Power System Reliability Analysis Considering The Smoothing Of Wind Power And Photovoltaic New Energy Fluctuation

The development of the world economy is inseparable from an adequate supply of electric energy.With its potential and advantages of being clean and pollution-free,the electric energy,once developed,has become an indispensable part of people’s production and life.Traditional electric energy is produced by thermal power generation,but coal is required for thermal power generation.It is non-renewable and will eventually be exhausted.For this reason,new energy generation is needed to maintain the sustainability of the power system.New energy,mainly wind and solar,are increasingly participating in the operation of the power system,but its inherent volatility will have an important impact on the power system that cannot be ignored,including an impact on the reliability of the power system.Based on the above reasons,this article conducts the following research on the impact of new energy fluctuations on the reliability of the power system and how to smooth the new energy fluctuations.New energy power generation has obvious volatility.The corresponding output model and reliability model are relatively complicated.This dissertation introduces the related models of new energy power generation,mainly the wind power and photovoltaics.Based on the mathematical modelling of the wind power and photovoltaic power generation,the dissertation sorts out the unit outage models of generator sets and conventional units,analyzes the unit outage models of new energy generator units and conventional units,introduces the load model,and summarizes the reliability evaluation indicators.In view of the volatility of new energy power generation output,this dissertation proposes an optimized configuration method for hybrid energy storage smoothing new energy power generation output based on the moving average method.The new energy output is smoothed by the sliding average method,the difference between the smoothed new energy output and the original data is used as the energy storage reference power,and the energy storage reference power is decomposed into a series of eigenmode functions through empirical mode decomposition.Then through the instantaneous frequency-time curve of the eigenmode function,the energy storage reference power is divided into a high-frequency part and a low-frequency part.To solve the capacity and power of energy storage,the high-frequency part is configured by power-type energy storage,and the low-frequency part is configured by energy-type energy storage.And finally the cost of energy storage configuration is obtained through the cost model.In view of the impact of the grid-connected new energy generation on the reliability of the power system,the hybrid energy storage capacity and power required by the system,and the energy storage investment cost,are obtained through the new energy generation smoothing method proposed.Then,according to the energy storage configuration,the smoothed waveform of the new energy output is obtained.In the case of equal power,the improvement level of the system reliability before and after the smoothing of the new energy is compared.The simulation results prove that the smoothed new energy is connected to the power system.The reliability improvement is more obvious.Based on the large-scale grid connection of new energy,the paper proposes a new energy storage configuration method for hybrid energy storage to smooth the fluctuation of new energy.On this basis,the reliability of energy storage participating in the grid connection of new energy is studied.The dissertation then compares the level of reliability of the system under the three grid-connected modes of single wind power,single photovoltaic,and wind power photovoltaic.It provides new ideas for reducing the volatility of new energy grid connections and improving the reliability of the new energy grid connection system,guiding a new direction for the safe and orderly operation of the grid.