Battery Pack Relay Drive Circuit With Low Sustaining Voltage
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Solution Overview
Problem
Existing relays for battery packs consume excessive power and generate heat due to high sustaining voltages required to maintain the on state, and lack effective monitoring for abnormal operations.
Innovation Solution
A driving control device for relays in battery packs that utilizes a buck-boost converter to output a lower sustaining voltage for maintaining the relay on state and includes a feedback control circuit with resistors and switches to manage voltage levels, along with a microcontroller for monitoring and diagnosing abnormal operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high sustaining voltage is applied to maintain the relay in an on state, then the relay remains reliably closed, but power consumption increases and heat generation occurs
Solution Approach 1:
The patent applies dynamics by transitioning the relay control from a static high-voltage state to a dynamic two-stage voltage regime. The controller initially applies a first reference voltage to turn on the relay, then switches to a second reference voltage (lower than the first) to maintain the on state. This dynamic voltage adjustment reduces power consumption while preserving relay functionality throughout operation.
Solution Approach 2:
The patent implements parameter changes by modifying the voltage parameter applied to the relay coil over time. The controller changes the voltage from a higher first reference voltage during turn-on to a lower second reference voltage for sustaining the on state. This parameter optimization maintains sufficient magnetic field strength to keep the relay closed while minimizing energy consumption and heat generation.
2Reliability
If a high sustaining voltage is applied to maintain the relay on state, then the relay remains closed, but heat generation increases
Solution Approach 1:
The dynamic voltage control strategy transitions from continuous high-voltage application to a time-dependent voltage regime. The controller applies the first reference voltage only during the turn-on phase, then switches to the lower second reference voltage for maintaining the on state. This dynamic approach reduces continuous heat generation while ensuring the relay remains reliably closed during operation.
Solution Approach 2:
The patent changes the voltage parameter from a constant high level to a variable level that decreases after initial turn-on. By reducing the sustaining voltage to the second reference voltage (lower than the first), the patent minimizes I²R heating in the relay coil while maintaining sufficient magnetic attraction to keep the contacts closed, thereby reducing temperature rise and heat generation.
3Reliability
If voltage monitoring is implemented to detect abnormal operations, then safety is improved, but device complexity increases
Solution Approach 1:
The controller performs multiple functions: it regulates the buck-boost converter output voltage, controls the relay switching sequence (applying first then second reference voltages), and monitors the voltage output for abnormal conditions. By integrating these diverse functions into a single controller unit, the patent avoids adding separate dedicated circuits for each function, thereby minimizing overall device complexity while achieving comprehensive safety monitoring.
Solution Approach 2:
The patent implements feedback by having the controller continuously monitor the voltage output from the buck-boost converter. When an abnormal condition is detected (such as voltage exceeding expected ranges), the controller can respond by adjusting operation or triggering safety protocols. This feedback mechanism provides safety monitoring using the existing controller resources without requiring complex external monitoring systems.
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
Improves energy efficiency by reducing power consumption and enhances safety through power reduction and abnormality detection in relay operations.
Implementation Method 1
a buck-boost converter configured to receive a voltage from an auxiliary battery, and output a buck-boost voltage
Implementation Method 2
The relay may include high current ends having a small resistance to reduce power consumption and heat generation, and coil ends having large inductive reactance and low resistance. The relay may be driven (e.g., opened or closed) based on voltages applied to the coil ends.
Data Source
AI summary
A driving control device for a relay for a battery pack, includes: a buck-boost converter to receive a voltage from an auxiliary battery, and output a buck-boost voltage; a feedback control circuit electrically connected to the buck-boost converter, and to transfer a feedback voltage to the buck-boost converter to control the buck-boost voltage output from the buck-boost converter; and a relay control circuit to apply or block the buck-boost voltage to a relay electrically connected to at least one of a positive electrode terminal or a negative electrode terminal of a main battery. The buck-boost converter is to output the buck-boost voltage according to the feedback voltage, and the buck-boost voltage has a smaller sustaining voltage for maintaining the relay in an on state than a first reference voltage for turning on the relay.