Study On The System Identification And Multivariable Predictive Control Of Microturbine-based Combined Cooling Heating And Power System

The microturbine-based combined cooling heating and power system(MGT-CCHP system)is one of the best ways of distributed energy.It can generate thermoelectric load at the same time,achieve cascade utilization of energy,and has significant economic and environmental benefits.However,the MGT-CCHP system has many complex characteristics,such as multivariable,strong coupling,nonlinear,parameter time-varying and so on.The conventional control method is difficult to meet the control requirements.The bat algorithm and particle swarm optimization algorithm with wide range optimization performance are combined with the cooperative search strategy and tabu search strategy.The improved hybrid bat algorithm is applied to MGT-CCHP system identification.Using centralized control strategy,the innovative multivariable DMC predictive control is applied to the design of the control system of the MGT-CCHP system.This paper provides a new idea to solve the identification modeling and multivariable control research of the MGT-CCHP unit.Based on the analysis of principal behavior of the bat algorithm and optimization features,with co-evolutionary framework improved bat algorithm,set parameters,tabu search criteria and termination criteria of amnesty,between the various elements of information communication is re-established,the bat group and particle groups learn from each other excellent particle elements to achieve the best effect on global optimization.Through the simulation experiments of multiple test functions optimization,simple and complex thermal process system identification,it is concluded that the improved bat algorithm has better performance and identification ability than other basic intelligent algorithms such as bat algorithm.The control targets and characteristics of the MGT-CCHP system are analyzed,the tasks and objects are clearly controlled,and the difficulties in the control of cold and heat load are deeply understood.To determine the amount of fuel,heat return valve opening,high pressure refrigerant valve opening as input system,microturbine speed,the chilled water outlet temperature and the hot water outlet temperature as the system output,through reference on work characteristics,the mechanism of MGT-CCHP system and the thermal process characteristics determine the transfer model of structure system.The improved bat algorithm is used to identify it.The results show that the proposed model can effectively reflect the operation characteristics of MGT-CCHP system,which is in line with the practical application needs of the project.The improved ERGA pairing rules are used to evaluate the correlation of each input and output,and the main control factors of the output are determined.Innovative multivariable predictive control is applied to MGT-CCHP system control.From the single variable DMC,a multivariable DMC predictive control method is introduced,a multivariable predictive control system is designed,and the influence of key control parameters on control performance is analyzed in detail.Control performance analysis of disturbing the result under the influence of the given value,inside and outside disturbance and time-varying disturbance,the design of the multivariable predictive control system control is more rapidly than conventional PID,smaller overshoot and excellent anti-interference ability,and the output of cold heat and power load is more stable,which is fully consistent with the actual application control requirements of MGT-CCHP system.