PLC-based Design Of Fishing Trawler Electric Propulsion Control System

China is the country with the largest number of fishing boats in the world,the oil consumption of fishing boats accounts for a very high cost of Marine fishery production.At present,the vast majority of fishing boats in China are confronted with low power efficiency,aging application of diesel engines,high energy consumption,serious emission pollution,and relatively backward control technology and automation level.Marine fishing is a kind of high energy consumption industry,and the research on energy-saving technology of its fishing boats has been highly valued by countries all over the world.Electric propulsion technology has many advantages,such as energy saving,environmental protection,low noise,excellent maneuverability,mobility and reliability,and has become an important direction for the development of the world's shipbuilding industry in the context of the development of low-carbon economy in all countries.In developed fishing countries,electric propulsion has been widely used by fishing boats,while in China,this field has just started.Most of the domestic electric propulsion system market is occupied by foreign suppliers,so it is particularly important to design and develop electric propulsion control system.In this dissertation,the following aspects of electric propulsion control system for fishing boats are studied.First of all,the power load calculation,short-circuit current calculation and selectivity coordination of electric propulsion system are carried out by power system analysis software.To select the capacity of generator set and propulsion motor,and to determine the breaking capacity of circuit breaker.In the next place,through the analysis and comparison of various schemes,choose the most cost-effective solution,the hardware of the electric propulsion control system is designed,including the hardware composition and the interface between the electric propulsion control system and the other system.At last,the software is designed,the low voltage ride-through of propulsion inverter is realized by means of special control mode.PLC is used for fuzzy adaptive PID control of electric propulsion control system,reasonable control and limitation of power,speed and torque,The best match among ship,engine and propeller is fully ensure,to ensure that the ship operates in the best condition.