Power Quality Monitoring: Protecting Equipment and Ensuring Reliability

• 2024-09-20

POWER QUALITY MONITORS 

PQM SERIES 

Newly launched PQM series of Multispan has important feature of Power Quality functions like THD (Total Harmonics Distortion) for both Current and Voltage for all three phase 

In this age, where automation and electrical distribution panels are widely used along with electrical equipment like Stabilizer, motors and AC drives plus stroke machines along with inverters for solar installation ; harmonics are found to be present everywhere and it does affect overall power quality and poses a situation where equipments under harmonics effect face gradual loss of life with time. 

It is important to monitor voltage and current waveforms with harmonics, interharmonics and subharmonics as well as simulation of voltage, current, phase shift and frequency variations as a function of time (dips, interruptions, swells, flicker, fluctuations and ramp signals).

Harmonics

Harmonics are voltages and currents with a frequency, that is an integral multiple of the fundamental frequency. Harmonic testing is defined in EN 61000-4-7 and EN 61000-4-13.

Interharmonics

Interharmonics are voltages with a frequency, that is a non-integral multiple of the fundamental frequency. For example, in 50Hz supply system, 150Hz is a harmonic (the third) but 175Hz is an interharmonic.

Interharmonic testing is defined in EN 61000-4-7 and EN 61000-4-13.

Dips, Interruptions, Swells and Shocks

Dips are a temporary reduction of the voltage below nominal (Interruptions below 1% nominal) and Swells are a temporary increase of the voltage above nominal up to 200% nominal for a time from 10ms up to several minutes.
 

Shocks (Inrush current) are a temporary increase of the current above nominal when first turned on of an electrical device. Dips, Interruptions and Swells testing are defined in EN 61000-4-11 and EN 61000-4-34.
 

Flicker

Flicker is a specific measurement, which sets out to measure the human sensitivity of a flickering light caused by supply voltage fluctuation around of a nominal value. Flickermeter testing is defined in EN 61000-4-15.