Three-phase multifunctional «MIRTEK-135-RU» high-voltage electrical energy metering devices are made to account direct switching and replace the points of commercial accounting.
They are used in three-phase three-wire AC networks with an industrial frequency of 6(10) kV with isolated neutral. The device has the possibility of organising a multi-tariff electricity accounting with the transmission of accumulated information via a 433 MHz radio interface and GSM/GPRS.
Devices are designed for installation on overhead lines made by cables (aluminium-steel wire without insulation) or (self-supporting insulated wire) near intermediate or terminal supports.
Key Features
Main galvanically isolated interfaces:
• RF1 radio channel at 433MHz
• GSM/GPRS
• Optical fiber interface (service channel)
• GLONASS/GPS (time synchronization).
• Structurally, the device consists of three blocks, two of which are measuring, one is connecting.
• Measuring units are connected according to the Aron scheme.
• To measure the current, electronic current sensors based on the Rogowski coil were used, instead of current transformers with a metal core used in PKU.
• A resistive divider is used to measure voltage instead of electromagnetic voltage transformers.
• Measure: two phase currents Ia (I1) , Ic (I2), two line voltages Uab (U1-2), Ubc (U2-3) and angles between them.
• On the basis of the obtained measurements, active, reactive and apparent energies are calculated, as well as the third phase current Ib (I2) and the line voltage Uca (U3-1).