Over-rotation resisting control strategy for ship electric propulsion system under non-orderly sea condition

Abstract

Provided is research of an over-rotation resisting control strategy for a ship electric propulsion system under the non-orderly sea condition. In order to lower the influence of external environment factors such as wind, waves, currents and surges under severe sea conditions on steady sailing of a ship, it is judged that the non-orderly sea condition occurs on the sea surface by detecting the situation that a propeller is exposed out of the water surface frequently, and then a direct-torque-control propulsion control strategy adopted under the orderly sea condition is switched to the over-rotation resisting control strategy. The over-rotation resisting control strategy comprises four main links of propulsion control, performance monitoring, ventilation detection and over-rotation resisting control, the speed of the propeller is decreased by lowering the torque of the propeller, the sudden rotating speed increase effect caused by sudden decrease of mechanical loads when the propeller is exposed out of the water surface is counteracted, and thus mechanical abrasion of the ship and propeller loss are reduced, and the ship is kept sailing stably under the non-orderly sea condition.

Description

technical field [0001] The invention belongs to the technical field of ship electric propulsion control, in particular to an anti-overspin control strategy for a ship electric propulsion system under non-calm sea conditions, and is a control algorithm similar to an automobile brake system for controlling the overspeed of a ship propeller. Background technique [0002] Electric propulsion is one of the propulsion methods of modern ships. The propeller is driven by the motor directly or through the reduction gear to propel the ship. It can be widely used in various civil ships and military ships. However, the characteristics of the ship system such as large inertia, nonlinearity, strong coupling, and time delay, as well as environmental changes such as wind, waves, swells, and currents during navigation, as well as interference and measurement inaccuracies, will cause uncertainty in the behavior of the system. In order to enhance the robustness of propulsion control, advanced ...

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Problems solved by technology

[0003] In view of the fact that there is currently no ship electric propulsion control strategy for ships encountering non-calm sea conditions that cause propellers to enter and leave the sea, the present invention proposes a ship electric propulsion anti-overspin similar to the anti-lock braking system of automobiles under non-calm sea conditions Control Strategy

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