A current-based model of the static synchronous series compensator (SSSC) for Newton–Raphson power flow

In this paper, a new approach to modeling a static synchronous series compensator (SSSC) for power-flow calculations by applying the Newton–Raphson method is presented. This new approach differs from known methods in terms of the interpretation of the device's branch. It is considered on the basis of its current and is therefore denoted as a current-based model of an SSSC. This approach might in principle be applicable also for other FACTS devices (i.e., UPFC, IPFC, GUPFC). In the paper, the current-based model of an SSSC is presented as the models of this device have difficulties with convergence in power-flow calculations and there are very few references covering these topics. First, the basic features of an SSSC are presented, as it is the basis for the current-based model that is incorporated into the Newton–Raphson load-flow model. The results of the tests at the IEEE 57-bus system are discussed in detail and compared with the existing injection SSSC load-flow model [X.P. Zhang, Advanced modeling of the multicontrol functional static synchronous series compensator (SSSC) in Newton power flow, IEEE Trans. Power Syst. 18 (November (4)) 2003].