An In-Situ On-Board Offline Diagnostic Method of IGBT Modules for Bond Wire Degradation Within High-Power 3L-NPC Converters

An In-Situ On-Board Offline Diagnostic Method of IGBT Modules for Bond Wire Degradation Within High-Power 3L-NPC Converters

Blog Article

Performing in-situ diagnosis is a crucial task during routine inspections of high-power converter systems, such as mine hoist.This paper presents an on-board offline condition assessment method for bond wire degradation of high-power IGBT modules within three-level neutral-point clamped (3L-NPC) converter.This method is based on the increment of the on-state voltage $V_{mathrm {on}}$ during series short-circuit (SSC).

The SSC is pride sundancer scooter formed by the conduction of the IGBT modules to be tested and the external constant current switch (CCS).In CCS circuits, a PI-controlled gate drive circuit is employed to achieve high constant short-circuit current and maintain the stability of the $V_{mathrm {on}}$.The improved $V_{mathrm {on}}$ detection circuit takes the decrement of charging time $t_{mathrm {cp}}$ of the capacitor as the parameter for aging assessment.

It simplifies the data processing of $V_{mathrm {on}}$ , while increasing the aging sensitivity.To validate the effectiveness of this method in practical applications, a single-phase 3L-NPC experimental platform was built to simulate the aging state of IGBTs by cutting off the bonding wires.The feasibility of the detection circuit, the dark red masquerade mask influence of short-circuit current and ambient temperature on $t_{mathrm {cp}}$ , and the reliability of the CCS circuit are analyzed in detail.