Study On Control Strategy Of Family Controllable Load And Its Influence On Distribution Network

The real-time balance of electricity generation and consumption in the power system is the basic requirement to support the safety and stability of the power system.The adjustment method of load balance in traditional power system is that the electricity generation follows the consumption.But in recent years,with the energy shortage and environmental pollution problems intensified,the pressure on energy-saving and emission-reduction becomes more and more.In addition,the continuous growth of the peak load and the rapid development of renewable energy increase the difficulty of the power grid dispatching,and new challenges have been put forward to the power system regulation.With the establishment of advanced measurement infrastructure,the development of information processing technology and communication technology and the emergence of a variety of controllable devices,smart grid promotes the control and management of electricity,and realizes the interaction between power grid and users.The family has a large number of controllable loads.In the context of smart grid,the demand response can be used to adjust the operation of devices at home to serve the function of the peak clipping and peak shifting.Among the domestic controllable loads,the load of air conditioning and electric vehicle have the property of long run time,high power and power storage function,so this paper describes how to use these two kinds of domestic controllable loads to accomplish the purpose of peak load clipping and peak load shifting.Firstly,taking the air conditioning load as the representative of adjustable load,the demand response control strategy of household air conditioning based on model predictive control strategy is established.The thermodynamic model and parameter estimation of building air conditioning are introduced,and the model predictive control strategy of single air conditioning is established,and the effect of weight coefficient on the control strategy is also analyzed.The demand response control strategy of air conditioning is formulated based on the model predictive control strategy which considers user’s comfort preference,and the effectiveness of such strategy is verified by simulations.Secondly,taking the electric vehicle as the representative of shiftable load,the electric vehicle charging control strategy is established by using the power limit value.This method applied by coordinated charging controller controls the sum of the residential area’s regular load and electric vehicle’s charging load to prevent power limit exceeded.By calculating electric vehicle charging priority,coordinated charging controller can ensure electric vehicle’s SOC satisfying user’s expectation to the utmost.When the control period is over,coordinated charging controller optimizes the aforesaid power limit.The effectiveness of such strategy is verified by simulations and then we analyze prediction error’s impact on power limit.Finally,taking IEEE 33 node distribution system as an example,this paper validates the effectiveness of adjustable load in peak clipping and the effectiveness of shiftable load in peak shifting.The optimization effect on node voltage and network loss,which is caused by the strategy formulated in this paper,is also analyzed.