Cooperative autonomous control for active power sharing in multi-terminal VSC-HVDC

Economical autonomous control for sharing active power among MTDC systems based on the availability of active power or on a power management policy is proposed in this paper. Power sharing among MTDC systems involves a priority or sequential procedural problem because of the use of the conventional droop strategy. On the other hand, the use of predefined or constant power sharing fails to identify the available power that can be shared when it is not consumed by another inverter. The proposed strategy addresses these issues through a variety of options. The test system presented in this paper consists of three simulated VSC terminals based on a detailed switching VSC model with two AC voltage levels. The MTDC system has been simulated in a PSCAD/EMTDC environment. The simulation results show a significant decrease in operating costs as well as the ability to provide effective protection with respect to the problem of overloading.