| As the proportion of new energy in the power grid increases and the structure of the power grid becomes more and more complex,the complexity of the power grid itself and the variability of the external environment make the power system standby configuration problem facing many new challenges.The increase in the scale of DC power transmission and the increase in the proportion of new energy output have led to a reduction in the moment of inertia of the system.Once a DC blocking fault occurs,a huge active power shortage will occur,causing the system frequency to drop,and the traditional power generation side reserve capacity is difficult to meet the control under high power loss demand.This dissertation considers the use of new energy frequency modulation,DC modulation and interruptible load as grid flexible backup,coordinated with the traditional power generation side backup to improve the grid’s ability to deal with high-power shortage events.The main research contents include:(1)Feasibility analysis and ability quantification of power grid flexible reserve to participate inactive power regulationThis dissertation considers the risk of insufficient reserve in the power grid under extreme conditions.New energy frequency modulation,DC modulation and interruptible load are classified as grid flexible reserve,and the mechanism of frequency modulation is analyzed.The reserve potential was modeled quantitatively and the flexible reserve capacity is evaluated.The research scope of operation reserve is expanded from single generation side reserve to new energy unit frequency modulation,DC modulation and interruptible load flexible reserve with global source network load coordination.(2)Demand side participation in reserve configuration optimization based on decomposition and coordinationBased on the analysis of the multi-level and multi time scale characteristics of power grid operation reserve,this dissertation proposes to classify the system operation reserve according to the response time characteristics,establishes the optimization model of demand side participating in system reserve allocation,and decomposes the solution of the model into the sub problem of unit commitment with limited fault State security constraints,the sub problem of checking the secondary negative reserve constraints based on Monte Carlo,the sub problem of optimizing the system reserve allocation based on decomposition coordination idea the frequency security constraint checking sub problem based on large disturbance long process time domain simulation analysis and the fault state static security constraint checking sub problem based on minimum load shedding are iterated alternately to achieve the optimal allocation of demand side resources.(3)Reserve optimization of power grid operation considering multiple types of flexible reserveFrom the perspective of “source-network-load” coordinated dispatch,the optimal acquisition of reserve capacity is examined,with the goal of minimizing the total operating cost of the system,a unit commitment optimization model that takes into account multiple types of flexible reserve is proposed.On the basis of the combined objective function,the conventional unit backup cost,wind abandonment cost,DC power modulation output cost,and interruptible load output cost are added to reduce the reserve capacity of traditional unit configuration,thereby reducing system power generation costs and the number of additional units.Economic losses and environmental pollution caused by frequent start and stop of units.In this dissertation,an improved IEEE-39 bus system is taken as an example to verify the effectiveness of the proposed method. |
