Multi-Pole Contactor for Electric Powertrain Battery Systems
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Solution Overview
Problem
High-voltage battery systems for electric vehicles face complexity and increased cost in implementing parallel-connected configurations of multiple battery packs, requiring numerous switches and redundant controls, which complicates charging and propulsion operations.
Innovation Solution
The use of multi-pole contactors with internal switches that operate in unison, allowing for both series and parallel configurations with a single switching control action, reducing the number of required contactors and associated controls, and enabling efficient high-voltage charging and propulsion modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple separately-controlled switches are used to implement parallel-connected battery pack configuration, then the battery system can achieve flexible switching between series and parallel configurations, but the device complexity and hardware cost increase significantly
Solution Approach 1:
The patent combines multiple switches (first switch, second switch, third switch) into a single multi-pole contactor with multiple poles. Each pole of the contactor corresponds to one switch in the original circuit, but all poles are controlled by a single control signal, merging the functions of multiple separately-controlled switches into one unified component that reduces hardware complexity while maintaining configuration flexibility.
Solution Approach 2:
The multi-pole contactor serves multiple functions simultaneously: it can connect or disconnect multiple circuit paths (charging current path, propulsion current path) with a single device, and enable both series and parallel battery pack configurations through one control action. This universal component replaces multiple specialized switches, reducing overall system complexity.
2Reliability
If numerous individual switches and redundant controls are implemented for parallel battery pack configuration, then complete control over charging and propulsion paths is achieved, but the cost and hardware quantity increase
Solution Approach 1:
The patent merges multiple individual switches into a single multi-pole contactor. The contactor has multiple poles (at least three poles in the disclosed embodiment) that correspond to different circuit paths, allowing one physical device to replace multiple separate switches while maintaining the ability to control each path independently through the same control signal.
Solution Approach 2:
The multi-pole contactor is segmented into multiple independent poles, where each pole can independently make or break contact with its corresponding circuit path. This segmentation allows the single contactor to control multiple distinct current paths (charging path, propulsion path, bypass path) while remaining a unified controllable device.
3Power
If multiple battery packs are connected in series for high-voltage charging, then the charging voltage capability is doubled, but the switching circuit topology becomes more complex
Solution Approach 1:
The patent implements a dynamic switching system where the multi-pole contactor can rapidly transition between different circuit configurations (series connection for charging, parallel connection for propulsion) based on operational requirements. The contactor's ability to dynamically reconfigure the battery pack connections allows the system to adapt between high-voltage charging mode and high-current propulsion mode without complex manual intervention.
Solution Approach 2:
The multi-pole contactor serves as a universal switching device that handles both series-connection switching (for charging configuration) and parallel-connection switching (for propulsion configuration) through the same control mechanism, eliminating the need for separate switching circuits for different operational modes.
Data Source
AI summary
A battery system includes high-voltage switches, including a multi-pole contactor. Multiple packs are connectable in a series or parallel configuration via the switches. The contactor includes first and second pairs of electrical terminals separated by a respective circuit gap, with respective contactor arms simultaneously closing or opening the gaps. At all times, internal switches formed by the gaps and arms have the same ON/OFF state corresponding to the circuit gaps both being closed or both being open. Two of the contactors may be used to connect the battery packs to a DC fast-charging station, and to connect electrode terminals of the battery packs to a bus rail, respectively. An electric powertrain includes the battery system and an electrical load, including a rotary electric machine, that is connected to a power inverter and to a mechanical load.