Dynamic line rating and optimal transmission switching for maximizing renewable energy sources injection with voltage stability constraint

Renewable energy sources (RES), such as wind and photovoltaic, has been widely integrated into power systems. However, the phenomenon of “wind curtailment” and “sunlight curtailment” is still a critical issue, resulting in the sharp decline of renewable resource utilization. The factors of reducing the renewable resources injection are the limited line thermal capacity, voltage magnitude limit, and voltage stability issues. This paper presents a maximizing RES injection (MRI) problem with voltage stability constraints, AC power flow constraints and operating constraints. A novel dynamic line rating (DLR) technique is proposed for dynamically assessing transmission line capacity of transmission line. By jointly DLR and optimal transmission switching (OTS), the proposed model’s solution can maximize power network’s transmission capacity and ensure the technique and physical operation requirements of power systems. Due to the difficulty in solving the proposed model, a prescreening technique is presented to screen out the ineffective lines by three indicators. The proposed approach has been applied to the IEEE 24-bus RTS system, the IEEE 118-bus power system, and the IEEE 3120-bus power system. The computational results show the effectiveness of the conducted model in maximizing the utilization of RES and improving the acceptable level of power grid for renewable resources.