Three-State High-Voltage Contactor for Battery Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-voltage battery systems for electric vehicles require complex circuit designs and additional controls to ensure mutually-exclusive switching states, leading to increased complexity and costs due to the use of two-terminal contactors.
Innovation Solution
A three-state high-voltage contactor is introduced, which provides two mutually-exclusive ON states and an OFF state, eliminating the need for dual contactors by using a contactor arm that translates orthogonally to connect or disconnect circuit paths, thereby simplifying the circuit and reducing overall complexity and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-terminal contactors are used to achieve mutually-exclusive switching states, then the switching function is achieved, but the circuit complexity and control requirements increase
Solution Approach 1:
The patent combines two separate two-terminal contactors into a single three-state contactor that provides mutually-exclusive switching between two circuit paths. The contactor includes a first circuit path with a first pair of terminals and a second circuit path with a second pair of terminals, where a single movable contactor arm can connect to either the first or second fixed contactor arm, but not both simultaneously. This merging eliminates the need for separate contactors and their associated control logic while maintaining the mutually-exclusive switching function.
Solution Approach 2:
The three-state contactor performs multiple functions within a single device: it can connect the first circuit path, connect the second circuit path, or disconnect both paths. The single contactor structure replaces what would traditionally require two separate contactors plus control logic, providing universal switching capability across multiple circuit configurations.
2Reliability
If two-terminal contactors with additional controls are used, then mutually-exclusive switching is ensured, but the number of components and costs increase
Solution Approach 1:
The patent merges the functionality of two separate two-terminal contactors into one three-state contactor. The contactor structure includes a first movable contactor arm and a second movable contactor arm that are integrally connected, allowing a single actuation to simultaneously control both circuit paths and ensure mutually-exclusive switching without requiring additional control components.
Solution Approach 2:
The contactor design includes inherent mechanical interlocking where the first and second movable contactor arms are connected such that when one closes a circuit path, the other automatically opens its path. This self-service mechanism ensures mutually-exclusive switching through the physical construction rather than requiring external control systems.
3Reliability
If additional control algorithms are implemented, then switching safety is improved, but the system complexity and diagnostic requirements increase
Solution Approach 1:
The contactor employs mechanical self-service features where the first and second movable contactor arms are integrally connected through a common actuator. This mechanical linkage automatically ensures that when one circuit path is closed, the other is opened, providing inherent safety without requiring complex control algorithms or diagnostic systems.
Solution Approach 2:
The patent introduces a common actuator as an intermediary mechanism that simultaneously controls both movable contactor arms. This single actuator serves as a mediator that ensures coordinated operation of both circuit paths, simplifying the control system while maintaining switching safety through mechanical coordination rather than electronic control logic.
Data Source
AI summary
A three-state contactor for an electrical system having a battery pack and voltage bus rail includes first and second pairs of electrical terminals. The first pair of terminals is separated by a first circuit gap in a first circuit path extending between the bus rail and an electrode terminal of the battery pack. The second pair of terminals is separated by a second circuit gap in a second circuit path extending between the bus rail and electrode terminal. A contactor arm, in response to a corresponding switch activation signal, translates in an orthogonal direction with respect to its longitudinal axis between a first ON state position, an OFF position, and a second ON position to close the first circuit gap, open both circuit gaps, or close the second circuit gap, respectively. A multi-pack battery system and an electric powertrain may use the contactor.