The effects of voltage stability boundaries on capability charts for shunt compensated power systems

The shunt compensation effects on the capability chart´s voltage stability boundaries of compensated long transmission lines are studied in this paper. Investigated schemes cover six different configurations. Considering the effects of power-factor, series (K_S) compensation ratio, and loss-factor, numerical results for critical sending-end reactive power, voltage and angular separation and corresponding boundaries on capability charts are given, as these charts are required in planning studies that aim at obtaining the maximum power which can be effectively supplied to the loads. In the planning of an electrical system, it is very useful to know the value of the critical power which can be delivered to the receiving end of a long transmission line while all technical and operation constraints are met. Capability boundaries can help in the comparison of network expansion plans as well as in judging the acceptability of a network plan. Moreover, it is possible to determine the effectiveness of the investment which can be made to improve the capability it self, or the risk of constraint violation resulting from the probability of the load being greater than the capability