Research On The Credible Capacity Of Wind-PV Power System Considering Energy Storage

In recent years,with the rapid development of social economy,people's demand for energy is also growing,but the traditional fossil energy reserves are decreasing,and the air pollution caused by the use of traditional fossil energy is becoming more and more serious,energy exhaustion and environmental pollution can not be ignored,in order to alleviate the rapid economic development,energy shortage and environmental pollution.Contradictions,many countries around the world have taken many measures,such as improving energy efficiency,relocating polluting enterprises,reducing carbon emissions.But in order to fundamentally alleviate this contradiction,only by changing the energy structure dominated by traditional fossil energy,vigorously developing and popularizing renewable energy sources such as photovoltaic power generation,wind power generation and hydropower,can we improve atmospheric pollution and energy shortage from the root cause.And so on.However,direct large-scale integration of photovoltaic and wind power into the grid will inevitably have a negative impact on the reliability of the grid.The main reason is that wind and photovoltaic power generation are vulnerable to environmental impact,and wind power output is often volatile.In order to better evaluate the value of wind photovoltaic to power system,it is necessary to evaluate the reliability and reliability of these two new energy sources.Estimate.With the development of energy storage technology,energy storage has a good application in regulating wind and solar output.The addition of energy storage can effectively alleviate the impact of wind and photovoltaic on power grid.Therefore,this paper will study the credible capacity of power system with wind-solar storage,explore the operation characteristics of wind-solar and energy storage and their impact on the reliability of power grid.The main contents of this paper are as follows:Firstly,the mathematical models of wind and solar energy are established,and then the access mode of energy storage system is considered.The energy storage system of lithium ion batteries is adopted and the corresponding mathematical model of energy storage is established by centralized access mode.The different wind speed simulation methods and fan output models are introduced in detail.The ARMA model is used to simulate the wind speed and the mathematical model of wind power generation system is established.Secondly,the solar radiation intensity is modeled.After the solar radiation intensity is simulated,the photovoltaic output is obtained by using the photovoltaic cell output power model.The 24-hour wind turbine output and wind power are simulated by using the established model.Photovoltaic output,by comparing the output waveforms of two new energy sources,proves the complementary characteristics of the two new energy sources.In order to formulate flexible and reasonable energy storage control strategy according to the actual situation to coordinate with the regulation of wind power and photovoltaic power,two energy storage control strategies are proposed from two aspects:suppressing the fluctuation of wind power and considering the real-time load level.The combined wind power and photovoltaic power are optimized respectively.Finally,the simulation software of MATLAB is applied,and the model of Chapter 2 is applied to the wind-photovoltaic power storage.The force system is modeled and simulated,and the validity of the strategy is verified.This paper evaluates the reliability of the power system with wind-solar storage after it is connected to the power grid.This paper briefly introduces the traditional reliability evaluation methods and indicators,and proposes a new evaluation method,recursive function method,to overcome the shortcomings of the traditional analytical method or simulation method in calculating reliability,such as too much calculation or too long calculation time.The method is validated by using MATLAB simulation software,and the feasibility of the method is proved by comparing the calculation speed and error with the traditional Monte Carlo simulation method.The new evaluation method is applied to evaluate the reliability of the two new energy sources.and different wind-to-solar capacity ratios,different energy storage control strategies and different energy storage capacity for electricity are explored.The influence of network reliability.This paper evaluates the credible capacity of the power system with wind-solar storage after it is connected to the power grid.Firstly,the definition of credible capacity is briefly introduced.Then.on the basis of applying recursive function method to evaluate the reliability of the system.a method of evaluating the credible capacity of the system by using recursive function method is put forward.Through the simulation verification of MATLAB,the feasibility of the recursive function method is verified by comparing with the simulation results of traditional dichotomy method and chord truncation method.A new evaluation method is applied to evaluate the credible capacity of the two new energy sources,namely,wind and solar energy.Estimate,and explore the impact of different proportion of wind and solar capacity,different energy storage control strategies and different energy storage capacity on the credible capacity of power grid.