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The use of renewable energies reveal specific requirements for electricity meters. General Meter testing reasons for incorrect operation. PTB Topic of ZMP 2011: 2 kHz - 150 kHz. Meter testing / Reasons for incorrect operation. How currents outside of the 50 Hz frequency range arise?
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The use of renewable energies reveal specific requirements for electricity meters
General Meter testing reasons for incorrect operation
Meter testing / Reasons for incorrect operation • How currents outside of the 50 Hz frequency range arise? • Why are some electricity meters get disturbed by a frequency from 2 kHz? • What type of meter is to be selected for which electricity consumers? • How can ensure the correct function of the meter? • How can you check the meter installation, easy, safty and fast?
How currents outside of the 50 Hz frequency range arise?Example: switched-mode power supply Circuit diagram of a switched-mode power supply Voltage- and Currentcurve
How currents outside of the 50 Hz frequency range arise?Example: switched-mode power supplyFourier Transformation Fourier Transformation for I Netz: 80% 150-Hz-Anteile 50% 250-Hz-Anteile 22% 350-Hz-Anteile Current profile of a switched-mode power supply
How currents outside of the 50 Hz frequency range arise?Examples
Why are some electricity meters get disturbed by a frequency from 2 kHz? EN 61000-2-2 und EN 50160 40. harmonic= 40 x 50 Hz = 2 kHz The frequency range from 2-9 kHz is in Europ curenntly not regulatet in the EMV Norm.
What type of meter is to be selected for which electricity consumers? Customers Transmission Production Production: Installation of highly accurate meters and measuring transformers in power plants Transmission: Transfer stations between different networks Customers: Installation of meters and measuring transformers on the consumer’s premises
What type of meter is to be selected for which electricity consumers? • The solar electricity-magazine PHOTON reported in the November 2010 edition already, that some electronic power meter are to slow … • … Some inverters are not compatible with electronic energy meters. Who is using the wrong combination of devices must be feared that his input meter shows too little income. The problem is known in professional circles for at least three years, some Operators even have blacklists.... Karsten PetersonItron Zähler& Systemtechnik GmbH(Vertriebsleiter Deutschland)… by the inverter generates extra power and pollution would have to actually work to avoid these … Typ Iskra MT171 showsupto 20% less Frank GreizerSMA Solar Technology AG(Bereichsleiter Technologieentwicklung) … be seen from any point of any failure or fault of SMA and see the buck at the meter manufacturers …
What type of meter is selected for electricity consumer? • The VDE-project team„ Measurement reliability and stability of electricity meters and accessories“ has conducted studies on this topic. • In the laboratory of the VDE Testing and Certification Institute, 12 electronic electricity meters has been tested. It has been determined error of over 70%. (graphicleft) • In the following customers are high-frequencys expected : • Solar invertersystems • Wind turbines • pumpingstations • commercial operation / metal working
How ensure the correct work of the meter? • Type testing and standards norms EN 50470-X (for electronic electricity meters) will soon be expanded and standardized. • At customer site with high frequency system size it is possible to check the meter with the real system size on site with appropriate measuring instruments • More possible disturbances: DC, DC voltage, stress peaks modulated frequency changes( Flicker) overburden of Current- and Voltagetransformer transport damage of the meter connection erros during the installation of the meter
On site test • Collectionofnetworkvariables • Connection check • Error measurement • logging
Thank you for your attention Matthias Heinzen Sales Manager ZERA GmbH Hauptstrasse 392 D-53639 Koenigswinter m.heinzen@zera.de