Research On Large-scale Temperature Control Load Dispatch Control

Nowadays,as the development of economic society leads to the increasingly prominent problems of resources and environment,the utilization of new energies has become an im-portant measure to solve such problems.However,the continuous penetration of new ener-gies has brought great challenges to the stable operation of the power grid.Under the back-ground of smart grid,demand response has become an important form of curbing new energy fluctuation and cutting peak and filling valley.As one of the most important resources of demand side,thermostatically controlled loads(TCLs)can improve the stability and econ-omy of power grid by participating its operation.However,due to its large number and com-plex thermodynamic characteristics,it is of great practical value to study how to effectively integrate large-scale TCLs into the operation of power system.In this thesis,TCLs is taken as the research object.The aggregation response model of large-scale TCLs is studied,and the scheduling strategy and control strategy for TCLs to participate in the operation of power system are proposed.The main works of this thesis are shown as follows:(1)The research background and the concept of smart grid and demand response are in-troduced,meanwhile the necessity and feasibility of TCLs participating in the operation of power system are pointed out.From three aspects of modeling technology,scheduling strat-egy and control strategy of TCLs,this paper briefly introduces the research status at home and abroad.And then the research contents of this thesis are clarified.(2)Based on the simplified first order equivalent thermal parameter mod.el,the aggrega-tion response characteristics of TCLs are studied.With considering the energy storage char-acteristics of TCLs,the power can be equivalent to the charging and discharging power,and the storage of heat/cool can be equivalent to the energy storage.Then the equivalent energy storage model of large-scale TCLs can be established,and in this model,the time-varying heat exchange power instead of the average power is adopted to calculate the charge and discharge power,meanwhile the equation relationship between the heat exchange power and the energy storage is established.Then the state-queuing(SQ)model is analyzed and to im-prove its accuracy,a modified SQ model is introduced.(3)The day-ahead scheduling model based on the TCLs equivalent energy storage model is put forward.To obtain the optimal cost-effectiveness,the minimum cost of power opera-tion,including generation cost,cutting wind cost,and compensation cost of the TCLs,is set as the goal.In addition to the traditional constraints,the charge and discharge power con-straints of TCLs,the energy storage constraints of TCLs and the relationship between the heat exchange power and the energy storage are also considered,in which the upper and lower limits of charge and discharge power are time-varying.The established scheduling model can not only effectively prevent the power and energy storage of TCLs from exceed-ing the limits,but also improve the economy and security of power system.(4)This thesis puts forward a method for the controller parameters optimization of TCLs based on the modified SQ model.The closed-loop control is used to construct the overall control framework for TCLs,which is a centralized architecture based on the two-way com-munications.The actual aggregate power of TCLs is set as the feedback signal.This control framework bases on the broadcasting control mechanism,in which the control signal is trans-formed into the switching probability of TCLs.The proportional-integral(PI)controller is adopted in the control system and the optimal parameters of this controller are obtained by genetic algorithm optimization.According to the load tracking control results of the opti-mized controller,the proposed control strategy can better track and control the reference signal,and further the good control performance of the controller is verified by analysis.