Series Power Injection in Line VFI UPS Bypass Mode
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Solution Overview
Problem
Existing uninterruptible power supplies (UPSs) face efficiency losses due to double-conversion processes and compromised output power quality when using bypass lines.
Innovation Solution
A power system with a series power injector and capacitor configuration that bypasses the rectifier and inverter under certain conditions, using a controller to manage input power distribution and correct deviations through the capacitor to maintain efficiency and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If double-conversion process is used in existing UPSs, then output power quality is regulated, but efficiency is reduced due to energy losses
Solution Approach 1:
The system dynamically switches between two operational modes: double-conversion mode (when input power quality is poor) and bypass mode with series power injection (when input power quality is good). This dynamic adaptation allows the UPS to optimize efficiency by minimizing double-conversion operations while maintaining output power quality through intelligent mode transitions controlled by the controller based on real-time input power assessment.
Solution Approach 2:
A series power injector is introduced as an intermediary component between the input power source and the load. This mediator injects corrective power in series with the input, compensating for power deviations and quality issues without requiring full double-conversion. The series power injector acts as a bridge that maintains output power quality while reducing energy losses associated with conventional double-conversion architecture.
2Loss of energy
If bypass line is used to improve efficiency, then energy losses are reduced, but output power quality is compromised
Solution Approach 1:
The series power injector serves as an intermediary that enables the bypass line to function effectively while maintaining output power quality. By injecting corrective power in series with the input during bypass mode, the power injector compensates for quality deviations that would otherwise pass through to the load, thus allowing efficiency improvement through bypass operation without sacrificing power quality.
Solution Approach 2:
The system changes the operational parameters of the UPS by introducing series power injection capability. This parameter change enables the bypass mode to maintain regulated output power quality by dynamically adjusting the series injected power to compensate for input power deviations, thereby allowing efficient bypass operation without the traditional quality compromise.
3Loss of energy
If series power injector with capacitor is used to bypass conversion circuits, then efficiency is improved by minimizing double-conversion, but device complexity increases
Solution Approach 1:
The UPS system is segmented into distinct functional modules: rectifier, inverter, series power injector, and capacitor. This segmentation allows the series power injector and capacitor to be added as a separate power quality management module without fundamentally redesigning the entire UPS architecture. The modular segmentation enables efficiency improvement through selective bypass operation while containing the increase in device complexity to a specific functional segment.
Solution Approach 2:
The series power injector with capacitor serves multiple functions: it corrects power deviations, maintains output power quality during bypass mode, and enables efficient operation by minimizing double-conversion. This multi-functionality justifies the added device complexity by consolidating several power quality management tasks into a single integrated module, thereby improving overall system efficiency without proportionally increasing complexity.
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
Improves efficiency by minimizing double-conversion while maintaining high output power quality by selectively bypassing conversion circuits and correcting power deviations.
Implementation Method 1
A series power injector and capacitor configuration that bypasses the rectifier and inverter under certain conditions
Data Source
AI summary
Examples of the disclosure include a power system comprising a first output configured to be coupled to a load, a second output configured to be coupled to the load, a first input configured to be coupled to a power source, a second input configured to be coupled to the power source, a switch configured to switchably couple the second input to the second output, a series power injector coupled to a capacitor, the capacitor being coupled in series with the second output, and at least one controller configured to control the switch to couple the second input to the second output, and disable, based on controlling the switch to couple the second input to the second output, an inverter output power to the load.