Impact Assessment On Voltage Quality Of The Distribution Network Connected With Distributed Generation And Related Reactive Power Optimization

With the development of new energy technologies,nowadays,intermittent distributed power supplies such as photovoltaic and wind power has been gradually connected to the distribution network.Under the circumstance of increasingly tense energy demand,the large-scale connection of clean energy generation is the future trend of the distribution network.Intermittent distributed power supply,due to its randomness,imposes adverse influences on the operation of distribution network,among which the influence on voltage quality is particular acute.Appropriate allocation of reactive sources can provide distribution network with effective voltage support.Traditional optimization of allocation of reactive sources in distribution network focus on that with given system network structure and system load level,choose appropriate compensation point where reactive power compensation equipment installs and the capacity of compensation.But traditional way of optimization cannot fully adapt to the circumstances of distributed power supplies being connected because there exists randomness as for the contribution of intermittent distributed power supplies and it’s necessary to fully consider the reactive power demand with different contribution,which is particular acute with large-scale connection of distributed power supplies.For the actual demand of distributed power supplies being connected to the distribution network,this paper will analyze in depth the influence of distributed power supplies on voltage quality of the distribution network and establish an evaluation model to quantize the influence.And on this basis,basing on scene decision method,establish a model of optimization of allocation of dynamic reactive power in distribution network which includes distributed power supplies and finally combines the application in actual distribution network in Longhua District,Shenzhen to verify the feasibility of this method.For the demand of dynamic reactive power compensation in distribution network which includes distributed power supplies,this paper brings forth a means of optimization of allocation of dynamic reactive power compensation.First,it brings forth an operation scheme that we dispose DSTATCOM control at the connecting point of distributed power supplies to control the voltage of the connecting point.Second,we establish a optimization mode of configuration and setting of capacity of DSTATCOM.Last,by means of an example,we verify the effect of the model we proposed on voltage quality promotion and network losses reduction of system operation.The means this paper proposed can provide the decision basis of allocation of reactive power in distribution networks with distributed power supply connected and has the guidance meaning of distribution system planning under the ground of the development of new energy technologies.