DC-side Harmonics Calculation And Filter Design Of HVDC

The converters of the HVDC system yield harmonic voltages and currents in both DC side and AC side because of their non-linearity, In DC side ,the main impact of such harmonics is the disturbance induced in communication circuits by the harmonic currents flowing in an HVDC line, it will endanger equipments and personal safety in serious cases. In order to keep the disturbance at the acceptable level, the dc filters should be equipped. Meanwhile, for the sake of satisfying the specification requirements while making the cost least, optimizing the parameters of dc filters as well as the configuration among dc filters and other elements such as the smoothing reactors and the HVDC line is necessary.The performance criterion equivalent disturbing Ieq, which is used to evaluate disturbing level of the harmonic currents in HVDC line, is researched systematically. The evaluation and limitation criterion of disturbing current Ieq is educed according the specification of China. The algorithm of the three-pulse voltage sources is present with piecewise linear analysis, which is more accurate and much easier to come true by program. Besides, the accretion and practicality of the algorithm is proved through the parameters of yun-guang project. The formula and optimization of dc filters parameters is educed by the characteristics of dc filters and the requirements of project. The harmonic currents of each node along the HVDC line and the harmonic impedance are calculated by setting up a general model of system network according to its characteristics and solving the model. Moreover, dc filter performance calculation of yun-guang project is done using the program designed by author.