UPS Transfer Timing Using Emulated Holdup Voltage
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Solution Overview
Problem
Existing UPS systems face inefficiencies in power transfer timing due to frequent switching between utility AC power and backup power, leading to system degradation and reduced reliability, especially during short-term utility AC voltage disturbances in data centers.
Innovation Solution
A system comprising a switch, a rectifier, and a control element with an emulation module that determines the optimal time for transitioning from utility AC power to a backup power source by comparing an emulated capacitor holdup voltage to a threshold voltage, based on instantaneous RMS voltage values, to delay power transfer and improve holdup time accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system switches to backup power source during AC voltage disturbances, then power availability is maintained, but system reliability deteriorates due to frequent unnecessary transitions
Solution Approach 1:
The system performs preliminary assessment of AC voltage disturbances by measuring RMS voltage and comparing it to threshold values before initiating a switch to backup power. This preliminary action filters out transient disturbances that would not cause actual power failure, thereby preventing unnecessary transitions and improving system reliability while maintaining power efficiency.
2Loss of energy
If the system delays power transfer to backup source, then power efficiency improves by avoiding unnecessary transitions, but power availability may be compromised during actual failures
Solution Approach 1:
The system continuously monitors AC voltage through RMS measurements and uses feedback control to determine whether to switch to backup power. By comparing real-time voltage measurements against predetermined thresholds, the system accurately distinguishes between transient disturbances and actual failures, enabling delayed switching that improves power efficiency without compromising power availability during genuine failures.
3Device complexity
If the system uses simple voltage threshold comparison, then device complexity is reduced, but measurement precision is insufficient to distinguish transient disturbances from actual failures
Solution Approach 1:
The system replaces complex mechanical or hardware-based voltage stabilization circuits with a computational approach using RMS voltage measurement and software-based threshold comparison. This substitution maintains low device complexity while achieving high measurement precision in distinguishing transient disturbances from actual failures through algorithmic analysis of voltage characteristics.
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
This approach enhances power efficiency and reliability by accurately determining the holdup time, reducing unnecessary transitions and maintaining power availability during AC voltage disturbances, thereby improving data center operations.
Implementation Method 1
obtaining an instantaneous root mean square (RMS) voltage of the system based on an alternating current (AC) source; determining, by a computing device, an emulated capacitor holdup voltage based on the instantaneous RMS voltage
Data Source
AI summary
Disclosed are devices, systems, and methods for operating a backup power source or an uninterruptible power supply (UPS) that can be used in data centers and that provide a backup power source to power the data center when utility power is compromised. A power delivery system that provides power to a primary system may include a UPS with a state timing control system that operates a bypass static switch. The state timing control system can determine when to transition the primary system from the utility power supply to the backup UPS, based on the current AC voltage conditions. The state timing control system may perform modeling to emulate the intermediate DC voltage of an actual rectifier, and particularly emulate the holdup capacitor voltage. The emulated capacitor voltage can be obtained in real time by both an input power model based on RMS utility voltage and the actual rectifier output load.