Studies Of Novel Dispatching And Control Strategies Of Power Grid Considering Increasing Of Uncertainty And Controllability

With the increasing depletion of fossil energy sources and emphasis on environmental protection issues in the world today,as well as the gradual reduction in the cost of new energy generation,represented by wind power,the penetration of new energy in the power grid increases continously,which will profoundly change the exsiting dispatching and control pattern of the transmission network and distribution network.The increase in the proportion of uncertain power sources,the proliferation of power generation entities caused by the inherent dispersion of new energy power generations,and the conflicts in the demand for interests between power plants,power grids and users due to the continuous advancement of power market reforms,all bring great challenges to the dispatching and operation of the transmission network and distribution network.Meanwhile,the improvement of energy storage technology and the reduction of the use cost,the increase of advanced metering facilities and interruptible or adjustable loads represented by electric vehicles have greatly improved the observability and controllability of the power grid,especially the distribution network,allowing the power grid dispatching and control methods to be greatly enhanced.It can be seen that the increase of uncertainty and controllability is both a challenge and an opportunity for the secure operation and economic dispatching of the power grid.Aiming at these new features and the new problems that follow,a lot of research has been done in academia and industry,and many new ideas and methods have been proposed.However,in general,taking into account the impact of uncertainties in the marketization scenario,rationally considering of the output characteristics,interest appeals of various power generation enterprises,including new energy power plants,and even the utility of power grids and power users,comprehensively using of energy storage technology technology,demand response and other new control methods to achieve the secure and economic operation of the power grid with multi-party participation in still face huge challenges.To this end,this disseration systematically studies the novel dispatching and control strategies of power grid under the background of increasing uncertainty and controllability.Economic dispatching of the power grid: In order to coordinate the conflict of interests between the thermal power plants and the wind farms under the scenario with high penetration of wind power,a dispatching model that takes into account the basic generation guarantee of thermal power plants and the wind abandonment balance index of wind farm has been established.On this basis,the uncertainty adjustment parameters are introduced to quantify the risk preference,and a robust economic dispatching strategy taking into account reasonable wind abandonment and risk preference is proposed,which provides a coordinated dispatching solution for different types of multi-generation entities under competition.In order to cope with the low power generation efficiency of thermal power plants and the large amount of water abandonment in hydropower plants caused by large-scale wind power integrations,as well as considering the cooperation opportunities and profit optimization space among the main participants in the power market,a multi-party cooperative economic dispatching strategy based on Shapley method has been proposed,which can improve the benefits of the alliance and achieve multi-win.This provides an idea for maintaining the stability of the power market and increasing the revenue of the main entities of the power grid in the context of future market-oriented operation of power system.At the distribution network level,existing dispatching methods have the disadvantages of being unable to fully utilize the controllable loads,energy storages and other favorable means: the optimization of the electricity pricing and the distribution network operation is divided,incapable of achieving the global optimization;the interruptible load protocols and models are designed for large industrial users,unsuitable for growing clusters of small users.To solve above problems,real-time demand response models of multiple controllable loads including new interruptible load model are firstly established,and a strategy for collaborative optimization of real-time electricity pricing and operation dispatching of active distribution network is proposed,which realizes a win-win situation between end users and distribution system operators.Operation control of the distribution network: Aiming at the problem of unreasonable power supply for the end user of remote distribution network,this disseration puts forward the idea of local balance of source and load,and designs a local multi-time scale coordinated control strategy for wind power/hybrid energy storage unit considering global-local coordination,including intraday control optimization layer and real-time control optimization layer.The proposed strategy can realize the coordination between the control requirements of the distribution network end and the economic dispatching of the whole network,and the coordination of wind power consumption and fluctuation suppression.Aiming at the problem of the traditional single-time section-based restoration strategy being unable to maintain the stable operation of the islands when the active distribution network is under isolated operation situation caused by external faults,a multi-period dynamic active distribution network restoration strategy with controllable loads is proposed.The proprosed strategy can achieve the balance between the re-power ratio and the number of load switching to avoid the frequent switching of important load,and take advantage of controllable loads to improve the stability of the recovered islands and improve the new energy output utilization rate of islands with new energy DG.