Storage Retrieval Unit Braking During Inverter Power Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rack storage systems fail to effectively manage electrical energy generated during deceleration when disruptions occur in the electrical network, preventing the energy from being fed back into the energy store, which can lead to unsafe conditions due to residual voltage.
Innovation Solution
Implement a method and system with a drive motor switching element and an energy store switching element that dynamically connect the drive motor to an inverter or a braking resistor based on supply voltage thresholds, ensuring safe braking even during network disruptions by using a braking resistor when the inverter is not sufficiently powered.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the energy store is used to store braking energy, then the braking capacity is improved, but the system becomes vulnerable to network disruptions
Solution Approach 1:
The system dynamically switches between two braking modes based on network status: during normal operation, braking energy is stored in the energy store (capacitor); during network disruptions, the system automatically transitions to using a braking resistor. This dynamic adaptation ensures reliable braking capacity regardless of network conditions.
Solution Approach 2:
A switching mechanism acts as an intermediary between the drive motor and the two braking options (energy store and braking resistor). The switch automatically connects to the appropriate braking component based on network availability, ensuring continuous safe operation without manual intervention.
2Reliability
If a mechanical brake is used, then safety during network disruption is improved, but the system complexity increases
Solution Approach 1:
The invention replaces mechanical braking systems with an enhanced electrical braking system that uses a braking resistor. This substitution maintains safety during network disruptions while reducing mechanical complexity, maintenance requirements, and improving overall system efficiency by utilizing electrical components throughout the braking process.
3Reliability
If the braking resistor is sized large to handle all braking energy, then the braking reliability is improved, but the energy efficiency deteriorates
Solution Approach 1:
The braking resistor is sized to handle only the excess braking energy that cannot be stored in the energy store, rather than being oversized to handle all braking energy. During normal operation, the compact energy store absorbs the majority of braking energy, allowing the braking resistor to be smaller and more energy-efficient while maintaining reliable braking capability.
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
Ensures safe and reliable braking of storage and retrieval units by eliminating the need for mechanical brakes, allowing manual movement post-stoppage and maintaining system safety by disconnecting the energy store from the inverter during network failures.
Implementation Method 1
the braking energy is fed into a braking resistor
Data Source
AI summary
In a method for operating a storage and retrieval unit with an inverter, which is connected to an energy store, and a drive motor, and a rack storage system including the storage and retrieval unit and the energy store, an electrical energy generated during the decelerating of the storage and retrieval unit is fed back into the energy store if a supply voltage for the inverter is above a first supply voltage threshold value and/or if the inverter is electrically connected to the energy store, and is otherwise fed into a braking resistor.