The COMTECH PQM-K is a compact device designed for power quality measurement in medium-voltage networks. It can be used both for permanent installation and for on-site, ad hoc measurements. Voltage transformers with any desired transformation ratio can be connected to its inputs, which have a nominal phase-to-neutral input voltage of 57.7 V. The nominal voltage of the network under test can be set to 11, 22 or 35 kV. In addition to measuring line-to-line voltages, the device is capable of real-time determination of voltage unbalance, flicker, THD and individual harmonic components, all expressed as line-related parameters. These functions are complemented by recording the minimum and maximum values within each measurement period and by classified storage of the number of rapid voltage changes.
Independently of the measurement cycle time, the PQM-K can register voltage dips and voltage swells using an event recording function that can be configured for immediate data transmission. It can also indicate power outages and loss of the supply voltage, as well as detect earth faults. In addition to standard-defined events, alarms can be generated when a freely configurable two-day voltage variation limit is exceeded, or when the lower or upper voltage limit is crossed.
The recorded data are transmitted to a local or Azure cloud-based database via a communication module supporting LTE, NBIoT, Cat-M and 2G, using standard TCP/IP or MQTT protocols. For flexible deployment, the communication module can be replaced with another type if required. If the telecommunications network becomes temporarily unavailable for any reason, the measured values are stored locally and transmitted once the connection is restored. To facilitate installation and commissioning, the PQM-K features a large LCD display, allowing the measured line-to-line voltages, phase sequence and key administrative parameters to be checked without accessing the database. The transmission of individual measured data items to the database can be enabled or disabled independently, allowing telecommunications costs to be optimized.
Simple installation is supported by an integrated 230 V power supply that is independent of the measured network, while optional GNSS positioning facilitates and speeds up post-installation administration. The devices are available with a wide range of options, as can be seen in the chart below.
Benefits:
