| Along with our country's environment pollution and energy shortage problem such as growing,importance is given to renewable energy,especially in the photovoltaic power generation has reached a larger scale.Photovoltaic power generation,however,there is the characteristics of "randomness and intermittent,volatility",it brings difficulties to power grid scheduling,and influences of photovoltaic power generation to connect with the grid.Therefore,using the new train of thought of hydro photovoltaic complementary,has important theoretical significance and application value.In this paper,taking the 320 MW photovoltaic power station that is the world's largest hydropower photovoltaic complementary station now as the research object,and a new kind of above the electric complementary and coordinated operation mode was adopted,to stduy grid-connected photovoltaic.To above the complementary coordination operation in the short-term scheduling were studied,the theory and methods of research results has strong systematic,scientific nature and operability,which provides a theoretical support for above the complementary.Paper's main research results are as follows:(1)The theory and method system of complementary and coordinated operation was built,which provides a new way for photovoltaic to connect with the grid.In contrast the hydropower and photovoltaic characteristics were analyzed,above the complementary characteristics,above the basic principle of complementary,above the complementary on the basis of the basic mode,put forward some new concepts,above the complementary and coordinated operation set up photovoltaic output prediction,and above the complementary and coordinated operation model,the development of the theory and method of the complementary and coordinated operation.(2)According to the characteristics of the randomness,intermittent,volatility in the photovoltaic,and quickly adjustment the characteristics of hydropower,and analyses the influence of short-term scheduling photovoltaic compensation ability and above the complementary power peaking capacity,reveals above the complementary mechanism,through a compensation of hydropower and photovoltaic sawtooth wave and secondary compensation of intermittent and randomness,volatility;Hydropower can support photovoltaic in capacity in the short-term scheduling,photovoltaic can in peak load regulating operation for medium and long term scheduling and hydro power support.(3)According to hydropower and photovoltaic characteristics,the analysis above the complementarity was compared and the basic pattern of the above the complementary was expounded;And the basic principle and calculating method of above complementary was studied;Also the concept of "virtual hydopower" was put forward,and its connotation was analyzed,packaged hydropower online new energy is recognized as a "virtual hydropower machine" in the hydropower station.(4)For short-term problem and super short term forecasting results photovoltaic power station,to establish the forecast model of the four different:markov chain model,the stepwise regression prediction model,adaptive BP neural network prediction model and adaptive Elman neural network model.The characteristics and advantages of each model were analyzed:Markov model is focused on the power output range of values between two days,and the modeling process is simple,easy to implement;The establishment of the BP neural network and Elman neural network model is to predict the output capacity of each hour forecast,using the adaptive optimal number of hidden layer nodes,through the grid search optimization to get the accurate parameters,the model prediction accuracy is high;Stepwise regression model that is linear prediction method is used,and the output of the sunny day forecast more accurate,but it's cloudy and rainy days the prediction error is bigger,in practice is not recommended.(5)The mathematical model of maximum peak load capability was established,which based on iterative thoughts of simulation optimization method,above the complementary effect on results peak load capability is studied.By working backward to solve the mathematical model of maximum load performance above the complementary and total output process.Sunny,cloudy and rainy,according to the results of three different kinds of typical model calculation,after above the complementary results load capacity can be increased by 18%,respectively,9%and 5%.Long series data,according to the results of calculation results maximum load performance can be increased by about 18%,can increase by about 10%on average,minimum does not improve.(6)The influence of water regulation in Longyangxia and Laxiawa axiwa two reservoirs was studied above the complementary to the results.Sunny,cloudy and rainy the calculated results show that the three models,after above the complementary results one day' s outflow water changed little,maximum outflow water variation within 0.21%;In addition,after of Laxiwa reservoir regulation,maximum water level fluctuation amplitude was only 1.32 m,compared to before the complementary growth of 0.07 m,accounting for 0.58%of the Laxiwa down reservoir depth,basic is not affected by above the complementary of water dispatching.(7)Above the complementary effects on downstream power plant generating capacity were analyzed.Because the water level of Laxiwa biggest gain is 0.07 m,the water level almost remains the same,so the results above the complementary after almost has no influence on the downstream power plant.Because of the Laxiwa reservoir ' s water outflow according to the requirements of downstream integrated water down the amount of water has nothing to do with above the complementary,so above the complementary and coordinated operation has no effect on downstream cascade hydropower peaking and frequency modulation.Above the Laxiwa reservoir regulation,the complementary barely impact on downstream integrated water that meet the requirement of the lower reaches of the Yellow River water resources comprehensive utilization. |
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