| China has abundant wind and solar resources.Renewable energy power generation such as wind power and photovoltaic(PV)have developed rapidly.China's power system is developing in the direction of intelligence,complexity,and diversification.Large-scale grid connection of renewable energy generation can effectively replace conventional thermal power units,reduce the power generation of thermal power,reduce power generation costs and environmental pollution.But due to the characteristics such as variability and uncertainty of renewable energy represented by wind power and photovoltaic,large-scale grid connection of renewable energy will seriously affect the security of the electric power system.The problem of curtailing wind power and photovoltaic in some areas is serious,so the renewable energy is difficult to absorbed by the power system.The unique pumping system of a pumped hydro storage(PHS)station can efficiently convert excess energy in the power system into potential energy to storage,and then convert it into electrical energy again at peak load,so as to achieve the purpose of "peak cutting and valley filling" to improve the level of renewable energy consumption.And a PHS station has a long life cycle,and is easy to control,the research on it started earlier at home and abroad.As a new solar power generation method,concentrating solar power(CSP)station started later than photovoltaic power generation.However,it has the advantage of being able to be equipped with thermal storage devices,it can significantly smooth the power generation,improve the stability of the power system,and the consumption of renewable energy.In some regions with abundant wind and solar resources in China,the conditions for simultaneous operation of wind power,PV,CSP,PHS and conventional thermal power have been established.Therefore,how to coordinate and dispatch all kinds of power sources including CSP stations and PHS stations,and to improve the capacity of the power system to absorb renewable energy as much as possible on the basis of ensuring safety and pursuing economy is urgent to research.To this end,this article first analyzes the operating characteristics of CSP stations,PHS stations,wind farms,and photovoltaic power stations.Based on the operation mechanism and the internal energy balance of CSP,the power generation model of the CSP station was established.And the multi-source joint power system scheduling strategy including CSP station and PHS station is discussed.Then,a PV-CSP system was established.And the optimal scheduling model was established after the PV-CSP system connected to the grid,with the goals of maximizing the benefits of PV and CSP connected to the grid and the best tracking capacity of the PV-CSP system.This model comprehensively considers the power generation cost,rotating reserve cost of conventional thermal power units,and the operation and maintenance costs of PV and CSP stations.In order to ensure the safety and stability of the power system,the operation constraints of the power system are taken into account.Examples show that the scheduling method can effectively improve the level of consumption of renewable energy by the power system.Finally,in order to adapt to the background of multi-source combined grid connection,and to explore the space of renewable energy consumption improved by CSP and PHS,a multi-source joint optimization scheduling model including wind power,PV,CSP,PHS and conventional thermal power units is established.And the safety constrains of the power system are taken into account.The model comprehensively considers the power generation cost,rotating reserve cost and environmental cost of thermal power units,as well as the operation and maintenance costs of various renewable energy sources.examples show that after the CSP station and the PHS station are connected to the grid,under the scheduling method,the consumption level of renewable energy can be effectively improved,and the economy can be further achieved under the safety constraints. |
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