The introduction of sensitive electronic devices for high voltage substation monitoring, control and automation has increased the risk of EMI problems. Electronic devices installed in such a harsh EM environment are supposed to comply with higher levels and a wider frequency range of immunity aspects than consumer electronics. In addition, installation practices should be based on a strict EM zoning concept and resulting earthing, bonding and segregation rules. However, daily practice teaches that these high level equipment immunity specifications are not always adhered to or more frequently, installation practices of cables between high voltage zones and control equipment zones are not consistent.
In this context, the more compact construction of modern GIS (Gas Insulated Switchgear) together with increased functionality of electronic monitoring and control systems is a major EMC challenge.
Lambda Engineering offers guidance in this field by offering a number of services:
- Assessment of induced voltages in parallel cables and associated electrical systems, including measurement of EMI during HV switching and (dis)connecting.
- EMC design of switchgear and substation lay-out on the basis of an EM zoning concept between HV equipment and electronic control equipment.
- Verification of EMC specifications and properties of equipment in line with the zoning concept.
- Determination of cable specifications and installation requirements for secondary equipment, e.g. voltage, current, pressure sensors to the control system in order to maintain a clear EM zoning concept. These requirements include the earthing lay-out, cable routing and segregation, termination and bonding of cable shields at EM zone barriers.
- Confirmation of the correct installation practice by measurement.