UPS Rectifier Fuse Layout for Lower Current Protection
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Solution Overview
Problem
Existing uninterruptible power supply (UPS) systems have large circuit volumes, inefficient utilization, high costs, and difficulties in protecting components due to large fuses and idle rectifier circuits when using energy storage apparatus.
Innovation Solution
A UPS system with a three-phase rectifier circuit, inverter circuit, and charge/discharge circuit, utilizing a switching circuit to connect energy storage apparatus electrodes to single-phase rectifier units through multiple fuses, allowing separate line connections for reduced fuse specifications and improved protection, and a controller for fast switching between power sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a large fuse is disposed for the fuse at the port connected to the energy storage apparatus to meet power requirements in energy storage mode, then the power requirement is satisfied, but the fuse brings a large current and makes it difficult to perform internal protection on the UPS system
Solution Approach 1:
The patent divides the single large fuse into multiple smaller fuses (first fuses and second fuses) connected in parallel between the positive and negative electrodes of the energy storage apparatus and the rectifier circuit. This segmentation allows each fuse to handle a portion of the total current, reducing the current burden on each individual fuse while maintaining the required power capacity. The segmented fuse configuration enables better protection characteristics and facilitates internal protection of the UPS system.
2Power
If the rectifier circuit is disposed to be completely independent from the charge/discharge circuit in the energy storage mode, then the power conversion function is achieved, but the rectifier circuit is in an idle state which reduces circuit utilization and brings disadvantages in costs and space
Solution Approach 1:
The patent designs the rectifier circuit to serve dual functions: it operates as a traditional rectifier when mains power is available, and it functions as a power conversion circuit connected to the energy storage apparatus when mains power fails. The switching circuit enables the rectifier circuit to be dynamically connected to either the mains power input or the energy storage apparatus, eliminating idle states and improving circuit utilization. This multi-functional design reduces space and cost requirements while maintaining full power conversion capability.
3Power
If the charge/discharge circuit is always in a working state in energy storage mode to meet rated power requirements, then the power supply continuity is ensured, but the required circuit volume is large
Solution Approach 1:
The patent merges the charge/discharge circuit with the rectifier circuit through a switching mechanism. The same power conversion circuitry is used for both charging the energy storage apparatus from mains power and discharging it to supply power during mains failure. This consolidation eliminates the need for separate dedicated charge and discharge circuits, significantly reducing the overall circuit volume while maintaining the ability to handle rated power requirements.
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
Reduces fuse current specifications, improves circuit utilization, and enhances component protection while minimizing costs and volume by enabling fast switching between mains power and energy storage modes.
Implementation Method 1
The three-phase rectifier circuit is configured to convert alternating currents input by the three-phase alternating current input ends into direct currents
Implementation Method 2
The three-phase inverter circuit is configured to convert the direct currents into alternating currents
Data Source
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AI summary
This application provides an uninterruptible power supply system, to reduce costs of an uninterruptible power supply, improve circuit utilization, reduce specifications of a fuse, and better protect a component in a circuit. The uninterruptible power supply includes three-phase alternating current input ends, a switching circuit, a three-phase rectifier circuit, a three-phase inverter circuit, a charge/discharge circuit, at least two first fuses, and at least two second fuses. Each phase rectifier circuit includes two single-phase rectifier units that are connected in parallel. One first fuse is separately connected in series to at least two phase lines in a three-phase line between a positive electrode of an energy storage apparatus and an input end of one single-phase rectifier unit in each phase rectifier circuit. One second fuse is separately connected in series to at least two phase lines in a three-phase line between a negative electrode of the energy storage apparatus and an input end of the other single-phase rectifier unit in each phase rectifier circuit. In this way, the positive electrode and the negative electrode of the energy storage apparatus may be connected to a plurality of fuses after being connected to the uninterruptible power supply system, thereby reducing the specifications of the fuse current of a single fuse.