Coordinated Control Strategy Of Micro-gird Voltage Stability Based On Multi-agent

Distributed Generation(DG)access location,capacity and inherent fluctuation affect the voltage stability of microgrid.DG and microgrid usually lack necessary coordination in power output,load distribution and other aspects,which causes a series of adverse effects such as voltage overrun.Coordinating the smooth operation of multiple DGs is very important to improve microgrid voltage stability.Multi-agent technology is one of the hot research fields of distributed artificial intelligence,computer and information technology.It is an effective method to solve the problem of distributed coordination.In this paper,the coordination between DGs in microgrid is studied,and the work is as follows:Firstly,the modes of interconnection,islanding and corresponding control strategies of microgrid are introduced.Combined with the improved pre-synchronization controller,a smooth switching control method is established,in which the initial output state of PQ controller determines the output state of V/f controller and finally realizes synchronous tracking.In addition,the performance of voltage and current double closed-loop control system under specified parameters is analyzed.The results of calculation and simulation show that the method has good performance,fast and smooth switching process,and meets the requirements of smooth switching.Then,the multi-agent technology is comprehensively introduced from the aspects of multi-agent principle,control structure,individual behavior,communication protocol,modeling method and development environment.The feasibility of using multi-agent technology to solve the voltage stability problem of micro-grid is summarized,that is,using distributed intelligent method to solve the distribution problem;What's more,the voltage stability of micro-grid is carried out.The influence of DG on voltage distribution of microgrid is analyzed from two aspects of access location and capacity.The results show that reasonable access location and appropriate access capacity can improve the voltage level of microgrid,otherwise it will bring the risk of voltage overrun.Finally,multi-agent technology is used to optimize the power/voltage of microgrid.To fix the issue of uneven DG output in microgrid,a DG multi-agent with single-layer network structure is proposed,which coordinates all DG output through consistency algorithm.To fix the issue of voltage stability in microgrid,a coordination strategy with multi-agent technology is proposed,which adopts centralized and decentralized management mode and optimizes the system by adjusting DG power output by agents.The reactive power distribution is integrated to realize the voltage adjustment of the microgrid.The simulation results mean that the way which is proposed in the paper could effectively solve the problem of microgrid voltage overshoot,and verify the effectiveness of the proposed multi-agent coordinated control strategy.