ALGORITHM FOR DETERMINING PHASE-ANGLE OBSERVABILITY IN THE PRESENCE OF LINE-CURRENT-MAGNITUDE MEASUREMENTS

The paper presents an algorithm for the phase-angle observability of n etworks containing real power as well as line current magnitude measur ements. It is assumed that all bus voltages are measured or known and the observability problem is solved only for the phase angles. The exi stence of line-current measurements creates the possibility of multipl e solutions. Available methods of testing network observability cannot identify such multiple solutions. The algorithm described ensures tha t a unique solution for the phase angles exists for the given set of m easurements. The algorithm is described in detail by using numerical e xamples.