Battery Module Sequencing for DC Bus Startup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In battery systems for vehicles and stationary applications, the high DC voltage required for efficient operation leads to significant expenditure and safety risks due to the need for charging switches and resistors, which are costly, heavy, and unnecessary for short charging periods.
Innovation Solution
A method involving a battery system with multiple series-connected battery modules, where the output voltage is increased in step-like increments by disconnecting and reconnecting modules with different numbers of cells, eliminating the need for charging switches and resistors by maintaining small voltage differences and constant charging currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a charging switch and charging resistor are provided to charge the DC voltage intermediate circuit, then the voltage can be stabilized during switching operations, but the cost, volume, and weight of the system increase significantly
Solution Approach 1:
The patent extracts and eliminates the charging switch and charging resistor from the system by using the existing battery modules in a different configuration. The battery modules are switched between series and parallel connections through coupling units, which naturally provides the charging function without requiring separate charging components, thereby removing the harmful elements while maintaining voltage stabilization.
Solution Approach 2:
The coupling units that originally serve to connect battery modules are made multi-functional by enabling them to perform both series/parallel switching and charging operations. This universal approach allows the same components to serve multiple purposes, eliminating the need for dedicated charging switches and resistors, thus reducing cost, volume, and weight while maintaining reliability.
2Reliability
If a charging switch and charging resistor are provided to charge the DC voltage intermediate circuit, then the voltage can be stabilized during switching operations, but the system cost increases due to additional expensive components
Solution Approach 1:
The patent extracts and eliminates the charging switch and charging resistor from the system by using the existing battery modules in a different configuration. The battery modules are switched between series and parallel connections through coupling units, which naturally provides the charging function without requiring separate charging components, thereby removing the harmful elements while maintaining voltage stabilization.
Solution Approach 2:
The coupling units that originally serve to connect battery modules are made multi-functional by enabling them to perform both series/parallel switching and charging operations. This universal approach allows the same components to serve multiple purposes, eliminating the need for dedicated charging switches and resistors, thus reducing cost, volume, and weight while maintaining reliability.
3Stress or pressure
If battery cells are connected in series to achieve high output voltage, then the voltage requirement is met, but the charging current becomes excessively high and dangerous
Solution Approach 1:
The patent implements dynamic switching between series and parallel connections of battery modules through coupling units. During charging, the system dynamically reconfigures from series to parallel connections, which automatically limits the charging current to safe levels while maintaining the required output voltage during operation. This dynamic adaptation eliminates the harmful high charging current risk.
Solution Approach 2:
The patent changes the electrical configuration parameters of the battery system by switching between series and parallel connections. This parameter change transforms the system from a high-voltage/low-current configuration during operation to a low-voltage/high-current configuration during charging, thereby maintaining safe operating conditions while meeting voltage requirements.
4Productivity
If the DC voltage intermediate circuit is charged with high current, then the charging speed is fast, but the voltage difference causes excessive current flow and safety risks
Solution Approach 1:
The patent implements dynamic switching between series and parallel connections of battery modules through coupling units. During charging, the system dynamically reconfigures from series to parallel connections, which automatically limits the charging current to safe levels while maintaining the required output voltage during operation. This dynamic adaptation eliminates the harmful high charging current risk.
Solution Approach 2:
The patent changes the electrical configuration parameters of the battery system by switching between series and parallel connections. This parameter change transforms the system from a high-voltage/low-current configuration during operation to a low-voltage/high-current configuration during charging, thereby maintaining safe operating conditions while meeting voltage requirements.
Data Source
AI summary
The disclosure presents a method for starting up a battery system having a battery and a DC voltage intermediate circuit which is connected to the battery. The battery has a plurality of battery modules which are connected in series and which comprise a first battery module having a first number of battery cells and at least a second battery module having a larger second number of battery cells. At the beginning of the method, all of the battery modules are deactivated, and therefore the output voltage of the battery is zero. During the course of the method, the output voltage of the battery is increased by successive second battery modules being activated. In the process, the first battery module is activated in each case between the activation of two second battery modules and is deactivated again when the further second battery module is activated.