Research On Energy Storage System Control Strategy To Track Photovoltaic Power Generation Schedule Output

With the gradual reduction of traditional energy sources, solar energy is recognized to be one of the most competitive energy in the future, because it has characteristics of abundant resources and green environmental protection. In recent years, the photovoltaic(PV) power generation market in the country has been developing rapidly and the new installed capacity has ranked first in the world. But PV power generation is intermittent energy sources and the output power is uncertain, it will bring bad influence when connects to grid. Through the PV prediction, it can help scheduling department arrange PV with conventional energy, and formulate scheduling plan, reduce the influence to electric power system. However, the PV prediction error is still large, to make up for the shortage, we can use energy storage system to compensate the difference between the actual and planned output power and achieve tracking effect, it also can make PV/energy storage system become conventional power and improve the prediction precision indirectly.In order to maximize the ability to improve the PV/energy storage system tracking schedule output, based on the short-term forecast power of PV and randomness of prediction deviations, an energy storage day-ahead control strategy that adopts chance-constrained programming is proposed. The PV/energy storage combination power generation within the upper and lower range of schedule plan is taken as the objective and then set mathematical model. The energy storage charge and discharge power and state of charge constraints are considered. In order to get each time charge and discharge power, the method adopts improve particle swarm optimization algorithm to solve. Compared tracking effect under the fixed coefficient and variation coefficient and energy storage situation through the analysis of examples, it provides a day-ahead reference project for energy storage charge and discharge control.In tracking PV schedule output model based on energy storage system, the target power control coefficient has disadvantage that only be adjusted by experience. This paper puts forward fuzzy control method to adjust the coefficient automatically. The example verifies the continuous adjustment process, and optimize the energy storage control strategy of tracking PV scheduling output.In order to utilize the advantage of power and energy comprehensively, On the basis of only considering power limitation of multi-type energy storage power allocation principle, this paper proposed the energy storage power allocation strategy of fuzzy control allocation and state of charge(SOC) adjustment and correction. It not only achieves the effect of tracking PV schedule output, but also reduces count of charge and discharge of energy storage. The power become main energy storage, the advantage of every kind of energy storage can be used, and the service life is also be extended.