Research On Risk Assessment And Coordination Optimization Of Active Distribution Network Considering Demand Response

Demand response(DR)and distributed generation(DG)have been continuously promoted with the rapid development of active distribution network(ADN)technology.It has not only further promoted the two-way interaction between the power grid side and the user side,but also affected the power supply reliability and economy of the distribution network.The reliability and economy of distribution network are a pair of contradictions.Coordinating and optimizing the cost of demand response and the improvement degree of distribution network reliability has become an urgent issue that needs to be solved.Therefore,based on the accurate assessment of the reliability and risk of the active distribution network considering the demand response,this paper has carried out the research on the operation strategy of coordinating and optimizing the demand response cost and the risk benefit of the distribution network from the operational aspect.Furthermore,from the planning aspect,a planning strategy study that coordinates and optimizes demand response cost,distribution network planning investment cost and risk has been carried out.Firstly,the research on various demand response models,active distribution network reliability and risk assessment models is carried out.Based on the fuzzy clustering method and the electricity price elasticity matrix,the price-based demand response(PBDR)model is established.On the basis of evaluating users’ comprehensive response capabilities,the grid-side dispatch model and user-side response model of the incentive-based demand response(IBDR)are built.In addition,based on the traditional distribution network reliability indicators,the concept of risk is introduced to quantify the reliability as a risk value.And comprehensively considering the time-varying failure rate model of components,the user outage economic loss model and the social benefit loss evaluation model,an assessment model for the reliability and refined outage risk of active distribution network is developed.Secondly,the research on the reliability and risk assessment method of active distribution network with distributed generation is carried out.Combining the influence of distributed generation,the load importance degree in the island is comprehensively evaluated by using the best-worst method(BWM)and an island operation strategy is proposed.Taking into account the time-varying load and the output of the distributed generation,the sequential Monte Carlo simulation method is applied to simulate in the improved IEEE RBTS BUS6 F4 system.The case study shows that the access of the distributed generation has a significant effect on improving the reliability of the distribution network,but the scope of improvement is relatively small.Then,from the operational aspect,a two-stage risk coordinated optimization strategy for the active distribution network that takes into account multiple demand responses is presented.On the first stage,on the basis of ensuring users’ satisfaction and grid revenue,a peak-valley time-of-use electricity price optimization strategy is proposed with the goal of minimizing peak load and peak-valley difference.On the second stage,combining the grid-side economic benefit as well as risk reduction benefit,user-side benefit and satisfaction,a two-layer optimization strategy for distribution network risk based on incentive-based demand response is proposed.And an iterative method is applied to search the optimal load reduction strategy and compensation strategy of typical scenes.The results of the case study show that the propounded optimization strategy can greatly reduce the operation risk of the distribution network with a lower cost.Finally,from the planning aspect,a distribution network planning strategy considering multiple factors such as demand response cost,the planning investment cost and the distribution network risk value is presented.Based on applying above the two-stage risk coordinated optimization strategy,the sum of the distribution network planning investment cost,the demand response cost and the risk value during the planning process is used as the objective function to build the active distribution network total cost and risk benefit optimization model.A comprehensive planning for the distribution network is carried out and the distribution network reliability investment and benefit ratio index is used to evaluate the effect.The case study compares and analyzes the reliability and economy of the distribution network before and after the implementation of the strategy,which shows that the proposed strategy and planning scheme are reasonable and practical.