Research On Anti-icing And De-icing Strategy Of Power System Considering Line Losses

In recent years,extreme freezing disasters with large impacts and high destructiveness have occurred frequently,posing a serious threat to the safe and stable operation of power systems.As we all know,electrical energy generates losses and heat during transmission.Therefore,in freezing-hazard,power system operation mode could be adjusted to change the power flow of the line and increase the loss and heat of the icecovered line,which can effectively delay the line’s ice accretion,and even meet the requirements of the line’s anti-icing and de-icing need.This thesis conducts research on the anti-icing and de-icing strategies of the power system considering the power loss.The research has important theoretical significance and practical value for improving the ice disaster prevention capability of the power grid and ensuring the safe and stable operation of the power grid in freezing weather.This article is funded by the National Natural Science Foundation of China International Cooperation and Exchange Project(51861145406).It focuses on the ice accretion model considering the power loss and the optimized anti-icing operation of the power system considering the power loss.And researches on the coordinated de-icing optimization model are carried out considering the de-icing mode and power system dispatching.The main research contents are as follows.A transmission line ice accretion model and de-icing calculation model considering power loss are established to accurately quantify the impact of the system operation mode on the line ice accretion.In the ice accretion model,the progress of ice growth on transmission lines is described from the perspective of thermodynamics considering power loss,and the increasement calculation models of two types of ice accretion including rain ice accretion and frost ice accretion are given.In the de-icing model,a calculation model of line current and de-icing duration is established based on the deicing heat balance equation.Case studies analysis the process of glaze icing and rime icing respectively.The relationship between de-icing current and de-icing duration is analyzed.The model provides a basis for the analysis of the ice coating and de-icing scenes in Chapter 3 and Chapter 4.Joule heat of line losses has the effect of delaying the ice accretion.An optimized anti-icing operation model of the power system considering the line loss is established to reasonably optimize the loss of ice-covered transmission lines and to enhance the power grid prevention capability against freezing disasters.Taking the glaze icing caused by short-term freezing rain as a background,a linear glaze icing accretion model considering line loss is established through the approximation and linearization of the icing model in Chapter 2.Then power system operation mode adjustment model is conducted.The decision variables of the model include active and reactive commitment output and demand response of the transferable load.Finally,an optimized anti-icing operation model of the power system is conducted based on icing accretion model and system operation mode adjustment model limited by Joule heat calculation.The model is solved by Lagrangian relaxation method.The case study on IEEE RTS-79 test system shows that the ice on some transmission lines could be reduced effectively by system operation mode adjustment and system anti-icing operation.In order to characterize the coordinated optimization effect of DC de-icing and operation mode de-icing,and to ensure the reliability and economy of the system,a coordinated de-icing model is proposed considering de-icing mode and system dispatching.Taking the rime ice as the research background,the DC de-icing plan model and the operation mode de-icing plan model are first established based on the de-icing operation principle.Then the system operation model is conducted based on system operation mode adjustment and the rime icing accretion model is proposed considering de-icing process.Finally,based on the above models,a coordinated de-icing model is conducted considering de-icing mode and system dispatching.The objective function of the model is to minimize the operation cost and icing thickness on the lines.The model is solved by elitist non-dominated sorting genetic algorithm.Test on IEEE RTS-79 bus system shows that the coordinated de-icing method can meet the system de-icing need in a lower cost,avoiding the load shedding caused by the concentrated de-icing.And the coordinated de-icing method takes into account both operating costs and line safety.