Three-Terminal Battery Module for Power Balance Monitoring
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Solution Overview
Problem
High power rechargeable battery systems face challenges in monitoring and balancing energy distribution among modules of varying capacities and ages, leading to safety and performance issues due to the impracticality of matching each module and the increased complexity and cost of current sensors in high power systems.
Innovation Solution
A three-terminal energy storage device module allows for arbitrary voltage, capacity, and power configurations by using two main power terminals for series connections and a third terminal for parallel energy sharing and monitoring, reducing impedance and cost while enabling scalable configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current sensors are placed in the series path to monitor current flow, then current monitoring is achieved, but the module's total impedance increases and system performance degrades
Solution Approach 1:
The patent introduces a third terminal as an intermediary path for current monitoring. Instead of placing sensors directly in the main series power path, the system uses the third terminal to create a separate monitoring circuit that measures current flow through voltage drop detection, thereby achieving current monitoring without increasing the impedance of the main energy path
Solution Approach 2:
The patent replaces traditional current sensors (which are mechanical/electrical devices that add impedance) with a voltage-based monitoring approach. By measuring voltage drop across a known resistance in the third terminal path and calculating current through Ohm's law, the system achieves current monitoring without the impedance penalties of direct current sensing
2Ease of operation
If power control switches are placed in each module for high power systems, then current control is achieved, but the system becomes too large and expensive
Solution Approach 1:
The patent segments the battery system into modular units, each with its own third terminal for monitoring. This segmentation allows distributed monitoring capabilities without requiring expensive power control switches in each module, as the monitoring function is separated from the power control function
Solution Approach 2:
The third terminal serves multiple functions: it enables parallel energy sharing between modules, provides a path for monitoring current flow, and allows the battery management system to verify proper operation. This multi-functionality eliminates the need for separate dedicated monitoring hardware in each high-power module
3Reliability
If modules are matched by capacity and age, then system safety is improved, but the system complexity and matching labor increase
Solution Approach 1:
The patent implements continuous feedback monitoring through the third terminal, allowing the battery management system to detect the state of charge and performance of each module in real-time. This feedback mechanism enables the system to identify and manage modules with varying capacities and ages, maintaining safety without requiring manual matching
Solution Approach 2:
The monitoring system automatically detects and tracks the state of each module, enabling the battery management system to self-regulate power distribution and identify weak modules. This self-service capability eliminates the need for manual capacity matching and ongoing manual balancing operations
4Quantity of substance
If parallel connections are made between separate strings of modules, then energy storage and peak power are increased, but the system complexity increases
Solution Approach 1:
The patent adds a third terminal dimension to the traditional two-terminal module configuration. This additional dimension provides a dedicated path for parallel connections and monitoring, simplifying the architecture of parallel-string configurations by providing a standardized interface for inter-string connections and centralized monitoring points
Data Source
AI summary
A system for power balance monitoring in an energy storage battery comprising a plurality of energy modules connected in a series-parallel configuration. The energy storage module comprises a plurality of cells. Each module is a three-terminal module. The three terminals comprise a positive output terminal and a negative output terminal for connecting the modules in a series string to a load and an energy sharing terminal for sharing energy between modules is other battery strings. A module power management sub-system comprising a current monitoring circuit is connected to each of the energy sharing terminals. Each module power management sub-system is in communication with a battery power management sub-system so that a weak module can be detected based on module current output. Advantageously, the module power management sub-system is not connected across the main power pathway of the module and so does not appreciably increase module impedance.