Research On The Optimal Configuration Of User-side PV-ESS Hybrid Generation System

Facing the energy crisis and environmental pollution,the effective use of renewable energy has become the theme of world.With the advantage of clean and environmental friendly,PV power generation is gradually introduced to the power system.User-side distributed PV generation can be directly supplied for the user,also can be connected to the grid,which has gradually become the focus of attention.Due to the randomness and volatility,the bad effect of PV power paralleling into grid on the operation and planning of the grid can't be neglect.What's more,the imbalance and insufficient consumption of PV power caused by the intermittent of power supply are urgently need to be studied.PV-ESS hybrid generation system can effectively improve the output power and the stability.As energy storage price is high,it is of great significance to study the optical allocation of energy storage.Under the support of relevant technology in smart grid,fully taping the potential of user-side resources to participate in DR has important significance in improving the load curve,promoting distributed power consumption.This thesis focuses on user-side PV-ESS hybrid generation system,launches research on the optimal allocation of energy storage and the demand response strategy,as well as energy management for the system.The main works are as follows:Firstly,structure and composition of user-side PV-ESS hybrid system are studied.The mathematical model of PV and energy storage devices is established,which lays the foundation for the optimal allocation of PV-ESS hybrid generation system and the demand response.Secondly,in view of the traditional LPF method is limited by the selection of the time constant and the delay of the signal,control strategy of energy storage system is built with the help of wavelet packet decomposition theory,which shows that wavelet packet decomposition is better than LPF method in power smoothing.Combined with the fluctuation rate requirements of distributed PV connected to the grid,the optimal allocation of energy storage model is established considering the storage charge and discharge power constraints and operational constraints.PSO algorithm is adopted to solve the model.Then,take the water heater as example,the thermodynamic model of thermostatically controlled load is established through the classification of residential loads.In the light of the insufficient consumption of PV and power imbalance,the multi-objective optimization control strategy is proposed,which aims at maximizing the consumptive PV electricity and minimizing the consumer's electric cost.The example simulation results show the strategy can further improve the load characteristics,realize the active interaction between power consumers and the grid and optimize the rational allocation of the supply side and demand side resources.Finally,this paper describes the composition of energy management system for the user-side PV-ESS generation system.The energy management strategy is put forward,which takes both the PV output and the energy state of energy storage,as well as demand response strategy and the electric price information into account.The example simulation results show that the proposed scheme can not only improve the consumption of PV power,but also effectively ensure the safe and stable running of the system.