New references for HVDC metering

HVDC power transmission is now being considered not only for point-to-point interties, but also as meshed grids where several operators may be connected into the grid, each having their own economic sphere. In this new situation it is important that transmitted energy can be distinguished from losses incurred in the converter stations, to enable a fair distribution of costs for grid operation. To this end, a metrology infrastructure is needed to provide traceable calibration and approval both for high-current and high-voltage transducers and d.c.-electricity meters. A resent research project funded by the European Commission tackled these questions in a concerted research effort. The pre-normative work carried out to define requirements both for d.c. energy meters with analogue digital input is described. The design and performance of new reference voltage transducers for precision measurement of HVDC are briefly presented. Measurement uncertainty below 0.01 % is demonstrated on voltages up to 1 000 kV.