Semiconductor Switch Control Circuit for Reducing Power Converter Losses
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Solution Overview
Problem
Power converters in electric and hybrid vehicles, which utilize semiconductor switches like power IGBTs, experience significant switching losses leading to heat generation and impaired performance due to inefficient switching methods.
Innovation Solution
A method and circuit arrangement for switching semiconductor switches that involve current-controlled switching in a first phase followed by voltage-controlled switching in a second phase, reducing switching losses and shortening switching duration, while eliminating the need for time measurement and additional control variables, thereby simplifying the switching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If voltage-controlled switching is used throughout the entire switching process, then the control circuit is simple, but switching losses are high and switching duration is long
Solution Approach 1:
The switching process is divided into two distinct phases: a first switching phase using voltage-controlled switching for simplicity, and a second switching phase using current-controlled switching to reduce losses. This segmentation allows each phase to utilize the most appropriate control method for its specific requirements, thereby reducing overall switching losses while maintaining control circuit simplicity.
Solution Approach 2:
The control method dynamically transitions between voltage-controlled and current-controlled switching modes based on the switching phase. The control circuit automatically switches control strategies mid-process, adapting to the changing requirements of the semiconductor switch during turn-off, thereby optimizing both loss reduction and control simplicity.
2Productivity
If current-controlled switching is used throughout the entire switching process, then switching losses are reduced, but the control circuit becomes more complex and requires additional components
Solution Approach 1:
The switching process is divided into two distinct phases: a first switching phase using voltage-controlled switching for simplicity, and a second switching phase using current-controlled switching to reduce losses. This segmentation allows each phase to utilize the most appropriate control method for its specific requirements, thereby reducing overall switching losses while maintaining control circuit simplicity.
Solution Approach 2:
The control circuit preliminarily applies voltage-controlled switching to initiate the switching process and prepare the semiconductor switch for the subsequent current-controlled phase. This preliminary action simplifies the overall control structure by using the simpler voltage control method for the initial phase, reserving the more complex current control for when it is most needed.
3Loss of time
If time measurement and additional control variables are used, then switching precision is improved, but the switching process becomes more complex
Solution Approach 1:
The control circuit uses feedback signals from the semiconductor switch to automatically determine when to transition between switching phases. By monitoring the switch state and using this feedback to control the phase transition, the system achieves precise timing without requiring external time measurement circuits or additional control variables, thereby reducing overall system complexity.
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 significantly reduces switching losses, shortens delay times, and simplifies the switching process, leading to improved performance and reduced heat generation in semiconductor switches, thus enhancing the efficiency and reliability of power converters in electric and hybrid vehicles.
Implementation Method 1
the capacity at the control connection of the semiconductor switch is reloaded, i.e. charged or discharged
Implementation Method 2
the control connection of the semiconductor switch is set to a predetermined voltage potential until the capacity at the control connection of the semiconductor switch is completely reversed
Data Source
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AI summary
The invention relates to a method for switching a semiconductor switch from a first static switch state to a second static switch state by controlling a control connection (SHS) of the semiconductor switch (HS1), having the following steps - switching (S410, S420, S440, S450) the semiconductor switch in a current-controlled manner starting from the first static switch state in a first switching phase (S1, S2) by imprinting at least one first specified actuating current (IAS1) at the control connection (SHS) of the semiconductor switch (HS1) in a controlled manner, and - switching (S430, S460) the semiconductor switch in a voltage-controlled manner in a second switching phase (S3) which follows the first switching phase (S1, S2) by applying at least one first specified actuating voltage (UAS1) to the control connection (SHS) of the semiconductor switch (HS1) in a controlled manner until the second static switch state is reached. In this manner, switching losses are reduced.