Redundancy system for continuous driving large motor drive equipment

Abstract

A compressor which is used in liquefied natural gas (LNG) plant is mainly driven by turbine engine, but consideration for electrically driven compressor by a motor is increasing. Particularly, application of a motor driven by an inverter has the advantage of adjustable speed control of compressor. However, there is a concern of compressor train stop due to inverter failure. To eliminate this concern, various redundancy system for continuous driving large capacity inverter TMdrive™-XL series are developed. The redundancies including the main inverter circuits realize inverter continuous operation even if a failure is occurred to some parts.

Innovative Application Technologies of AC Motor Drive Systems

“…11. Output voltage and motor current of 5 level inverter for large scale drive in gas and oil industry (23) ac voltage with lower frequency, including dc voltage is impossible or hard to output in this circuit because the capacity of a capacitor in each cell is limited. To cope with the such problem in variable speed ac motor drive, a method to start induction motor with reducing the capacitor voltage to output lower phase voltage as shown in Fig.…”