A Generalized Representation of VSC-HVDC Based AC/DC Microgrids for Power Flow Studies

In this paper, a general representation of multi terminal VSC-HVDC based microgrids appropriate for power flow studies using Newton-Raphson method is developed and presented. To such aim, active loads and ideal synchronous machines are employed in order to incorporate both converter losses and power balance, respectively. The proposed representation takes into account the practical limitations, switching and conduction losses of semiconductors and the different VSC-HVDC stations control strategies. Moreover, the proposed generalized representation of VSC-HVDC systems can be easily extended to incorporate multi terminal VSC-HVDC based microgrids in an efficient manner. The proposed representation for VSC-HVDC systems and load flow solution are applied to a test system, followed by discussion on results of written computer program. Results show the proposed algorithm is able to solve ac/dc power flow problems with considerable less time in comparison to other existing algorithms. Developed presentation for multi-terminal VSC-HVDC can be effectively applied to power flow solution of AC and DC microgrids.