Two Levels Of Coordination Optimization Scheduling Strategy Of Power System With New Energy Based On Reliability Quantization

With the continuous increase of the penetration rate of new energy generating units with photovoltaic and wind power,the environmental uncertainty of the new energy generators at the same time,the uncertainty of the new energy generators has caused a huge impact on the reliability and economic operation of traditional power systems.Therefore,traditional scheduling methods based on deterministic methods are limited in solving the operational reliability problems caused by random fluctuations in renewable energy,and cannot achieve the optimal economic dispatch of complex power systems flexibly.Under the above background,the following research has been carried out on the premise that the grid of uncertainties meets reliability and achieves optimal economic dispatch:Firstly,the photovoltaic and wind power uncertainty models are modeled and analyzed using fuzzy set theory and probability theory,respectively,as the basis for power system energy optimization management.Then,based on the idea of dividing operation reliability into two indexes of system security and system adequacy,two kinds of optimization that deal with stochasticity are proposed from two aspects of the impact of uncertainty of renewable energy on scheduling accuracy and reliability Scheduling strategy:The one is a variable time scale optimal scheduling strategy based on reliability quantification.Considering that the prediction error of renewable energy increases with the advancement of the prediction time scale,and there is a strong coupling relationship between the time period and the time period,on the basis of the traditional multi-time scale scheduling model,the interval threshold method is used.Based on the traditional multi-time scale scheduling model,the interval threshold method is used to analyze the safety This paper proposes a time-scale coordinated scheduling model: when the renewable energy is expected to fluctuate little,the time scale is increased to reduce the system Economic operating costs;and when the projected large fluctuations in renewable energy power generation,by reducing the time scale to improve the accuracy of prediction to reduce the number of interruptible loads to ensure system reliability requirements.In the model,the unit operation and reserve capacity plan are determined by a short-term forecast a few days ago;the fuzzy function is used to calculate the forecast error membership degree in the day,and the constraint criteria of different reliability quantification were compared to determine the next scheduling time scale dynamically.In the example,the relationship between security and operating costs under different weight coefficients was analyzed,and the correctness of the model and the effectiveness of the solution are verified.The another is a chance constrained rolling optimization scheduling strategy with spare high and underestimated costs.In order to reduce the impact of new energy prediction error accuracy on system operation,the prediction error of renewable energy output is taken as a random variable,and based on a combination of risk theory and reliability,the prediction error is organically linked to the reserve capacity adjustment..Then,the mathematical analysis method is used to deduce the high and underestimate costs of the corresponding positive rotation reserve and negative rotation reserve,and add them to the objective function.Finally,according to the rolling update of renewable energy output forecasting information,an intra-day rolling optimal scheduling method that satisfies the constraints of line flow is proposed,which can meet the reliability of system operation and improve the system economy.In the example,the IEEE-RTS 24-node distribution network system is used as an example for simulation analysis.The results show that the proposed method quantifies the amount of reserve capacity adjustment,effectively controls the risk brought by the prediction error,and reduces the consumption of renewable energy.The cost of consumption,under the constraints of line capacity,has been used to optimize the output and spare capacity of the unit and to achieve economical optimal scheduling.