Computer Aided Verification of Voltage Dips and Short Interruptions Generators for Electromagnetic Compatibility Immunity Test in Accordance with IEC 61000-4-11:2004 + AMD: 2017

The operation of electrical and electronic equipment may be affected by disturbances in the supply network. Voltage dips and short interruptions are common disturbances that involve sudden reduction of the supply voltage below a certain voltage level followed by restoration after a short interval. They are usually caused by faults in the electricity supply network such as presence of short circuit or by sudden large variation in electric loading. These unwanted electromagnetic interferences may cause malfunctioning of or even damage to the equipment. Therefore, it is important to conduct voltage dips and short interruptions immunity tests on electrical and electronic products. Voltage dips and short interruptions generators are key equipment for conducting immunity tests and these generators need to be verified. This paper describes a computer aided system developed by the Standards and Calibration Laboratory (SCL) for verification of voltage dips and short interruptions generators in accordance with the international standard IEC 61000-4-11 (2004-03). The parameters that can be calibrated are: ratios of the residual voltages to the rated voltage; the rise time, fall time, overshoot and undershoot of the switching waveform; and the accuracy of the phase angle at switching. A specially built adapter is used to convert the high voltage output waveforms of the generators to lower level signal to be acquired by a digital oscilloscope. An in-house developed software then analyses the captured signal to calculate the required parameters. The paper also discusses the uncertainty evaluations for the measured parameters.