UPS Bypass Switch Timing via Emulated Holdup Capacitor Voltage
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Solution Overview
Problem
Existing UPS systems face challenges in determining the optimal timing for transitioning from utility AC power to a backup power source, leading to inefficiencies and reliability issues due to frequent and premature switching, which affects datacenter availability and power efficiency.
Innovation Solution
A system comprising a switch, a rectifier, and a control element with an emulation module that determines the emulated capacitor holdup voltage based on the instantaneous RMS voltage of the AC source, allowing for a delayed transition to the backup power source when the holdup voltage falls below a threshold, thereby improving power efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system transitions to backup power source immediately when AC power abnormality is detected, then reliability is improved by ensuring continuous power supply, but power efficiency deteriorates due to frequent and premature switching to backup source
Solution Approach 1:
The system performs preliminary assessment by calculating emulated capacitor holdup voltage based on instantaneous RMS voltage before triggering the transition to backup power source. This preliminary action allows the system to determine whether the AC power abnormality is transient or sustained, avoiding premature switching and improving power efficiency while maintaining reliability.
2Device complexity
If the system uses simple voltage threshold comparison for transition timing, then device complexity is reduced, but measurement precision deteriorates leading to inaccurate holdup time determination
Solution Approach 1:
The system introduces an emulated capacitor holdup voltage as an intermediary parameter that bridges the simple voltage threshold comparison and accurate holdup time determination. This intermediary allows the control system to maintain simplicity while achieving precise measurement by comparing the emulated voltage against threshold values, thereby resolving the contradiction between device complexity and measurement precision.
3Loss of energy
If the system delays transition to backup power source, then power efficiency is improved by avoiding unnecessary switching, but reliability deteriorates due to extended operation on compromised power supply
Solution Approach 1:
The system continuously monitors instantaneous RMS voltage and recalculates emulated capacitor holdup voltage in real-time, creating a feedback mechanism that dynamically adjusts the transition timing. This feedback allows the system to delay transition only as long as the emulated voltage indicates sufficient holdup capacity, ensuring reliability is maintained while improving power efficiency by avoiding premature switching.
4Measurement precision
If the system performs real-time RMS voltage analysis and emulated voltage calculation, then measurement precision is improved for accurate transition timing, but device complexity increases due to additional computational requirements
Solution Approach 1:
The system creates a simplified computational model (emulated capacitor holdup voltage) that copies the essential behavior of the actual capacitor voltage without requiring complex real-time simulation. This copying approach maintains measurement precision for transition timing while reducing device complexity by using a tractable mathematical model based on instantaneous RMS voltage rather than full system state simulation.
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 solution enables more accurate determination of the holdup time, reducing unnecessary transitions and improving datacenter availability by delaying the switch to the backup power source, thus enhancing both power efficiency and reliability.
Implementation Method 1
The emulated capacitor holdup voltage may be determined based on a root mean square (RMS) voltage value associated with the AC source
Data Source
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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.