The actual design is not yet done. However some preliminary measurements have been done on commercially
available AD converter/measurement circuits. These
measurements also indicate that the main problem will be
offset errors and their temperature dependence.
VI. CONCLUSION,FURTHER WORK
The design issues for a class 0.2 HVDC meter have been
analyzed. One major issue is offset and its temperature
dependence. Low offset circuits and possibility for offset
correction must be considered. The voltage and current
channel inputs should be differential and of instrumentation
amplifier type with high impedance. During the next 6
months a design will be realized and tested. Results of these
will be presented at the conference.
ACKNOWLEDGEMENT
This work is funded by the European Union on the basis of
Decision No 912/2009/EC, and identified in the European
Metrology Research Programme (EMRP) as Joint Research
Project (JRP) ENG07 HVDC, Metrology for High Voltage
Direct Current.
REFERENCES
[1] IEC 62053-21, Electricity metering equipment(