Research On Modeling And Simulation Of Hu-Liao DC System Based On PSCAD

The highly developed HVDC(high-voltage direct current transmission) can not only satisfy the needs of the long-distance large-capacitance power transmission, but also can connect the two power grids with asynchronic frequencies. The rapid development of power grid gives raise to the requirement of increasing the simulation technology, especially after the HU-LIAO DC project being put into operation.The enormous absorption of reactive power produced during the accessing to the grid has great influence on the operation and regulation of the northeast power grid and exerts great impact on the power quality of the whole grid.Therefore,the research of AC, DC power system simulation for the safe and stable operation of power grid is necessary and is of great importance to the study of HVDC power system.In this paper, the basic structure and parameters of HU-LIAO DC transmission system are researched, and modeling methodsare proposed. To study the characteristics of the electrical components under different working conditions of HU-LIAO DC system, simulation models of the components are developed, including the converter valve, converter transformer, smoothing reactor, and AC/DC filter. After that, the stable and transient characteristics of the components are simulated in PSCAD. The model of the whole HVDC system is constructed based on software PSCAD and the interactions of the AC and DC system of the North-East grid are analyzed according to the waveforms calculated by the proposed model. The research conducted in this paper lays a solid foundation for the further study of interaction between AC and DC system as well as the influence of the faults occurred in DC system.