Dual-Structure Power Cell Inverter for High Voltage
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Solution Overview
Problem
Conventional 6-level cascaded H-bridge multilevel inverters face increased development and manufacturing costs, as well as reduced reliability, when dealing with high input voltages due to insulation and core switching element rating restrictions, necessitating the development of new SMPS capable of handling various DC voltages.
Innovation Solution
The implementation of an inverter with a dual structure power cell, where two power cells receiving low voltage are connected in series to form a high voltage power cell, allowing the use of existing SMPS and reducing the need for separate high voltage SMPS development, and utilizing a single controller to control two SMPSs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional 6-level cascaded H-bridge multilevel inverter is used with high input voltage, then the inverter can handle high voltage applications, but development cost and manufacturing cost increase due to insulation and core switching element rating restrictions
Solution Approach 1:
The power cell is divided into two separate low-voltage power cells (first and second power cells) that operate independently at lower voltage levels. Each power cell has its own rectification unit, DC link unit, and inverter unit, allowing them to be manufactured using existing low-voltage components and processes, thereby reducing development and manufacturing costs while achieving high-voltage capability through series connection
Solution Approach 2:
Two low-voltage power cells are combined in series connection to create a high-voltage power cell. The series connection of the two power cells results in an output voltage that is the sum of individual power cell voltages, enabling the system to handle high input voltages (e.g., 1270V) using existing low-voltage components
2Adaptability or versatility
If separate high voltage SMPS is developed for high voltage power cells, then the SMPS can be optimized for high voltage operation, but product development cost increases
Solution Approach 1:
The SMPS designed for low-voltage power cells is made universal by applying it to both the first and second power cells. The controller controls both SMPS units, and the SMPS can operate with DC voltages from both power cells (e.g., 890V and 1270V), eliminating the need for separate high-voltage SMPS development and reducing product development costs
3Power
If multiple independent power cells are used to achieve high voltage, then the inverter can operate at high voltage levels, but inverter volume increases
Solution Approach 1:
Two power cells are merged into a single dual-structure power cell configuration, reducing the overall number of separate power cell units. The series connection of the first and second power cells creates one functional high-voltage power cell, which helps minimize inverter volume while achieving the desired high voltage output
Data Source
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AI summary
The present disclosure relates to an inverter with power cell of dual structure for use in high input voltage by changing a conventional 6-level cascaded H-bridge multilevel inverter to thereby reduce product development cost, manufacturing cost and volume of the product, the inverter including a first SMPS (Switching Mode Power Supply) connected to a first power cell region, a second SMPS connected to a second power cell region and a controller connecting the first and second SMPSs, where each phase is formed by serially connecting a plurality of power cells formed with a plurality of stages operated by receiving a power supplied from a phase shift transformer, and each of the plurality of power cells is mutually connected, and includes the first power cell region and the second power cell region independently operating.