MPC Of The Hybrid Wind And Solar Generation System

Nowadays,the energy crisis and the environmental pollution are becoming more and more serious.Therefore,the use of renewable energy has been paid more and more attention.As one of the major forms of the utilization of renewable energy,research on wind and solar power generation system attracts widespread attention in recent years.As we know,power generation units in wind and solar generation system is usually of large scale,and their operation states are different.What's more,their geographical distribution is more decentralized.For the above reasons,this paper has applied distributed model predictive control to the active power distribution of the system.The distributed control structure could reduce computation load and decrease the influence of generation parts' cut-in and cut-out,which makes the system more flexible.At the same time,the output power of wind-solar generation system varies with weather condition and the total output power of the system needs to tract the load demand.What's more,the operation of system also needs to take into account the economy and security,which is a very high demand for system control.To solve above problems,this paper has designed a multilevel distributed control structure for the system.Every local controller has a two level structure: the upper level is the power distribution level,providing power references for the lower level;the lower level is the power output level,realizing the tracking of power references.When designing the controller of the upper level,we add some economic indicators which usually mean the stability of bus voltage and wind turbine to decrease the cost of power generation.In order to ensure the tracking performance and improve the economic performance of the lower level,the supervisory model predictive control algorithm is adopted in the lower level controller.On the basis of the basic PI control,the algorithm adds the upper level predictive control to optimize the set value,in order to optimize the overall performance of the controller.The simulation experiments indicated the system operation status under normal weather conditions and extreme external conditions when applying the control method.They also displayed the system operation condition after adding the control of bus voltage.Finally,the dynamic characteristics of the system are tested when some wind turbine generation system cut in and cut out.The above simulation experiments validate the advantages of the proposed method.