Research On Congestion Dispatching Of Active Distribution Network With Flexible Load

With the gradual improvement of the flexible load and the distributed power supply in the active distribution network,it is bringing the new challenge in the safe and stable operation of the distribution network while alleviating the energy tension and decreasing the environmental pollution.On the one hand,the non-restraint or non-guiding behavior caused by large-scale development of electric vehicle,is unfavorable to the power balance control of distribution network,it can even cause the obstruction of networks.On the other hand,the intermittent distributed power output,which is represented by photovoltaic and wind power,has obviously randomness characteristics.It can cause frequent variations in the size and direction of power flow when it access to distribution networks.But the active power distribution network also has its controllable distributed power supply,and the electric vehicle charging under the control of the market owns good flexibility.So,coordinating dispatching distributed power supply and electric vehicle to alleviate congestion has great significance in improving system stability and economy.Firstly,unlike traditional distribution network,active distribution network can manage the controllable power supply and flexible load.Considering the probability distribution characteristics of electric vehicle charging power,this paper proposes an active distribution network congestion scheduling strategy,which has the flexible charging and discharging time transfer ability of EV group in active power distribution network on the basis of studying the scheduling factors of active distribution network.The operation mode of charging and discharging service charge is set up on the basis of considering the probability characteristics of intermittent distributed power and EV,which is based on the actual situation of China's electric power market.The dual response control between dispatching mechanism and charging and discharging facility operator is realized,and the owner of Electric vehicle is designed to make charging and discharging plan reasonable.The mode can finally realize the control of blocking power of active distribution.Secondly,with the flexibility of distributed power generation output in active power distribution network,This paper establish a model which includes the market structure of controlled distributed power agents,dispatching mechanism of distribution system,charging and discharging facility operators and vehicle owners.Based on the minimum charging and discharging cost of electric vehicle and the lowest cost of generating system,a multi-objective congestion scheduling strategy is proposed for active distribution network under the adjustment strategy of charging and discharging service charge.The mode realizes to decrease the owner.cost of charging the car and realizes the optimum economical operation on consider of the flexible characteristics of charging and discharging of electric vehicle,the electric vehicle group,the controllable distributed power supply and the purchasing power from the large power grid are the dispatching objects.Finally,the proposed congestion scheduling model is verified by the improved IEEE33 node calculation example,and the results show that the congestion scheduling strategy can reduce the congestion effect and improve the safety and economy of the power grid.