UPS Bypass Switching Circuit Phase Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing power supply systems for uninterruptable power-supply systems (UPS) face challenges in quickly switching power supplies without causing magnetizing inrush currents when the UPS is stopped, and in synchronizing the voltage of the bypass power supply with the output voltage of the UPS.
Innovation Solution
A power supply system that includes a switching circuit which turns on a thyrister switch when the phase of the bypass power supply's output voltage matches the phase of the UPS's output voltage at the time of UPS shutdown, allowing for rapid switching and synchronization, thereby reducing the switching time and suppressing magnetizing inrush currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the bypass power supply is connected to the load immediately when the UPS is stopped, then the switching time is shortened, but a large magnetizing inrush current flows into the load transformer
Solution Approach 1:
The switching circuit performs preliminary action by detecting the phase of the bypass power supply voltage in advance and determining the optimal switching timing before actually connecting the bypass power supply to the load. This preliminary phase detection and timing determination ensures that the switch is turned on only when the voltage phases align, preventing magnetizing inrush current while enabling rapid switching.
Solution Approach 2:
The switching circuit uses feedback by continuously monitoring the phase of the bypass power supply voltage and comparing it with the required phase at the stopped timing. This feedback mechanism allows the circuit to determine the precise moment when phase equality occurs and trigger the switch at that optimal timing, thereby suppressing inrush current while achieving fast switching.
2Loss of time
If the output switch of the UPS is turned off immediately, then the switching time is shortened, but the magnetizing inrush current may flow into the isolation transformer
Solution Approach 1:
The switching circuit acts as an intermediary between the output switch and the isolation transformer by controlling the timing of the output switch turn-off. It mediates the switching process by coordinating the turn-off timing with the phase detection of the bypass power supply, ensuring that the switch is turned off at the optimal moment when phase equality occurs, thereby preventing inrush current into the isolation transformer while maintaining fast switching.
3Productivity
If the bypass power supply voltage is not synchronized with the UPS output voltage, then the switching can be performed, but a large magnetizing inrush current flows and voltage instability occurs
Solution Approach 1:
The switching circuit applies parameter changes by monitoring the phase parameter of the bypass power supply voltage and determining the optimal switching timing based on phase equality. By changing the timing parameter dynamically based on real-time phase detection, the circuit ensures that switching occurs only when voltage parameters are synchronized, thereby maintaining both switching capability and voltage stability.
Data Source
AI summary
A power supply system includes an uninterruptable power-supply apparatus supplying power to a load, a switch connecting a bypass power supply to the load, and a switching circuit turning the switch on when the uninterruptable power-supply apparatus is stopped. In a case where the uninterruptable power-supply apparatus is stopped, the switching circuit turns the switch on when a phase of an output voltage of the bypass power supply is equal to a phase of an output voltage of the uninterruptable power-supply apparatus at a stopped timing.