ENIEC 61803:2020 pdf free.Determination of power losses in high-voltage direct current (HVDC) converter stations with line-commutated converters (IEC 61803:2020).
As a general principle, it would be desirable to determine the efficiency of an HVDC converterstation by a direct measurement of its energy losses.However，attempts to determine thestation losses by subtracting the measured output power from the measured input powershould recognize that such measurements have ‘an inherent inaccuracy,especially ifperformed at high voltage.The losses of an HVDC converter station at full load are generallyless than 1 % of the transmitted power. Therefore,the loss measured as a small differencebetween two large quantities is not likely to be a sufficiently accurate indication of the actuallosses.
In some special circumstances, it may be possible，for example, to arrange a temporary testconnection in which two converters are operated from the same AC source and alsoconnected together via their DC terminals. In this connection,the power drawn from the ACsource equals the losses in the circuit. However, the AC source shall also provide var supportand commutating voltage to the two converters.Once again， there are practical measurementdifficulties.
In order to avoid the problems described above，this document standardizes a method ofcalculating the HVDC converter station losses by summing the losses calculated for each itemof equipment. The standardized calculation method will help the purchaser to meaningfullycompare the competing bids. lt will also allow an easy generation of performance curves forthe wide range of operating conditions in which the performance has to be known. In theabsence of an inexpensive experimental method which could be employed for an objective verification of losses during type tests, the calculation method is the next best alternative as it uses，wherever possible,experimental data obtained from measurements on individual equipment and components under conditions equivalent to those encountered in realoperation.
The calculation of harmonic currents and voltages in HVDCequipment is described inAnnex A.
lt is important to note that the power loss in each item of equipment will depend on the ambient conditions under which it operates, as well as on the operating conditions or duty cycles to which it is subjected. Therefore,the ambient and operating conditions shall be defined for each item of equipment,based on the ambient and operating conditions of the entire HVDC converter station.ENIEC 61803 pdf download.