Electric motor starting using generating set group - involves using variable voltage which reduces start current by factor of 3 with respect to normal methods

摘要

The method of starting an electric motor from a generating set group uses a voltage variation technique. It utilises a star-delta type system. The generating plant group (1, 3) is first coupled in 'delta', so as to supply the smallest possible voltage and then connected in 'star' to supply normal voltage. The starter (4) consists of an housing in which is fitted an inverter. Into the starter (4) are connected the six output (U, V, W, X, Y, Z) connections of an alternator (1-3) on generator of the group. The connections are arranged such that they are connected in delta for starting, then into 'star' for normal operation several seconds after starting. The system is suitable for diverse power generating set groups, and in particular for immersed electrical pumps fed from 3 phase 220/380 volt supplies.