Enhanced Phase Verification For Power Networks From Megger
- Published: Wednesday, 03 May 2017 08:24
To simplify the vital task of guarding against the costly, dangerous and destructive accidents that can result from incorrect phasing in power distribution systems, Megger has released an upgraded version of its unique PVS phase verification system.
The new PVS100i offers the same performance as its successful predecessor, but offers even more convenient communication between the local and remote units using standard mobile phone SIM cards.
The new PVS100i has a wide range of applications, including verifying cable markings in existing networks without the need for de-energisation, and avoiding the lost production that would result from incorrect phasing when changing feeders in industrial distribution systems.
For safe network operation, it is essential to be able to determine absolute phasing at every point in the network – simply confirming phase rotation is not sufficient. To reliably and accurately determine absolute phasing, the Megger PVS100i uses two identical units, one configured as a base station, which is connected to a low-voltage reference phase, the other configured as the phase measuring device, which is used as a mobile unit.
Ultra-precise synchronisation of the two units is achieved with the aid of the same GPS signals used by satellite navigation systems. Synchronisation data is passed between the units using the mobile telephone network, which in the PVS100i is accessed using an ordinary mobile phone SIM card.
For maximum versatility, the PVS100i phase verification system offers two operating modes. Mains operation mode is used where a low-voltage supply is available at the phase measurement location, and requires only one-time synchronisation of the base station and remote units. Battery operation mode offers full flexibility when no low-voltage supply is available – for example, when testing on overhead lines – and requires continuous synchronisation of the base units via the mobile phone network.
The PVS100i provides an option to enter phase angle correction for transformers vector groups, and features intuitive operating software. The instrument can be connected directly to supply systems up to 400 V. At higher voltages, up to 120 kV, tests are performed using a high voltage sensor that communicates with the instrument via a bidirectional wireless link.