The state-of-the-art PQI-D Power Quality Interface for medium and high voltage networks is the main component of a system for carrying out all of the required measurement tasks in electrical networks.
The PQI-D can be used as both a Power Quality Interface compliant to DIN EN 50160 and as a measurement device for measuring all physically defi ned measurement quantities in AC electrical networks. The component is primarily designed to monitor special reference quantities and quality agreements between the energy supplier and the customer, as well as to record, analyse and save the data. Modern voltage quality measurement devices operate according to the IEC 61000-4-30 standard.
This standard defi nes measurement methods and so provides the user with a basis for comparison. Devices from different manufacturers which function according to this standard must give approximately the same readings. For medium- and low voltage grids the dial-rail version type PQI-DA has been developed, which is covering in a very compact design the same functionality. The standard defines two measurement device classes. Class A measurement devices are used primarily for measurements related to contracts in customer/supplier relationships, while class B measurement devices can be used for determining statistical quality values. A class B device is sufficient for measurements according to EN 50160.