전기추진 냉각계통의 에너지 절감 기법

Energy Saving Strategy of Cooling System for Electric Propulsion

Generally, cooling system for electric propulsion system of under water vehicles is consisted of fresh water system and sea water system. A primary cooling is used for cooling in motor and inverter with fresh water, and the fresh water is cooled by a secondary cooling system with sea water. Secondary cooling system is to use seawater for cooling fresh water and fresh water is used to cool the heat load of entire under water vehicle. Cooling fresh water which is controlled by valve consequently for adjusting fresh water temperature. This paper suggests the method for saving energy by controlling the pump RPM using PID controller to change sea water flow rate according to fresh water temperature. This paper confirmed the stability of control system through simulations.