Evaluating voltage drop snapshot and time motor starting study methodologies-An offshore platform case study

This paper presents a comparison between static (Snapshot) and dynamic (Time Study) motor starting study methodologies in terms of buses voltage drop and power flow, using a case study of an offshore platform. For this purpose, the Power Tools for Windows (PTW) software and the real-time digital simulator (RTDS) were used to performing the analysis of the Snapshot and Time-Domain methodologies, respectively. The investigation has focused on differences in the parameter requirements necessary for each methodology, with a special application in a complex isolated system, such as the case of an offshore platform typical composed of synchronous generators and the large induction motors. The advantages and disadvantages of each methodology will be analyzed according to the strict operating and handling requirements of an actual offshore platform. Simulation results demonstrated that a motor starting study in the time domain contributes better information than the static one, even more for this type of particular system. This work reveals the need that selection criterias between the two methodologies must be defined in the IEEE 3002.7-2018 standard and for isolated systems is highly recommended to perform an analysis in the time domain.