Modular Power Conversion Circuit for Reliable Auxiliary Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medium voltage direct current bus with energy storage systems face challenges in providing reliable auxiliary power supply due to low isolation voltage and inefficient modular design, leading to potential power losses and safety hazards during uninterrupted operation.
Innovation Solution
A power conversion system with at least two power modules and a diode configuration, where each module includes a switching circuit, an auxiliary power supply unit, and capacitors in parallel connections, forming an energy transfer loop to ensure continuous power supply even when one module outputs zero voltage, eliminating the need for grid frequency transformers and enhancing modularization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If power is drawn from the input port of each power module through an isolation transformer, then the auxiliary power supply can be easily implemented, but the isolation voltage is low and reliability is reduced when power modules fail or are bypassed
Solution Approach 1:
The system divides the power supply function into two independent parts: the first capacitor provides power to the auxiliary power supply unit within the same module, while the second capacitor receives power from adjacent modules through diodes. This segmentation ensures that each module's auxiliary power supply has both local and external power sources, maintaining reliability even when other modules fail or are bypassed.
2Reliability
If grid frequency transformers are used for each power module to ensure high reliability and high output power, then the auxiliary power supply is reliable, but the module becomes bulky and inefficient, making modularization difficult
Solution Approach 1:
The system merges the power supply functions of multiple modules by connecting second capacitors of adjacent modules in series through diodes. This allows power to be transferred between modules, enabling a single power source to support multiple modules and reducing the need for individual grid frequency transformers in each module, thus maintaining reliability while improving modularization.
3Reliability
If the first capacitor provides charge to the auxiliary power supply unit and the second capacitor receives charge from adjacent modules, then the auxiliary power supply reliability is guaranteed, but the circuit structure becomes more complex
Solution Approach 1:
The diode acts as an intermediary component that enables unidirectional power transfer between modules through the second capacitors. This simple passive component facilitates the complex function of inter-module power sharing without requiring active control circuits, thereby maintaining reliability while minimizing the increase in circuit 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
This configuration guarantees reliable auxiliary power supply, reduces module size, and simplifies the circuit structure, thereby improving power density and economic efficiency while ensuring uninterrupted operation.
Implementation Method 1
a first capacitor, where a first port of the first switching circuit is in a parallel connection with the second capacitor, a first port of the first auxiliary power supply unit is in a parallel connection with the first capacitor, the first capacitor is configured to provide charge to the first auxiliary power supply unit
Implementation Method 2
at least two power modules and at least one first diode, where the at least two power modules include a first module and a second module... two ends of the first diode are connected to the first capacitor and the third capacitor, respectively
Data Source
AI summary
A power conversion system, including a first module which includes a first switching circuit, a first auxiliary power supply unit, a first capacitor and a second capacitor, a second module which includes a second switching circuit, a second auxiliary power supply unit, a third capacitor and a fourth capacitor, and a first diode. The first switching circuit is in parallel with the second capacitor, the first auxiliary power supply unit is in parallel with the first capacitor, the first capacitor is connected to the first switching circuit; the second switching circuit is in parallel with the fourth capacitor, the second auxiliary power supply unit is in parallel with the third capacitor, the third capacitor is connected to the second switching circuit; and the first switching circuit is in series with the second switching circuit, and the first diode are connected to the first capacitor and the third capacitor.