Regenerative Drive for Elevator Automatic Rescue
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Solution Overview
Problem
Conventional elevator drive systems shut down during utility voltage sags or power losses, leaving passengers stranded, and current automatic rescue systems are complex, expensive, and unreliable, requiring dedicated chargers for backup power.
Innovation Solution
A regenerative drive system that continuously powers the elevator hoist motor using a main power supply during normal conditions and switches to a backup supply during failures, with a controller managing power flow to ensure uninterrupted operation and recharge the backup supply during normal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drive systems are used during utility voltage sags, then the drive shuts down to avoid component damage, but the elevator becomes stalled and passengers are trapped
Solution Approach 1:
The patent combines the backup power source charging function with the existing regenerative drive system. The regenerative drive normally converts motor energy back to electrical energy during elevator descent or regenerative braking, and this same drive is used to charge the backup power source during normal operation, eliminating the need for a separate dedicated charger and reducing system complexity
Solution Approach 2:
The regenerative drive performs multiple functions: it operates as the primary drive during normal operation, serves as the charger for the backup power source during normal operation, and enables automatic rescue operation during power failures. This multi-functionality reduces the number of components needed and simplifies the overall system
2Reliability
If current automatic rescue systems are implemented, then power failure rescue capability is provided, but the systems are complex and expensive to implement
Solution Approach 1:
The patent merges the automatic rescue function with the existing regenerative drive system. The controller that manages normal drive operations also manages the automatic rescue operation by detecting power failures and switching the backup power source to supply the hoist motor. This integration eliminates the need for separate rescue system hardware and reduces complexity
Solution Approach 2:
The regenerative drive system is designed to perform both normal elevator operation and automatic rescue operation using the same hardware components. The backup power source and controller serve dual purposes: charging during normal operation and providing rescue power during failures, reducing system complexity and cost
3Reliability
If current automatic rescue systems are used, then rescue operation is provided, but dedicated chargers are required for the backup power source
Solution Approach 1:
The patent combines the backup power source charging function with the existing regenerative drive system. The regenerative drive normally converts motor energy back to electrical energy during elevator descent or regenerative braking, and this same drive is used to charge the backup power source during normal operation, eliminating the need for a separate dedicated charger
Solution Approach 2:
The system uses its own regenerative capability to charge the backup power source. During normal operation, when the motor generates regenerative energy, the system automatically routes this energy to charge the backup power source, making the system self-sufficient and eliminating external charging infrastructure
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 system provides continuous operation of the elevator hoist motor during normal and power failure conditions, ensuring passenger safety by maintaining power to the elevator and efficiently recharging the backup power supply, reducing the need for dedicated chargers and simplifying implementation.
Implementation Method 1
A regenerative drive delivers power to a hoist motor from a main power supply during a normal operating condition and from a backup power supply during a power failure operating condition
Data Source
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AI summary
A system (10) continuously drives an elevator hoist motor (14) during normal and power failure operating conditions. A regenerative drive (30, 34, 36) delivers power to the hoist motor (14) from a main power supply (17) during the normal operating condition and from a backup power supply (24) during the power failure operating condition. A controller (12) operates the regenerative drive (30, 34, 36) to provide available power on the regenerative drive (30, 34, 36) to the backup power supply (24) during the normal operating condition.