Bi-directional Stacked Voltage Source Converter with Segmented DC Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion technologies for AC systems require high-cost semiconductor components and result in low operating frequencies due to high switching losses, necessitating an inverter that can operate with high switching frequency and high efficiency for applications like renewable energy, electric vehicles, and data center power management.
Innovation Solution
A bi-directional stacked voltage source converter system with multiple DC sources and an AC source, utilizing full bridge converters with local controllers to generate sinusoidal voltage waveforms or constant DC outputs, and a system controller for error signal generation and inverter activation, allowing for high-frequency operation and efficient power conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If high voltage switching components are used for parallel grid application, then voltage output capability is improved, but semiconductor component cost increases and operating frequency decreases due to high switching losses
Solution Approach 1:
The patent divides the high voltage power conversion system into multiple independent low voltage modules, each handling a portion of the total power. These modules operate in parallel to achieve the required voltage and power levels without requiring expensive high voltage semiconductor components in each unit. The segmentation allows use of cheaper low voltage switches while maintaining high voltage output capability through modular architecture.
2Stress or pressure
If high voltage switching components are used for parallel grid application, then voltage output capability is improved, but operating frequency decreases due to high switching losses
Solution Approach 1:
By segmenting the power conversion into multiple low voltage modules operating in parallel, each module can switch at high frequencies with low switching losses. The combined output of these high-frequency switching modules achieves the required high voltage capability while maintaining high operating frequencies, avoiding the low-frequency limitation of conventional high voltage switching approaches.
3Loss of energy
If low switching frequency is used due to high switching losses, then semiconductor component stress is reduced, but large and expensive low pass filtering components are required
Solution Approach 1:
The patent employs multiple parallel low voltage modules that switch at high frequencies, which reduces individual module switching losses. The high switching frequency operation naturally produces smaller required filter components compared to low frequency operation, and the modular structure allows for distributed filtering that reduces overall component size and cost.
4Power
If multiple DC sources are converted to AC in parallel, then power output capability is improved, but system complexity increases due to synchronization requirements
Solution Approach 1:
The patent implements feedback control mechanisms in each modular unit to maintain synchronization with the grid voltage. Each module independently monitors grid voltage phase, frequency, and magnitude, and adjusts its output accordingly. This feedback-based synchronization approach manages the complexity of parallel operation while enabling high power output capability through coordinated multi-module 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 solution enables a highly efficient, scalable, and reliable power conversion system with reduced material costs, capable of operating at high switching frequencies, suitable for various grid applications including renewable energy, electric vehicles, and data center power management.
Implementation Method 1
each full bridge converter having an inductor electrically coupled thereto
Data Source
AI summary
A multiple dc sources bi-directional energy converter includes a plurality of direct current (DC) power sources; one alternating current (AC) power source; at least one stacked alternating current (AC) phase, each stacked alternating current (AC) phase having at least two or more full bridge converters, each respectively coupled to one of the direct current power sources, each full bridge converter having an inductor electrically coupled thereto; and a local controller coupled to each full bridge converter controlling the firing sequence of the switching devices in said full bridge converter to generate an approximately nearly sinusoidal voltage waveform when operated as a voltage source inverter in one direction or generate an approximately nearly constant direct current (DC) output when operated as a full-wave active rectifier in the opposite direction.