Font Size: a A A

Research On Power Sharing Strategy For Paralleled Virtual Synchronous Generators

Posted on:2020-05-09Degree:MasterType:Thesis
Country:ChinaCandidate:C WangFull Text:PDF
GTID:2392330590473363Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
The core of the microgrid control is the inverter,and the most promising inverter control method is the Virtual Synchronous Generator(VSG).VSG can simulate the advantages of large inertia and damping of synchronous generator,and realize various functions such as frequency modulation and automatic power load distribution.In practice,it is not enough to use only one VSG,and multiple parallel operation modes are used.This paper focuses on the work of VSG parallel systems.This paper analyzes the control principle of a single VSG in detail and designs and implements the VSG algorithm.Discuss the impact of key parameters on a single VSG.The adaptive control strategy of the moment of inertia and damping coefficient of the virtual synchronous machine is proposed.This strategy can suppress the fluctuation of the system frequency when the load changes,and improve the stability of the VSG system.The VSG multi-machine parallel characteristics are analyzed for the influence of line impedance on power coupling and power sharing.The stability analysis of the parallel VSG system is carried out,and the influence of key parameters on the stability of the parallel system is obtained.An adaptive virtual inductor power sharing algorithm is proposed to improve the system reactive power sharing accuracy.Since the virtual inductance algorithm can not solve the voltage drop caused by virtual inductance,an adaptive virtual capacitor algorithm is proposed.The implementation method of adaptive virtual capacitance algorithm is analyzed and combined with adaptive virtual inductance algorithm.The effectiveness and of adaptive virtual capacitor combined with adaptive virtual inductive algorithm are verified by simulation analysis and comparison of various control algorithms.The control method for improving the power sharing effect under the condition of line impedance fluctuation is studied.The line impedance observer is designed and the effectiveness of the line impedance observer is verified.On the basis of observing the line impedance value,the voltage drop difference caused by the line impedance change is compensated,and the system power sharing is improved.
Keywords/Search Tags:Virtual Synchronous Generator, power sharing, virtual inductance, virtual capacitor, line impedance observer
PDF Full Text Request
Related items