Universal method of preventive unloading of the ship's electric power system
The method of preventive protection for the purposes of safe operation of the ship's electric power system in emergency situations associated with malfunctions of its elements arising during operation is considered. It is shown that existing devices form a command to unload power sources at the moment of overload, when an emergency has already occurred. At the same time, the disconnection of consumer groups occurs with a time delay. For this reason, stopping even one of the working generator sets by protection often leads to de-energization of the vessel due to overload of the remaining operational machines. A notable place in the work is given to the consideration of the method of unloading the network, in which the automatic mode is used to form a command to turn off selected electricity consumers at a time when at least one of the parallel generator sets is already inoperable, but the quality indicators of the generated electrical energy are still within acceptable limits. Within the framework of the proposed approach, the energy state of the entire ship's electric power system is predicted in the event of a decrease in its generating capacity and, if necessary, a team is formed to unload the network. The conditions under which unloading should be carried out are formulated and presented in the form of logical expressions. It is shown that the proposed approach is universal, since it does not depend on the number of generator sets operating in parallel, nor on the number of machines that have failed, nor on the type of malfunctions that have occurred. The functional diagram and description of the original device for preventive unloading of the ship's electric power system, implementing the proposed approach of preventive protection in practice, are presented.
Authors: A. V. Saushev, N. V. Shirokov
Direction: Electrical Engineering
Keywords: marine electric power system, disconnection of consumers, overload of generator sets, preventive protection, area of operability
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