Research On Planning Method Of Energy Storage System In Photovoltaic Distribution Network

Due to the growing concerns on the current severe energy crisis and environmental issues,the development of renewable energy and access to the power system has become an important part of global energy conservation and emission reduction and environmental protection.And the increasing penetration rate of photovoltaic systems has brought great challenges to the planning and safe operation of distribution networks.As the energy storage system technology continues to mature and the cost continues to decline,energy storage system becomes an important part of the planning and operation control of the distribution network.By using the mathematical optimization method,this paper studies the planning and operation of energy storage system in high-penetration photovoltaic distribution networks,aiming to ensure that the distribution of voltage in the distribution network is reasonably distributed,which could reduce the total operation costs of the distribution network to a great extent and improve the resilience of distribution network.The main research contents and contributions of the paper are as follows(1)Based on the high-penetration photovoltaic distribution network,the safety and economic operation were studied.With full consideration of source and load uncertainty,a two-stage robust optimization scheduling model based on second-order cone programming is proposed,combining the structure and operating characteristics,which can obtain the minimum operating cost and scheduling plan in the worst scenarios.Then the second-order cone programming is used to solve the max-min problem through the column and constraint generation algorithm,which can also get the current worst case The simulation results verify the effectiveness and rationality of the proposed method in solving operation problems.At the same time,the good convergence of the column and constraint generation algorithm also ensures the feasibility of the method(2)In order to solve the multiple uncertainties,which brings challenges to the energy storage system planning problem in the distribution network,a three-layer robust optimization problem is proposed to solve the energy storage system planning problem by using the Benders decomposition theory.The first layer determines the location and size of the energy storage system,the second layer solves the voltage over-limit situation in the worst scenario,and the third layer solves the minimum operating cost and scheduling plan in the worst scenario.Simulation results verify that the proposed three-layer robust decomposition algorithm is more effective than traditional robust optimization methods.The proposed three-level robust planning-operation joint optimization model can deal with the uncertainty more effectively,and the configuration scheme generated by the algorithm is also more robust.By returning the bender cut constraint of the subproblem,the uncertainty of photovoltaic output and load power is fully considered,and the convergence of the program is accelerated,ensuring the feasibility of the method.(3)A path planning method for mobile energy storage systems based on resilience improvement is proposed,aiming to maximize the recovery of load,which combines the distribution network reconstruction with the real-time scheduling of the mobile energy storage systems.At first,the operator analyzes the scale of the failure caused by the disaster and divides the distribution network into islands.And then,the operator develops the maintenance plan,and the crews repair the fault.Next,the path of mobile energy storage systems is planned,and the mobile energy storage system is scheduled at several access points to recover the load in the access point area.The simulation results show that the disaster recovery strategy mentioned in this chapter is more effective and reasonable than the traditional restoration strategy.The strategy proposed in this chapter can make full use of the space-time characteristics of the mobile energy storage systems.By planning the path of the mobile energy storage systems,more load can be restored.