Parallel Battery Pack Balancing Relay Control
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Solution Overview
Problem
Existing technologies face challenges in balancing State Of Charge (SOC) and voltage differences between battery packs connected in parallel, leading to potential relay damage during SOC equalization, requiring separate time for voltage balancing.
Innovation Solution
An apparatus and method using a communication device and processing unit to determine SOC and voltage differences between battery packs, entering a balancing mode based on reference thresholds, and controlling relays for charging or discharging to equalize SOC without separate voltage equalization time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If battery packs with SOC difference are connected in parallel to increase capacity, then battery capacity is improved, but relay damage occurs due to rapid current generation during SOC equalization
Solution Approach 1:
The control device performs preliminary SOC comparison before closing relays. When SOC difference exceeds threshold, the control device delays relay closure until SOC equalization is complete, preventing rapid current generation that would damage relays while still allowing parallel connection for capacity increase
2Reliability
If separate SOC equalization process is used to match battery packs, then relay damage is prevented, but additional time is required for voltage balancing
Solution Approach 1:
The control device merges the SOC equalization check into the relay control process itself. By continuously monitoring SOC differences and dynamically controlling relay closure timing, the equalization function is integrated into normal battery management operations rather than requiring separate dedicated equalization time
3Speed
If relays are closed immediately to connect battery packs, then system responsiveness is improved, but relay damage occurs due to SOC difference
Solution Approach 1:
The control device implements feedback control by continuously monitoring SOC values of all battery packs and using this information to dynamically adjust relay closure decisions. This feedback mechanism ensures relays are only closed when SOC differences are within safe thresholds, maintaining both responsiveness and reliability
Data Source
AI summary
An apparatus and a method for balancing batteries connected in parallel are provided. The apparatus collects States Of Charge (SOCs) of at least two or more battery packs, determines whether the at least two or more battery packs enter a balancing mode based on the collected SOCs of the at least two or more battery packs, determines a balancing control mode based on a vehicle state, when it is determined that the at least two or more battery packs enter the balancing mode, and controls a relay of at least one of the at least two or more battery packs depending on the determined balancing control mode to perform charging or discharging and performs balancing between the at least two or more battery packs.