SATEC has added further enhancements and advanced features for power quality monitoring with the PM180. The latest release incorporates disturbance direction detection and analysis, allowing identification and location of voltage sags or voltage swells, relative to the monitoring location. The PM180 Power Quality Analyser is a Class A device for PQ metering.
Damage Resulting and Disturbances PQ Network
Detecting network disturbances, such as voltage sags/dips and swells, is an important aspect of power quality monitoring. However, it is often difficult to determine and locate the cause responsible for the disturbance detected. This of course presents a further challenge in preventing such future events.
A power quality analyser is normally situated in a network operator’s substation or at a client/facility’s grid connection. The functionality is identical but has different interests and outcomes. Since poor power quality can damage equipment, the client wants to record and document such cases, analyse and take appropriate actions.
Accordingly, the operator must conduct its own independent monitoring, to confirm such PQ disturbances occurring. Likewise, the monitoring is needed for providing internal alerts for power quality issues, before any damage is incurred.
Causes and Detection
Voltage sags/dips or swells occur as the result of sudden events within the network, such as short circuits, the energizing of a transformer or the introduction of big loads. For example, a big industrial client turning on an induction motor could cause a notable voltage sag/dips experienced by neighboring facilities as well. Determining this is extremely important for a network operator for preventing such events and for deflecting charges from clients.
When a power quality analyser records a disturbance, the questions above are phrased asking whether the event has taken place upstream or downstream. Upstream indicates occurrence on the generation side / provider side of the analyser; downstream indicates the consumer / load side of the analyser. Other Power Quality concerns include, harmonics, interruptions, fluctuations, notches flicker, frequency, unbalance and transients.
Disturbance Direction Detection with the PM180 Power Analyser
Providing this detection is not trivial and is not featured by most power analysers on the market. The PM180 uses synchronous voltage and current waveforms, recorded before and during an event, to determine the location of the disturbance source. Depending on the characteristics of the fault, the device can apply different methods of analysing the collected data to give the most reliable indication of the direction of the fault.
Symmetrical (three-phase) sags/dips and swells are analysed using the relative level of the fault or inrush current and the fundamental power angle. Asymmetric (single-phase and two-phase) sags/dips and swells can be analysed using the negative sequence power angle or, in the case of insufficient information, using the fundamental power angle.
The PM180 Analyser
The PM180 is a Class A, Edition 3, multifunction power quality analyser. Functionality includes: Digital Fault Recorder, PMU (per IEEE C37.1118), PLC controller and more. For more information, visit our PM180 product page.
