Research On Resilience-Oriented Fault Recovery And Repair Strategy For Regional Integrated Electricity-Natural Gas Systems

With the increasing shortage of traditional energy sources such as coal and oil and the increasingly severe global environmental pollution problems,the disadvantages of over-dependence on traditional energy sources are gradually increasing.In order to alleviate the double pressure brought by energy shortage and environmental protection needs,many countries have started to vigorously develop renewable energy sources and improve energy utilization.Compared with traditional thermal power generation,natural gas power generation is more efficient and environmentally friendly,so the installed capacity of gas-fired power generation is increasing,and the coupling relationship between power system and natural gas system is getting closer and closer,Regional Integrated Electricity-Natural Gas System(RIENGS)has been developed rapidly.However,the occurrence of extreme disaster events seriously threatens the safe and reliable operation of RIENGS.Due to the impact of climate change,the probability of extreme disasters has been increasing in recent years.To enhance the resilience of RIENGS to cope with the disturbances caused by extreme disasters is a common concern of all countries.To this end,a coordinated optimization strategy of RIENGS fault recovery and maintenance scheduling for resilience enhancement is proposed in this paper.The strategy takes into account the disaster and post-disaster phases.When RIENGS encounters an extreme disaster,the topology of the distribution system is reconfigured by means of contact switches installed in the distribution system,and the rapid recovery of RIENGS during the disaster phase is realized by means of distributed generation(DG)and energy storage and energy conversion equipment in the system.In the post-disaster recovery phase,by arranging maintenance personnel to repair the damaged components in the system and reduce the load shedding of the system,the system is finally restored to normal operation,and the RIENGS resilience is achieved by reducing the comprehensive load shedding of the system with a phased recovery strategy.The main completion elements are as follows:1)The regional electric power subsystem and the natural gas subsystem are modeled separately,and the related models of the coupling element gas turbine and electric drive compressor in RIENGS are also considered to lay the theoretical model foundation for the subsequent study.2)This strategy aims to minimize the reduction of critical loads in the system,reconfigure the distribution system topology by means of contact switches installed in the distribution system,and realize the rapid power supply restoration of critical loads in RIENGS during the disaster stage by cooperating with DG and energy storage and energy conversion equipment in the system.RIENGS E13-G7 and RIENGS E123-G20 systems are used for case analysis to verify the effectiveness of the proposed rapid RIENGS fault recovery strategy to prioritize the restoration of critical loads in mid-disaster.3)A two-stage RIENGS disaster recovery and repair strategy for resilience enhancement is proposed,and the failure recovery and repair strategy is divided into two stages: In the mid-disaster phase,the two subsystems in RIENGS are restored in a coordinated manner through a network reconfiguration strategy,and priority is given to restoring energy supply to critical loads.In the paper,a RIENGS fault recovery optimization model is developed and solved to determine the DG,gas source,gas turbine output and contact switch operation.Then,in the post-disaster phase,based on the contact switch action results obtained by solving the mid-disaster optimization model and the final topology of the system in the mid-disaster phase,the components damaged in the system due to extreme disasters are repaired with the dual objectives of minimizing the load reduction in RIENGS and minimizing the total time to repair the damaged components,and ensuring that the distribution network reconfiguration strategy and the repair strategy are solved optimally at the same time.Finally,the correctness and effectiveness of the proposed strategy in reducing the load loss of RIENGS is verified by conducting an arithmetic analysis with the RIENGS E13-G7 and RIENGS E123-G20 systems.