Study On Sampling Period And Controller Cooperative Optimization Of Robust Networked Control Performance Constraints In Micro-grid

Micro-grid is a control system which composed by the energy grid and communication network.The stability analysis for the control of the Micro-grid system can not only consider the energy network but ignore the role of the communication network.With the development of micro-grid control technology and network communication technology,the combination of two technologies for collaborative optimization control is a trend of micro-grid development in the future.In order to realize the collaborative optimization,a two level networked control structure of islanded micro-grid based on local primary control and remote secondary network control is presented.And based on the characteristics of time delay in different communication networks,the whole analysis model of control system including communication network model and small signal model of micro-grid is established.Moreover,the sampling period and controller cooperative optimization control algorithm for robust networked control performance constraints is proposed in two cases of single source constant time delay and multi source time-varying delay.The specific work of this article is as follows:1.From the angle of the basic structure and control strategy of the micro-grid,the control performance constraints of the micro-grid are analyzed.And in different communication network conditions,the influence of communication network on the performance of networked control system of micro-grid is analyzed.2.When the time-delay of the communication network is small and can be simplified as a constant time delay,the robust performance index of the micro-grid network is minimized as the control target.The energy network and the communication network are combined to establish a whole analysis model of the single micro source constant time delay control system including the communication network model and the micro-grid small signal model.The stability condition of micro-grid control system and the collaborative optimization design method of sampling period and controller are discussed.3.The small signal modeling method for the micro-grid is studied under the condition of large communication network time delay and multiple micro sources,and the model of communication network including delay and packet loss is established,Then the whole analysis model of the time-varying delay system with multi micro source is constructed.Moreover,the stability condition of the control system and the collaborative optimization design method of sampling period and controller are studied.4.Based on the theoretical research of the sampling period and controller cooperative optimization control of the micro-grid and communication network,the proposed cooperative optimization control strategy is verified under the condition of simultaneous model error,network delay and external disturbance.The simulation test shows that the sampling period optimization control algorithm of robust networked control performance constraints in islanded micro-grid proposed in this paper can obtain the optimal sampling period of the micro-grid accurately.And under the condition of model error,network delay and external disturbance,the collaborative optimization control strategy can effectively maintain the stability and and get the optimal robust performance.