Electromagnetic Interference in Smart Grids

The increasing conducted interference caused by modern electronic equipment is causing more problems for electronic, or static, energy meters. If equipped with a communication link they are called smart meter. Because the smart meter is a key device in smart grids, any deviation has huge impact on the reliability of any prediction of the energy consumption or production. It is known that conducted electromagnetic interference, for instance due to active infeed converters as used in photovoltaic systems, can cause a lower static energy meter reading. In a controlled environment it was found that three-phase meters can also give higher energy readings. These experiments were performed using an ideal sinusoidal voltage from a fourquadrant power amplifier with defined power supply impedance. Increased energy reading of +276 %, but also decreased energy meter reading of -46%, was observed. Measurements were repeated, with more meters, and supplied from a standard, low internal impedance, mains supply in the laboratory. Now positive reading up to +582%, and negative reading down with -32% were registered.