Applies to all line-commutated high-voltage direct current (HVDC) converter stations used for power exchange in utility systems. Presumes the use of 12-pulse thyristor converters but can also be used for 6-pulse thyristor converters. Presents procedures for determining the total losses of an HVDC converter station. Cover all parts, except synchronous compensators or static var compensators and address no-load operation and operating losses together with their methods of calculation which use, wherever possible, measured parameters.