PQ-Check & Electrical Fingerprint

New high-frequency analysis measures currents, voltages and resonances up to 150 kHz

When components of a PV system fail, this may be due to harmonic distortions in the electrical internal or external grid. They can have a massive impact on the connected devices, restrict functions and thus accelerate wear or ageing processes of the components. This leads to recurring repair costs due to failures and defects, of which the exact causes are often unknown.

High transparency of the grid topology

By an high sampling rate, our analysis determines impedances even in the high-frequency range up to 150 kHz. In contrast to common standard power quality measurements, this provides completely new and much more detailed insights into the nature and quality of the electrical network – and the resulting challenges for the plant.

Derive and implement measures for trouble-free and long-term plant operation

From the results of the measurements, indications of defective components will be derived. They can be replaced in the next step being designed according to the existing grid conditions. For new systems, for example, recommendations for the filter design of inverters can be derived and implemented before major damage occurs. In addition, it is possible to find out whether sources of interference outside the PV system have a negative influence on the operation of the system.


Get to the bottom of frequent failures or recurring defects in the system:

  • Reveals causes for frequent / recurring failures on specific plant components
  • Indicates increased stress of certain components
  • Enables effective protective or precautionary measures
  • Reduces repair costs and yield losses

Electrical Fingerprint

Focus on plant health right from the start and ensure the basis for a long and efficient service life:

  • Reduces wear and stress on new equipment right from the start
  • Enables longer maintenance intervals / reduces costs
  • Provides transparency on the condition of the system after completion of construction and at recurring intervals
  • Provides an objective asset valuation (e. g. in case of sale)

High-frequency analysis for photovoltaic systems PQ-Check and Electrical Fingerprint


  • Measurement of currents, voltages and impedance in the high-frequency range.
  • Measuring points usually on the low-voltage side of the transformer station.
  • Scope depending on the number of transformer stations and inverter layout and on the respective system type and the installed components.
  • Data acquisition and transmission by the Online Network Impedance Spectrometer “ONIS”.
  • Analysis of the data and evaluation of the measurement results.
  • Preparation of a comprehensive report.
  • Including consideration and evaluation of normative specifications for the low frequency range, additional with definition and adjustment of further limit values in the high-frequency range.
  • Evaluation of the conspicuities according to relevance in the form of a traffic light system with corresponding recommendations for action.

Measurements with significant target-actual deviations (target value: red / actual value: blue)

Deviating behaviour from the nominal condition: from 27 kHz steadily increasing impedances, from 37 kHz too high impedances

Consequence: the plant fed 20 % less power into the grid. Loss of revenue over 6 months more than 100.000 €


from EUR 2.950, —:

This is an indicative price that includes the analysis for systems between 1 and 3 MW with 4 measuring points. Travel costs will be charged additionally. Since we know that every plant is different, we will work out an individual measurement concept for you that takes the type of plant as well as the installed components and already known issues into account.