DETERMINING THE LIMIT OF ACTIVE POWER EXCHANGE IN A 3-NODE POWER-SYSTEM

The ultimate capabilities of active power exchange between three nodes with constant voltages are studied. The nodes are interconnected eith er by means of a pi-network or a T-network, whose branches have impeda nces. For this case an analytical description is given of two known an d one new kind of conditional limit of active power transmitted from t he nodes. The conditional limits are compared with unconditional limit s in networks with two and three nodes. The limits are compared graphi cally in coordinates of nodal powers, mutual angles, and power transmi tted over the branches of a pi-network. The lines of the limit are com pared, and possibilities of their deformation are followed It is noted that, for a network without active power losses, the conditional limi t of the power at one node obtained for a given power at the other nod e coincide with the steady-state stability limit. Copyright (C) 1996 E lsevier Science Ltd.