A transmission line DC de-icer using a single-arm modular multilevel converter

Abstract

This thesis studies the operating principles, parameter design, and harmonics performance of an HVDC converter topology: SAMMC (single-arm modular multilevel converter), and develops a DC deicer system using this converter as a rectifier to melt ice on iced conductors. Ice formation on power lines is a common problem in cold climate jurisdictions. It could cause severe danger to power systems since the weight of ice could damage the power line or transmission towers. This thesis develops a portable DC deicer with SAMMC technology to convert AC power into DC power and use DC current to melt ice on the power line efficiently and economically. The SAMMC DC deicer system is firstly validated by EMT simulation models. Then, a scaled-down laboratory prototype is developed to validate the performance of the SAMMC rectifier and the harmonics suppression controller.