Computer Simulation of a High-Frequency Signal Propagation in the Ship�s High-Voltage Electro-Energy System

Abstract

The computer modeling of changes in the shape and amplitude of a high-frequency signal at its propagation in the ship high-voltage cables is considered in the paper. The computer simulation was carried out on the basis of the real parameters of the ship high-voltage electric power system of gas carrier vessel Corcovado LNG. On the basis of the ship's technical documentation, it was concluded that the overwhelming number of the electricity receivers are connected to high-voltage switchboards using cables of 60 meters long. Only cargo pumps for liquid natural gas have a cable length of 200 meters. Thus, the computer simulation of a high-frequency signal propagation is performed in the ship high-voltage cables of 60 and 200 meters long. A theoretical description of change in the shape and the amplitude of a high-frequency signal at its propagation is presented using mathematical equations. The simulation is produced in Matlab/Simulink program. The cables of 60 and 200 meters long are described by means of a quadripole (RLCG section). The cable parameters and other simulation parameters are set in the program dialog window. Based on the obtained simulation results, the additional mathematical calculations were performed to obtain the attenuation coefficient and the propagation constantan. The graphs show the dependence of the change in the shape and the amplitude of the high-frequency signal on its frequency, taking into account the influence of the cable length. As a result, on the basis of the computer simulation, it was concluded that a partial discharge with a frequency of 30 MHz can be successfully measured in the high-voltage cable of 60 m long and a partial discharge with the frequency of 10 MHz can be measured in the high-voltage cable of 200 m long.