Statistical Time-Domain Analysis of Equipment in Low-Voltage Networks

The increased use of non-linear equipment results in conducted electromagnetic interference problems. As an example, static energy meters, used to measure the energy consumption in households, show misreadings due to pulsed currents from a speed controlled water pump or dimmed lighting equipment. To determine the existence of similar equipment in low-voltage networks, this letter surveys current waveforms drawn by equipment in the low-voltage network. These waveforms are analyzed and compared to critical waveforms from previous research that caused static energy meter interference. In this way the extent of critical situations in a real-world environment is determined. The equipment survey is performed using a multi-channel time- domain measuring method able to capture the voltage and currents synchronously. Then using a time-domain parametric model a statistical overview of parameters such as the charge, crest factor, peak value, pulse duration, and rising slope is given. The survey shows the existence of a large variety of non-linear signals, and 43% contained critical parameters related to static energy meter interference.