Three-level Rectifier Modular Bridge Arm Stray Inductance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional three-level rectifiers face challenges with high voltage stress, electromagnetic interference (EMI), and complex control due to the increased number of semiconductor switching devices, which also result in a bulky and difficult-to-install structure with high stray inductance.
Innovation Solution
A modular design for three-level rectifiers is implemented, where the upper-half and lower-half bridge arm circuit modules are disposed side by side and facing each other, using a combination of connecting busbars and insulated wires to reduce stray inductance and facilitate installation, and the power semiconductor devices are connected in series to manage voltage stress effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If more power semiconductor switch modules and diode modules are connected in series to achieve higher voltage levels, then the voltage stress of switching devices is reduced, but the bridge arm volume increases and installation becomes difficult
Solution Approach 1:
The bridge arm is divided into multiple independent modules (power semiconductor switch modules and diode modules) connected in series. Each module handles a portion of the total voltage, allowing the system to achieve high voltage capability while maintaining manageable individual module sizes for easier installation and maintenance.
2Reliability
If more power semiconductor switch modules and diode modules are connected in series to achieve higher voltage levels, then the voltage stress of switching devices is reduced, but the stray inductance of commutation loop increases and EMI deteriorates
Solution Approach 1:
The patent combines the power semiconductor switch modules and diode modules into a compact integrated structure with minimized commutation loop area. By merging these components closely together and optimizing their spatial arrangement, the stray inductance is reduced while maintaining the series connection configuration needed for high voltage capability.
3Reliability
If three-level technology is used to reduce voltage stress and improve harmonic waves, then the voltage stress of switching devices is reduced, but the number of semiconductor switching devices increases and control becomes more complex
Solution Approach 1:
The three-level rectifier circuit is segmented into standardized modular units (switch modules and diode modules) that can be systematically arranged. This modular segmentation makes the control of multiple switching devices more manageable by providing a regular, repeating structure that simplifies control strategy implementation.
4Power
If conventional bridge arm structure is used with series-connected modules, then higher voltage levels are achieved, but installation and maintenance become difficult
Solution Approach 1:
The bridge arm is divided into independent, standardized modules that can be easily assembled and disassembled. This segmentation allows for simplified installation procedures and easier maintenance, as individual modules can be replaced without affecting the entire bridge arm structure.
Solution Approach 2:
The modules are designed with pre-configured connection terminals and standardized interfaces, allowing for quick connection and disconnection during installation and maintenance operations. This preliminary preparation of connection structures significantly reduces the time and complexity of assembly and repair tasks.
Data Source
AI summary
A three-level rectifier includes at least one phase bridge arm that includes an upper-half and a lower-half bridge arm circuit modules. The upper-half bridge arm circuit module includes a first diode unit and a second diode unit that are in series connection, and a first power semiconductor switch unit. The lower-half bridge arm circuit module includes a third diode unit and a fourth diode unit that are in series connection, and a second power semiconductor switch unit. These first and second power semiconductor switch units are connected to the neutral point of the capacitor unit; the second diode unit and the third diode unit are connected to the alternating-current terminal; the first diode unit and the fourth diode unit are respectively connected to the positive terminal and negative terminal of the direct-current bus. The two circuit modules are disposed side by side and facing each other.