The Coordinated Control And Application Of Fractional-order Multi-agent Systems

In recent years,there has been an increasing interest in the research on the distributed coordination of multi-agent systems because of the self-organization and complex collective behaviors.Its widespread applications exist in many fields,such as physics,science and mathematics.Most of existing results for distributed coordination of multi-agent systems primarily assume an integer-order multi-agent systems,and there is not much research on fractional-order multi-agent systems.Many significant results have been developed for fractional-order systems is about continuous control,but the research of impulsive control is still lacking.Distributed coordination has been utilized in many practical applications,one of which is micro-gird coordinated control.More and more research results shows that,having two more adjustable parameters than integer-order PID controller,the control performance of factional-order PID controller is more deal.On this basis,the factional-order PID control loop of the micro-grid voltage and current are designed.And a distributed coordinated control strategy is designed to realize the coordinated operation of the micro-grid.The main contents of this paper are considered as follows:(1)The coordination of fractional-order nonlinear multi-agent systems with distributed impulsive control is studied.For a fractional-order nonlinear multi-agent systems,the distributed impulsive coordination control strategy is designed to realize the coordination by using the state error as the feedback control input signal.Based on the theory of impulsive differential equation,Mittag-Leffler function and Lyapunov stability,the stability domain of impulsive control interval and pulse gain are given.The distributed impulsive control strategy only requires the system to obtain its state information and the neighbor's state information at the pulse time,then respond accordingly,which greatly reduces the control cost.(2)The distributed cooperative control structure and mathematical model of micro-grid are studied.The structure includes three modules: the primary control,the distributed secondary coordinated control and the distributed economic dispatch.The power control loop adopts the droop control while the voltage and current control loop adopts fractional-order PID control.The structure makes the communication network simple and reduces the communication traffic,which is easy to expand and greatly improve the reliability and extensibility of the micro-grid system.(3)Based on research of the multi-agent system,the distributed secondary coordinated control of micro-grid is studied.A distributed coordinated control strategy is designed for the secondary control problem of micro-grid.The controller in this protocol only needs each distributed generator to obtain its own signal and its neighbor's signal,and make the corresponding control response,thus the coordinated control of the distributed generator can be realized.At the same time,the distributed generator output active power is allocated according to proportional distribution.