Probabilistic Evaluation Method Of AGC Control Performance For Two-area Interconnected Power Grid Based On DIgSILENT/PowerFactory

Automatic Generation Control(AGC)is an important means for modern power system to carry out power frequency control and maintain system frequency quality and interchange power plan.The basic task of AGC control performance evaluation is to quantitatively analyze and evaluate the consequence of power frequency control under AGC.The evaluation results are the basis of the management and assessment of the frequency and tie-line of regional power grids by the dispatch center,and also be the important reference for power grids to improve AGC control strategy and enhance the level of power frequency control.The conventional practice of AGC control performance evaluation is to statistically analyze the historical data of frequency and the interchange power deviation of regional grids.A few studies also consider the impact of future load changes on the AGC system.But the existing research is basically a category of “certainty” evaluation,and the study on probabilistic evaluation of AGC control performance is very limited.In recent years,with the sustainable development of wind,light and other new energy,the power grid is facing increasingly uncertain factors.How to take the impact of uncertain factors into account,and evaluate the AGC control performance scientifically,comprehensively and reasonably,has become a new problem for AGC field.Under the support of the project “Dynamic optimization of AGC dispatch strategies in a power system with renewable energies”,which subsidized by the National Natural Science Foundation of China(No.51307186),this dissertation studies on the probabilistic evaluation method of AGC control performance.The main contents and achievements are as follows:(1)Modeling and simulation of AGC in two-area interconnected power grids based on DIgSILENT/PowerFactory is implemented.The modeling of frequency controller in interconnected power grids under the mode of “Flat Frequency Control” and “Tie-line Frequency Bias Control” based on the simulation language DSL and custom function of PowerFactory is built.Combined with the built-in governor model of PowerFactory,the modeling of AGC of two-area interconnected system is built based on the IEEE-14 node system.The effectiveness of the simulation system is verified by the dynamic response of the primary and secondary frequency control under a variety of load disturbance scenarios.(2)A probabilistic evaluation method for AGC control performance of two-area interconnected power grids based on PowerFactory dynamic simulation is proposed.Based on the Monte Carlo method and the Latin hypercube sampling technique,this paper uses the programming language and its secondary development function of PowerFactory to probabilistically evaluate the AGC control performance from both technical and economic aspects by probabilistic simulation of the dynamic response of the AGC.The probabilistic evaluation method is verified by the two-area interconnection system above.Compared with the existing AGC probabilistic evaluation method,the proposed method makes full use of the time domain simulation function of PowerFactory,and considers the dynamic process of the primary and secondary frequency control of interconnected power grid in detail.