Research On Energy Management And Control Strategy Of Ship Gas-electric Hybrid Power System

Gas engine,with its green,economic and safety advantages,has become an effective way to solve the environmental protection laws and energy crisis and other problems faced by ship power.However,natural gas engine itself has the disadvantages of worsening combustion and poor dynamic response under low load conditions.In order to solve this problem,this paper,taking a certain type of tug as the research target,the motor and battery was added into the traditional power tug hybrid system renovation,with the appropriate design of energy management system control strategy to achieve gas engine and motor coordination control,hybrid system average efficiency and ability of the dynamic response.Firstly,this paper takes a certain river tug as the research target,analyzes the characteristics of the tug and its sailing conditions,demonstrates the applicability of the gas-electric hybrid power system to the tug,and determines the system architecture of the gas-electric hybrid power.Aiming at improving the power performance and economy of the system,the matching and selection of gas machine,motor and battery are carried out,and the hybrid power system models such as gas machine model,motor model,battery model and clutch model are established,which serve as the verification platform of the energy management system.Then,aiming at the stable working condition of the tugboat,aiming at reducing the operation of the gas engine in the low-load working condition,and constrained by the good real-time performance of the system,a rule-based energy allocation strategy is designed.The boundary conditions of the propulsion mode of hybrid power system are determined by analyzing the external characteristic curves of gas machine and motor,and the energy distribution strategy based on the determination rules is formed by adding the SOC constraints of battery.In order to further improve the efficiency of the system,the fuzzy algorithm is used to optimize the energy management and distribution strategy based on certain rules,and the fuzzy rules are extracted into the form of MAP,forming the energy distribution strategy based on fuzzy rules.Finally,for the purpose of improving the dynamic response of the hybrid power system under the transient condition of the tug,dynamic coordination strategies in the full working condition such as start-up,acceleration and deceleration were designed,and a real-time simulation platform for the gas-electric hybrid power energy management system was built based on the ETAS LABCAR system.Through the design of starting,accelerating and typical operating conditions of tugboat,the performance improvement of tugboat based on rule-based energy management system is analyzed.The results show that compared with the traditional power tugboats,the average load rate of the gas machine can be increased by 33.17%,the average efficiency of the system by 1.755%,and the dynamic response time by 22.2% by adopting the energy management control strategy based on the determination rules.The energy management and control strategy based on fuzzy rules can increase the average load rate of gas machine by 37.86%,the average efficiency of the system by 2.737%,and the dynamic response time by 44.4%,thus solving the problems of poor dynamic response of gas machine and low efficiency under low load.