| With increasing energy demand,new-type power systems with a high proportion of renewable energy sources and coordinated source-grid-load-storage interaction are the inevitable trend in grid development.Compared to traditional power grids,the newtype power system has many power electronic components and the use of smart gridrelated technology has increased its flexibility and regulation capability.However,the main source of power generation in the new-type system has changed.The intermittency,volatility,and uncertainty of renewable energy increase the difficulty of stable operation of power systems.At the same time,the application of a high proportion of power electronics has led to a series of problems in the grid,such as reduced system inertia and weakened anti-interference ability.In addition,the frequent occurrence of extreme natural disasters worldwide in recent years has increased the challenges faced by power systems.Under extreme events,new-type power systems are able to use the rich resources that can be regulated to support the load side,but are also exposed to more cumbersome forms of disturbance,with a two-sided impact on system resilience.In this paper,the study of methods to improve the resilience of new-type power systems provides important theoretical and engineering value.In this paper,research is carried out at three levels: evaluation,planning and operation of new-type power system resilience.Firstly,at the level of new-type power system resilience evaluation,the impact of differences in power source characteristics on system resilience is fully considered,and a rapid evaluation method of power system resilience based on graph theory is proposed,which can provide guidance for power system resilience planning and operation.Then,at the planning level,the support capability of battery energy storage system on the source side,grid side and load side are analysed,and a method for battery energy storage system planning considering system resilience enhancement is proposed.Finally,at the operational level,a corresponding method for optimizing the resilient operation of the power system is proposed for conventional operation and extreme events respectively,combining the characteristics of the new-typw power system.The innovative results contained in this study are as follows:(1)A grid resilience evaluation method that integrates source-side characteristics and grid topology is proposed.Firstly,based on complex network theory,a power system resilience evaluation method based on power supply capacity and network topology is proposed by analogising power system resilience to the process of change in operating state under the action of mechanical external forces.Then,integrating the optimal power system dispatch model under extreme events and the differences in characteristics of different types of power sources,the source-side resilience evaluation metric is proposed in terms of capacity,regulation capability and vulnerability.Finally,the validity of the proposed method is verified by the IEEE 39-bus system,the IEEE 14-bus system and a 500 k V power system in a Chinese province.(2)A method of battery energy storage system planning considering resilience enhancement is proposed for new-type power systems containing a high proportion of renewable energy to be connected.Firstly,in the proposed model,multiple dimensions of operating environment such as typical day,time period and fault scenarios are set up to fully considered the support ability of the battery energy storage system on the source side,grid side and load side.Secondly,a two-stage optimization method is proposed for effective solution.In the first stage,candidate nodes for the installation of battery energy storage system and fault scenarios are identified based on the graph theory metric evaluation results,and in the second stage,the planning model is decoupled in the two dimensions of fault scenarios and typical days using benders decomposition,so as to avoid dimensional disasters.Finally,the effectiveness of the method is verified through a 500 k V power system in a Chinese province.(3)A method for optimizing the resilient operation of power systems considering topology optimization and fast control of power electronic components is proposed.Firstly,an operation optimization model of the power system considering conventional fault security constraints is proposed.In this model,the uncertainty of renewable energy sources and the security constraint of short-term post-contingency capacity increase operation are considered,and the security and economy of the system are improved by topology optimization and fast control of power electronics.Secondly,a two-stage optimisation method is proposed for the model to improve the efficiency of the model solution by finding an effective line switch.Finally,the effectiveness of the method is verified with two modified IEEE systems and a 500 k V power system in a Chinese province.(4)An optimal dispatching method for power systems under extreme events considering frequency stability constraints and topology optimization is proposed.Firstly,A model for optimal dispatching of power systems under extreme events is proposed.In this model,topology,unit commitment and new-type power source output optimization are used to improve system economy and stability.In order to address the power imbalance caused by system unbundling,a frequency-related constraint is proposed that can be applied to islanding and topology optimization.Secondly,the scheduling scheme is solved for each time period in the model by rolling optimization.Finally,the effectiveness of the method is verified with two modified IEEE systems and a 500 k V power system in a Chinese province. |
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