Modular Power Cell for Medium Voltage Inverters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional medium voltage drive systems are cumbersome, bulky, and expensive due to large DC link capacitors and complex customized isolation systems, limiting scalability and modularity, especially as voltage and power requirements increase.
Innovation Solution
A modular design for medium voltage drive systems incorporating a power cell chamber with moveable and fixed portions, a modular transformer configuration, and a master-slave control scheme, allowing for scalable and reconfigurable power and voltage capabilities, and efficient use of space and materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional fixed enclosed module design is used for power cells, then voltage and power requirements can be met, but foot print and weight increase significantly
Solution Approach 1:
The power cell is divided into two separate portions: a fixed portion containing the DC link capacitor and a moveable portion containing the rectifier and inverter stages. This segmentation allows the heavy capacitor to remain stationary while the power processing components become portable, reducing the effective weight that moves during operation while maintaining full power capability.
Solution Approach 2:
The patent transitions from a monolithic three-dimensional module to a distributed configuration where components are separated in space. The moveable portion can be slidably positioned within the cabinet, effectively using spatial dimensionality to decouple weight from mobile components while maintaining electrical connectivity through the fixed portion.
2Power
If conventional fixed enclosed module design is used for power cells, then voltage and power requirements can be met, but system becomes bulky and less scalable
Solution Approach 1:
By separating the power cell into fixed and moveable portions, the patent reduces the footprint of any single unit. The moveable portion can be compactly designed since it doesn't need to house the large capacitor, and multiple such modules can be efficiently arranged in the cabinet to achieve desired power levels with optimized space utilization.
Solution Approach 2:
The moveable portion is designed to be slidable within the cabinet, providing dynamic reconfigurability. This allows the system to adapt its internal layout based on cooling requirements, maintenance access, or different operational configurations, thereby optimizing the use of available space while maintaining full power capability.
3Power
If customized isolation system is implemented for medium voltage applications, then voltage levels up to tens of kilovolts can be handled, but system complexity and cost increase
Solution Approach 1:
The fixed portion containing the DC link capacitor serves multiple functions: it provides energy storage for the inverter, establishes the reference potential for high voltage isolation, and acts as a common interface between the moveable power processing portions. This universal component simplifies the isolation architecture by providing a stable reference point that reduces the complexity of insulation coordination across different voltage levels.
Solution Approach 2:
The fixed portion acts as an intermediary between the moveable rectifier/inverter stages and the external high voltage environment. By placing the large capacitor in this fixed intermediary position, it shields the moveable components from direct exposure to full voltage stress, simplifying the isolation requirements for the moveable portions while still enabling tens of kilovolts capability.
4Reliability
If power cells are designed as fixed enclosed modules, then each module is self-contained, but adaptability to different power and voltage ratings is limited
Solution Approach 1:
The segmentation into fixed and moveable portions creates a hierarchical modularity where the fixed portion serves as a universal platform that can accommodate different moveable portions configured for various power and voltage ratings. This maintains self-containment at the component level while enabling system-level adaptability through reconfiguration of the moveable sections.
Solution Approach 2:
The slidable moveable portion enables dynamic reconfiguration of the power cell architecture. Different numbers and types of moveable portions can be installed or removed from the fixed portion to adapt to different power and voltage requirements, while each configuration remains a self-contained, reliable module during operation.
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
The modular design reduces cell footprint and weight, increases power density, and enables efficient scalability to meet a wide range of power and voltage requirements, improving system efficiency and reducing costs.
Implementation Method 1
The moveable portion includes a rectifier stage to rectify an input signal received from a secondary winding of a transformer to provide a rectified signal
Implementation Method 2
an inverter stage having a plurality of switching devices to receive a DC signal and output an AC signal
Implementation Method 3
The fixed portion includes a DC link having at least one capacitor to receive the rectified signal and provide the DC signal to the inverter stage
Data Source
AI summary
In one embodiment, a power cell chamber for a drive system includes moveable and fixed portions. The moveable portion includes a rectifier stage to rectify an input signal received from a secondary winding of a transformer to provide a rectified signal and an inverter stage having a plurality of switching devices to receive a DC signal and output an AC signal. This moveable portion can be slidably adapted within a cabinet of the drive system. In turn, the fixed portion includes a DC link having at least one capacitor to receive the rectified signal and provide the DC signal to the inverter stage.