Shared Inductor Front-End Converter for UPS Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing uninterruptible power supply (UPS) systems face inefficiencies and increased component costs due to the need for separate converters and high-rated components during both online and on-battery modes, as well as complex control requirements and space constraints in three-phase applications.
Innovation Solution
The implementation of a front-end converter with shared components, including a single inductor and current transformer, and a floating battery configuration, which allows for reduced component count, simplified control, and improved efficiency by using relays to switch between AC and battery sources during different operational modes, and bypassing diodes during on-battery mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate converters and high-rated components are used for both online and on-battery modes, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the online mode converter and on-battery mode converter into a single integrated front-end converter. The same converter circuitry processes power from either AC input or battery input, eliminating the need for separate converter designs. This merging reduces component count and complexity while maintaining reliable power conversion in both operational modes through a unified power processing path.
Solution Approach 2:
The front-end converter is designed with universal functionality to handle multiple power sources (AC input and battery input) and multiple operational modes (online and on-battery modes) using the same hardware infrastructure. The converter can seamlessly switch between processing AC power and battery power without requiring mode-specific converter circuits, thereby reducing overall system complexity while ensuring reliable operation across all modes.
2Reliability
If separate converters are used for online and on-battery modes, then operational reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the online mode converter and on-battery mode converter into a single shared front-end converter, significantly reducing the total number of components that need to be manufactured and assembled. This consolidation lowers manufacturing costs by reducing parts count, assembly steps, and quality control requirements, while the converter maintains reliable operation in both modes through unified circuit design.
Solution Approach 2:
The universal front-end converter design allows a single component to serve multiple functions across different operational modes, reducing the bill of materials and manufacturing complexity. By designing the converter to universally handle both AC and battery inputs with the same circuitry, the patent reduces per-unit manufacturing costs while ensuring consistent reliability across mode transitions.
3Reliability
If high-rated components are used for both operational modes, then system reliability is improved, but device volume and weight increase
Solution Approach 1:
The patent combines the power processing functions for online and on-battery modes into a single converter, allowing the use of appropriately rated components rather than oversized components designed for the worst-case scenario of two separate high-power converters. This merging enables optimized component selection based on actual operational requirements, reducing overall converter volume while maintaining sufficient reliability margins.
4Reliability
If complex control systems are used to manage mode transitions, then operational reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the control functions for online mode and on-battery mode into a single unified control system. The same controller manages power conversion, monitors input sources, and executes mode transitions, eliminating the need for separate control circuits for each mode. This unified approach simplifies the overall control architecture while maintaining reliable mode transitions through centralized monitoring and control logic.
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 solution reduces the number of components, lowers costs, enhances efficiency, and simplifies control implementation, allowing for higher power density and reduced heat sinking, while maintaining stable voltage levels across both online and on-battery operations.
Implementation Method 1
the boost circuit configured to rectify incoming alternating-current (AC) power to provide a positive voltage across a positive capacitor coupled between the positive node and the neutral node and to provide a negative voltage across a negative capacitor coupled between the negative node and the neutral node
Implementation Method 2
an inductor coupled to the first input of the boost circuit; where the inductor is shared between an online mode of the converter and an on-battery mode of the converter and the battery is coupled through the inductor to the first input of the boost circuit during the on-battery mode
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A front-end converter in an uninterruptible power supply system includes: a boost circuit having first and second inputs, and positive, negative, and neutral output nodes, and being configured to provide a positive capacitor voltage between the positive and neutral nodes and to provide a negative capacitor voltage between the negative and neutral nodes; an inductor coupled to the first input; first AC and neutral AC inputs to receive AC power; a battery; a first device to selectively couple the inductor to the first AC input or a positive port of the battery; and a second device to selectively couple a negative port of the battery to the second input; where the inductor is shared between an online mode of the converter and an on-battery mode of the converter and the battery is coupled through the inductor to the first input during the on-battery mode.