Page 131 - SACE Tmax XT - Catalogue

ENERGY MEASUREMENTS 5/5

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Network Analyzer

Thanks to the Network Analyzer function available in all Ekip Touch trip units,
the quality of energy based on harmonics, micro-interruptions or voltage dips
is monitored without the need for dedicated instrumentation.

Thanks to Network Analyzer, effective preventive Distortions of the voltage value (sags, swells)
and corrective action can be implemented through and/or frequency can have fatal consequences,
accurate analysis of faults, thereby improving the especially for process industries, leading to pos-
efficiency of the system. sible production stoppages with consequently ex-
pensive downtime, damage to motor drives and
Applications damage to PLCs. Examples of process industries
that can be badly hit by voltage instabilities in-
Electrical equipment is designed for optimum op- clude the plastics, petrochemicals, textiles, pa-
eration under constant and uniform voltage level, per, semiconductor, and glass industries.
as close as possible to the rated value. In addi- Voltage sag is defined as when the value of the
tion, industrial equipment, working on a three voltage is reduced below the rated one for a cer-
phase supply, requires the three phase voltage tain amount of time. Similarly, voltage swell is de- 05
levels to be balanced. Power quality is a descrip- fined as when the voltage is increased above the
tion of how well a power system complies with rated value for a certain amount of time.
the above ideal conditions. Power quality issues RMS voltage values and frequency are two funda-
can have negative consequences on the compo- mental features of a voltage signal, but the “pure-
nents and on the energy efficiency of the network. ness” of the voltage waveform is also an import-
Thus, power quality monitoring is becoming more ant point. An ideal voltage waveform should be a
important in modern power systems, and will be a perfect sinusoid, but this is not something that is
key part of the smart grid of the future. normally seen in the real world. Frequencies other
In particular, power quality evaluation includes than the fundamental are always present.
the following aspects: These frequencies are called harmonics: a har-
• Deviations of voltage average value from the monic of a signal is a component frequency of the
rated value wave spectrum that is a multiple of the funda-
• Short decreases (sags) or increases (swells) of mental frequency. Harmonic content is an issue
voltage value that is becoming increasingly debated: techno-
• Voltage unbalance, i.e., difference in voltage val- logical developments in the industrial and house-
ues between different phases hold field have led to the spread of electronic
• The presence of current and voltage harmonics. equipment which, due to their operating princi-
ples, absorb a non-sinusoidal current (non-linear
load). Such current causes a non-sinusoidal volt-
age drop on the supply side of the network with
the consequence that the linear loads are also
supplied with a distorted voltage.