Open AccessExperimental characterisation and performance evaluation of a coaxial current transformer for measurement of insulated gate bipolar transistor switching current
Author(s) -
Ghosh Saikat Subhra,
Narayanan Gopalaratnam
Publication year - 2015
Publication title -
iet science, measurement and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.418
H-Index - 49
eISSN - 1751-8830
pISSN - 1751-8822
DOI - 10.1049/iet-smt.2014.0247
Subject(s) - insulated gate bipolar transistor , linearity , electrical engineering , electrical impedance , transistor , bipolar junction transistor , coaxial , current transformer , output impedance , inverter , current injection technique , materials science , electronic engineering , transformer , engineering , voltage
Measurement of device current during switching characterisation of an insulated gate bipolar transistor (IGBT) requires a current sensor with low insertion impedance and high bandwidth. This study presents an experimental procedure for evaluating the performance of a coaxial current transformer (CCT), designed for the above purpose. A prototype CCT, which can be mounted directly on a power terminal of a 1200 V/50 A half‐bridge IGBT module, is characterised experimentally. The measured characteristics include insertion impedance, gain and phase of the CCT at different frequencies. The bounds of linearity within which the CCT can operate without saturation are determined theoretically, and are also verified experimentally. The experimental study on linearity of the CCT requires a high‐amplitude current source. A proportional–resonant (PR) controller‐based current‐controlled half‐bridge inverter is developed for this purpose. A systematic procedure for selection of PR controller parameters is also reported in this study. This set‐up is helpful to determine the limit of linearity and also to measure the frequency response of the CCT at realistic amplitudes of current in the low‐frequency range.