Medium-Voltage UPS Transformer Winding Configuration
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Solution Overview
Problem
Current low-voltage uninterruptible power supplies (UPS) face challenges in powering large data centers due to increased current demands, which can exceed the limits of low-voltage switchgear, and medium-voltage conversion offers advantages in efficiency and cabling costs, but existing solutions struggle to efficiently handle and regulate medium voltages effectively.
Innovation Solution
A multi-mode medium-voltage UPS system that includes a transformer with primary, secondary, and tertiary windings, a rectifier, an inverter, and a voltage-boost converter, configured to receive medium voltage input and provide a well-regulated three-phase output, using a double-conversion path with a bypass option, and controlled by a processor to manage power quality and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low-voltage UPS is used to power large data centers, then the system can provide quality power without interruption, but the current magnitude increases significantly exceeding the limits of low-voltage switchgear
Solution Approach 1:
The patent transforms the UPS system from low-voltage operation to medium-voltage operation by changing the voltage parameter. The medium-voltage UPS receives 4.16kV or 13.8kV input and provides medium-voltage output, which reduces current magnitude for the same power level, allowing it to power large data centers without exceeding switchgear limits while maintaining power quality
2Loss of energy
If medium-voltage conversion is implemented in the UPS, then operating efficiency increases and cabling cost decreases, but the system complexity increases
Solution Approach 1:
The patent changes the operating voltage parameter from low-voltage to medium-voltage, which reduces current and thereby decreases I²R losses in cables and equipment, improving operating efficiency. The medium-voltage design also reduces cabling costs due to lower current requirements
Solution Approach 2:
The patent introduces a medium-voltage transformer as an intermediary component that steps down the medium-voltage input to appropriate levels for internal UPS operations and output. This transformer enables efficient medium-voltage operation while managing the complexity through a well-understood isolation and voltage transformation device
3Power
If medium-voltage input is received, then the current to be handled by the UPS and output cables decreases, but voltage regulation becomes more challenging
Solution Approach 1:
The patent employs multiple voltage transformation stages with precisely controlled turns ratios to achieve accurate voltage regulation. The system transforms medium-voltage input through intermediate stages to produce stable output voltages, with each transformer stage contributing to the overall voltage precision
Solution Approach 2:
The patent implements feedback control mechanisms that monitor output voltage and adjust transformer tap positions or switching operations to maintain precise voltage regulation. This feedback system compensates for input voltage variations and load changes, ensuring stable output despite the challenges of medium-voltage operation
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 system efficiently operates from medium voltage inputs, providing reliable and well-regulated power to loads, reducing harmonic content, and minimizing footprint and device stress, while maintaining high efficiency and reliability, even during low-line conditions or power outages.
Implementation Method 1
a transformer configured to receive input power, the transformer including a primary winding, a secondary winding, and a tertiary winding
Implementation Method 2
rectifying, using a rectifier coupled to the secondary winding, the input power to regulate a DC link voltage across a DC link
Implementation Method 3
generating a first regulated voltage using the inverter coupled to an output of the rectifier
Data Source
AI summary
An uninterruptible power supply (UPS) and methods of operation are provided. The UPS includes a transformer configured to receive power from a utility. The transformer includes a primary winding, a secondary winding, and a tertiary winding. The UPS also includes a rectifier coupled to the secondary winding and an inverter coupled to an output of the rectifier, wherein a connection between the rectifier and the inverter defines a DC link. The inverter is configured to output a first regulated voltage configured to be provided to a load. The UPS further includes a voltage-boost converter coupled to the tertiary winding and is configured to output a second regulated voltage to be combined with the first regulated voltage.