Parallel Battery Pack Energization Check for Loose Connection Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting loose connections in parallel-connected battery packs in electric vehicles are inaccurate and time-consuming, leading to potential damage due to excessive current flow and unreliable energization confirmation.
Innovation Solution
A power supply system with parallel-connected power storage packs, each equipped with a switch, voltage measurement unit, and control unit, where the system determines energization state by measuring voltages across switches and switches are controlled to confirm normal or anomalous conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage difference method is used to detect loose connection, then detection capability is provided, but accuracy is insufficient when battery packs have substantially the same voltage
Solution Approach 1:
The invention segments the detection process by individually controlling and measuring each battery pack's voltage separately through relay switching, rather than measuring parallel voltages simultaneously. This allows independent verification of each battery pack's energization state, eliminating the accuracy loss that occurs when voltage differences are negligible in parallel connections.
Solution Approach 2:
The invention performs preliminary action by pre-charging each battery pack individually through relay switching before parallel connection, and sequentially verifying energization states. This preliminary individual verification ensures accurate detection of loose connections before the system operates with parallel-connected battery packs.
2Measurement precision
If voltage measurement is performed with significant voltage variations between battery packs, then energization can be detected, but detection time increases due to cross current
Solution Approach 1:
The invention employs periodic action through relay switching that sequentially connects and disconnects each battery pack for individual voltage measurement. This periodic switching enables accurate energization detection for each battery pack without the time delay caused by cross currents, as measurements are taken during brief individual connection periods.
3Quantity of substance
If battery packs are connected in parallel to increase capacity, then power system capacity increases, but loose connection detection becomes unreliable
Solution Approach 1:
The invention segments the verification process by individually controlling relays for each battery pack and measuring voltages separately through sequential switching. This segmentation enables accurate loose connection detection in parallel-connected battery packs, maintaining measurement precision while preserving the capacity benefits of parallel connection.
4Ease of operation
If physical or magnetic detection methods are used for battery pack mounting confirmation, then mounting detection is provided, but energization confirmation remains unreliable
Solution Approach 1:
The invention introduces an intermediary verification mechanism using relay switching and voltage measurement as a mediator between physical mounting and energization confirmation. This intermediary electrical verification method provides reliable energization confirmation that complements physical or magnetic mounting detection, ensuring both mounting and energization states are accurately confirmed.
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
Accurately confirms the energization state of each power storage pack, preventing damage by identifying and correcting loose connections, reducing current limits, and eliminating cross-current issues.
Implementation Method 1
a voltage measurement unit that measures a voltage across both ends of the switch and the power storage module connected in series
Data Source
AI summary
A switch in one power storage pack is turned ON and when all of a plurality of voltages respectively measured by voltage measurement units in all power storage packs including the switch that has been turned ON indicate energization, it is determined that the current state is normal, and when a voltage indicating energization is measured by the voltage measurement unit in the one power storage pack including the switch that has been turned ON and a voltage indicating de-energization is measured by the voltage measurement unit in a power storage pack other than the one power storage pack including the switch that has been turned ON, it is determined that there is an anomaly in a power line for a power storage pack included in a plurality of power storage packs.