Research On Coordinated Operation And Control Of Photovoltaic Power Generation System With Energy Storage

With the increasing depletion of fossil energy, solar photovoltaic (PV) powergeneration, as renewable energy, has been more and more attention. Randomness andvolatility of solar radiation leads to output of photovoltaic power generation systemuncontrollable. It becomes the important factors that will influence the increasing of PVpenetration. Application of energy storage technology is considered to be effective inimproving the controllability of the PV power generation system. Since introducing energystorage device, research on coordinated operation and control of PV power generationsystem with energy storage is essential.This paper describes the modeling principles of the PV cells. The output characteristiccurves of PV array are obtained through simulation and these curves have been analyzed.Based on Incremental conductance method and design of Boost converter maximum powerpoint tracking of PV array is achieved. By designing the three-phase inverter and itscontroller, PV power system is connected to grid. Simulation results show that active outputof grid-connected PV systems is random fluctuations due to the change of the workconditions of PV cells.Based on PSCAD/EMTDC platform, third-order dynamic simulation model oflead-acid battery is built. The output characteristic curves of lead-acid battery are gottenand the validity of the simulation model is verified. Simplified equivalent method of batterypack is proposed and this method proves accuracy by simulation.This paper describes two access methods of energy storage device used in distributedPV systems. According to the proposed DC access method of energy storage devices, thecorresponding controller is designed and simulation is carried out. Simulation studies showthat the output of PV system with energy storage device can be controlled.To address the over-voltage problems of PV system connected point caused by reversepower flow, this paper proposes and implements four coordination and control strategies. Simulation studies show that four kinds of coordination and control strategy can improveover-voltage problems, although the effect is different. Comparative analysis shows that,from the perspective of meeting the grid voltage requirement and reducing storage capacity,the voltage control operation is the better strategy. However, other strategies have theiradvantages. Combination of factors should be considered in the practical application.