Order Publications

Reference: ISH2017_569

ISH Collection

Measurement of the internal inductance of impulse voltage generators and the limits of LI front times



The recent push to higher testing voltages for research and production tests on UHV system components rated above 800kV class has led to difficulties in achieving the standard waveshapes as required by IEC60060 Parts 1 and 2 and other existing IEC, IEEE/ANSI and other standards. One of the limiting components in achieving the maximum capacitive loading on an impulse generator for standard lightning impulse front times is the inductance of the circuit. The total inductance of the circuit is comprised of the internal inductance of the impulse generator and the inductance of the loop to connect to the load. The higher the voltage class of test objects, the larger the loop, yielding more inductance that in turn, reduces the test capacitance that can be connected and still remain inside the overshoot requirements of the standards. The internal inductance of the impulse generator is comprised of the wiring of the stages and the stage capacitor inductance and/or the inductance of the waveshaping resistors. This paper shows the results of methods to measure and calculate the internal inductance of several impulse generators and we review the formulas for calculating the maximum load of an impulse generator with a given internal inductance. We believe these methods give more realistic values than adding up nameplate inductance values from an impulse generator. The paper also reviews the pros and cons of higher stage capacitances in impulse generators to test larger loads that are ultimately limited by the circuit inductance value. The intent of this paper is to assist in the revision of future IEC and IEEE standards for impulse testing apparatus in the UHV range.

File Size: 772 KB

Pages NB: 5

Year: 2017

FREE free
Non member
FREE free

Your AccountYour Account

Password forgotten


may download free of charge all publications including most recent ones

Non Members

may download free of charge publications over three years old and purchase all publications

For any questions in connection with the on-line library, contact:

Publications and Editions Manager