Research On Shipboard Photovoltaic Grid Control And Power Management

Human is faced with the important issue of energy crisis on the sustainable development path,the renewable energy represented by solar power has characteristics of no pollution,no noise,easy maintenance and etc,showing an incomparably broad development space and application prospect.In recent years,with the IMO and governments increasingly putting more attention to the problem of ship fuel consumption and exhaust emission,the advantages of the ship which adopts the solar energy as main or auxiliary electrical power has been increasingly prominent and received widespread attention and research.According to the different current direction,the ship solar power system can be divided into off-grid and grid-connected two operation modes.As opposited to off-grid system,the grid-connected photovoltaic system has features of high energy utilization,wide power supply range,easy to implement comprehensive energy scheduling management and etc,becomes the future direction of solar energy applying and developing in the ship.The paper regarded a car ro-ro ship photovoltaic power generation system as prototype,built the solar-ship electricity grid-connected power system simplified simulation model in the PSCAD/EMTDC emulation platform,studied the key techniques such as ship solar grid inverter strategy,solar energy management and etc,the main work as follows:(1)Based on the performance parameters of a certain photovoltaic panel,built the photovoltaic array PSCAD simulation model,revealed the impact of environmental parameter changes on PV output characteristics,described the necessity and materiality of maximum power point tracking,built the MPPT controller simulation model to study the incremental conductance MPPT strategy,the result showed that the algorithm could improve the efficiency of PV utilization;(2)The solar power grid inverter which adopts the conventional constant power(PQ)control strategy exists problems like lack of damping and inertia,difficult to achieve rational management and scheduling of the solar power and etc in parallel operation with ship power station,the paper proposed to introduce Virtual Synchronous Generator(VSG)technology into the design of the ship solar grid inverter control strategy,through in-depth analysis of the virtual inertia control,droop control,double closed-loop control basic principles,the ship VSG control algorithm and control flow are designed;(3)Completed the hardware parameter setting and model building of the VSG inverter,combined with the basic principle of the synchronous generator,built the ship diesel engine generator simulation model,analyzed the basic principles of marine diesel generator and established a whole model of the solar-ship electricity grid-connected power system,analyzed the grid system working condition under different conditions,simulation results showed that the proposed inverter control strategy could effectively enhance the stability of the grid-connected systems and solar energy schedulability;(4)In order to achieve comprehensive utilization of the PV and diesel-electric energy,set up the three-layer control system of the PV-Marine electric micro-grid system and proposed an energy management strategy based on advanced version of the logic threshold value,simulation result confirmed that the strategy could achieve efficient use of the solar-diesel hybrid energy;At last,according to the basic functions of the ship solar energy management system,completed the design of the system’s hardware and software architecture and system implementation.