Congestion Management In Active Distribution Networks

With the large-scale access of distributed resources such as distributed generators,electric vehicles,microgrids,and energy storage to the distribution network,the distribution network is changing from a traditional passive distribution network to the active distribution network(ADN).Due to the uncertainty and complexity of distributed resources and the market behavior of the electricity market operation,ADN is prone to congestion and endangers the safety,reliability,quality and economy of the ADN.For this reason,it is necessary to carry out research on the regulation and management of congestion in the ADN,effectively solve the problem of network congestion in active distribution networks,and adapt to the development of ADNs.The structure,operating characteristics,and related technologies of the ADN are the basis for congestion management of active distribution networks.Based on the flexibility and controllability of the distribution network topology,this paper uses network reconfiguration to establish a congestion management model,with the condition to eliminate congestion of meeting security constraints,with the goal of reducing network loss and increasing the power output,with the NSGA-II optimization algorithm as the reconfiguration algorithm,and the verification is performed through an example.The components,operating mechanisms,and demand response methods of the electricity market are the basis for the congestion management of the electricity market.This paper establishes a congestion management model based on the day-ahead scheduling market,and uses aggregators as distribution system operators and flexible load intermediaries to submit electrity-consumption planning based on demand plan of flexible loads.Based on the day-ahead trading and energy information exchanges between distribution system operators and aggregators,the flexible demand of users is guided by electricity prices,thereby alleviating peak power and eliminating congestion,improving the security of the operation of the distribution system.And it is proposed to use genetic-particle swarm optimization algorithm to solve the day-ahead congestion management model,and the verification is performed through an example.Aiming at the congestion phenomenon of ADN,this paper proposes a two-level congestion management model.The model is implemented based on the two-level control strategy formed by a combination of network reconfiguration and electricity market mechanisms.In the day-ahead scheduling market,when congestion occurs,in order to maximize resource utilization,improve the ability of market subject to participate in the market,First of all,the distribution system operator usesnetwork reconfiguration to optimize the distribution network topology and maintain system stability.Secondly,calculate the power supply cost of the distribution system operator based on the congestion cost,and calculate the power purchase cost of the aggregator,and then optimize their energy plans and optimize the line transmission current,so as to solve the congestion and maximize their own benefits.The IEEE 33-bus and PG&E69-bus systems are compared with the traditional single strategy to verify the effectiveness and superiority of the two-level control strategy.