Average-value modeling of thyristor controlled line-commutated converter using voltage and current source formulations

Line-commutated converters (LCC) can operate in both rectifier and inverter modes and are widely used in various high-power applications including the HVDC systems. So far, many average-value modeling (AVM) techniques have been introduced to model the rectifier operation of the LCCs. However, to extend these models for the inverter mode may be challenging. In this paper, the voltage-source and current-source average-value modeling (VS-AVM and CS-AVM) formulations are introduced based on the well-posedness of the underlying state equations. It is shown that the proposed CS-AVM will have advantages for modeling the thyristor controlled LCC operating as an inverter, whereas a more conventional VS-AVM may not result in a convergent model.