Design of commutator configurations for the protection of a line commutated converter

The author establishes design procedures and design illustrations for the following three practical commutator configurations: series commutator; half-bridge shunt commutator; and coupled full-bridge shunt. The first two commutators are designed for small load inductances. In contrast, the design of the third commutator is based on the assumption that the load inductance is significantly greater than the line inductance. A simplified equivalent circuit for obtaining design related information is presented. An equivalent inductance and averaged voltage are proposed for the purpose of characterizing the DC transformed AC network. These values represent conservative estimates suitable for gaining insight and for designing the commutators.<>