Controllable Energy Store for DC Voltage Generation
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Solution Overview
Problem
Conventional energy storage systems in electric and hybrid vehicles, as well as wind turbines, face reliability issues due to the series connection of battery cells, where a single failed cell can cause the entire system to fail, and integrating these systems into conventional energy supply networks is challenging because they do not provide a constant DC voltage.
Innovation Solution
A controllable energy store with n parallel branches, each containing series-connected energy storage modules with coupling units that can bridge or switch energy storage cells, allowing them to be directly connected to a reference rail for use in an n-phase electrical machine, enabling efficient DC voltage generation for electrical loads without a separate inverter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If battery cells are connected in series to achieve high voltage, then the voltage requirement is met, but the reliability deteriorates because a single failed cell causes the entire system to fail
Solution Approach 1:
The battery system is divided into multiple independent battery module strands, where each strand contains series-connected battery modules. This segmentation allows the system to maintain functionality even if one strand fails, as other strands can continue to supply power independently.
Solution Approach 2:
Each battery module within a strand is equipped with its own controllable coupling unit that can independently control the connection state of that specific module. This local control capability allows failed modules to be isolated without affecting the entire strand, maintaining local functionality while ensuring overall system reliability.
2Power
If additional battery cells are connected in parallel to increase maximum current, then the current capacity is improved, but the device complexity increases
Solution Approach 1:
The parallel battery structure is organized into distinct strands with series-connected modules, where each module has its own coupling unit. This segmented architecture manages complexity by providing a modular framework that scales systematically with power requirements.
Solution Approach 2:
The controllable coupling units dynamically adjust the connection states of battery modules based on system requirements. This dynamic control allows the system to optimize current distribution and manage complexity through intelligent switching rather than fixed complex wiring.
3Ease of operation
If a separate inverter is used to control the electrical machine, then the control functionality is achieved, but the device complexity and hardware requirements increase
Solution Approach 1:
The controllable coupling units are integrated directly into the battery structure, combining the energy storage function with the control function. This merging eliminates the need for a separate inverter, as the coupling units can directly control the electrical machine by switching battery modules in and out of the circuit.
Solution Approach 2:
The controllable coupling units serve multiple functions: they manage battery module connections for voltage control, provide overcurrent protection, enable regenerative braking, and directly control the electrical machine. This multi-functionality replaces what would traditionally require separate dedicated components.
Data Source
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AI summary
The invention relates to a power supply system comprising an n-phase electric machine (1), where n = 1, and a controllable energy store (2) used for controlling and supplying electric power to the electric machine (1). The controllable energy store (2) has n parallel power supply branches (3-1, 3-2, 3-3), each of which includes at least two serially connected energy storage modules (4). Each energy storage module comprises at least one electric power cell (5) having an associated controllable coupling unit (6) and is connected to a reference bus (T-) and to one respective phase (U, V, W) of the electric machine (1). The coupling units (6) bridge the associated power cells (5) or connect the associated power cells (5) to the respective power supply branch (3-1, 3-2, 3-3) in accordance with control signals. In at least one of the power supply branches (3-3), the power cells (5) of the energy storage module (4-3m) connected directly to the reference bar (T-) are connected directly to the reference bar (T-). Said power cells (5) are used as energy stores for an intermediate DC circuit.