4
6
Power Quality - a guide ........................................................................ 43
6.1
Basic Information .......................................................................................... 43
6.2
Current measurement ................................................................................... 44
6.2.1
Current transformer clamps (CT) for AC measurements ..................................... 44
6.2.2
AC/DC measurement clamps .............................................................................. 44
6.2.3
Flexible current probes ....................................................................................... 45
6.3
Flicker ........................................................................................................... 45
6.4
Power measurement .................................................................................... 46
6.4.1
Active power ....................................................................................................... 46
6.4.2
Reactive power ................................................................................................... 47
6.4.3
Reactive power and three-wire systems .............................................................. 50
6.4.4
Reactive power and reactive energy meters ....................................................... 51
6.4.5
Apparent power .................................................................................................. 52
6.4.6
Distortion power D
B
and effective nonfundamental apparent power S
eN
.............. 53
6.4.7
Power factor ....................................................................................................... 54
6.5
Harmonics .................................................................................................... 54
6.5.1
Harmonics characteristics in three-phase system ............................................... 56
6.5.2
THD .................................................................................................................... 57
6.6
Unbalance .................................................................................................... 57
6.7
Detection of voltage dip, swell and interruption ............................................ 59
6.8
CBEMA and ANSI curves ............................................................................. 60
6.9
Averaging the measurement results ............................................................. 62
7
Technical specifications ...................................................................... 65
7.1
Inputs ............................................................................................................ 65
7.2
Sampling and RTC ....................................................................................... 66
7.3
Measured parameters - accuracy, resolution and ranges ............................. 66
7.3.1
Reference conditions .......................................................................................... 66
7.3.2
Voltage ............................................................................................................... 66
7.3.3
Current ............................................................................................................... 66
7.3.4
Frequency ........................................................................................................... 67
7.3.5
Harmonics .......................................................................................................... 67
7.3.6
Power and energy ............................................................................................... 67
7.3.7
Estimating the uncertainty of power and energy measurements .......................... 68
7.3.8
Flicker ................................................................................................................. 70
7.3.9
Unbalance .......................................................................................................... 70
7.4
Event detection - voltage and current RMS .................................................. 70
7.5
Event detection - other parameters .............................................................. 70
7.5.1
Event detection hysteresis .................................................................................. 71
7.6
Inrush current measurement......................................................................... 71
7.7
Recording ..................................................................................................... 71
7.8
Power supply,battery and heater .................................................................. 72
7.9
Supported networks ...................................................................................... 73
7.10
Supported current clamps ............................................................................ 73
7.11
Communication ............................................................................................. 73
7.12
Environmental conditions and other technical data ...................................... 73
7.13
Safety and electromagnetic compatibility ..................................................... 74
7.14
Standards ..................................................................................................... 74
8
Equipment ............................................................................................. 75
Summary of Contents for PQM-700
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