Voltage tester for testing transformer coil arc

Electric arc is a physical phenomenon that Huayi Electronics has quantified through extensive statistical and customer feedback data, making it a measurable physical quantity. Generally, the high-frequency pulses generated by high impedance electric arc and corona can vary in frequency from less than 30 kHz to more than 1 MHz, and their duration may be very short. These pulses often last less than 10 microseconds (as shown in Figure 1), and these short-term pulses or spike signals may not immediately cause breakdown discharge, so they can be ignored.

Figure 1

There is a specialized arc detection system in Huayi Safety Instrument (as shown in Figure 2), which inputs high-frequency pulse signals above 10KHz into a comparator through a high pass filter that responds to frequencies above 10KHz. Then, it compares the data generated by a sensitivity regulator inside the instrument, because Huayi believes that arc pulses above 10KHz have the highest probability of directly affecting the quality of the tested object after long-term statistics and customer feedback. The internal sensitivity of the instrument is divided into 1-9 levels, each level representing the detected peak current. (As shown in Table 1)

Figure 2

The significance of instrument arc failure alarm display:

For example, when the instrument is set to ARC ON and the ARC sensitivity is selected as the factory preset value of 5, the instrument detects an alarm prompt ARC Fail on the DUT, which means that the safety instrument of the instrument has detected a high-frequency arc pulse with a peak value greater than 12mApeak and a frequency greater than 10KHz inside the DUT.

How to determine the sensitivity of the selection?

The preset value of arc sensitivity for Huayi's safety instruments at the factory is 5, because we have conducted our own statistics, and some of our clients such as IBM have also calculated the results after long-term use, and believe that 5 is a relatively acceptable number. IBM has also notified its outsourcing factories in writing to set the arc sensitivity to 5 when using Huayi's safety instruments. Too high sensitivity may result in a high defect rate, which is not in line with cost balance, while too low sensitivity may leave long-term concerns for product quality. Therefore, how to choose the sensitivity level should be determined by the user based on the product characteristics and after a period of statistical analysis, taking into account various factors such as the high or low defect rate, to determine the sensitivity level.

Huayi ARC level error judgment interval: