Elevator Backup Power Circuit for Regenerative Energy Storage
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Solution Overview
Problem
Traditional elevator backup power systems face challenges in managing excess energy generated by elevator motors during operation, particularly with regenerative modules, and fail to provide uninterrupted power supply during emergencies while adhering to regulatory standards.
Innovation Solution
An advanced elevator power system (EPS) that absorbs and stores excess energy, utilizes it for battery charging during outages, and provides uninterrupted power to critical loads, while also conditioning grid power for consistent delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional backup power systems are used, then the system structure is simple, but the system cannot effectively manage excess energy generated by elevator motors during regenerative braking
Solution Approach 1:
The patent combines the backup power supply function with the regenerative energy management function into a single integrated system. The battery backup system is merged with the regenerative module, allowing the same battery array to both provide backup power during outages and store regenerative energy during normal operation. This eliminates the need for separate dummy loads or energy dissipation systems, resolving the contradiction by making the system multi-functional without proportionally increasing complexity.
Solution Approach 2:
The battery backup system is designed to perform multiple functions: it serves as both an emergency power source during grid failures and an energy storage device for regenerative braking. The static bypass switch and control logic enable the system to automatically switch between different operational modes (backup power mode, regenerative charging mode, and normal grid operation mode), making the system universally applicable to both emergency preparedness and energy efficiency requirements.
2Loss of energy
If separate emergency lighting systems are used, then the lighting can be provided during outages, but the excess energy from elevator motors cannot be effectively utilized
Solution Approach 1:
The patent merges the emergency lighting system with the elevator backup power system. The same battery array that provides backup power to the elevator motor also powers the emergency lighting during outages. The control system automatically routes power to both loads when needed, eliminating the need for completely separate emergency lighting infrastructure and allowing regenerative energy to charge the batteries that subsequently power both the elevator and lighting during emergencies.
3Reliability
If the system absorbs regenerative energy during braking, then battery charging during outages is enabled, but additional circuitry is required to manage power flow direction
Solution Approach 1:
The patent introduces a static bypass switch as an intermediary device that automatically manages power flow direction between the grid, battery array, and elevator motor. This solid-state switching device serves as a mediator that routes regenerative energy to the battery array during braking and switches to battery power during outages, without requiring complex mechanical switches or manual intervention. The control logic acts as an intelligent mediator, automatically making switching decisions based on system state, thereby achieving reliable power management with controlled complexity.
4Reliability
If online power conditioning is implemented, then grid power quality is improved and elevator faults are prevented, but the system complexity increases
Solution Approach 1:
The patent combines power conditioning functions with the existing backup power and regenerative energy management circuits. The same battery array and power electronics that manage backup power and regenerative charging also perform power conditioning by filtering and stabilizing the power supplied to the elevator motor. This integrated approach provides voltage regulation, frequency stabilization, and harmonic filtering without requiring completely separate power conditioning equipment, thereby improving reliability while controlling the increase in system 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
Ensures uninterrupted power supply to elevators and emergency lighting, efficiently manages energy, and complies with NEC regulations, preventing elevator faults due to grid disturbances.
Implementation Method 1
a third circuit for directing power from the motor/generator to the battery backup when the motor/generator is braking
Implementation Method 2
a first module for converting a first power signal to a second power signal, wherein the first power signal comprises alternating current (AC) from the grid, and the second power signal comprises direct current (DC)
Implementation Method 3
a second module for converting the second power signal to a third power signal, wherein the third power signal comprises direct current, and the third power signal is characterized by a third voltage different than the second voltage
Implementation Method 4
a third module for converting the third power signal to a fourth power signal, wherein the fourth power signal comprises alternating current
Data Source
AI summary
An emergency power system for providing emergency power to an elevator motor/generator is disclosed. The emergency power system comprises a battery backup, a static bypass switch operatively connected to the elevator motor/generator; and a power conditioning circuit. The power conditioning circuit may comprise a first circuit for directing power from the grid to the motor/generator via the static bypass switch when power from the grid available; a second circuit for directing power from the battery backup to the motor/generator when power from the grid is unavailable; and a third circuit for directing power from the motor/generator to the battery backup when the elevator motor/generator is braking. The first circuit may comprise an AC-to-DC rectifier connected to a power grid, a DC-to-DC converter, and a DC-to-AC inverter operatively connected to the static bypass switch. As such, the first circuit is configured to operate as a power conditioning circuit, and that conditioned power supplied to the elevator motor/generator when available. When conditioned power is unavailable because the power grid is non-operational, for example, the battery backup is configured to power the elevator motor/generator via circuit including the DC-to-DC converter, the DC-to-AC inverter, and the static bypass switch.