Cascaded H-Bridge Interface Without DAB Converters
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Solution Overview
Problem
Current systems for interfacing AC and DC systems, particularly using cascaded H-bridge inverters with dual-active bridge-isolated DC-DC converters, face issues with battery management, stability, reliability, and high power losses, as well as increased operational costs.
Innovation Solution
A system is provided that includes multiple H-bridge inverters and battery modules, with battery packs placed on the high-side floating DC busses, bypassing dual-active bridge converters for improved efficiency and reliability, and incorporating dedicated DC/DC converters for voltage regulation, along with insulation and cooling enhancements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If cascaded H-bridge inverters are combined with dual-active bridge-isolated DC-DC converters to interface AC and DC systems, then the system can achieve voltage matching and power conversion, but power losses increase and operational costs rise
Solution Approach 1:
The patent extracts and removes the dual-active bridge-isolated DC-DC converter from the traditional cascaded H-bridge inverter system. By eliminating this intermediate converter stage, the system directly interfaces the AC system with the DC system through the H-bridge inverters, thereby reducing the number of conversion stages and associated power losses while maintaining the essential power conversion capability.
2Stability of the object's composition
If dual-active bridge-isolated DC-DC converters are used in the interfacing system, then voltage regulation is achieved, but system complexity and operational costs increase
Solution Approach 1:
The patent removes the dual-active bridge-isolated DC-DC converter from the system architecture. The voltage regulation function is then achieved through optimized control strategies of the H-bridge inverters and direct DC bus voltage management, eliminating the need for the complex intermediate converter stage while maintaining stable voltage regulation.
3Adaptability or versatility
If traditional interfacing systems are used, then AC and DC systems can be connected, but battery management and system reliability are compromised
Solution Approach 1:
The patent eliminates the dual-active bridge-isolated DC-DC converter that was causing reliability issues in battery management. The simplified direct interfacing approach through H-bridge inverters provides better control over battery charging and discharging operations, improving overall system reliability while maintaining the ability to connect AC and DC systems.
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 configuration reduces power losses, enhances system stability and reliability, and lowers operational costs by optimizing battery management and converter efficiency, while allowing for seamless integration with medium-voltage grids and low-voltage battery systems.
Implementation Method 1
the two or more H-bridge inverters may be configured for receiving an AC power from the AC system... converting the AC power into a DC power... transmitting the DC power to one or more of the two or more battery modules and the DC system
Implementation Method 2
The two or more battery modules may be configured for storing the DC power based on charging of two or more batteries... supplying the DC power to the two or more H-bridge inverters... based on discharging of the two or more batteries
Data Source
AI summary
The present disclosure provides a system of provisioning an interface between an AC system and a DC system. Further, the system may include an inverter device comprising two or more H-bridge inverters. Further, the two or more H-bridge inverters include a first H-bridge inverter and a second H-bridge inverter. Further, the first-primary positive terminal and the first-primary negative terminal of the first inverter may be connectable with the AC system and the second-primary positive terminal of the second inverter respectively. Further, the system may include two or more battery modules. Further, a first-secondary terminal of the first inverter and a second-secondary terminals of the second inverter is connected with a first battery module and a second battery module respectively. Further, each of the first-secondary terminals and the second-secondary terminals may be connected with the DC system.