Nowadays a secure infrastructure is not only life standard but also an advantage in competition. National and international regulations describe the quality of energy supply and especially for electrical power there are several standards and reports which need to be monitored:

• EN50160
• IEEE 519
• IEC61000-2-x
• IEC61000-3-x
• IEC61000-4-x
• ITIC (CBEMA)
• UNIPEDE

The required parameters to be monitored vary from standard to standard, but with the use of DEWETRON PNAs (Power Network Analyzers) all of them can be measured, stored and analyzed:

•  Voltage (IEC61000-4-30 Class A)
• Current
• Power
• Frequency
• Harmonics (IEC61000-4-7)
• Interharmonics
• THD
• Flicker (IEC61000-4-15)
• Symmetrical components (unbalance)
• Signal voltages
• Supply interruptions
• Overvoltages
• Transient recordings
• Disturbance recordings

In addition with the tool PMT, strong reports can be generated - a set of standard reports is of course part of the delivery.

Testbenches for electrical power are one of the applications where DEWESoft with the POWER option was developed for. Several special features are implemented for an overall analysis of motors and generators.

In addition frequency converters and pulse wide modulated driver systems require very fast and accurate measurement instruments. DEWETRONS solution for this application are instruments with the DEWE-ORION boards 1616-500 or 0816-1000 and DAQP-HV modules for voltage or DAQP-V-B modules for current measurements.

• ±1400 V peak
• 4 kV isolation
• 180 kHz bandwidth
• 500 kS/s (1 MS/s) acquisition rate
• Accuracy typical < 0.05 %

But the storing advantages are coming also from our DEWESoft POWER software package:

• Individual number of channels
• Multiple power systems on one instrument
• Different frequencies for each power module (software PLL) at the same time
• DC, 16 2/3 Hz, 50 Hz, 60 Hz, 400 Hz, 800 Hz or variable speed
• Harmonics analysis and full frequency analysis in parallel
• Math library (e.g. calculation of efficiency)
• Mechanical parameters in parallel (rpm, torque, temperature, ...)
• Video in parallel
• CAN bus in parallel
• Order tracking
• Torsional and rotational vibration

The typical required functions of an energy distribution grid company is fault recording of voltage and current. Nowadays the discussions around permanent power quality monitoring round up the need of them. In addition the need is to know the permanent power flow in the grid and more details when blackouts have happened. An other fact is that older paper recorders are coming into their days and need to be replaced.

• Power fault recording (waveform typically 20 kHz; U, I)
• Disturbance recording (RMS shape typically period values; U, I, P, Q, S, PF, etc.)
• Data logging (typically 10 min; U, I, P, Q, harmonics, ...)
• Replacement of paper recorders
• Power flow monitoring
• Power Quality monitoring

DEWETRON combines all this functions in one instrument - the PFR systems. As a logical consequence of the used computer technology all this PFRs can be interconnected over standard data lines (Ethernet) and the data can be sent to one central server where they can be analyzed in a very comfortable way with the use of the PMT sofware.

A time synchronous sampling (network time server) guaranties a common storing time in several substations. An absolute synchronous sampling (DEWETRON GPS systems) allows even the comparison of phasors between substations over a wide distance.

The system DEWE-820-PFR is designed for standard substations where 1, 2 or 3 power systems (3~) need to be monitored at the same time.

With the flexible DEWE-818-PFR system also larger systems can be built up. Customized requirements like harmonic monitoring on DC lines (150 channels) have been mounted as well as PFRs in substation with up to 10 feederlines.

The energy demand is growing and the prices for energy are growing as well. To reduce costs of energy is a topic of nowadays. Traiffs and contracts are one thing of course - reducing the demand another. But to be able to reduce the demand you first need to know the actual demand and the internal load flow.

To really measure this multi channel power meters are needed. With the help of them (for example DEWE-560-ELOG or any other DEWETRON instrument) you can easily measure the demand on several lines at the same time, in one or more distribution boards and also in different buildings.

With the help of the data processing software PMT you can easily generate your load diagrams, compare different engines each to each other, generate your load management studies and handle data from numerous instruments in one step.

• Measurement of load flow
• Total load flow
• Details of different instruments
• Measuring typically for 2 weeks
• Storing in 1 minute interval
• Storing other parameters in parallel (temperature, humidity, brightness, ...)

And as a nice add-on you can analyze the power quality in parallel and even catch faults with the broad range of trigger possibilities.

Renewable energy sources are coming more and more. The most famous are wind and photovoltaic. Beside the standard measurements of power faults and power quality several additional functions are required to make a full analysis of those power plants:

• Power fault recording
• Power quality monitoring
• Power flow monitoring
• Frequencies up to 100 kHz and more
• DC measurements in the frequency converters and on photovoltaic cells
• Analysis on the grid side and on the motor side
• Voltages up to 700 Vrms (DAQP-HV module)
• Reports according to certain standards for wind mills on power grids
• Environmental parameters like wind speed and temperature
• Mechanical parameters like vibration and rpm

DEWETRON instruments are able to combine all this functions in one box. With the broad variety of DEWETRON modules (and adequate sensors) all parameters can be measured synchronous and the evaluation can be made easily.

The DEWESoft POWER option allows the measure not only up to 50 Harmonics but even up to 200 (20 kHz!) and the full Interharmonics as well.

For long term measurements the database tool PMT can be used to compare the data from different locations or even to generate fully customized reports.

HVDC lines (High Voltage DC lines) are used to transport energy over long distances, sometimes for sea cables or to connect power grids with different frequencies. Typically we are talking about 1 Megavolt and some thousand Ampere.

When we talk about HVDC we talk about semiconductors and converters. These converters are electronic switches and they are producing harmonics. All of them must be limited and if necessary filtered. A lot of coils and capacitors are necessary to do this task. If the filters are detuned an alarm should be set up and also some certain values like THD, THFF and EDC are necessary to be monitored. In total we talk about some 100 points of measurement. On each point 50 Harmonics including the DC value must be calculated and this all 200 milliseconds.

Also the measurement of DC values need a solution and an interesting detail is that the fundamental oscillation which is necessary to calculate harmonics is not available in DC values, because they are DC of course - so the frequency needs to be taken from the AC side!

• AC Harmonics on lines
• AC Harmonics on filters
• DC line Harmonics (according AC frequency)
• THD
• TIF
• THFF
• EDC
• Power fault recording (waveform typically 20 kHz; U, I)
• Data logging (typically 10 min.; U, I, Harmonics, ...)
• Alarms on dry contacts

Based on the DEWE-818 series, the hardware solution is easy to define. The 19" rack systems fit perfect to all other equipment. As measurement inputs DEWE modules of type HV and V with internal shunts are used.

The interconnection between the computers is done based on a fibre optical LAN. Special racks for DC modules and relais boxes as well as 19" keyboard / display sets complete the system.

As basic measurement software DEWESoft with POWER module was used. Some special functions like THFF and EDC calculation are available asl PlugIns.