Font Size: a A A

Research On Improved Droop Control Of Inverter Parallel Operation Under Fractional-order PI Control

Posted on:2020-04-07Degree:MasterType:Thesis
Country:ChinaCandidate:Y H ShenFull Text:PDF
GTID:2392330620465058Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
With the continuous development of economy,the distribution of power load is expanding.Thus,the distributed generation is widely used in modern power system.Due to the characteristics of distributed and near access,local generation and consumption,parallel operation control of microgrid system composed of distributed inverter power generation has become a research hotspot at home and abroad.In the inverter parallel system,the traditional droop control is an effective control approach.However,the approach has the problem of power coupling and residual difference of reactive power in steady state.Besides,the anti-interference ability of the inverter to disturbance is not strong under the control of traditional PI double-loop controller.Aiming at the deficiency above,some research is conducted in this paper.Firstly,the stability of commensurate and incommensurate fractional-order system is studied.A concise and effective graphic approach of fractional-order system is proposed,which can effectively determine the stability of commensurate and incommensurate fractional-order system.The approach proposed extends the determine range of fractional-order system and lays the theoretical foundation for subsequent research.In addition,in order to improve the anti-interference ability of system,fractional-order theory is introduced into the droop control system.The fractional-order PI controller is used to replace classic integer-order PI controller in the inverter current inner-loop.Furthermore,an improved droop control strategy is proposed in order to reduce the power coupling and the residual difference of reactive power in steady state under the traditional droop control.Finally,the inverter parallel running simulation based on the improved droop fractional-order control is established in MATLAB/Simulink.The simulation result shows that the strategy above can effectively enhance the anti-interference ability of system,reduce the power coupling and improve the equalization precision of reactive power.
Keywords/Search Tags:microgrid, distributed generation, inverter running in parallel, droop control, stability of fractional-order system
PDF Full Text Request
Related items