Battery Protection Circuit with Capacitor-Driven Latching Contactor
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Solution Overview
Problem
Existing battery protection systems for vehicle engines face challenges in preventing damage from excessive current or depth of discharge, particularly when using normally open or normally closed contactors, which either require external switches or lead to ongoing power consumption that can drain the battery.
Innovation Solution
A current protection circuit incorporating a latching circuit and a capacitor-driven contactor circuit that automatically switches to an open configuration when excessive current or voltage thresholds are met, disconnecting the battery to prevent damage without relying on external switches and minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a normally open contactor is used in the battery power circuit, then the battery is protected from excessive current or excessive depth of discharge, but the complexity of the vehicle design and operation increases due to the necessity of installing and operating an external switch
Solution Approach 1:
The battery protection system automatically monitors its own state through the microcontroller that continuously measures voltage and current parameters. The system self-activates protection by triggering the contactor to open when abnormal conditions are detected, eliminating the need for external manual intervention or complex external switching mechanisms.
Solution Approach 2:
The microcontroller continuously monitors battery parameters (voltage and current) and provides feedback to the contactor control circuit. When the monitored parameters exceed predetermined thresholds indicating excessive current or depth of discharge, the feedback loop automatically triggers the contactor to open, providing continuous closed-loop protection without external switches.
2Ease of operation
If a normally closed contactor is used in the battery power circuit, then no external switch is required for engine start profile, but ongoing power consumption to energize the coil and keep the contactor open may completely drain the battery cells of energy and damage the battery
Solution Approach 1:
Instead of continuous power consumption to maintain the contactor in the open position, the system uses periodic monitoring by the microcontroller that only activates the contactor coil when protection is needed. The contactor remains closed (power-saving state) during normal operation and only opens (power-consuming state) when abnormal conditions are detected, converting continuous energy loss into intermittent, controlled action.
Solution Approach 2:
The patent replaces the traditional mechanical contactor control system with an electronic control system using a microcontroller. This substitution eliminates the need for continuous electrical power to maintain a mechanical switch position, as the microcontroller can detect abnormal conditions and trigger the contactor only when necessary, dramatically reducing ongoing energy consumption.
3Reliability
If the contactor is opened to protect the battery from excessive current or excessive depth of discharge, then the battery is protected, but the coil requires ongoing power consumption that may completely drain the battery cells of energy and damage the battery
Solution Approach 1:
The microcontroller continuously monitors battery parameters in advance and detects abnormal conditions before they cause damage. By detecting excessive current or voltage thresholds beforehand, the system can trigger the contactor to open preventively, protecting the battery before critical damage occurs while minimizing the duration and amount of power consumed by the coil.
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
The solution effectively protects batteries from excessive current and depth of discharge, allowing for engine start profiles without external switches and reducing the risk of battery drain, thus enhancing safety and efficiency.
Implementation Method 1
a capacitor electrically coupled to the first circuit region. In some embodiments, the capacitor is configured to store power collected from the first circuit region and the microcontroller is configured to monitor a current or a voltage from the energy storage device and, if the current is above a current threshold value or the voltage is below a voltage threshold value, cause the capacitor to discharge to the operational switch of the latching circuit
Data Source
AI summary
A protection circuit for protecting an energy storage device includes a first circuit region between a first terminal of the energy storage device and a first connector node, a second circuit region between a second terminal of the energy storage device and a second connector node, a latching circuit to electrically couple the first connector node to the first terminal of the energy storage device when the latching circuit is in a closed configuration, and a contactor circuit electrically coupled to an operational switch of the latching circuit, the contactor circuit comprising a capacitor to store charge and a microcontroller to monitor an electrical property of the energy storage device to determine if a short circuit occurs and, if a short circuit does occur, cause the capacitor to discharge to the operational switch of the latching circuit to cause the latching circuit to transition to the open configuration.