Computing method of unbalancedness of multi-circuit power transmission lines on same tower

The invention relates to a computing method of unbalancedness of multi-circuit power transmission lines on the same tower. The method comprises the steps of computing the initial impedance and admittance matrix of each line according to the conductor type, conductor division method, pole and tower type and lightning conductor connecting method of each power transmission line; selecting electric parameters and building a model of the multi-circuit power transmission lines on the same tower based on computing results in the PSCAD/EMTDC environment; setting a short circuit and an open circuit of the tail end of each power transmission line, computing the current value of the short circuit of the tail end of each power transmission line and the current value of the open circuit of the tail end of each power transmission line, and obtaining sequence components of the current of the short circuit of the tail end of each power transmission line and the open circuit of the tail end of each power transmission line by means of the symmetrical component method through conversion; computing the electromagnetism and static electricity unbalancedness of the multi-circuit power transmission lines on the same tower based on the sequence components of the current of the short circuit of the tail end of each power transmission line and the open circuit of the tail end of each power transmission line. The computing method of the unbalancedness of the multi-circuit power transmission lines on the same tower is capable of computing the unbalancedness of the multi-circuit power transmission lines on the same tower comprehensively, accurately and conveniently and provides theoretical guidance for optimal design and operation of the multi-circuit power transmission lines on the same tower with different voltage classes, different pole and tower types and different phase sequence arrangement methods.