Research On Cooperative Generation-Load Active Power Control Incorporating Flexible Loads

Frequency adjustment and active power control have always been the most important links in the operation of power system.At present,automatic generation control(Automatic Generation Control,AGC)is widely used.With the access of large-scale renewable energy,the traditional AGC mode,which only relies on the output of conventional units to maintain the active power balance of power system,is challenged.Flexible]oads have the ability to participate in the regulation and control of power grid and realize the interaction between supply and demand of power system and have a certain potential in participating in power network frequency modulation.In this paper,the cooperative generation-load active power control strategy considering the participation of flexible loads is studied.Firstly,the cooperative control strategy of energy storage resources participating in AGC is studied.A simulation model which can fully characterize the dynamic characteristics of battery energy storage is established.In order to make full use of the fast response performance of energy storage resources and take into account the limitation of energy storage SOC state on its charge and discharge power,the advantages of partition dynamic proportional distribution mode and high and low frequency distribution mode of AGC frequency regulation signal are considered comprehensively.The cooperative active power control strategy based on a hybrid allocation method of ACE signal is proposed,which can dynamically allocate energy storage resources with conventional frequency modulation units.Secondly,a double layer distributed source-load cooperative control method based on temperature-controlled load participating in AGC is proposed,which includes the upper layer AGC frequency modulation signal allocation method,and the high-frequency part of the frequency modulation demand is borne by the temperature-controlled load resource.It can make full use of its fast response characteristics;The control strategy of the lower load aggregation layer to the temperature control load response mode of the cluster,considering the difference of different types of temperature control load,and the constraints of the users’willingness to participate and comfort,the priority coefficient of each temperature control load response is defined.The controlled temperature control load is sorted,and the on/off state of some temperature controlled load is changed.Finally,the complete source load cooperative control is realized.Finally,in order to verify the effectiveness of the above two cooperative control strategies in dealing with the renewable energy access scenario,taking wind power grid connection as an example,the calculation examples of energy storage resources and temperature control load involved in the AGC system with wind power are analyzed.The results show that these two control strategies can effectively restrain the influence of wind power uncertainty on the grid frequency,and improve the frequency modulation performance of the system.