Research On The Key Technologies Of Energy Management For The Shipboard Power System

All-electric ship gradually becomes the main development direction and important research field for future ships because of its good operation efficiency,high reliability and strong functionality.The ship integrated power system is the key to realize the integration of ship all-electricity.With the modernization of the ship integrated power system,the increasing capacity,the complexity of operation conditions and the increasing degree of automation,it is necessary to develop the ship integrated power system energy management technology for the unified scheduling and optimal management of all-electric ship electric energy in order to operate safely and economically and to meet the development needs of the ship electric system.In order to achieve the best and reliable operation in the dynamic environment under the hardware limitation and operation constraint.Therefore,it is very important to carry out research on the energy management technology of ship integrated power system.In this paper,several key technical issues of energy management of integrated power system in all-electric ships are investigated.Firstly,it reviews the domestic and international development status of all-electric ships and the research status of key technology of ship integrated power system energy management,summarizes the current problems of current ship integrated power system power coordination control technology,grid fault reconstruction control technology and power quality stability control technology,points out the necessity of research on key technology of ship integrated power system energy management,and gives the The main research content of this paper is given.Secondly,the research on the composition structure and operation mechanism of ship integrated power system is carried out,and the system is divided into power generation system,propulsion system,area load and distribution system according to the function,and the mathematical model of each component is established in turn,which provides the necessary model basis for the next research on the key technology of ship integrated power system energy management.According to the recommendations of energy management system provided by IEEE and ESRDC,the architecture of ship integrated power system energy management technology research is designed,and the control structure of ship integrated power system energy management is given,and the ship integrated power system energy management research is divided into three key technologies according to different control requirements in order to carry out the subsequent research.Then,the ship integrated power system power coordination control technology is studied.The power coordination control technique based on model predictive control is proposed with the purpose of coordinating the balance between the demand-side power of ship load and the output power of ship power generation system in the ship integrated power system and optimizing the dynamic performance of the ship integrated power system.Combining model predictive control and operational constraints,the power coordination control objective function is established according to the control demand and dynamic performance index.To solve the nonlinear objective function,an intelligent optimization algorithm is used instead of the traditional gradient optimization algorithm to avoid the nonlinear and nonconvex limitations of the optimization problem,and a rolling small-scale particle swarm optimization algorithm is proposed to improve the search performance of the algorithm by introducing the methods of particle re-birth and particle information interaction.An example test of power coordination control technology for ship integrated power system is conducted to verify the effectiveness of the power coordination control technology proposed in this paper.Then,the fault reconstruction technique for ship integrated power system grid is studied.The ship integrated power system grid topology and each component in the grid structure are explained.In order to realize the dynamic performance optimization control of the grid fault reconstruction of the ship integrated power system,the use of hybrid system theory is proposed to analyze and design the grid fault reconstruction technology.The dynamic changes of the system involve continuous state variables and discrete switching actions during the grid fault reconstruction of the ship integrated power system,which is in line with the category of hybrid system analysis.A hybrid logic dynamic approach is used to develop a hybrid model predictive control objective function for the fault reconstruction problem of ship integrated power system grid fault reconstruction problem by utilizing the model predictive control method to modify the objective and operational constraints.The solution of the objective function is divided into a discrete part and a continuous part,and the solution of the discrete part is accelerated by means of relaxation constraints,and the Pontryagin’s maximum value principle is used to solve for the remaining continuous part.A simulation study of the ship integrated power system fault reconstruction example is conducted to verify the effectiveness of the proposed ship integrated power system grid fault reconstruction technique.Finally,the uncertainty factors of the operation of the ship integrated power system are analyzed,and the ship integrated power system power quality stability controller is designed for the problem that the fluctuation of the system load power under the influence of the external environment random disturbance in the actual navigation of the ship leads to the ripple of the bus voltage,which reduces the power quality of the power system.An online prediction algorithm based on the limit learning machine with kernel function is proposed to predict online the predicted value of ship load power under the disturbance of external environment randomness for the ship integrated power system as an additional control signal for the anti-disturbance control of the ship integrated power system.Meanwhile,it is proposed to use the predicted output of the online prediction algorithm to update the optimized multi-generation system sag control coefficients online to improve the dynamic performance of the ship integrated power system adaptive control.The performance of the online prediction algorithm and the stability controller are tested separately with the ship navigation history data to verify the effectiveness of the power quality stability controller ofthe ship integrated power system proposed in this paper.