Capacitive Coupling DCDC Converter for Low Voltage Power Supply
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Solution Overview
Problem
Existing battery systems for electric vehicles face challenges in providing a cost-effective and space-efficient low voltage power supply for security-relevant components, as they often require galvanic isolation which increases electromagnetic interference and costs.
Innovation Solution
A battery system with a high voltage battery subsystem and a low voltage subsystem connected via a DCDC converter, where a switch-controlled primary coil in the HV system wirelessly transfers energy to a secondary coil in the LV system, allowing for redundant power supply to security-relevant loads while minimizing electromagnetic interference by omitting additional shielding or filtering components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a galvanically isolated DCDC converter is used to provide redundant power supply to the LV board net from the HV battery system, then power supply reliability is improved, but electromagnetic interference increases and construction space requirements increase due to necessary filters or shielding means
Solution Approach 1:
The patent extracts and removes the harmful shielding and filtering components from the system. By using a capacitive coupling mechanism instead of galvanic isolation, the patent eliminates the need for electromagnetic shielding means and filters, thereby removing the source of increased construction space requirements while maintaining power supply reliability through the redundant power path.
Solution Approach 2:
The patent replaces the mechanical/electromagnetic isolation approach (galvanic isolation with physical shielding) with an electrical field-based capacitive coupling mechanism. This substitution allows power transfer without direct electrical connection, eliminating the need for physical shielding while maintaining electrical isolation benefits.
2Reliability
If a galvanically isolated DCDC converter is used to provide redundant power supply to the LV board net from the HV battery system, then power supply reliability is improved, but construction space requirements increase due to necessary filters or shielding means
Solution Approach 1:
The patent extracts and removes the harmful shielding and filtering components from the system. By using a capacitive coupling mechanism instead of galvanic isolation, the patent eliminates the need for electromagnetic shielding means and filters, thereby removing the source of increased construction space requirements while maintaining power supply reliability through the redundant power path.
3Object-affected harmful factors
If additional shielding or filtering components are added to reduce electromagnetic interference in the redundant power supply system, then electromagnetic interference is reduced, but costs increase
Solution Approach 1:
The patent extracts and removes the harmful shielding and filtering components from the system. By using a capacitive coupling mechanism instead of galvanic isolation, the patent eliminates the need for electromagnetic shielding means and filters, thereby removing the source of increased construction space requirements while maintaining power supply reliability through the redundant power path.
Solution Approach 2:
The patent converts the potential harm of electromagnetic interference into a benefit by using the capacitive coupling mechanism that naturally provides electrical isolation without requiring additional shielding. The system design turns what would normally be a problem (need for isolation) into an opportunity to simplify the overall system architecture.
4Object-affected harmful factors
If additional shielding or filtering components are added to reduce electromagnetic interference in the redundant power supply system, then electromagnetic interference is reduced, but construction space requirements increase
Solution Approach 1:
The patent extracts and removes the harmful shielding and filtering components from the system. By using a capacitive coupling mechanism instead of galvanic isolation, the patent eliminates the need for electromagnetic shielding means and filters, thereby removing the source of increased construction space requirements while maintaining power supply reliability through the redundant power path.
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 configuration reduces the costs and space requirements of the electric vehicle by ensuring reliable power supply to security-relevant components while minimizing electromagnetic interference, thus enhancing the overall efficiency and reliability of the battery system.
Implementation Method 1
a switch-controlled primary coil in the HV system wirelessly transfers energy to a secondary coil in the LV system
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to a battery system (100) for an electric vehicle (200), wherein the battery system (100) comprises a high voltage, HV, battery subsystem (101) having a battery cell stack (51) with a plurality of battery cells (10) electrically connected between stack nodes (11, 12) and a low voltage, LV, battery subsystem (102) having a LV battery (52) and a supply node (13) connected to the LV battery (52). The battery system (100) further comprises a DCDC converter (60) with a primary coil (61) in the HV battery subsystem (101) and a secondary coil (62) in the LV battery subsystem (102), wherein the primary coil (61) is connected to one of the stack nodes (11, 12) via a switch (14). A threshold signal (70) indicative of a voltage at the supply node (13) is generated in the LV battery subsystem (102) and is transmitted to the HV battery subsystem (101), and the state of the switch (14) is controlled based on the threshold signal (70). The present invention further relates to a vehicle (200) with a battery system (100) of the present invention.