| Along with population of ultra-high voltage power transmission, network interconnection of the whole nation is coming up. Because some electrical problems posses feature of locality, network partition has been an important system control method, which depend on judge electrical connect by electrical distance. There are many divergences in definition and compute method about electrical distance, which contain two methods in the final analysis:one is sensitivity method based on sensitivity (?)V/(?)Q and sensitivity (?)θ/(?)P, which represent relation about electrical parameters, however, the precondition is decoupling of this parameter and distinguish of active power and reactive power, so it is no confident of the result; the other is impedance method, which posses clear physical meaning compare sensitivity method, but without the precondition, impedance cannot describe the distance of power transmit exactly. After analysis physical meaning of electrical distance based on power tract in depth, this paper gives a new method to describe electrical distance. Electrical distance of two nodes connected by one branch is voltage phase coming from the length of transmit line, and electrical distance of many branches is phase by compositions of vectors about each transmit line. Compare to traditional method, phase method posses clear physical meaning and sharp computational result. At last, we use the three methods to compute electrical distance in order to distinguish electrical network of IEEE-39. |
