Battery Block Chassis Referencing for High-Voltage Insulation
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Solution Overview
Problem
Commercial energy storage systems face challenges in increasing voltage while maintaining insulation constraints, as connecting multiple battery packs in series leads to voltage exceeding the designed insulation levels during normal operation and potential short circuits.
Innovation Solution
The system comprises multiple blocks of electrical modules connected in series, with each block having a positive and negative terminal, where each chassis is set to a reference potential between the block's terminals, allowing the voltage across the system to exceed 1500 Volts without exceeding insulation limits by using conductive shields and additional terminals to manage reference potentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple battery blocks are connected in series to increase voltage, then the system voltage increases, but the voltage between terminals and ground exceeds insulation limits
Solution Approach 1:
The system divides the high-voltage battery stack into multiple blocks, each supported by its own chassis with a reference potential set between the positive and negative terminals of that block. This segmentation allows each block to be electrically isolated with its own insulation reference, enabling series connection of multiple blocks without proportionally increasing the voltage stress on any single insulation barrier.
Solution Approach 2:
Each chassis acts as an intermediary element that provides a reference potential between the battery block terminals and ground. The chassis is connected to both the battery block (providing structural support and electrical reference) and ground (through insulation), thereby mediating the voltage relationship and allowing the system to achieve higher terminal voltages while maintaining acceptable insulation stress levels.
2Power
If battery blocks are connected in series to achieve voltage increase, then maximum voltage reaches 3000 Volts, but the voltage between terminals and ground during short circuit exceeds designed insulation levels
Solution Approach 1:
By segmenting the battery system into multiple blocks with individual chassis references, the voltage stress on any single insulation barrier is limited to the voltage of one block rather than the total system voltage. During a short circuit, only the insulation of the affected block experiences maximum stress, while other blocks maintain their reference potentials, preventing system-wide insulation failure.
Solution Approach 2:
The chassis with reference potential set between the terminals provides a pre-established voltage reference that cushions the insulation system during fault conditions. This reference potential acts as a buffer that limits the voltage excursion across insulation barriers during short circuits, preventing the harmful voltage stress from exceeding designed insulation levels.
3Reliability
If chassis is connected to earth for safety, then insulation constraints are violated, but if chassis is isolated, then safety is compromised
Solution Approach 1:
The chassis of each battery block is given a specific local quality - a reference potential set between the positive and negative terminals of its supported block. This local reference potential allows each chassis to be electrically distinct from ground while maintaining safety through controlled insulation, rather than requiring all chassis to be either grounded or completely isolated.
Solution Approach 2:
Each chassis is brought to equipotential with its reference potential (set between the block terminals), creating a stable electrical reference that eliminates dangerous potential differences. This equipotentiality approach ensures that no chassis develops a hazardous voltage relative to ground or adjacent components, maintaining safety without requiring direct earth connection.
Data Source
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AI summary
The present invention relates to an energy storage system (10) comprising several blocks (12) of electrical modules connected in series, each block (12) of electrical modules having a positive terminal and a negative terminal, the voltage across each block (12) of electrical modules being equal to the potential difference between the positive terminal and the negative terminal of the block (12), the voltage across the system (10) being equal to the sum of the voltages of the connected blocks (12) of electrical modules, each block (12) of electrical modules being supported by a chassis (20), each chassis (20) being set to a reference potential, characterized in that the reference potential of each chassis (20) is broadly understood to be between the potential of the positive terminal and the potential of the negative terminal of the block (12) of electrical modules supported by the chassis.