Research On Control Strategy Of Diesel-electric Hybrid Power System For Inland Ships

In recent years,with the continuous strict emission regulations and the wide application of hybrid power system technology for inland river ships,it is necessary to conduct relevant research on diesel-electric hybrid power system for inland river ships.In this paper,aiming at the hybrid power system of an inland river ship and its typical load conditions,the equipment selection and capacity configuration are carried out according to the topological framework of the power system and the ship-machine propeller matching model,so as to establish the simulation power model and control model of the hybrid power system.On this basis,Dynamic Programming,DP)energy management control strategy.Through the establishment of the control strategy under power system optimal power output with minimum fuel consumption optimization index equation,so as to realize the optimal allocation of energy of the system scheduling,good economy and reliability,and the composite energy storage system charged state limit under the condition of strategy simulation comparison,verify that the control strategy of control performance under the critical state.The main contents of this paper are as follows:(1)According to the ship type parameters and the power form,the ship-machine propeller matching modeling was carried out to determine the power demand at the design operating point,so as to select the appropriate power form of diesel generator and composite energy storage system.To give full play to the advantages and complementarity between different power equipment,shall be borne by the diesel generator working in high efficient area typical working conditions of the average load power,energy storage system in load power frequency band,have the effect of its peak "cut",and the energy storage system from two aspects of power restriction and energy limit capacity allocation scheme.(2)Aiming at the topology structure of hybrid power system,the simulation model and corresponding control model of diesel generator,three-phase PWM rectifier,lithium iron phosphate battery,super capacitor and half-bridge bi-directional DC/DC converter are established respectively,and the simulation verification is carried out,thus laying the foundation for the research of energy control strategy.Due to the need to carry out reasonable power distribution of the ship’s hybrid power system in typical working conditions,and the large fluctuation of the power grid when the simulated load is absorbed,it is necessary to design an effective energy control strategy.(3)The energy management strategy based on dynamic programming was designed.The optimal output power of each energy equipment in the power system was taken as the decision variable,and the optimization equation of the minimum fuel consumption target was established.The optimal output power and minimum fuel consumption of diesel generator and energy storage system under typical load conditions of the ship were solved,and the energy distribution strategy of the control method was explored under the critical condition of the energy storage system under charged state.Through the simulation analysis found that the control strategy based on dynamic programming can make diesel generators stable working in its power high efficient area,ensure the battery and super capacitor to the low frequency and high frequency power load power fluctuations to effectively share,and in the charged state under the condition of critical this policy still has good control performance,realizes the battery and super electric Rong Jian power allocation.