Research On Voltage Coordination Control Strategy Of Active Distribution Network With Distributed Generation

In the context of low carbon,it is of great significance to consider the optimal operation strategy of Active Distribution Network(ADN)for low carbon,economic and stable operation of ADN.A large number of distributed power sources,mainly photovoltaic power generation and wind power generation,are connected to the distribution network.Due to the randomness and uncertainty of the output of distributed power sources,and in order to improve the absorption ability of distributed power sources in the distribution network,the concept of Active Distribution Network is proposed.Distributed power supply access is easy to cause the power grid voltage rise,which easily leads to the risk of power grid voltage exceeding the limit.Therefore,the research on voltage coordination control of Active Distribution Network contributes to the safe and stable operation of the distribution network,improves the power quality of the system,and is of great significance to the research on voltage coordination control of active distribution network.In this thesis,the voltage coordination control of Active Distribution Network is carried out based on the voltage regulator of traditional distribution network,energy storage and demand-side response,and the main research contents are as follows:(1)Introduce the characteristics and development of Active Distribution Network,briefly introduce the solution method of Active Distribution Network model according to the research status at home and abroad,and analyze and study each voltage regulator,energy storage and demand-side response control method.(2)Analyze and study the voltage instability mechanism caused by distributed power supply accessing the distribution network,establish the mathematical model of Active Distribution Network,and restrict the optimal power flow and safe operation of Active Distribution Network.The traditional voltage regulator is coordinated and its characteristics are analyzed and summarized,and the mathematical model conforming to the safe and stable operation of the system is established.The large M method is introduced to change the battery energy storage model so as to facilitate the solver to solve it,build a comprehensive demand response characteristic model on the load side,guide the schedulable resources on the load side to participate in the coordinated and optimal control of the Active Distribution Network voltage,and improve the traditional situation of relying only on the controllable unit regulation.The model is solved by CPLEX solver in Matlab,and the output of each coordination control device,energy storage and time-shifting load participating in the voltage coordination control of Active Distribution Network is obtained.(3)The mathematical model of Active Distribution Network after phase Angle relaxation is further relaxed through second-order cone optimization,and the mixed integer linear mathematical model is obtained.A stepped carbon trading mechanism is introduced,a lowcarbon voltage coordination control model of Active Distribution Network is built,and the coordination ability of Active Distribution Network voltage coordination control between economy and low carbon is deeply explored,and the system voltage is guaranteed to be within the permissible range.The objective function is established with the lowest network loss cost,the lowest interruptible load cost and the lowest carbon transaction cost.Finally,the improved IEEE33-node system is simulated and verified.The system is solved by CPLEX solver,and the proposed voltage coordination control strategy is verified.The effectiveness of the proposed method is verified.Compared with the traditional distribution network,the proposed control method can effectively reduce the carbon emission of the system,effectively reduce the risk of voltage exceeding the limit,and improve the absorption ability of the system to distributed power supply.