Research On Distribution System Planning Method Considering Distributed Generation

With the rapid development of the social economy,the traditional fossil fuel energy is increasingly depleted and the ecological environment problems are becoming increasingly prominent.Wind power and photovoltaic,as a renewable and distributed renewable energy source with huge reserves,have received extensive attention from various countries in the world and have been rapidly developed.The inertia of the original power system,the transmission power of the line,and the distribution of the power flow have been changed to varying degrees due to the access of the distributed power supply.How to realize the efficient operation of the distributed power supply is regarded as a major global challenge.In the planning stage,the distributed power supply and its supporting measures are taken into consideration.At the same time,according to the output characteristics of the distributed power supply and the user's demand for different energy sources and the future development direction of the power distribution system,a planning platform will be built to facilitate the development of the energy market and develop the degree of acceptance of distributed energy in distribution systems and the efficient integration of distribution systems with other energy networks.Based on this,this paper studies the distribution system planning method of distributed power supply considering the active management measures that can be used for distributed power generation and the integrated energy market that can be established in the future.Active management measures that can be used at present can not only meet the reactive power demand of distribution network operation by switching reactive power compensation equipment at the distributed power supply access node,but also ensure the distribution system by adjusting the variable tap on the primary side of the transformer.The voltage is within the specified range;it is also possible to control the distributed power supply output to adjust the voltage of the distributed power supply node,thereby improving the distribution of the power flow and reducing the impact on the power grid.Therefore,a distributed power coordination planning model based on multi-scenario technology to take active management measures for distributed power output has been proposed.First,consider the distribution and installation capacity planning of distributed power sources,and establish an upper-level planning model with the goal of minimizing the investment cost per year of the life cycle,including the construction cost of distributed power sources,annual operation and maintenance costs,annual direct power outage losses,and the cost of higher-level power grids.Annual cost of electricity purchase and active management costs.Then,the seasonal scene set is constructed through the synchronous generation elimination method to the distributed power supply;finally,the minimum output of the distributed power source is taken as the objective function under the seasonal scene set,and the node power balance,node voltage,branch power,The lower-level planning model was constructed with the constraints of distributed power output removal,reactive power compensation device switching and load transformer regulation as constraints.According to the IEEE 33-node system,the proposed model was solved by the cuckoo search algorithm and the original dual-dot interior point method.This verified that the distribution of the typical power of the distributed power source is divided according to the season and the weather,and the distributed model is distributed within the model.The output model of the power supply is more accurate and reduces the amount of computation of the solution planning model.After adopting active management measures,the access capacity of the distributed power supply in the power distribution system is greatly improved,and the adverse effects brought by the distributed power supply after accessing the power distribution system are improved,and the voltage stability at the access node is maintained.At the same time,through various active management measures,controlling the output of distributed power sources,changing the taps of the on-load transformers,and the reactive power compensation amount are separately adjusted.This improves the power distribution of the distributed power supply while improving the utilization of the distributed power supply and reducing the load of power distribution system on the distributed power supply during the low load period.With the gradual intersection and integration of various energy networks such as natural gas networks and thermal energy networks with the power grid,the energy market is gradually opening up.With high-permeability and renewable energy accessing the distribution network,integrated energy suppliers become a new type of interest in integrated energy market.Firstly,an energy concentrator model was used to describe the integrated energy units with built-in distributed power,cogeneration,electricity conversion,and gas-fired boilers and other energy conversion devices.Based on the principle of competitive bidding in the market,two regional energy suppliers and integrated energy management centers were established.Large-stakeholder integrated energy market.Based on this,a bi-level planning model that considers the double maximization of net income of regional energy suppliers and integrated energy management centers has been proposed.The upper level is the capacity planning of each unit within the integrated energy center,and the lower level is the determination of the electricity and gas purchasing strategies of the integrated energy management center.At the same time,the model considers the active management measures and the timing of distributed power output.The cat-cluster algorithm and the improved genetic algorithm are used to solve the proposed model.Taking the IEEE 33-bus system including electric and natural gas networks as an example to analyze the integrated energy planning model,it verifies that the comprehensive energy market model proposed in this paper fully reflects the rules and characteristics of future energy market development,and establishes the supervision of the energy trading process.With the executing agency,the market competition mechanism can fully optimize the benefits of participation in the game players.Regional energy suppliers can fully satisfy users' needs for various energy sources without affecting normal energy use while maximizing their own benefits through multi-energy complementarity.In place of users' participation in demand response,distributed power output and load fluctuations in the distribution system are suppressed,and supply and demand of multiple energy sources are complemented.