Battery Stage Impedance Measurement Using Unique Binary Sequences
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Solution Overview
Problem
Existing battery management systems face challenges in precisely determining the state-of-health and other operating parameters of electrochemical accumulators, particularly in embedded systems, due to limitations in measuring capacitance, resistance, and open-circuit voltage, which leads to inefficient battery optimization and premature aging.
Innovation Solution
A system comprising series-connected stages with unique binary sequences applied to each stage to measure impedance, allowing for precise identification and parameter determination, reducing galvanic insulation constraints and cabling needs, and enabling robust communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full charging/discharging cycles are performed to measure capacitance for state-of-health determination, then measurement precision is improved, but productivity deteriorates due to time consumption and battery availability loss
Solution Approach 1:
The patent applies periodic action by using short current pulses instead of full charging/discharging cycles to measure capacitance. The method performs multiple measurements at different states of charge during normal operation, accumulating data periodically to determine state-of-health without requiring the battery to be fully charged or discharged, thus maintaining battery availability while achieving precise measurements
Solution Approach 2:
The patent performs preliminary measurements at various states of charge during normal operation before a full cycle is needed. By accumulating capacitance measurements at different charge levels throughout the battery's operational life, the system prepares state-of-health data in advance without requiring the battery to be taken out of service for extended periods
2Measurement precision
If resistance measurement is performed in laboratory conditions with current surges at high frequency, then measurement precision is improved, but device complexity increases due to specialized equipment requirements
Solution Approach 1:
The patent enables the battery management system to perform its own resistance measurements using the battery's existing operational currents. By utilizing current surges that naturally occur during normal charging and discharging operations, the system eliminates the need for separate specialized measurement equipment, reducing device complexity while maintaining measurement precision through proper signal processing
Solution Approach 2:
The patent makes the battery management system multi-functional by enabling it to perform both normal battery control functions and resistance measurements using the same hardware infrastructure. The existing current sensors and control circuits are used dual-purpose for both operational control and diagnostic measurements, eliminating dedicated measurement equipment
3Adaptability or versatility
If electrical models with complex identification algorithms are used to determine state-of-health, then adaptability is improved, but device complexity increases due to excessive computations for embedded applications
Solution Approach 1:
The patent segments the state-of-health determination process into multiple simpler measurements taken at different states of charge throughout normal operation. Instead of using one complex algorithm requiring excessive computation, the method divides the problem into multiple manageable measurement steps that can be processed incrementally, reducing computational burden while maintaining adaptability
Solution Approach 2:
The patent performs partial measurements at selected states of charge rather than requiring complete characterization at all possible charge levels. By measuring capacitance at key operational points (e.g., 20%, 40%, 60%, 80% charge) and using interpolation or simplified models, the system achieves sufficient adaptability without the excessive computation required for exhaustive characterization
4Power
If multiple series-connected stages are used to achieve high voltage, then power is improved, but device complexity increases due to galvanic insulation constraints and cabling needs
Solution Approach 1:
The patent merges the communication and measurement functions into the existing power cabling infrastructure. By using the same electrical connections that provide power to transmit measurement signals and data, the system eliminates separate communication cabling and reduces galvanic insulation requirements, maintaining high voltage capability while simplifying the overall system architecture
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
This approach allows for precise management of battery parameters, reducing electrical risks and costs, and improving battery performance by accurately identifying defective zones and optimizing operating conditions.
Implementation Method 1
determine the impedance of the stage identified for the first frequency from the measured voltage variation
Data Source
AI summary
An accumulator battery system has stages, a power connection, a controller, and circuits. The stages are series-connected. Each has an electrochemical accumulator and a switch. A power connection connects a load to the stages. Each the circuit is associated with a stage. Each circuit generates a voltage variation at terminals of its associated stage, and applies, to a switch of the associated stage, a binary sequence at a frequency. The sequence differs from those of other stages, thus allowing distinguishing between stages based on the sequence. The controller, which is connected to the stages by the power connection, measures a voltage variation across terminals of the stage in response to application of the binary sequence to the stage, identifies a stage from which the variation originates by searching for its associate sequence, and determines, from the variation, an impedance of the identified stage for that frequency.