An Indirect UPFC Model to Enhance Reusability of Newton Power-Flow Codes

Abstract

Power-flow modeling of a unified power-flow controller (UPFC) increases the complexities of the computer program codes for a Newton-Raphson load-flow (NRLF) analysis. This is due to the fact that modifications of the existing codes are needed for computing power injections, and the elements of the Jacobian matrix to take into account the contributions of the series and shunt voltage sources of the UPFC. Additionally, new codes for computing the UPFC real-power injection terms as well as the associated Jacobian matrix need to be developed. To reduce this complexity of programming codes, in this paper, an indirect yet exact UPFC model is proposed. In the proposed model, an existing power system installed with UPFC is transformed into an augmented equivalent network without any UPFC. Due to the absence of any UPFC, the augmented network can easily be solved by reusing the existing NRLF computer codes to obtain the solution of the original network containing UPFC(s). As a result, substantial reduction in the complexities of the computer program codes takes place. Additionally, the proposed model can also account for various practical device limit constraints of the UPFC.Index Terms-Flexible ac transmission systems (FACTS), Newton power flow, unified power-flow controller (UPFC).

Preventive Security-Constrained Optimal Power Flow Considering UPFC Control Modes

“…The abovementioned two UPFC models will both be used in the following power flow calculation method, considering their own advantages and disadvantages. At present, two kinds of steady-state model are mainly used to solve power flow calculation with UPFC, namely a power injection model and an additional node model [23,24], as shown in Figure 2. The control effect of UPFC is equivalent to the power injection in the power injection model and has been well-studied.…”

Developed generalised unified power flow controller model in the Newton–Raphson power‐flow analysis using combined mismatches method

“…The complexity of NR implementation with FACTS has been subject to investigation to make codes reusable and less independent on the original Jacobian matrix [15][16][17]. The matrix partitioning approach has been applied to model UPFC in NR load flow algorithm [15], which still requires a special code to be solved with the Jacobian matrix.…”

Analysis And Effect Of Generalized Unified Power Flow Controller An Optimal Location Strategy

“…Power Injection Model (PIM) of UPFC and its effect, based on location are analyzed in [16,17]. Advanced UPFC model to reuse NR Load flow has been developed in [18]. The complete working procedure and fundamental frequency model of GUPFC is described in [19].…”