Research On Dispatch Strategy And Evaluation Of Ship Power Grid Based On Semi-physical Simulation

As fossil fuels become depleted and pollution becomes more severe,countries around the world have proposed a series of strict restrictions on various industries to alleviate the crisis,and the shipping industry is no exception.In this context,the energy-saving and emissionreducing advantages of hybrid-powered ships are gradually emerging.The energy management strategy of the ship power system can coordinate the collaborative work of each power generation unit,improve operational efficiency,and achieve energy saving and emission reduction.This article focuses on optimizing the scheduling strategy of the ship power system,which is composed of diesel generator sets and hybrid energy storage systems,using a semiphysical simulation experimental platform to simulate the scheduling scheme and evaluate the simulation results to select the optimal scheduling scheme.First,the rated capacity and power of the hybrid energy storage system for the ship power system were optimized,and the energy management was optimized based on this result.A life consumption model of batteries and supercapacitors was built with the objective function of minimizing the equivalent annual cost of ships over the lifecycle of the energy storage system.A two-layer optimization algorithm combining traversal and particle swarm optimization was used to optimize the number of energy storage modules.To explore the effect of different scheduling strategies on the ship’s voyage,wind,waves,and currents affecting the ship’s speed were considered.Three typical scheduling methods were used to optimize the speed-energy coordinated scheduling of the ship power system for typical voyages considering the optimized configuration of the energy storage system,and three different scheduling schemes were obtained.Then,a pure digital simulation model for the ship power system was built in the simulation software,and a semi-physical simulation model for the ship power system was built based on the NI(National Instruments)semi-physical simulation system to verify the scheduling scheme.Digital simulation models for power generation units,energy storage units,and load units in the ship power system were built in the simulation software.The digital simulation model was split into control circuits and hardware topology circuits,and a semi-physical simulation model was obtained after compilation processing.The semi-physical simulation platform was built by connecting the hardware-in-the-loop(HIL)equipment and rapid control prototyping(RCP)equipment through the IO interface board,and the scheduling scheme was simulated using the platform.The simulation results provided data support for evaluating the scheduling scheme.Finally,some static and dynamic indicators were used to evaluate the scheduling scheme and the ship power system.Some static indicators were selected from economic,environmental,technical,and overall energy efficiency perspectives,and some dynamic indicators were selected based on the analysis of the ship power system’s dynamic characteristics using simulation results.The Analytic Hierarchy Process(AHP)was used to determine the subjective weight of the indicators,the Criteria Importance Though Intercrieria Correlation(CRITIC)was used to determine the objective weight of the indicators based on their correlation,and the improved comprehensive weighting method was used to determine the comprehensive weight of the indicators.Finally,the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)was used to rank the scheduling schemes.The optimal scheduling scheme was selected based on the evaluation of the simulation results.This article introduces an engineering implementation process for comprehensive use of semi-physical simulation technology in scheduling scheme simulation and dynamic performance evaluation.The simulation modeling of electric propulsion ships,hierarchical control of the ship network,and construction process of the semi-physical simulation platform have certain reference value for related engineering and scientific research.