Gate Drive Circuit for Power Converter Surge Suppression
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Solution Overview
Problem
In polyphase bridge type power converters, the uneven energy absorption by semiconductor switches due to dispersion in voltage regulation diode characteristics leads to overheating and increased loss, necessitating large heat dissipation circuits, which hinders miniaturization and weight reduction, especially in vehicle applications.
Innovation Solution
A gate drive circuit design where the voltage between the main terminals of the power semiconductor switch is limited to a predetermined value only during the switching off of the self-phase switch, preventing energy absorption from other phases and ensuring uniform losses across switches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional gate drive circuit with voltage regulation diode is applied to polyphase bridge type power converter, then surge voltage is limited to predetermined voltage, but energy of parasitic inductance concentrates on specific phase semiconductor switching element causing overheat break
Solution Approach 1:
The invention divides the energy absorption function by phase, ensuring that each semiconductor switching element absorbs energy only from its own phase's parasitic inductance. This is achieved through the bridge circuit topology where each switch's gate drive circuit independently limits surge voltage and absorbs energy from its corresponding phase, preventing concentration of energy from multiple phases on a single element.
Solution Approach 2:
The invention applies local surge voltage suppression by configuring each phase's gate drive circuit with voltage regulation diodes that operate independently. Each switching element has its own localized energy absorption mechanism tailored to its specific phase's parasitic inductance, rather than a unified approach that would cause energy concentration on one element.
2Reliability
If heat design is carried out to correspond to semiconductor switching element having greatest loss, then overheating is prevented, but heat dissipation circuit becomes large
Solution Approach 1:
The invention segments the thermal management requirement by ensuring uniform loss distribution across all semiconductor switching elements through phase-specific energy absorption. Since each element handles only its own phase's parasitic inductance energy, the maximum loss per element is reduced and equalized, allowing for smaller, lighter heat dissipation circuits rather than designing for the worst-case concentrated loss scenario.
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 design prevents overheating by ensuring each power semiconductor switch only absorbs energy from its own phase, reducing maximum loss and allowing for a miniaturized heat dissipation circuit, thus supporting the miniaturization and weight reduction of power converters.
Implementation Method 1
a series circuit of a voltage regulation diode and a reverse blocking diode is connected as a gate drive circuit between a gate terminal and a drain terminal of a MOS-FET in order to limit surge voltage generated between the drain terminal and the source terminal of the MOS-FET to the predetermined voltage
Implementation Method 2
a series circuit of a voltage regulation diode and a reverse blocking diode is connected as a gate drive circuit between a gate terminal and a drain terminal of a MOS-FET
Implementation Method 3
when the MOS-FET is off-driven and the current flowing to a load is cut off, parasitic inductance of a power supply line causes surge voltage between the drain terminal and the source terminal of the MOS-FET
Data Source
AI summary
In a bridge type power converter including series connectors of power semiconductor switches having first and second main terminals and a control terminal; plural steps of the series connectors connected in parallel, a gate drive circuit for limiting voltage between the first and second main terminals of the power semiconductor switch to a predetermined value only in turning off the power semiconductor switch is provided between the first main terminal and the control terminal of the power semiconductor switch.