Glaze ice melting on overhead power lines with controllable rectifying installations

Resumo

General information on controllable rectifying installations that are used in Russia and abroad for melting of glaze ice on overhead power lines (OHLs) involving shutdown is given. There are two types of ice melting plants (IMPs): with pulse-phase control and discrete (relay) control. We develop multipurpose ice melting plants (MIMPs) with discrete control for alternate and simultaneous glaze ice melting on a three-phase OHL and insulated earth wire, as well as on multiple grounded wires induced by the overfrequency current. Calculation formulas of the admissible current were proposed. Coordination procedure of the permissible load for all elements of the glaze ice melting pattern (GIMP) is given: OHL wires, the IMP, and a power transformer. The GIMP development procedure suitable for two types of controllable IMPs and for two transformers of different powers–an already present one and recommended new one–is considered in a specific context. Conclusions about the advantages of MIMP are drawn made on the basis of comparative analysis of four GIMP variants, and recommendations on the mode of application are given.