Partial discharge measurement and analysis in PPIs

Abstract

Electrical insulation capability is one of the most critical challenges for press-pack insulated gate bipolar transistors (IGBTs), but the knowledge of its insulation failure mechanism is much less mature. To understand the insulation failure mechanism, partial discharge (PD) measurement and analysis in press-pack IGBT (PPI) submodule were performed in this study. A dedicated PD measurement system for PPIs was designed and fabricated, and fast oscilloscope, PD detector and ultraviolet (UV) image camera were employed to observe the PD. PD-induced insulation failure phenomenon in the submodule was observed under direct current voltage, and UV images indicated that the discharge occurred at the periphery of the die. Phase-resolved PD (PRPD) analysis method for PPIs was developed and three elementary structures were used to simulate the PD in the electric field reinforcement areas identified by electric field analysis. According to PRPD patterns, the observed PD in the submodule was considered to be mainly caused by a mismatch between the electric field and critical electric field on the surface of passivation layers of the die. The inference was verified at different gas pressures because a decrease of PD inception voltage in the submodule and the bare die was observed at lower gas pressure.

Influence of Rise Time and Fall Time on Surface Discharge Characteristics of PEEK Under Positive Repetitive Square Voltage

“…as the package insulation material of high voltage and high power press-pack IGBT (insulated gate bipolar transistor) device, has good insulation, mechanical and thermal properties [1,2]. PEEK material withstands the unipolar repetitive square voltage, and the electric field applied on the PEEK material is dominated by tangential direction under normal working conditions [3,4]. Therefore, it is of practical significance to investigate the surface discharge behavior and mechanism of PEEK under the positive repetitive square voltage for the packaging insulation design of high voltage and high power devices.…”

Transient electric field of the combined insulation structure under positive periodic square waveform voltage: Analytical analysis and application

“…Moreover, electric field analysis under this working voltage is also conducted extensively [25,26]. Many scholars approximate the electric field distribution under the PPSW voltage with the static electric field distribution under the electrostatic field [27][28][29][30] or DC field [31]. However, the transient characteristics of field distribution were ignored, and the reasonability of this approximation also needs to be testified.…”

Influence of frequency on the surface discharge characteristics of PEEK under positive repetitive square voltage

“…Polyetheretherketone (PEEK) material, as insulation material for high voltage and high power press‐pack insulated gate bipolar transistor (IGBT) device package, needs to withstand repetitive and periodic unipolar pulse width modulation voltage in normal operating conditions [1, 2]. Moreover, PEEK mainly bears tangential electric field inside the device package [3, 4]. Therefore, studying the surface discharge properties of PEEK material under positive square wave voltage is of great significance for insulation design of IGBT device package.…”