MI 2893 / MI 2892 / MI 2885 Table of contents
5
4.2.2 Connection to the MV or HV Power System ....................................................................... 146
4.2.3 Current clamp selection and transformation ratio setting ................................................. 150
4.2.4 Connection check ................................................................................................................ 154
4.2.5 Temperature probe connection .......................................................................................... 156
4.2.6 GPS time synchronization device connection ..................................................................... 157
4.3 Remote instrument connection (over Internet / Internet(3G/GPRS) / Intranet (LAN)) .............. 158
4.3.1 Communication principle .................................................................................................... 158
4.3.2 Instrument setup on remote measurement site ................................................................ 159
4.3.3 PowerView setup for instrument remote access ................................................................ 160
4.3.4 Remote connection ............................................................................................................. 161
4.4 Number of measured parameters and connection type relationship ....................................... 172
5 Theory and internal operation ............................................................................................... 179
5.1 Measurement methods ......................................................................................................... 179
5.1.1 Measurement aggregation over time intervals .................................................................. 179
5.1.2 Voltage measurement (magnitude of supply voltage) ....................................................... 179
5.1.3 Current measurement (magnitude of supply current) ....................................................... 180
5.1.4 Frequency measurement .................................................................................................... 181
5.1.5 Modern Power measurement ............................................................................................. 181
5.1.6 Classic Vector and Arithmetic Power measurement .......................................................... 186
5.1.7 Energy .................................................................................................................................. 189
5.1.8 Harmonics and interharmonics ........................................................................................... 190
5.1.9 Signalling ............................................................................................................................. 192
5.1.10 Flicker .............................................................................................................................. 193
5.1.11 Voltage and current unbalance ...................................................................................... 193
5.1.12 Under-deviation and over-deviation .............................................................................. 194
5.1.13 Voltage events ................................................................................................................ 195
5.1.14 Alarms ............................................................................................................................. 198
5.1.15 Rapid voltage changes (RVC) .......................................................................................... 199
5.1.16 Data aggregation in GENERAL RECORDING .................................................................... 200
5.1.17 Flagged data .................................................................................................................... 204
5.1.18 Waveform snapshot........................................................................................................ 204
5.1.19 Waveform recorder ........................................................................................................ 204
5.1.20 Transient recorder .......................................................................................................... 208
5.2 EN 50160 Standard Overview ................................................................................................. 209
5.2.1 Power frequency ................................................................................................................. 210
5.2.2 Supply voltage variations .................................................................................................... 210
5.2.3 Supply voltage unbalance ................................................................................................... 210
5.2.4 THD voltage and harmonics ................................................................................................ 210
5.2.5 Interharmonic voltage ......................................................................................................... 211
5.2.6 Mains signalling on the supply voltage ............................................................................... 211
5.2.7 Flicker severity .................................................................................................................... 211
5.2.8 Voltage dips ......................................................................................................................... 211
5.2.9 Voltage swells ...................................................................................................................... 212
5.2.10 Short interruptions of the supply voltage....................................................................... 212
5.2.11 Long interruptions of the supply voltage........................................................................ 212
5.2.12 MI 2893/MI 2892/MI 2885 recorder setting for EN 50160 survey ................................. 212
6 Technical specifications ......................................................................................................... 214
6.1 General specifications ............................................................................................................ 214
6.2 Measurements ...................................................................................................................... 214
6.2.1 General description ............................................................................................................. 214