Research On Short-term Optimal Dispatch Method Of Power System For Promoting Atmospheric Environmental Benefit

Although clean renewable energy generation has developed rapidly in China,coal-fired thermal power will dominate the energy structure of China’s power grid for a long time,and its impact on atmospheric environment cannot be ignore d.In terms of optimal dispatch of power system,the current total air pollutant emission control method lacks of pertinence and sustainability.Regarding the frequent occurrence of heavy pollution weather(HPW)in key human settlement in China,it is necessary to develop more adaptive power dispatch methods.To this end,this dissertation takes into account the time-and space-differentiated distribution of meteorological conditions and atmospheric environmental capacity(AEC),and uses short-term energy/environment incentive measures and multi-regional power grid mutual benefit strategy to drive the reasonable and dynamic deployment of power generation resources at key temporal and spatial points,for regulating the surplus and deficiency of atmospheric environment resources within larger scales.The impact of power system operation mode on atmospheric environment involves the complex constraints of multiple electrical and non-electrical source flows and the cross-combination of multiple temporal and spatial scales,thus the essential impacting elements should be clarified first.In order to analyze the impact of power system operation mode on key links of air pollution chain,the calculation model of air pollutant emission,the temporal and spatial distribution model of pollutant dispersion and the calculation model of AEC of polluted region were built,respectively.On this basis,several indicators were established to evaluate the total and distributional impact of power system operation mode on atmospheric environment.Case studies demonstrated the validity of the evaluation indicators,pointed out the drawbacks of control method based on total indicators in improving the air quality for key areas and stated the necessity of optimizing distributional indicators in power dispatch methods.Considering the established distributional pollution evaluation indicator,the differentiated regional AEC constraints were constructed and added to traditional unit commitment and economic dispatch problem.The power output of coal-fired units with greater impacts on key human settlement is limited to reduce emission,thereby improving the air quality in relevant areas.The AEC-constrained day-ahead optimal power dipsatch model was built in form of mixed-integer programming,and its validity was demonstrated by case studies.The proposed method is beneficial for transforming and upgrading power dispatch from system total emission control to key area decentralized control.With the construction of national ecological GDP accounting system,the environmental benefits of emission reduction of coal-fired units attracted attention.To this end,the day-ahead optimal power dispatch method under ecological GDP accounting system was constructed,which can be regarded as a feasible solution for optimizing distributional pollution indicators: the newly implemented environmental protection tax was applied instead of traditional emission charge to calculate the taxation of multiple air pollutants from coal-fired units;the differentiated ecolocial compensation of air quality improvement was used to calculate the ecological benefit brought by re-scheduling of coal-fired units,and the adjustment coefficients of compensation price were set according to regional AEC differences.Including environmental protection tax and ecological compensation in optimization function,the day-ahead optimal power dispatch model under ecological GDP accounting system was established,and its validity was demonstrated by case studies.The discussion on the linkage between compensation price and air quality improvement effect can provide decision-making reference for all-level governments to formulate environmental protection tax law and ecological compensation policies.Besides the environmental protection tax and the ecological compensation of air quality improvement,the mutual environmental benefit of multi-regional power grids was further considered to establish the day-ahead optimal power dispatch method facing the control of HPW.The green certificate of HPW was used to incent clean energy replacement such as wind power;meanwhile,through rescheduling the cross-regional tie-line power,the electric support from power grid with surplus AEC to power grid under HPW was realized.Based on the principle of ‘inner-regional optimization and inter-regional coordination’,the regional power grid day-ahead optimal dispatch model optimizing environmental benefit and the multi-regional power grid coordination model promoting mutual environmental benefit were established respectively,and their vadility was demonstrated by case studies.The proposed strategy can alleviate HPW in key human settlement to some extent,promote clean energy accommodation and provide convinient and feasible technical support for ‘coutry-division-province’ multi-level power grid dispatch in China.