Steady-State Model of VSC based FACTS Devices using Flexible Holomorphic Embedding: (SSSC and IPFC).

For proper planning, operation, control, and protection of the power system, the development of a suitable steady-state mathematical model of FACTS devices is a key issue. The Fast and Flexible Holomorphic Embedding (FFHE) method converges faster and provides the flexibility to use any state as an initial guess. But to investigate the effect and ability of FACTS devices using FFHE technique, it is necessary to develop an embedded system for these devices. Therefore, this paper presents an FFHE-based embedded system for VSC-based FACTS controllers, such as SSSC and IPFC. The embedded system is also proposed for their controlling modes. The introduced embedded system is flexible which allows to take any state as an initial guess instead of fixed state, which leads towards the reduced runtime and decreases the required number of terms, as compared to standard HELM. To demonstrate the effectiveness and practicability, the proposed FFHE-based models of FACTS devices have been tested for several cases. Further, the developed recursive formulas for power balance equations, devices' physical constraints, and their controlling modes are thoroughly investigated and examined. From several tests, it is found that the proposed FFHE-based FACTS models require less execution time and reduce the error at higher rate.