Power Conversion Device Commutation Unit for Recovery Current Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-cost and crystal defects in wide bandgap semiconductor devices with large current capacity hinder their practical application in power conversion devices, making it difficult to achieve high efficiency and reliability.
Innovation Solution
A power conversion device configuration that includes a power supply unit, a booster unit, a smoothing unit, a backflow prevention element, and a commutation unit, where the commutation unit commutates current flowing through the backflow prevention element to suppress recovery current, ensuring efficient and reliable operation without requiring new devices with large current capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If wide bandgap semiconductor devices with large current capacity are used, then power loss is reduced and efficiency is improved, but cost increases and crystal defects occur
Solution Approach 1:
The patent introduces a commutation unit as an intermediary component between the booster unit and smoothing unit. This commutation unit includes a commutation element (such as a diode or switch) that mediates the current flow, allowing the backflow prevention element to operate in a more favorable condition by commutating part of the current away from it, thereby reducing recovery current and improving reliability without requiring expensive wide bandgap semiconductor devices with large current capacity
Solution Approach 2:
The patent changes the operating parameters of the backflow prevention element by introducing the commutation unit. By controlling the commutation element to turn on during specific periods, the current through the backflow prevention element is reduced, changing its operating conditions to reduce recovery current and improve reliability without requiring a change in the semiconductor material itself
2Loss of energy
If wide bandgap semiconductor devices with large current capacity are used, then efficiency is improved, but cost increases
Solution Approach 1:
The commutation unit acts as an intermediary that allows conventional semiconductor devices to achieve efficiency comparable to expensive wide bandgap devices. By introducing this additional control stage, the system can reduce power loss through optimized current management without incurring the high cost of wide bandgap semiconductor materials
Solution Approach 2:
The patent uses conventional, cost-effective semiconductor devices instead of expensive wide bandgap semiconductors. By combining these cheaper devices with the commutation unit control strategy, the system achieves high efficiency at a lower cost, effectively replacing expensive components with a combination of cheaper components and control mechanisms
3Device complexity
If recovery current is not suppressed, then device simplicity is maintained, but reliability deteriorates
Solution Approach 1:
The commutation unit is introduced as a relatively simple intermediary component that significantly improves reliability by suppressing recovery current. While it does add some complexity, the structure remains straightforward with mainly switching elements and control logic, achieving a favorable balance between complexity and reliability improvement
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 allows for the suppression of recovery current, thereby enhancing the reliability and efficiency of the power conversion device, reducing power loss, and enabling effective use in refrigeration/air-conditioning systems.
Implementation Method 1
a commutation unit that is connected to the backflow prevention element in parallel to commutate a current flowing through the backflow prevention element toward the commutation unit itself
Implementation Method 2
a booster unit that boosts a voltage supplied from the power supply unit by switching control
Data Source
AI summary
A power conversion device according to the present invention includes a power supply, a booster unit (a reactor, a switch) that boosts a voltage supplied from the power supply by switching control, a smoothing circuit that smoothes an output voltage from the booster unit, a rectifier that is arranged between the booster unit and the smoothing circuit to prevent a current reverse flow toward the booster unit, and a commutation unit that is connected to the rectifier in parallel to commutate a current flowing through the rectifier toward itself.