TY - JOUR AU - Knezevic, Ilija AU - Calasan, Martin AU - Dlabac, Tatijana AU - Filipovic, Filip AU - Mitrovic, Nebojsa PY - 2024/12/18 Y2 - 2025/01/01 TI - Exact Analytical Solutions for Modelling the Speed-Time Characteristics of Direct-Start Induction Machines under Various Operational Conditions on Ships: Review and Experimental Validation JF - Elektronika ir Elektrotechnika JA - ELEKTRON ELEKTROTECH VL - 30 IS - 6 SE - DO - 10.5755/j02.eie.38518 UR - https://eejournal.ktu.lt/index.php/elt/article/view/38518 SP - 4-12 AB - <p>Induction machines (IMs) are crucial to driving auxiliary machinery and devices of ships, such as pumps, fans, winches, and elevators, which are essential for maintaining the operational functions of a ship and are characterised by various types of loads. This is of critical importance because high surges of starting current can cause instabilities and fluctuations in a ship’s power system, directly affecting the safety and efficiency of ship operations. This paper provides a comprehensive review of analytical expressions for modelling the start-up time of directly started IMs under different ship operational conditions (no-load, linear load, fan load, and gravitational load). Validation of the analytical models was performed by comparing the speed-time characteristics obtained from the experimental measurements with the corresponding ones obtained by simulations in a MATLAB Simulink environment. The observed 1.5 kW IM reached a steady state for 0.1356 seconds when driving the load with a fan characteristic. However, when subjected to linear and gravitational loads, the IM requires longer times to reach a steady state - 0.1400 and 0.1606 seconds, respectively. The results of the simulations and experimental tests highly corresponded with the analytical predictions, confirming the reliability and practical applicability of the analytical models.</p> ER -