Parallel IGBT Gate Driving Circuit for Turn-On Timing Synchronization
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Solution Overview
Problem
Existing switching element driving devices struggle to synchronize the timing of turning on multiple switching elements connected in parallel, leading to shifts in activation times due to differences in characteristics and voltage drops across rectifying elements.
Innovation Solution
A switching element driving device with a main switch and sub-switch configuration, where rectifying elements and balance resistors ensure even current distribution across switching elements, and a control circuit manages the switches to maintain synchronized operation by adjusting current flow based on potential differences and switching between main and sub-switches to adjust the number of driven elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate drive circuits are provided for each switching element, then the number of driven switching elements can be changed, but the timing of turning on the switching elements shifts due to characteristic differences and voltage drops
Solution Approach 1:
The drive circuit is segmented into a common drive circuit and individual switching element drive circuits. The common drive circuit generates a base drive signal, which is then distributed to multiple switching element drive circuits. Each switching element drive circuit receives the same base signal but processes it independently to account for individual component variations, thereby maintaining timing synchronization while enabling flexible configuration of different numbers of switching elements.
Solution Approach 2:
The patent employs a configuration where the drive signals for multiple switching elements are derived from a common potential reference point. By ensuring that all switching elements receive drive signals referenced to the same potential baseline and by using matched impedance paths, the circuit compensates for characteristic differences and voltage drops, eliminating timing shifts while maintaining adaptability to different switching element configurations.
2Manufacturing precision
If a common drive circuit is used for all switching elements, then timing synchronization is improved, but the ability to drive different numbers of switching elements is reduced
Solution Approach 1:
The drive circuit incorporates dynamic switching capability through control switches that can selectively connect or disconnect individual switching element drive circuits. This dynamic configuration allows the common drive circuit to maintain timing synchronization for all active switching elements while adapting to different operational requirements by enabling or disabling specific channels, thus achieving both precision and versatility.
Solution Approach 2:
The common drive circuit is designed with universal functionality to drive any number of switching elements from a single circuit architecture. By incorporating multiple output channels with individual control switches and matching networks, the circuit can universally drive 1, 2, 3, or 4 switching elements simultaneously, maintaining timing synchronization across all configurations without requiring separate drive circuits for each switching element.
3Power
If switching elements with different characteristics are connected in parallel, then the current handling capacity is increased, but the timing shift between switching elements increases
Solution Approach 1:
The patent applies local quality by providing individual drive circuits for each switching element that are connected to a common drive signal source. Each switching element drive circuit is independently optimized to match the specific characteristics of its associated switching element, while all circuits receive the same base drive signal. This allows parallel switching elements with different characteristics to operate at their optimal performance levels while maintaining synchronized timing through the common reference signal.
Solution Approach 2:
The drive circuit incorporates parameter adjustment capability through variable components such as adjustable resistors or digitally controlled attenuators in each switching element drive circuit. These parameters can be tuned to compensate for differences in switching element characteristics (such as gate charge, threshold voltage, or switching speed), thereby maintaining timing synchronization while allowing the parallel configuration to handle increased current capacity through the use of switching elements with different rated parameters.
Data Source
AI summary
A switching element driving device includes a main on switch that is connected to gates of a first and second IGBTs and that, when brought into a conductive state, turns on the first and second IGBTs, diodes each disposed between the main on switch and one of the gates of the first and second IGBTs, the diodes having a forward direction from the main on switch to the gates of the first and second IGBTs, an on sub-switch that is connected to the gate of the second IGBT and that, when brought into the conductive state, turns on the second IGBT, and a control circuit that controls the conductive state and a non-conductive state of the main on switch and the on sub-switch.