of the switch is improved, but the size and cost of the device increases

Engineering Contradiction:

Improvecontact closure pressure maintenanceVSAvoidswitch size

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces the traditional mechanical spring-based contact pressure maintenance system with a magnetic field-based latching mechanism. Magnetic latching relays use electromagnetic fields to hold contacts closed without requiring continuous mechanical force, eliminating the need for strong springs and large solenoids while maintaining contact closure pressure during fault currents.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the heavy mechanical components (strong springs and large electromechanical solenoids) from the switch mechanism. By using magnetic latching relays, the design eliminates these bulky components while achieving the same functional outcome of maintaining contact pressure during high-current conditions.

Inventive Principle:

Principle #2Taking out (Extraction)

2Object-affected harmful factors

If contacts are physically separated sufficiently to prevent arcing between power sources, then safety is improved, but the arc length increases requiring larger forces for rapid contact opening

Engineering Contradiction:

Improvearcing preventionVSAvoidcontact opening force

Core Design Contradiction:

Object-affected harmful factorsVSForce

Solution Approach 1:

The patent replaces the mechanical force-based contact opening system with a magnetic field-based control system. Magnetic latching relays use electromagnetic fields to open contacts in a controlled manner, reducing the need for large mechanical forces while maintaining safe arc lengths between contacts of different power sources.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Weight of stationary object

If magnetic latching relays are used instead of traditional multi-pole bi-stable switches, then the size and cost of the ATS system is reduced, but the capability to handle large fault currents must be maintained

Engineering Contradiction:

Improveswitch sizeVSAvoidfault current handling capability

Core Design Contradiction:

Weight of stationary objectVSReliability

Solution Approach 1:

The patent replaces traditional multi-pole bi-stable switches with magnetic latching relays, which are smaller and less expensive. The magnetic field-based actuation mechanism of these relays provides sufficient force to maintain contact closure during large fault currents without requiring the bulky mechanical components of traditional switches.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 reduces the size and cost of ATS systems while ensuring safety by using magnetic latching relays and a safety board to prevent back-feeding and destructive arcing, providing a more efficient and cost-effective power transfer mechanism.

Implementation Method 1

The ATS described herein utilizes multiple magnetic latching relays

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

Minimizing this arc length requires rapid contact opening which again implies large forces required for movement

Methodology Applied

Scientific EffectElectric arc: Electric Arc

Data Source

PatentUS9595846B2Automatic transfer switch

Publication Date: 2017.03.14 MILBANK MANUFACTURING CO

AI summary

Aspects of the present disclosure involve systems, methods, and the like, for an automatic transfer switch (ATS) of a power system. The ATS allows for switching between two or more power systems while preventing back-feeding of the power systems. To provide the safety features of the ATS, a safety circuit and control board may be implemented with the magnetic latching relays to control the actions of the latching relays and provide the switching function of the ATS. In one particular embodiment, the safety board comprises one or more electromechanical relays positioned between the controlling electronics of the control board and the magnetic latching relays. The safety board design contains measures to ensure it still functions if one of the disconnect switches is not connected, if one of the connections to a first load phase, a second load phase or neutral is lost and if the main control board is not connected.