Analysis On The Monthly Power Consumption Of Large-scale Hydropower Plants

With the gradual implementation of relevant policies in the southwest hydropower and power market and the continuous expansion of the West-East Power Transmission Grid,China’ s hydropower has entered a new stage of large capacity,long distance,marketization and largescale consumption across provinces and regions.However,unlike the participation of thermal power in market competition,hydropower faces many scientific and technological problems to be solved urgently due to the uncertainties of water supply,large differences in reservoir regulation performance,mutual constraints of cascade power generation,large demand for comprehensive utilization of reservoirs,lagging construction of transmission channels,and lack of guarantee mechanism for hydropower consumption.Based on the background of Yunnan power grid pilot operation in China ’s power market,this paper takes more than 50 hydropower stations in Lancang River,Jinsha River,Honghe River and Irrawaddy River as the research objects,focuses on the key scientific problem of monthly power consumption of large-scale hydropower stations,and conducts in-depth research on the sub-issues of monthly decomposition and consumption of hydropower within the province and the evaluation of intraprovincial transmission assessment of hydropower,including the following aspects :(1)Aiming at the problem of local consumption of hydropower,this paper puts forward a method for the monthly decomposition and consumption of large-scale hydropower stations within the province.Two objective functions are to minimize progress deviations of that day between the monthly power generation and planned power generation in the flood season and to minimize deviations between the total power generation and planned power generation in the dry season.The solution is that the daily load is predicted by rolling.The remaining load is calculated by deducting the thermal,wind,solar and parts of hydropower generation from the daily load.Then,the monthly trading energy is decomposed to daily with the heuristic information of the completion progress deviation,an executable day-scale power generation plan is formed to improve the level of hydropower consumption within the province.(2)Aiming at the problem of hydropower intra-provincial consumption,this paper puts forward an analysis model of the intra-provincial transmission consumption assessment of large-scale hydropower stations.In this model,the runoff process of different months is obtained by using the evaluation method of floody season-dry season.Secondly,the energy maximization model is used to calculate the maximum theoretical power generating of hydropower system under water inflow at different frequencies.Thirdly,the power balance analysis of the power grid is carried out.If the daily generating capacity of the system after deducting the inter-provincial and overseas load demand is larger than the total capacity of the intra-provincial transmission channel,it indicates that the current transmission channel cannot meet the demand of external transmission,and more transmission channels should be added to avoid spilling water.(3)Aiming at the problem of hydropower intra-provincial consumption under the market economy,this paper puts forward an analysis model of the intra-provincial transmission consumption assessment of fairness-considering large-scale hydropower stations.The model consists of two submodels: the energy maximization model and the monthly decomposition model.Firstly,use the maximum power generation model to calculate the maximum theoretical power generation of each hydropower station under the actual inflow of water in each month of the year.Secondly,the energy generation is used as the monthly trading energy boundary condition of the decomposition check sub-model.Thirdly,the theoretical maximum energy generation is decomposed to the daily scale by the power decomposition checking model,and the objective is to minimize the maximum utilization value of the total transmission channel.Finally,analyze the intra-provincial transmission capacity of hydropower.This paper takes more than 50 hydropower stations in Yunnan Power Grid as the example to study,the result indicates that the monthly decomposition and consumption of large-scale hydropower stations within the province,the intra-provincial transmission consumption assessment of large-scale hydropower stations mentions in this paper can effectively solve some of the key problems caused by the monthly electricity consumption of large-scale hydropower stations.For the practical application,these models also have reference value.