Analytical Approach to Grid Operation With Phase Shifting Transformers

Abstract

Abstract-Analytical expressions are derived to gain insight in the operating principles of phase shifting transformers (PSTs) in a highly meshed grid. To this extent, the dc load flow algorithm is adapted to account for such devices. This leads to a linear expression for the relation between PST settings and the active power flow in the lines. Based on these equations, the total transfer capacity (TTC) can be described mathematically, which allows for optimization. Furthermore, the linear least squares method is used to distribute a cross-border transport evenly over the interconnectors. Both criteria are demonstrated by two examples.Index Terms-dc load flow, load flow control, phase shifting transformer, total transfer capacity.

Minimal Reduction of Unscheduled Flows for Security Restoration: Application to Phase Shifter Control

“…With reference to Fig. 1, the two PSTs can be controlled in a coordinated way to reduce the fraction of power flow passing through as a result of the transaction from G to D. More PSTs are likely to be installed for increased control of transit flows, as testified by the situation in Belgium, where three PSTs are going to be put in operation on the Northern border of the country [14], [15].…”

A Simple and Unified Method to Model HVDC Links and FACTS Devices in DC Load Flow

“…The PAR (Phase Angle Regulator) phase shifters are used to control the active power flow of transmission lines by changing the phase difference between buses [11]. The influence of this device on the line power flow can be modeled by the phase shift, , and can be expressed by the following equation:…”

Border-Flow Control by means of Phase Shifting Transformers

“…which can be identified with (7). The change in phase shifter settings that results in the best approximation of an equal loading scenario can be found by using (9).…”