Research On Multi-stage Active Distribution Network Planning Considering Complex Operation Scenarios

The distribution network planning directly affects the quality of power supply and the vital interests of users,which needs consideration of the economy of the network upgrade and the reliability of operation.With the coordinated operation of the various distributed flexible resources in active distribution networks,both the peak and valley difference of the load and the increasement of renewable resources permeability are reduced effectively,which delays the construction need of distribution network.Meanwhile,the complexity of the massive scenarios is increased due to the uncertainty of the flexible resource such as distribution generations,electric vehicles and loads.It is generally considered that conventional distribution network planning method based on peak load forecast brings about large investment and low utilization efficiency.Thus,the information fed back by power system operators is also required during practical distribution network planning process.With the increase of active distribution network planning operation scenario complexity,it becomes difficult for operators to select effective information depending on their experience.This paper focuses on the technologies of distribution network planning considering complex operation scenarios.The main contents are as follows:Considering the complex uncertainties of operation scenarios,shadow price is used as an index to evaluate the restricted degree of candidate resources in operation scenarios,to select out the restricted operation scenarios with planning targeted.A bi-level optimization model for multi-stage planning of active distribution network considering the restricted operation scenarios is proposed,in which the lower level is used to solve the operation problem of each scenario in the complex operation scenario set of distribution network.The operation scenarios are evaluated by the operation shadow price and scenario probability,the operation-restricted scenario set is constructed.The upper level with the operation-constrained scenario set as the boundary constraints of multi-stage planning is used to solve the planning problem.The interaction process between decision makers of planning and operation of distribution network in actual production is simulated,and the closed-loop feedback of the bi-level optimization is modeled.With the further refinement of the time scale of operational sub-problems in active distribution network planning,it is difficult for operation restricted scenarios to cover the universal degree of restriction of candidate resources.Given this background,a bi-level integrated distribution network planning model is proposed to reach a trade-off between typical and restricted operation scenarios considering coordinated operation of distributed generation,energy storage systems and interruptible loads.Based on the shadow prices of the candidate resources in all operation scenarios,the cost-benefit of investment is revised and the selection-strategy of restricted operation scenarios is proposed,which ease the computational burden substantially due to the decoupling of operation and planning to a great extent.The proposed method is simulated as an information feedback from operators to planners to minimize the total revision cost of planning and operation by balancing non-network solutions and network solutions.