Landis+Gyr E650 Series User Manual page 21

Device description
Network frequency
Phase angles
Direction of rotating
field
Total harmonic
distortion
D000030108 en m – E650 Series 3 – ZMD300AT/CT – User Manual
The signal processor calculates the network frequency f
reciprocal from the time t
The signal processor calculates the phase angles between voltages U1-U2
and U1-U3 from the times t
the various voltages.
The signal processor calculates the phase angle between voltage U1 and
current per phase from the times t
passages of the voltage U1 and the phase currents.
2 forms of representation are available for displaying the phase angle.
These can be selected by parameterisation.
Case 1: All voltage and current angles are displayed clockwise with
reference to the voltage in phase 1. The values of the angles are always
positive and can be from 0 to 360°.
Figure 14. Phase angle case 1
Case 2: The voltage angles are displayed as in case 1. The angles of the
currents are displayed, however, with reference to the associated phase
voltage and can have values between -180° and +180°.
Figure 15. Phase angle case 2
The direction of the rotating field is calculated by the microprocessor based
on the phase angle of the 3 voltages. If the direction of rotation
corresponds to that specified by the parameterisation, the phase voltage
indications L1, L2 and L3 are continuously lit. Otherwise they flash every
second.
The measuring system produces information about the total harmonic
distortion of the active energy.
For that purpose, the voltages are fed through notch filters, which remove
between two zero passages of voltage U1.
U1-U1
, t and t
U1-U1 U1-U2 U1-U3
, t and t
U1-I1 U1-I2
by forming the
n
between zero passages of
between zero
U1-I3
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