| With the rapid development of national economy and urban industrialization, the demand for electricity is growing, especially in middle east area which has densely population and economy is developed, construction land become increasingly scarce, how to realize the balanced development of power demand and power delivery has become urgent problems to solve. In order to effectively solve the power transmission and the shortage of transmission line corridors, the realization of economic and efficient transport, double circuit lines on the same tower, multi-circuit lines on the same tower, UHV AC transmission, AC and DC hybrid transmission, such power transmission scheme has been widely concerned and used.According to the characteristics of multi-circuit transmission lines on the same tower,220/110 kV four circuit on the same tower mixed level transmission line as the research object,with ATP-EMTP and ANSYS carries on the simulation analysis of the maintenance line induced voltage, current and maintenance personnel field strength outside body. The introduction introduces the research background and significance, domestic and foreign about multi-circuit transmission lines on same tower, live work development and the research present situation. The necessity to consider the maintenance operation of induced voltage,current and working personnel of the surface field strength theory and its principles is introduced in detail; when set up the model, full consideration is given to the actual situation of multi-circuit transmission lines on the same tower, simulation model is established according to the actual parameters of line and tower, the live workers; the influence of operation, line operation current, phase arrangement sequence, horizontal spacing, loop spacing is researched on the induced voltage and current in maintenance line, the influence of temporary grounding wire spacing on the induced current flow through the live worker, and the electric field distribution of live worker in typical working position of the tower under different operation.The results showed that the operation current mainly affect electromagnetic induction component of maintenance line, almost no effect on the electrostatic induction component;the induced voltage, current of maintenance line with maximum value when same phase sequence, then negative phase sequence, different phase sequence at last; with the increasing of horizontal spacing and circuit vertical spacing, decreases the degree of coupling between the lines, the induced voltage and current will be reduced; when the sides temporary grounding wire is hang in both side of maintenance position, a greater induced current still flow through the body of live worker, in order to ensure security of live worker, temporary grounding line needs to be hang in maintenance point; the most important factors which influence surface electric field is the distance between the worker and charged conductors,the characteristics of the human body. For multi-circuit transmission line on the same tower,when part of transmission lines to be maintenanced, other operate normally, electric field strength in a few work position far beyond human perception level, should be out of the way to live the high potential line operations, live workers should wear a full shield clothing and use insulated tools and instruments out of high potential. According to the above results, there is some significance to choose a suitable grounding switch, make methods to maintenance and work safety protection when live working. |
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