Research On Reactive Power And Voltage Control Strategy Of Active Distribution Network Considering Multi-agent Benefits

With the deepening of the energy crisis,the continuous growth of electricity demand and the gradual emergence of environmental pollution,the traditional centralized power supply model can barely meet the requirements of environmental friendliness and operational flexibility.Under this circumstance,the model transformation intensifies,and distributed power supply models are widely connected to the distribution network.Among them,the flexible and environmentally friendly photovoltaic industry is particularly developing rapidly under the influence of state subsidies and other policies.The continuous increase of the permeability of distributed photovoltaic in the distribution network brings severe challenges to the voltage control of the distribution network.Therefore,it is urgent to fully mobilize the voltage regulating resources in the distribution network and deeply develop the voltage regulating capacity of each equipment in order to maximally ensure the safe operation of the voltage.In the active power distribution network,the distributed power supply can change the power flow on the line by optimizing power output,and then realize the voltage regulation,which provides a more diversified voltage control means for the distribution network.Most voltage control strategies in existing studies take the minimum network loss or voltage deviation of the distribution network as the objective function.Starting from the interests of the distribution network,the unified dispatching method is adopted for both the distribution network and photovoltaic,which fails to take into account the PV’s own interests and makes it difficult to comprehensively describe the interaction and interest demands of different subjects.To settle above problems,this paper proposes the multi-objective dynamic reactive voltage control strategy from the perspective of technical control.and the reactive voltage control strategy of active distribution network using multi-agent game theory with the consideration of technical control and economic guidance.Specific research contents are as follows:Firstly,the basic theories involved in this paper are introduced,including the principle of photovoltaic voltage regulation,non-cooperative game,two-layer optimization and particle swarm optimization.Through test examples,the good global search performance of the adaptive particle swarm optimization algorithm is verified.Secondly,aiming at the problem of coordination and cooperation between photovoltaic and traditional voltage regulating equipment in reactive voltage control of active power distribution network,a multi-objective dynamic reactive voltage control method with embedded pre-action table satisfying the constraints of switching times of equipment was proposed,taking photovoltaic reactive power benefit and active power loss of distribution network as the objective function.An example is given to verify that this strategy can effectively solve the problem of coordination and optimization between capacitor bank and distributed photovoltaic considering the limitation of equipment movement times.Meanwhile,the photovoltaic reactive power benefit is taken as one of the objective functions,and the voltage control strategy can reflect the photovoltaic benefit to a certain extent.Thirdly,the interaction and interest between distribution network operators and distributed power supply operators in the reactive voltage control process are analyzed,and the mathematical model of distribution network operators considering network loss cost,photovoltaic reactive power purchase cost and OLTC operation cost is constructed.The photovoltaic reactive power cost function is improved,and the mathematical model of photovoltaic operators whose objective function is to maximize their own interests is constructed.Based on the non-cooperative game theory and the two-layer optimization method,the reactive voltage control method of active distribution network considering the multi-agent game is proposed.Finally,an example is given to analyze the reactive voltage control of an improved IEEE 33-node distribution network in different scenarios.The results showed that the active distribution network voltage control strategy considering the multi-agent game can effectively improved the voltage quality of the distribution network and the operating income of PV,meanwhile gave play to the autonomy of PV in voltage regulation.Compared with pure technical means,the voltage regulation strategy guided by market mechanism can meet the demand of voltage control of distribution network under different reactive power abundance.Reactive power cost has a significant influence on the game result.Through analyzing the influence of government subsidy policy,photovoltaic power generation cost and other factors on the game result,some conclusions are drawn for reference.