Power Converter Stub Circuit for Switching Oscillation Suppression
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Solution Overview
Problem
High-speed, low on-resistance switching elements in power converters are susceptible to oscillation and malfunction due to circuit parasitic components, leading to efficiency loss and increased size, which existing solutions like gate diodes and snubber capacitors exacerbate.
Innovation Solution
An oscillation suppression circuit using a stub connected to the drain, source, or gate terminal of the switching element, with a length of an odd multiple of 1/4 wavelength, to cancel out oscillation frequencies without increasing switching element loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If voltage transformation is performed using conventional methods (mechanical transformers or DC-DC converters), then voltage conversion is achieved, but the system becomes bulky, heavy, and complex with multiple components
Solution Approach 1:
The patent combines the voltage transformation function with the power conversion function into a single integrated circuit. The microcontroller unit directly generates pulse width modulated signals to control power switching elements, eliminating the need for separate mechanical transformers or DC-DC converter modules. This integration reduces component count while maintaining full voltage transformation capability through electronic switching and rectification circuits.
Solution Approach 2:
The patent replaces conventional mechanical transformers with an electronic voltage transformation system. Instead of using electromagnetic induction through physical transformer cores, the system uses pulse width modulated switching of power elements followed by rectification and filtering to achieve voltage conversion. This substitution eliminates bulky mechanical components while maintaining the essential voltage transformation function.
2Productivity
If battery charging is performed without intervention, then charging continues automatically, but overcharging occurs causing battery degradation or safety issues
Solution Approach 1:
The patent implements a feedback control system where the microcontroller unit continuously monitors battery charging status by detecting voltage and current parameters. Based on this feedback information, the controller dynamically adjusts the pulse width modulated signals to power switching elements, regulating the charging current to prevent overcharging while maintaining optimal charging speed. The system can detect when the battery is fully charged and automatically stop or reduce charging current.
Solution Approach 2:
The patent enables the power conversion system to automatically manage its own charging process without external intervention. The microcontroller unit autonomously monitors battery status, controls power switching elements, and regulates charging current based on predefined charging algorithms. The system self-adjusts charging parameters and can detect fault conditions, eliminating the need for manual charging supervision while ensuring battery safety.
3Loss of energy
If power conversion is performed without regeneration, then simple control is maintained, but energy is wasted during regenerative braking
Solution Approach 1:
The patent designs a universal power conversion system that performs multiple functions through the same hardware components. The bidirectional power converter can operate in both charging mode (converting AC to DC for battery charging) and regenerative braking mode (converting DC from motor generators back to AC for grid feedback or battery storage). The microcontroller unit dynamically switches between operating modes based on vehicle conditions, enabling energy recovery during regenerative braking without requiring separate dedicated circuits.
Solution Approach 2:
The patent utilizes parameter changes in the power switching elements to achieve different power conversion modes. By adjusting the pulse width modulation duty cycle and switching frequency of the same power switching elements, the system can efficiently convert power in both directions - from AC to DC during charging and from DC to AC during regenerative braking. This parameter-based control allows a single set of hardware components to handle multiple operational requirements.
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
Effectively suppresses oscillation and malfunction of switching elements, maintaining efficiency and reducing the size of the power converter.
Implementation Method 1
a capacitor connected across the output terminals of the bridge rectifier
Implementation Method 2
the electromagnetic motor acts as a generator during regenerative braking
Implementation Method 3
the electromagnetic motor acts as a generator during regenerative braking
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
In order to suppress oscillation and malfunction of a switching element in a power converter, the power converter includes a switching element 11; and an oscillation suppression circuit having a stub 14 which is electrically connected to a terminal of the switching element 11.