| Wind power output has volatility,and micro gas turbine has the advantage of flexible adjustment of output power.The two can be coupled to form a gas-electricity integrated system with wind power,so that the micro gas turbine can be used to quickly adjust the output power,stabilize the fluctuation of wind power,then improve the accommodation of wind power.The close coupling of power system with wind power and natural gas system also brings new challenges.Specifically,In order to match the fluctuation of wind power,the output power of micro gas turbine must be adjusted frequently and quickly,and the resulting frequent changes of natural gas load will affect the operation status of natural gas system.Based on this,this paper analyzes the coupling effect of gas-electricity integrated system considering wind power fluctuation.(1)A coupling influence analysis model of gas-electricity integrated system with wind power is established.Firstly,the slow dynamic model of natural gas pipeline is simplified,and the power droop control module is established to improve the dynamic model of micro gas turbine,the dynamic model of gas-electricity integrated system with wind power is established;Then,based on the dynamic model,the coupling effect of the gas-electricity integrated system with wind power is simulated and analyzed.The simulation results show that because of the coupling effect,the fluctuation of wind power will lead to the fluctuation of natural gas system pressure.(2)An energy assessment method for the coupling effect of gas-electricity integrated system considering the fluctuation of wind power is proposed.Referring to the idea of energy hub model,based on energy conservation,this paper analyzes the conversion relationship between different forms of energy in the system,and proposes an energy calculation method of gas-electricity integrated system considering wind power fluctuation,the coupling influence is analyzed numerically by calculating the energy propagation across the system.Based on the established dynamic model,the actual trajectory of each state variable is obtained by simulation,and then the cross system energy propagation value is calculated.The calculation results verify the correctness of the proposed method.(3)A coupling effect suppression method based on variable pressure ratio gas regulator is proposed.The principle of this method is to change the pressure difference between the two ends of the gas pipeline by adjusting the pressure regulating ratio,so that the inlet mass flow of the pipeline can keep up with the change of the outlet mass flow more quickly,so as to reduce the change of the gas storage in the pipeline and then can reduce the pressure fluctuation.The simulation analysis of the system with and without the proposed method is carried out.The simulation results show that the proposed method can effectively reduce the pressure fluctuation caused by the coupling effect,so as to ensure the normal output of gas turbine and better match the wind power fluctuation. |
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