전기식 추진체계 함정의 프로세서 레버 제어기 적용에 관한 연구

Abstract

With the advent of a high-power weapon system, the propulsion system of the naval ship is shifting from a mechanical propulsion system to an electric propulsion system with the aim of strengthening anti-submarine capabilities and reducing the operating cost of the ship. An efficient control logic design that can satisfy the operational requirements of the ship while preventing over-torque and overload of the shaft and propulsion engine is essential for the propulsion control system of the ship. It is common to optimize the propulsion control system through a so-called tuning process that modifies the parameter values of the propulsion control software during a test run. As with the ship control system, PI controllers are generally widely used in the propulsion control system of the ship to control shaft rotational speed, and by adjusting the P and I setting values during a test run, the transient state is improved and the stable propulsion control state is set. However, during this process, if the error of the initial setting value is large, the tuning time may take too long, or the propulsion equipment can be seriously damaged due to over-torque, over-speed and over-power. Especially, since the electric propulsion system has a higher power increase/decrease speed than the mechanical propulsion system, there is a high possibility of mechanical damage. In addition, the problem caused by the occurrence of regenerative power must be taken into account. Therefore, in this study, we conducted research on the design of a propulsion controller that applied a Processor lever even for inexperienced people with relatively little experience in tuning propulsion control software to be able to reduce the tuning time while protecting the propulsion system. To this end, we performed ship form and propulsion system modeling that could calculate the power, torque and revolutions of the propulsion system, thrust of propeller, and speed according to the change in thrust. We also verified the stability and reliability of the Processor lever controller by developing a propulsion controller model applying a Processor lever controller. In simulations, the propulsion controller model performs the propulsion motor, controllable pitch propeller, and rudder control. The propulsion motor model that receives control commands generates torque, and the propulsion shaft model determines the number of shaft revolutions by rotating the propulsion shaft through the calculation of the torque generated from the propulsion motor, the speed of the ship, the pitch of the controllable pitch propeller, the difference between the torque according to the rotation speed. Based on the advance ratio according to the rotation speed and pitch angle, the ship model finally calculates the thrust, and determines the speed according to the thrust and the current speed of the ship. Through this dynamic simulation, by comparing the execution result of propulsion control lever commands through the PI controller without applying the Processor lever controller with that of propulsion control lever commands through the PI controller applying the Processor lever controller, we analyzed the improvement of the Overshoot and propulsion performance. The simulation results showed that the safety of the propulsion system increased because Overshoot of approximately 9.74%, which occurred when the Processor lever function was not applied, did not occur. However, the propulsion performance (acceleration) of the ship decreased as the system responded slowly. We confirmed that the reduction in propulsion performance could be addressed stably by adjusting the parameter values of the Processor lever. In order to secure the maneuverability required for combat performance, the electric propulsion system of the ship should adopt a high-power propulsion motor relative to the propulsion shaft load, and secure high acceleration and deceleration performance. In order to solve equipment safety problems that could occur during the tuning process of the propulsion control system and to reduce the tuning period, which are attributed to these characteristics, we suggested a Processor lever controller application method.