Control Optimization Model Of Power Price Risk For Electric Supply Company Under Electricity Market

Electricity price is the economic lever in the electricity market and the reform of electricity price is the major content in the electricity market.With the further deepening of the power system reform,electricity price can be divided into generation price(electricity purchase price),transmission and distribution price and sales price.Generation price and sales price are formed by market competition,whose fluctuation will bring risks to the power supply corporation.Transmission and distribution price is regulated by the government.And if it not reflect the construction and operation cost reasonably,oower supply corporation will also suffer from risks.Under the electricity market environment,as an independent market participant,power supply corporation will make different decisions on purchasing and selling electricity according to different conditions in view of benefit maximization and risk minimization.The paper does researches and the innovations on the problems of electricity price risks as follows:Firstly,general risk management theory is introduced.According to the procedures of general risk management,the theories of risk identification,risk assessment and risk control are illustrated,and their applications in electricity price risk management in power supply corporation are discussed.Secondly,fractal theory is introduced with its corresponding characteristic function. Based on the data of generation price in California and PJM electricity market,the generation price obeys fractal distribution resulting from the estimation of parameters in fractal characteristic functions by stable program.Then according to the definition and property of risk value,formulas of VaR risk measurement,CVaR risk measurement under fractal distribution and fractal calibration parameter risk measurement are deduced.Based on traditional portfolio model,an optimal combination model of purchasing electricity is built with VaR risk measurement under fractal distribution,a dynamic combination model of purchasing electricity on the basis of CVaR risk measurement under fractal distribution and a combination model of purchasing electricity on the basis of admissible mean-calibration parameters in fractal distribution theory.Also,the problem of optimal quantity of purchasing electricity should be solved before power supply corporation make decisions in multiple markets.Then the optimal strategy for purchasing electricity can be obtained,thus providing some references to power supply corporation.Thirdly,analyze the risks which the transmission and distribution electricity price bring to power supply corporation.Have studied the risk variables which impact the power supply corporation benefit in the power grid investment,make a proposal of a risk assessment method of power grid investment program in market environment,establish a risk assessment model using "addition method" to evaluate the power grid investment risks under the fluctuations of transmission and distribution electricity price.From the viewpoint of power grid structure,with this basis the transmission and distribution charges are converted into two parts,i.e.,the transmission and distribution price at generation side and that at consumer side. For the part at generation side,the transmission and distribution price model is constructed by two-part postage stamp method;for the part at consumer side,tne transmission and distribution price model is constructed by two-part postage stamp method related to different voltage grades,it can better reflect the cost of transmission and distribution electricity price and demand of users,and it is better to recover the transmission and distribution grid fund and re-construct the power grids,thus it can control the transmission and distribution electricity price risk.Lastly,the electricity consumptions in peak and valley periods are forecasted by value at risk(VaR) method based on historical data.Then by use of interval method a risk assessment model is proposed to weigh up the risk of practicing time-of-use(TOU) electricity price for power supply corporation.A linkage model optimized by two steps is presented taking the generating side and the retail side into account,and it can allocate the benefit and risk of both generation companies and electricity supply corporations reasonably from after implementing the time of use electricity price.CvaR method is adopted to measure the risk of practicing interruptible electricity price by power supply corporation.Then according to the supply and demand theory in economics,by combining interruptible electricity price and time-of-use electricity price in peak-valley period,an integrated optimization model is built on the analysis of cost and benefit of power supply corporation,and the model can be solved by decomposition algorithm.Thus,the problem of incentive mechanism in interruptible price is to be settled.