Modular DC Chopper Energy Storage System for Voltage Management

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Solution Overview

Problem

Existing energy supply systems with series-connected battery cells face challenges such as high logistical effort for maintenance, increased weight and cost due to excessive voltage requirements, and safety concerns with high voltages, making it difficult to replace individual cells and requiring expensive circuit breakers.

Innovation Solution

The system employs a series-connected DC chopper configuration with a control device that adjusts voltage and current based on state variables of storage modules, allowing for modular design and reduced voltage clamping, enabling flexible voltage selection and omission of high-voltage circuit breakers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If battery cells are connected in series to achieve high operating voltage, then the required voltage is improved, but the current flows through all cells in series making the system vulnerable to single cell failure and requiring expensive high-voltage circuit breakers

Engineering Contradiction:
Improveoperating voltageVSAvoidsystem vulnerability to cell failure
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The energy storage system is divided into multiple independent storage modules, each with its own DC chopper. This segmentation allows the system to operate with lower voltages per module while achieving the required total voltage through the series connection of DC choppers on the output side, reducing the vulnerability associated with high-voltage series-connected cells.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

DC choppers are introduced as intermediary components between the storage modules and the output. These DC choppers convert the lower voltages from individual storage modules into the required output voltage, acting as mediators that eliminate the need for direct high-voltage series connections and expensive high-voltage circuit breakers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If a large number of battery cells are connected in series to meet high voltage requirements, then the voltage is improved, but the weight and volume of the battery system increase

Engineering Contradiction:
Improveoperating voltageVSAvoidbattery system weight
Core Design Contradiction:
PowerVSWeight of stationary object

Solution Approach 1:

The system changes the voltage parameter distribution by using multiple storage modules operating at lower voltages (e.g., 48V each) instead of requiring a single high-voltage system. The DC choppers on the output side series-connect to achieve the required total voltage, allowing for optimized cell configurations that reduce weight while meeting voltage requirements.

Inventive Principle:
Principle #35Parameter changes

3Power

If high voltage series connection is used to meet power requirements, then the voltage is improved, but the complexity of assembly and maintenance increases requiring specially trained specialists

Engineering Contradiction:
Improveoperating voltageVSAvoidassembly complexity
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The system is segmented into standardized storage modules with integrated DC choppers. Each module can be assembled and tested independently at lower voltages, simplifying the manufacturing process. The modular design allows for easier assembly and maintenance without requiring specialized high-voltage handling expertise.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The DC choppers serve as intermediary components that handle the voltage conversion, isolating the storage modules from direct high-voltage connections. This reduces the complexity of assembly and maintenance for the storage modules themselves, as they operate at safer, lower voltages.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Power

If excessive number of battery cells are used to meet voltage and current requirements, then the power capability is improved, but the cost of the battery system increases

Engineering Contradiction:
Improvepower capabilityVSAvoidnumber of battery cells
Core Design Contradiction:
PowerVSQuantity of substance

Solution Approach 1:

The system changes the voltage parameter distribution to use multiple modules at lower voltages (e.g., 48V) instead of fewer cells at high voltage. This parameter change allows for more efficient cell utilization and reduces the total number of cells required while maintaining the same power capability through the series-connected DC choppers on the output side.

Inventive Principle:
Principle #35Parameter changes

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 reduces logistical effort, weight, and cost by allowing for modular design and flexible voltage selection, enhancing safety and efficiency in energy storage systems, particularly in electric vehicles.

Implementation Method 1

The energy transmitter has a plurality of DC choppers, which are connected to one another in series on the output side and each of the DC choppers can be connected with its inputs to a storage module of the energy storage system

Methodology Applied
Scientific EffectElectrical energy conversion:

Implementation Method 2

with the charge transport taking place through electrochemical processes within the battery cells

Methodology Applied
Scientific EffectElectrochemical processes:

Data Source

PatentEP2514063B1Energy storage system and method for the operation thereof
Publication Date: 2019.10.02 ROBERT BOSCH GMBH
  • EP2514063B1 patent drawingFigure 1~2
  • EP2514063B1 patent drawingFigure 3

AI summary

The invention relates to an energy supply system (10) comprising an energy storage system (12), in particular a battery system, provided with several electric energy storage modules (38, 40), a determination device (64) for determining the state variables of the storage modules (38, 40) and an energy transmitter (14) for transmitting energy between the storage modules (38, 40) and a downstream electric device (16). According to the invention, the energy transmitter (14) comprises several direct current regulators (26, 28) which are connected in parallel and/or in series on the output side and each direct current regulator (26, 28) can be respectively connected to a storage module (38, 40) of the energy storage system (12) and the energy supply system comprises a control device (66) for controlling the direct current regulator (26, 28) in accordance with the determined state variables of the respectively connected storage module (38, 40). The invention also relates to a method for operating an energy supply system (10).