Contactor Actuation Control in Traction Systems
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Solution Overview
Problem
The existing traction systems in electric vehicles face challenges in safely managing different operating states, requiring precise control of contactors to ensure safe and efficient interconnection of AC batteries and electric motors, while adhering to safety and risk analyses demands.
Innovation Solution
A method and system utilizing a hardware-programmable processor with a control program and state machine to manage contactor actuations, storing switching times and positions in tables, ensuring safe and timed operations across various modes and states, with a meta-state machine for feedback and error handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hardware solution is implemented for contactor actuation based on safety considerations, then safety and reliability are improved, but device complexity increases due to the need for hardware-programmable processors and fixed circuit structures
Solution Approach 1:
The control program is configured at the start of operation, preparing the hardware-programmable processor unit in advance. This preliminary configuration establishes the fixed circuit structure before actual contactor actuation begins, ensuring safety requirements are pre-established while avoiding complexity during runtime operations.
Solution Approach 2:
The patent replaces traditional mechanical or purely software-based control systems with a hardware-programmable processor unit that creates a fixed circuit structure. This substitution provides deterministic, hardware-level reliability for safety-critical contactor actuation while maintaining programmability for different operating states.
2Reliability
If precise control of contactor actuation is implemented to meet safety demands, then safety is improved, but switching time precision requirements increase system complexity
Solution Approach 1:
The patent stores specific switching times for different contactors in a table of switching times, allowing precise control parameters to be configured and adjusted. This approach enables accurate timing control for each contactor based on its specific characteristics and safety requirements, while keeping the control logic flexible and adaptable.
Solution Approach 2:
The state machine monitors the actual state of contactors and compares it with the expected state, using feedback to ensure precise switching timing. This feedback mechanism guarantees that contactors are actuated at the correct moments according to safety requirements while adapting to real-time system conditions.
3Adaptability or versatility
If different operating states with multiple contactor configurations are implemented, then adaptability is improved, but control complexity increases due to multiple states and switching sequences
Solution Approach 1:
The patent divides the control logic into distinct operating states (e.g., charging, discharging, idle) with specific contactor configurations for each state. This segmentation allows the system to handle different operating modes independently through a state machine, making complex multi-contactor control more manageable and adaptable to various traction system requirements.
Solution Approach 2:
The hardware-programmable processor unit serves multiple functions by implementing different control programs for various operating states. The same hardware infrastructure adapts to different traction system configurations and operating conditions, providing universal control capability without requiring separate dedicated circuits for each function.
Data Source
AI summary
A method for actuating contactors in a traction system. The traction system includes an AC battery, an electric motor, at least one peripheral unit, a plurality of voltage and current sensors, a plurality of contactors, which are arranged in electrical connections to the AC battery and to the electric motor and to the at least one peripheral unit, and a controller having a hardware-programmable processor unit on which a control program for actuating the contactors is configured at the start of operation. After the configuration, a fixed semiconductor circuit structure relating to the actuation of the contactors is available to the processor unit. The traction system has multiple modes of operation. A respective mode of operation is predefined by a general vehicle controller. A respective mode of operation has a plurality of states formed by at least one respective target state and at least one intermediate state.