Power Control Assembly for Lithium Utility Vehicles
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Solution Overview
Problem
Lithium-battery powered utility vehicles require efficient power control systems to manage high current for electric motors and low current for auxiliary loads, while preventing over-discharging, without the need for multiple high-current contactors.
Innovation Solution
A power control assembly incorporating an electro-mechanical contactor for high current and a low power switching device, along with control circuitry to independently manage power delivery from a lithium battery to various loads, ensuring safe discharging prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple high-current contactors are used to control power delivery, then power control capability is improved, but device complexity increases
Solution Approach 1:
The power control system is segmented into two distinct components: a high-current contactor for motor control and a low-power switching device for auxiliary loads. This segmentation allows each component to be optimized for its specific function, reducing overall system complexity while maintaining comprehensive power control capability.
Solution Approach 2:
The control circuitry is designed to universally manage both the high-current contactor and low-power switching device through a single control system. This multi-functional control approach eliminates the need for separate control systems, thereby reducing device complexity while preserving adaptability.
2Device complexity
If a single high-current contactor is used for both traction and auxiliary power, then device complexity is reduced, but power control precision deteriorates
Solution Approach 1:
The power control function is segmented into two separate switching mechanisms: a high-current contactor optimized for traction power delivery and a low-power switching device optimized for auxiliary loads. This segmentation enables precise control for each power category without compromising the other, achieving both simplicity and precision.
Solution Approach 2:
Different switching devices are selected for different power control applications based on their specific requirements. The high-current contactor provides robust control for motor power, while the low-power switching device provides precise control for auxiliary devices. This local optimization of component selection achieves precise power control across all functions.
3Reliability
If the secondary contactor opens to prevent over-discharging, then battery safety is improved, but power delivery capability deteriorates
Solution Approach 1:
The power delivery path is segmented into two independent channels: a high-current path through the contactor for motor power and a low-power path through the switching device for auxiliary loads. This segmentation allows the battery to safely prevent over-discharging by controlling the high-current path while maintaining limited power delivery through the low-power path, thus preserving both safety and partial power delivery capability.
Solution Approach 2:
When the battery approaches discharge limits, the system applies partial action by maintaining power delivery to essential auxiliary devices through the low-power switching device while restricting high-current motor power. This partial power delivery prevents complete system shutdown while still protecting the battery from dangerous over-discharge conditions.
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 effectively controls power delivery, reduces system complexity by eliminating the need for multiple high-current contactors, and safeguards the lithium battery from over-discharge, while maintaining power to auxiliary devices during motor operation.
Implementation Method 1
an electro-mechanical contactor constructed and arranged to carry high current
Implementation Method 2
a low power switching device constructed and arranged to carry low current
Data Source
AI summary
A utility vehicle includes a utility vehicle body, a set of electrical loads supported by the utility vehicle body, and a power control assembly supported by the utility vehicle body and coupled with the set of electrical loads. The power control assembly includes an electro-mechanical contactor constructed and arranged to carry high current, a low power switching device constructed and arranged to carry low current, and control circuitry coupled to the electro-mechanical contactor and the low power switching device. The control circuitry is constructed and arranged to separately open and close each of the electro-magnetic contactor and the low power switching device to control power delivery from a lithium battery to the set of electrical loads.