Computer simulation and measurements of HVDC harmonics

A simulation model is developed to compute the harmonic values in a high-voltage direct-current (HVDC) power system. The simulation procedure is presented by analysing a typical HVDC system. The loop current method is used in simulating the operation process of the power converter. The relation between rectifier, inverter and transmission line is considered in the mathematical model. The effects on the harmonic of the unbalance in AC voltages, system impedance, transformer parameters and the frequency difference between AC power systems connected with rectifier and inverter are analysed. The simulation result is compared with the data collected from the Gezhouba-Shanghai HVDC power converter. The harmonic phenomena found in the measurement are interpreted