20-09-2017, 12:13 PM
The constant power model and VSC-HVDC control modes are briefly presented first. Based on the stable VSC-HVDC model, a new sequential iterative power flow algorithm is proposed. As one of the key technologies for large-scale access to distributed energy resources, the HVDC transmission system has great potential for further development. Therefore, in the last few decades, the problem associated with HVDC converters connected to weak CA networks has become an important field of research. The one that has a particular interest, and the highest one in the consequences, is the stability of AC voltage in the HVDC terminals of AC / DC systems.
The model may have different structures under different network failures due to the action of the switches. Therefore, the power flow of the system based on this model is analyzed under steady state and different types of transient failure situations in the network. Two main control methods applied to the VSC-HVDC linkage in this dual feed HVDC system are investigated, and a comparative analysis of them is presented in a transient situation. A simulation model is constructed in PSCAD / EMTDC to verify the theoretical analysis. The simulation results indicate that this dual HVDC feed system can achieve greater stability than the single feed HVDC system. And the different control strategies in a VSC-HVDC link may result in different influences on the alternating voltage and oscillation of the active power during the transition.
The model may have different structures under different network failures due to the action of the switches. Therefore, the power flow of the system based on this model is analyzed under steady state and different types of transient failure situations in the network. Two main control methods applied to the VSC-HVDC linkage in this dual feed HVDC system are investigated, and a comparative analysis of them is presented in a transient situation. A simulation model is constructed in PSCAD / EMTDC to verify the theoretical analysis. The simulation results indicate that this dual HVDC feed system can achieve greater stability than the single feed HVDC system. And the different control strategies in a VSC-HVDC link may result in different influences on the alternating voltage and oscillation of the active power during the transition.