Event-trigger Tracking For Maximum Power Point Of Photovoltaic Arrays

In order to address the challenges of lack of non-renewable resources and environmental issues such as global warming.Renewable and clean energy plays an increasingly important role.Among them,solar energy is widely used due to its abundant resources,simplicity of energy facility conversion and environmental friendliness.With the continuous innovation of power electronics technology and the gradual increase of the grid's requirements for grid-connected stability of photovoltaic power generation,Photovoltaic(PV)power system tracking power point should meet following requirements: Under normal circumstances,in order to pursue high efficiency of power generation,the maximum power output of the photovoltaic power generation system is required;in the case of high peak power generation,the power output of the photovoltaic power generation system needs to be limited to avoid grid overload.Based on the above,an event-based power management algorithm is proposed to optimize the power generated by the PV power generation system.According to the grid,load and energy storage device demand,the operating modes are divided into Maximum Power Point Tracking(MPPT)and Limited Power Generation(LPG).In the maximum power mode,the grid absorbs all the electrical energy provided by the PV power generation system.At this time,the Event-Triggered Dual-mode control technology is adopted,so that the system can operate efficiently and stably under both uniform lighting and local shadow conditions.The P&O algorithm is used to track the maximum power point under uniform illumination;When the photovoltaic power generation system is in a local shadow environment or a photovoltaic panel is partially damaged,the current flowing through its bypass diode will be used as a trigger signal to cause the system to switch to Particle Swarm Optimization(PSO)to track the Global Maximum Power Point(GMPP).In the limited power mode,the grid only absorbs part of the energysupplied by the PV power generation system,and the power needs to be injected according to the grid demand.At this time,the optimized disturbance observation algorithm based on event triggering is used to limit the power generation system's power generation.The algorithm sets the event trigger conditions to adjust the PV output power according to the demand,and flexibly selects the operating point corresponding to the limited power.The event triggering device ensures smooth transition between maximum power point tracking and limited power point,so as to achieve high performance and smooth operation of the system.Finally,through a rough estimation of the Levelized Cost of Energy(LCOE)of a photovoltaic inverter,the feasibility of limiting the power output of photovoltaic power generation is qualitatively analyzed.