Semiconductor Switch for Simultaneous DC Link Charging and Impedance Measurement
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Solution Overview
Problem
Existing battery management systems face challenges in accurately measuring complex impedance of battery cells due to factors like structure, temperature, and state of charge, and require separate circuits for DC link capacitor charging and excitation current generation, which add complexity and inefficiency.
Innovation Solution
A semiconductor-based battery disconnect switch (BDS) is used to simultaneously charge the DC link capacitor and generate excitation current for impedance monitoring, eliminating the need for separate circuits and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate circuits are used for DC link capacitor charging and excitation current generation, then the functions are performed reliably, but the system complexity increases
Solution Approach 1:
The patent combines the DC link capacitor charging function and the excitation current generation function into a single circuit path. The battery disconnect switch is controlled to simultaneously perform both functions: charging the DC link capacitor and generating the excitation current for impedance measurements, thereby reducing the number of separate circuits and components needed in the system
Solution Approach 2:
The battery disconnect switch is designed to serve multiple purposes: it acts as a safety disconnect switch, a DC link capacitor charger, and an excitation current generator for impedance measurements. This multi-functional design eliminates the need for dedicated separate circuits for each function, simplifying the overall system architecture
2Adaptability or versatility
If multiple separate circuits are used for battery management functions, then each function can be performed independently, but the number of components and system complexity increase
Solution Approach 1:
The battery disconnect switch is designed to serve multiple purposes: it acts as a safety disconnect switch, a DC link capacitor charger, and an excitation current generator for impedance measurements. This multi-functional design eliminates the need for dedicated separate circuits for each function, 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 efficient and simultaneous DC link capacitor charging and excitation current generation, reducing system complexity and improving accuracy of complex impedance measurements in battery cells.
Implementation Method 1
a plurality of battery cells connected in series to form a battery system
Implementation Method 2
The DC link capacitor can provide several benefits to the system
Implementation Method 3
a semiconductor power switch circuit configured to connect a plurality of battery cells to a DC link capacitor
Data Source
AI summary
This disclosure describes a driver circuit configured to control an ON/OFF state of a semiconductor power switch circuit, wherein the semiconductor power switch circuit is configured to connect a plurality of battery cells to a DC link capacitor associated with an electric motor. According to this disclosure, the driver circuit is configured to: control the semiconductor power switch circuit to cause the plurality of battery cells to charge the DC link capacitor; and control the semiconductor power switch circuit to generate and deliver an excitation current from the plurality of battery cells, wherein the excitation current is defined for a complex battery impedance measurement operation.