Battery Pack Relay Activation With Selective Pre-Charge Testing
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Solution Overview
Problem
Existing electric working machines with multiple battery packs face inefficiencies in activating the internal relays due to inrush current, leading to potential damage and prolonged activation times when all relays are concurrently switched, necessitating extensive testing that prolongs the activation process.
Innovation Solution
Implementing a controller to selectively test and pre-charge specific battery packs based on their requirements, using external relays to manage connections and internal relays, thereby optimizing the activation process by reducing unnecessary testing and concurrent relay switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If all internal relays are concurrently switched from open to closed state, then all battery packs are electrically connected to the electric device, but inrush current causes relay contacts to lock and internal circuit damage occurs
Solution Approach 1:
The patent applies preliminary action by switching external relays to connect battery packs to the electric device before switching internal relays. This preliminary connection allows the system to prepare for the inrush current event, enabling subsequent pre-charging operations that prevent relay contact locking and internal circuit damage while maintaining fast activation.
Solution Approach 2:
The patent uses external relays as intermediary components between the battery packs and the electric device. These external relays mediate the connection process by initially establishing the electrical connection, allowing controlled pre-charging through pre-charge circuits before the internal relays are switched, thereby protecting the internal relay contacts from direct inrush current damage.
2Reliability
If operating tests are performed on all internal relays prior to activation, then relay functionality is verified, but activation time becomes longer
Solution Approach 1:
The patent applies self-service by using the electric device itself to perform the testing function. The electric device acts as a test load that automatically verifies relay functionality during the connection process, eliminating the need for separate external testing equipment and reducing activation time while maintaining reliability.
Solution Approach 2:
The patent merges the connection process with the testing process. By combining these two functions into a single integrated operation where the electric device serves dual purposes as both the operational load and the test load, the system eliminates redundant steps and reduces overall activation time while ensuring relay functionality is verified.
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
Facilitates rapid connection of battery packs to electric devices while minimizing relay damage and reducing activation time, ensuring efficient and safe operation of the electric working machine.
Implementation Method 1
when inrush current acts on the internal relays, their contacts may be locked (fused)
Data Source
AI summary
An electric working machine includes an electric device, electric circuitry, battery packs to be connected sequentially to the electric device such that they are connected in parallel, and a controller. The electric circuitry includes external relays corresponding to the respective battery packs. The controller is configured or programmed to specify each battery pack as being a battery pack requiring a test process to examine opening and closing actions of internal relay(s) of the battery pack or a battery pack not requiring the test process, and in connecting the battery packs to the electric device, perform the test process on battery pack(s) that have been specified as requiring the test process to examine the opening and closing actions, and not perform the test process on battery pack(s) that have been specified as not requiring the test process to examine the opening and closing actions.