What does it take to design a low inrush large induction motor?

Abstract

The need for a low inrush A. C. motor is usually based on a weak power system where conventional starters are not desirable. Low inrush motors are often used in marine services like Floating Production, Storage & Offloading (FPSO) and Liquefied Natural Gas (LNG) plants where weight and space is at a premium. They are also needed for pulpwood refiners in paper industry or at remote sites like mining operation where the electrical power system is weak, and there is a concern that a normal inrush motor could create a significant voltage drop causing a negative impact to other equipment in the electrical system. In such cases, a low inrush motor is preferred even though there may be some operating performance drawbacks. Customized low inrush motors are challenging to a machine designer when one is trying to meet application as well as performance requirements. This paper covers all those areas of concern and addresses them in order to design low inrush induction motors.