UNDAM uMETER 500

A frequency and ROCOF meter with unique features:

Frequency, ROCOF and RMS voltage spanned over 1, 5, 10, 25 and 50 cycles simultaneously.
Measurements are updated every 10 milliseconds (reporting rate of 100 samples per second).
Synchronized measurements exactly at 10-ms UTC ticks.
PTP and NTP synchronisation.
Each frequency and ROCOF measurement is provided alongside its uncertainty, enabling validation and assessment. ROCOF is also provided with a coefficient of determination to improve the uncertainty metric.
Continuous recording in the built-in storage for several months.
An inbuilt battery provides up to 20 minutes of backup in the event of a power failure, enabling blackout and restoration recording.
Increased reliability thanks to robust transient overvoltage protection.
Rack 19-inch form factor for standard industrial cabinets.
Online measurements are possible via HTTP REST, MODBUS TCP/RTU interface and MQTT.
Historic measurements can be accessed via the HTTP REST interface, with CSV output for easy export to data mining and analysis platforms, such as Excel, Power BI or Python Pandas.
Specific custom relay functions, including voltage-free contacts, can be implemented on demand.

The device has been intensively tested and debugged across Europe on a set of test sites.

Fastest dynamics

Even the fastest events can be captured within a 1-cycle window, and the average dynamics can be observed by using 5, 10, 25 or 50 cycles simultaneously (other values available on request).

Furthermore, the ROCOF is calculated using dynamic slope approximation, enabling the capture of even the fastest dynamic events without compromising accuracy.

Last but not least, uncertainty and the coefficient of determination are yielded every 10 milliseconds, enabling each measurement to be assessed and validated. In this way, perfect 'hammer' oscillations in the power network can be easily identified as the most significant oscillatory signal.

Voltages are evaluated for each calculated period so that they are not averaged down by arbitrary window sizes. This enables the easy identification of oscillations in RMS voltage.

In short, it can capture both the fastest and slowest dynamics, enabling its use in various applications, such as:

Islanding detection.
Power oscillation damping.
Frequency Containment Reserve (FCR).
Limited Frequency Sensitive Mode (LFSM).
Virtual inertia.

Thanks to collaboration with experts across Europe

A set of devices was installed and monitored across Europe to enable debugging and improvement in different electromagnetic environments.

Test sites have been set up in the following locations:

Seville (Spain).
Barcelona (Spain).
Bilbao (Spain).
Paris (France).
Zumikon (Switzerland).
Walsrode (Germany).
Dresden (Germany).
Clausthal (Germany).
Vienna (Austria).
Brno (Czech Republic).
Skellefteå (Sweden).

Without the selfless help of these people, it would be very difficult to improve and debug the device.

Ready to install

Its 19-inch rack form factor allows for easy integration into standard cabinets.

It has a full set of connectivity protocols and interfaces for straightforward integration:

Dual 1-Gb Ethernet ports.
RS232/RS485 serial interface.
MODBUS TCP/RTU allows for straightforward integration with any SCADA, control system or device.
HTTP REST allows for off-the-shelf integration with standard IT web platforms.
Historical data is available via CSV over HTTP REST for coupling to data mining platforms.
Fully documented API and no need for proprietary software.

Moreover, full synchronisation via PTP and NTP with atomic or GPS clocks enables synchronised measurements across distant sites. This is particularly useful for monitoring power oscillations across large regions.