PQA-FLEX | Power Grid Monitoring

HIGHLIGHTS

Modular architecture, allowing a combination of one CPU module and up to six selected input modules into one meter.

High channel count and high-speed sampling to measure supra-harmonics.

The CPU module is equipped with FPGA receiving all digital input data, and the real-time controller running meter firmware and providing all interfaces and data storage.

Multifeeder and Phasor Measurement Unit monitor also available.

Real-time data refreshed every 200 ms with historical data stored for 12 months.

The firmware calculates power quality parameters according to EN50160. It fully follows requirements as described in IEC 61000-4-30, Ed. 3 Class A and others (61000-4-7, 61000-4-15).

Main Measurement Features

U, I, P, Q, S, frequency, THD U, THD I, power factor, energies – AP, AQ, AS, APin, APout, all quantities are per phase and total
Harmonics – U and I, each harmonic up to 50th (optionally up 180th), optionally supraharmonics 2-9kHz spectra
All quantitates are calculated on 200 ms (10/12 period basis) according to IEC 61000-4-30
Voltage quality according to EN50160, IEC 61000-4-30 ed. 3 Class A (U, freq., THD U, flicker, unbalance, harmonics)
Voltage events according EN50160, IEC 61000-4-30 ed. 3 Class A (dip, swell, interruption – time, extrema, length)
Waveform capture – in case of trigger, the device captures the waveform
- Trigger can be activated by selected quantities (U, I, P, Q, S, freq., PF) crosses specified limits
- Waveform means raw voltage/current signal with sampling rate at 192 or 256 samples/period, waveform length is 50 periods (0,2 s pre-trigger, 1 s length)
- Waveforms are stored in files in standard protocol and the device is able to hold at least 100 of them in local storage

Smart Software Solution

Our engineers have designed a dedicated sofware solution for automatic reading of real-time and historical data from all meters simultaneously. These can be displayed in multiple visualization panels including tables, graphs, single line diagrams, voltage/frequency profles, vectors, harmonics, digital indicators, maps, historical trends and tables, energy summarization and profles etc.

Data is provided in two ways, either in real-time using standard protocol (MODBUS) and refreshed every 200 ms and/or historical; the device calculates (gapless) true RMS/average of all quantities in user predefned intervals. The historical data also includes voltage events details according to EN50160.

Phasor Measurement Unit (PMU)

A PMU – Phasor Measurement Unit - is a device that delivers accurate synchrophasor measurements using a GPS. The PMU frmware measures voltage and current phasors with a Total Vector Error of less than 0.5 %. Additionally, it measures the frequency and calculates the positive symmetrical components of voltages and currents.

The PMU applies measuring transformers error correction. The measured data is sent according to the IEEE C37.118-2005 communication protocol. The measurement results are used for online detection of electrical grid status. It is based on comparing the phase angle of the fundamental harmonics measured at different points of the distribution or transmission network using several devices at synchronized points in time.