Four-Quadrant UPS Inverter for Main Power Supplementation
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Solution Overview
Problem
Existing uninterruptible power supplies (UPSs) face challenges in providing sufficient power to loads when the main power source is insufficient, as they are limited by the current rating of the UPS, leading to a shortfall in meeting the power demands of the load, which can result in the tripping of circuit breakers.
Innovation Solution
A power device equipped with a four-quadrant inverter that operates in both current-source and voltage-source modes, allowing it to supplement main power with backup power from a backup power source when the load's power requirements exceed what is available from the main source, ensuring continuous and reliable power delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the UPS current rating is increased to meet higher power demands, then the power delivery capability is improved, but the device complexity and cost increase
Solution Approach 1:
The UPS system is segmented into two independent power sources (main power source and backup power source), each with its own power delivery capability. The controller divides the total power demand between these two sources, allowing the system to meet high power demands without requiring a single oversized UPS component that would increase complexity.
Solution Approach 2:
The backup power source serves multiple functions: it supplements the main power source during high demand, provides full power during main source failure, and can be charged from the main power source when demand is low. This multi-functionality allows the system to achieve high power capability without proportionally increasing device complexity.
2Reliability
If the UPS current rating is increased to prevent circuit breaker tripping, then the reliability of power supply is improved, but the device complexity and cost increase
Solution Approach 1:
The power supply system is segmented into main and backup sources, with the controller managing power distribution to ensure continuous supply. This segmentation allows the system to maintain reliability during main source failures without requiring the entire UPS to be oversized for peak demand scenarios.
Solution Approach 2:
The controller acts as an intermediary that monitors power demand and source availability, dynamically adjusting power distribution between the main and backup sources. This mediation ensures reliable power supply by preventing circuit breaker tripping through intelligent load management rather than hardware oversizing.
3Reliability
If the UPS operates in voltage-source mode during main power failure, then the power quality is improved, but the ability to supplement power during main power availability is reduced
Solution Approach 1:
The UPS operates in different modes (voltage-source mode and current-source mode) depending on real-time conditions. During main power failure, it switches to voltage-source mode for high power quality. During main power availability with high demand, it switches to current-source mode for power supplementation. This dynamic adaptation resolves the contradiction between power quality and operational flexibility.
Solution Approach 2:
The operational parameters of the UPS (voltage-source vs. current-source mode) are changed based on system conditions. The controller adjusts these parameters to optimize performance for the current operational state, allowing the system to maintain both high power quality when needed and operational flexibility for power supplementation when needed.
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 the UPS to provide output power derived from both the main and backup sources, effectively addressing the shortfall in main power, ensuring uninterrupted power supply to loads by dynamically adjusting power distribution between the two sources.
Implementation Method 1
a four-quadrant inverter coupled to the first input, the second input, and the output; and at least one controller configured to control the four-quadrant inverter to provide power derived from the first input to the second input to charge the backup power source, and provide power derived from the second input to the output to supplement the main power
Data Source
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AI summary
According to at least one aspect of the disclosure, a uninterruptible power supply (102) includes a first input (200) configured to be coupled to, and receive main power from, a main power source (104), a second input (202) configured to be coupled to, and receive backup power from, a backup power source (106), an output (204) configured to be coupled to at least one load (108), at least one current sensor (206), a four-quadrant inverter (214) coupled to the first input, the second input, and the output, and at least one controller (218) configured to control the four-quadrant inverter to provide power derived from the first input to the second input to charge the backup power source, and provide power derived from the second input to the output to supplement the main power.