Multilane DC Power Bus Bypass Path for Inrush Current Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In aircraft DC power distribution systems, connecting multiple batteries can result in unwanted inrush current and current flowing among batteries, potentially triggering battery protection and thermal runaway.
Innovation Solution
A multilane power distribution system with a bypass path that includes a bypass resistor and a switchable element, which limits inrush current by providing a high resistance path and allows voltage alignment before full connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple batteries are connected in a multilane power distribution system, then power sharing and redundancy are enabled, but inrush current and current flowing among batteries occur causing battery protection triggering and thermal runaway
Solution Approach 1:
The bypass path is activated before the main connection to pre-limit the current flow. The bypass resistor is connected in parallel with the switchable element, creating a controlled current path that prevents inrush current from damaging the batteries during the connection process. This preliminary action ensures safe battery connection while enabling power sharing and redundancy.
2Ease of operation
If switchable elements are used to connect power buses, then battery connection control is improved, but initial current transients trigger battery pack main protection
Solution Approach 1:
The bypass resistor acts as an intermediary element that mediates the current flow during battery connection. It provides a controlled path for initial current transients, preventing them from triggering the battery pack main protection. The bypass path works in conjunction with the switchable element to enable controlled battery connection while protecting against harmful current transients.
3Device complexity
If batteries are connected directly without bypass path, then system complexity is reduced, but current transients cause thermal runaway
Solution Approach 1:
The bypass path provides beforehand cushioning by limiting current transients before they can cause thermal runaway. The bypass resistor is positioned in parallel with the switchable element to cushion the impact of initial current surges during battery connection. This protective measure is built into the system architecture to prevent catastrophic failures while maintaining manageable complexity.
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
The bypass path effectively dampens initial current transients, preventing battery protection triggering and thermal runaway, while allowing safe and efficient connection of batteries.
Implementation Method 1
the bypass path includes a bypass resistor and a further switchable element... the bypass resistor limits any inrush current when the two DC power sources are connected
Implementation Method 2
the bypass resistor may be or include an inductor having an inductive resistance... due to self-induction, a voltage is induced in each inductor. The induced voltage, according to Lenz's law, counteracts the cause of its generation, i.e., the current flow through the coil
Data Source
AI summary
A multilane power distribution system includes a plurality of DC power sources and a plurality of load devices. Each DC power source powers at least two load devices, and each load device is powered by at least two of the DC power sources. The system further includes a DC connection network including power buses for connecting the DC power sources and the load devices. The power buses have a high side voltage rail for the positive voltage and a low side voltage rail for the negative voltage. At least two power buses are connectable by switchable elements, namely, a first switchable element for the positive voltage rails and a second switchable element for the negative voltage rails. The switchable elements, when switched on, electrically connect the terminals of two of the DC power sources connected by the respective power buses. A bypass path is provided that bypasses a switchable element.