Double-Gate IGBT Gate Waveform Control for Low-Noise Switching
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Solution Overview
Problem
Existing semiconductor devices and control methods for double-gate IGBTs face issues with increased noise and reduced robustness due to short time differences in gate terminal operations, leading to higher switching losses and surge voltages.
Innovation Solution
A semiconductor driving device with a timing generation unit, gate reference waveform generation unit, and signal amplification unit that controls and amplifies gate reference waveforms to follow a feedforward control, allowing for precise management of gate terminal voltage changes, thereby suppressing noise and surge voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a short time difference is set between voltage waveforms given to two gate terminals of a double-gate IGBT, then the active gate effect is obtained and switching loss is reduced, but noise and surge voltage increase
Solution Approach 1:
The patent applies dynamics by making the gate resistance variable during the switching operation period. The gate resistance is switched between a first resistance value and a second resistance value at different timings for the first and second gate terminals, creating dynamic control that enables the active gate effect while suppressing noise and surge voltage.
Solution Approach 2:
The patent changes the gate resistance parameter during switching operations. By switching the gate resistance between different values at different timings for each gate terminal, the patent achieves both reduced switching loss and suppressed noise/surge voltage through parameter variation.
2Productivity
If a short time difference is set between voltage waveforms given to two gate terminals, then transient switching characteristic control is achieved, but robustness against voltage change rate and noise decreases
Solution Approach 1:
The patent uses dynamic switching of gate resistance values at different timings for each gate terminal. This dynamic control achieves both improved switching operation efficiency through the active gate effect and enhanced robustness by controlling the voltage change rate through resistance modulation.
Solution Approach 2:
The patent applies preliminary action by switching the gate resistance before the actual switching operation. The gate resistance is changed at different timings for each gate terminal in advance, preparing the device for controlled switching that maintains both efficiency and robustness.
3Loss of energy
If gate resistance is switched during turn-on operation period, then trade-off between turn-on loss and recovery voltage change rate is improved, but device complexity increases
Solution Approach 1:
The patent achieves multi-functionality by using a single gate resistance switching mechanism that simultaneously controls both turn-on loss and recovery voltage change rate. The same switching structure serves multiple functions: reducing turn-on loss through active gate effect and controlling voltage change rate for robustness.
Solution Approach 2:
The patent combines the control of turn-on loss reduction and voltage change rate control into a unified gate resistance switching mechanism. By merging these functions into one control system with coordinated switching timings, the patent avoids the need for separate complex control circuits.
Data Source
AI summary
A semiconductor driving device according to the present disclosure includes: a timing generation unit which generates gate ON reference signals respectively for a plurality of gate terminals; a gate reference waveform generation unit which generates a first gate reference waveform and a second gate reference waveform on the basis of the gate ON reference signals, and controls the first gate reference waveform and the second gate reference waveform in shifting from a non-conductive state to a conductive state of a multi-gate semiconductor switching element and shifting from a conductive state to a non-conductive state of the multi-gate semiconductor switching element; and a signal amplification unit which receives, as an input waveform, the first gate reference waveform and the second gate reference waveform, and amplifies the input waveform so that an output waveform follows the input waveform.