UPS Neutral Voltage Control via Relay and LC Circuit
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Solution Overview
Problem
Conventional UPS systems face issues with potential unbalance between output neutral and ground terminals, leading to unsafe power delivery to loads and increased costs due to the use of isolated transformers, which reduce efficiency.
Innovation Solution
A UPS system design that includes a rectification circuit, power calibrating conversion circuit, inverting conversion circuit, LC circuit, and relay switch, where the relay switch connects the input neutral terminal with the output neutral terminal through the LC circuit, forming a common neutral status and maintaining low voltage levels, eliminating the need for isolated transformers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If isolated transformers are installed to achieve specific voltage requirements, then the voltage level between output neutral terminal and output ground terminal can be controlled, but the costs and occupying spaces of the UPS system increase
Solution Approach 1:
The patent extracts and eliminates the isolated transformer from the UPS system by implementing a direct connection between input and output neutral terminals through a relay switch. This removes the unnecessary transformation component while maintaining the required voltage level control through the LC circuit and relay-based neutral point connection.
Solution Approach 2:
The relay switch serves multiple functions: it connects the input neutral terminal to the output neutral terminal to establish a common neutral reference, it works with the LC circuit to control voltage levels, and it enables the system to operate without isolated transformers. This multi-functional approach replaces the specialized transformer component.
2Reliability
If isolated transformers are installed to achieve specific voltage requirements, then the voltage level between output neutral terminal and output ground terminal can be controlled, but the total power supply conversion efficiency of the UPS system is reduced
Solution Approach 1:
The patent replaces the electromagnetic transformation mechanism of isolated transformers with an electronic switching mechanism using relay switches and LC circuits. This substitution eliminates the energy losses associated with transformer magnetic core hysteresis and copper losses, thereby improving power supply conversion efficiency while maintaining voltage level control.
3Adaptability or versatility
If the output neutral terminal is under floating status, then the voltage level between output neutral terminal and output ground terminal cannot be controlled, but potential unbalance occurs and safe power delivery to load cannot be ensured
Solution Approach 1:
The patent implements a dynamic neutral point connection system where the relay switch can connect or disconnect the input neutral terminal to the output neutral terminal based on system conditions. This dynamic adjustment allows the system to transition between floating and grounded neutral states, ensuring voltage level control and safe power delivery while maintaining adaptability to different operating conditions.
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 design ensures safe and efficient power delivery to loads by matching voltage levels and reducing the risk of electric shock, while also saving costs and maintaining high power supply conversion efficiency.
Implementation Method 1
The LC circuit is coupled between an output neutral terminal and an output ground terminal. The LC circuit includes a first inductor and a first capacitor.
Implementation Method 2
The first capacitor is coupled between the output neutral terminal and the output ground terminal.
Implementation Method 3
The relay switch is coupled between the input neutral terminal and the LC circuit. Moreover, when the relay switch is turned on, the input neutral terminal is connected with the output neutral terminal through the LC circuit.
Implementation Method 4
The rectification circuit is coupled to the main electricity. The rectification circuit is a full-bridge circuit.
Implementation Method 5
The inverting conversion circuit is coupled to the power calibrating conversion circuit.
Data Source
AI summary
An uninterruptible power supply system including a rectification circuit, a power calibrating conversion circuit, an inverting conversion circuit, an LC circuit, a first output switch, a second output switch and a relay switch is disclosed. The rectification circuit couples to the main electricity. The power calibrating conversion circuit couples to the rectification circuit, and includes an independent drive unit and a switch unit. The inverting conversion circuit couples to the power calibrating conversion circuit. The LC circuit couples between output neutral terminal and output ground terminal. The first output switch couples between the LC circuit and the inverting conversion circuit. The second output switch couples between the inverting conversion circuit and output live terminal. The relay switch couples between the input neutral terminal and the LC circuit. When the relay switch turns on, the input neutral terminal connects with the output neutral terminal through the LC circuit.