Resonant Converter Switching Scheme for X-Ray Tube
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Solution Overview
Problem
Resonant converters experience hard commutation of paralleled diode switches during mid/low power operations, leading to increased losses and voltage spikes due to extended dead time, which can cause short circuits at light load conditions.
Innovation Solution
Implementing an alternating switching scheme for transistor switches during mid/low power modes, reducing switch-off time and employing a reduced number of switches to optimize operations, with the controlling module adapting output power thresholds based on operational conditions such as temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If extended dead time is used to prevent short circuits during mid/low power operations, then switching safety is improved, but switching losses increase and voltage spikes occur
Solution Approach 1:
The patent applies dynamics by making the dead time variable rather than fixed. The controlling module dynamically adjusts the dead time duration based on the detected power operation mode (high power vs. mid/low power mode). During mid/low power operations, the dead time is reduced from the extended value to a shorter value, optimizing both safety and efficiency for different operating conditions.
Solution Approach 2:
The patent changes the parameter of dead time duration based on operating conditions. By detecting whether the converter is operating in high power mode or mid/low power mode, the system adjusts the dead time parameter accordingly - using extended dead time only when necessary for safety, and reducing it during mid/low power operations to minimize losses and prevent voltage spikes.
2Reliability
If extended dead time is used during mid/low power operations, then short circuit prevention is improved, but voltage spikes increase
Solution Approach 1:
The system dynamically adjusts dead time based on power operation mode detection. During mid/low power operations, the dead time is reduced to prevent voltage spikes, while maintaining sufficient safety margins. The controlling module adapts the dead time parameter in real-time based on operating conditions.
Solution Approach 2:
The dead time parameter is changed according to the detected power mode. The system uses different dead time values for high power mode versus mid/low power mode, optimizing the parameter to prevent both short circuits and voltage spikes under different operating conditions.
3Power
If all paralleled IGBT modules operate in high power mode, then maximum power output is achieved, but switching losses increase during mid/low power operations
Solution Approach 1:
The patent implements dynamic operation mode switching for the IGBT modules. The controlling module detects whether the converter is operating in high power mode or mid/low power mode and dynamically adjusts the dead time and switching parameters accordingly. This allows the system to optimize for maximum power output when needed while minimizing switching losses during lower power operations.
Solution Approach 2:
The system changes operating parameters based on power level detection. When mid/low power mode is detected, the controlling module adjusts dead time and switching parameters to reduce losses, while maintaining the capability to operate in high power mode when maximum power output is required.
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 approach reduces switching losses, prevents voltage spikes, and ensures safe operation by optimizing switch-off times and power distribution across fewer active switches, enhancing efficiency and reliability in high-power applications like medical imaging systems.
Implementation Method 1
The present invention relates to electrical inverters based on resonant current oscillation
Data Source
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AI summary
The present invention relates to a resonant converter (100) comprising: at least two transistor switches (S1-S8), out of which at least two are connected in parallel, and out of which a number of available transistor switches (S1-S8) is available for performing a current switching of the resonant converter (100); a controlling module (101) configured to determine whether an output power of the resonant converter (100) is below an output power threshold value; and a switching module (102) configured to employ a reduced number of transistor switches out of the number of available transistor switches (S1-S8), if the output power of the resonant converter (100) is below the output power threshold value, wherein the reduced number is at least declined by one compared to the number of available transistor switches (S1-S8), wherein the switching module (102) is configured to permute the employed reduced number of transistor switches over the available transistor switches (S1-S8).