UPS Bypass Switchover Using Voltage-Potential Fault Response
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Solution Overview
Problem
Conventional uninterruptible power supplies (UPS) experience a delay in switching from an inverter to a bypass unit when a load fault is detected, leading to reduced power supply reliability due to the time required for the controller to determine the fault and trip circuit breakers or fuses.
Innovation Solution
The UPS system automatically switches to a bypass unit based on a change in voltage potential, ensuring the inverter outputs a higher voltage than the input, thereby reducing the switchover time and enabling the bypass to provide a larger current to disconnect faulty loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller determines fault and switches from inverter to bypass unit, then power supply reliability is improved, but switchover time is extended due to controller determination delay
Solution Approach 1:
The patent applies preliminary action by pre-configuring the bypass unit with bidirectional SCRs and establishing voltage comparison thresholds before faults occur. The system continuously monitors inverter output voltage and prepares the bypass path in advance, so when a fault occurs, the switchover can execute immediately without waiting for controller determination, thus reducing switchover time while maintaining reliability
Solution Approach 2:
The patent replaces the controller-based determination system with a voltage-comparison-based automatic switching mechanism. Instead of relying on the controller to detect faults and initiate switching, the system uses voltage threshold comparison to automatically trigger the bypass unit when inverter output voltage drops below the threshold, eliminating controller determination delay and reducing switchover time
2Extent of automation
If the inverter outputs higher voltage than bypass input, then automatic switchover is enabled, but voltage control complexity increases
Solution Approach 1:
The patent applies parameter changes by establishing a specific voltage relationship where the inverter output voltage is controlled to be higher than the bypass input voltage. This voltage parameter difference enables automatic current redirection to the bypass unit when faults occur, achieving automatic switchover through simple voltage comparison without complex control logic
Solution Approach 2:
The patent uses voltage comparison as an intermediary mechanism between the inverter and bypass unit. By comparing the inverter output voltage with the bypass input voltage, the system automatically determines when to switch without requiring complex controller intervention, thus achieving automation while keeping control complexity manageable
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 supply reliability by minimizing the switchover time from the inverter to the bypass, allowing normal loads to continue operating while faulty loads are disconnected.
Implementation Method 1
The controller is configured to: detect a voltage that is input by the first power input to the bypass, and control a voltage that is output by the inverter unit to be greater than the voltage that is input by the first power input to the bypass, so that when currents are input to the bypass and the inverter unit separately, the current that is output by the inverter unit is transmitted to the load end
Data Source
Figure 1~2
Figure 3
Figure 4A
AI summary
This application provides an uninterruptible power supply and a power supply switchover method. The uninterruptible power supply includes a first power input, a second power input, a load end, a bypass, a main circuit, and a controller. The bypass includes a bidirectional switch, and the main circuit includes a rectifier unit and an inverter unit. The controller is configured to control a voltage that is output by the inverter unit to be greater than a voltage that is input to the bypass, so that when currents are input to the bypass and the inverter unit separately, a current that is output by the inverter unit is transmitted to the load end. In response to a fault at the load end, the voltage that is output by the inverter unit suddenly drops below the voltage that is input to the bypass, and a current that is output by the bypass is transmitted to the load end. The uninterruptible power supply provided in this application is used, so that when the fault occurs on the load end, because the voltage that is output by the inverter unit suddenly drops below the voltage input to the bypass, based on a change in an electric potential, the inverter unit is switched to the bypass to output the current to the load end. This reduces switchover time from the inverter unit to the bypass, and improves power supply reliability of the uninterruptible power supply.