Research On Sizing And Location Of Distributed Generation Based On Multi-objective Planning

With the development of carbon peaking and carbon neutrality goals,distributed generation,as the key to promoting the transformation and upgrading of the power system,has the advantages of clean and efficient,rapid regulation,flexible distribution,and high power supply efficiency.It has become a key research direction for the power industry in various countries around the world.Considering that the access of distributed generation will have adverse effects on the power flow distribution and relay protection of the original distribution network,in order to ensure the safe,stable and reliable operation of the power grid,it is necessary to establish a reasonable distributed generation capacity selection plan considering multiple influencing factors.Therefore,the focus of this paper is as follows:(1)Starting from the background significance,this paper deeply studies the distribution network planning methods including distributed generation,briefly introduces the current research status of distributed generation optimal configuration issues,and the advantages of two-level planning theory in solving power grid planning-operation coordination optimization.Several types of distributed generation that are relatively mature and widely used in power generation technology are listed,and the impact of distributed generation access on various aspects of the distribution network is explained in detail theoretically.(2)Aiming at the situation that grid connection of distributed generation can cause abnormal operation of the original relay protection devices,current protection is incorporated into the optimal configuration model of distributed generation in the form of constraints.A multi-objective function is established that takes into account grid connection capacity and economic costs.The model is solved and optimized using particle swarm optimization algorithm.The proposed model is applied to an IEEE33 node distribution network for example simulation,and a fixed capacity location scheme for distributed generation considering current protection is obtained.The obtained configuration scheme can ensure the normal operation of the original protection device of the system in the event of a fault,maintain the safe and reliable operation of the power grid,and thus verify the importance of considering current protection.(3)From the perspective of source load interaction,this paper studies the problem of fixed capacity and location selection for distributed generation.Based on the demand response mechanism of peak valley time of use price,a multi-objective bilevel programming model is established to realize the overall research of distribution network planning and operation.The upper level planning model takes the grid connected capacity and location of distributed generation as optimization variables,establishes a multi-objective function that considers economic efficiency and grid connected capacity,and then substitutes the solved distributed generation optimization configuration scheme as input into the lower level model.The lower level is a distribution network operation optimization model with distributed generation,using time-of-use electricity prices as optimization variables to construct an objective function that considers network losses and load fluctuations.The optimization results are the electricity sales prices for each time period,which are then substituted into the upper level model to further optimize the capacity and location of distributed generation.The IEEE33 bus system is used to simulate the proposed model,and the results show that the peak valley TOU demand response mechanism can produce the effect of peak shaving and valley filling on the load curve,and highlight the advantage of the bilevel programming model in effectively coordinating comprehensive resources.