Abstract

Invertor as a virtual synchronous generator (VSG) to provide virtual inertia and damping can improve the stability of a microgrid, in which the damping is one of the fundamental problems in dynamics. From the view of the Hamiltonian dynamics, this paper researches the damping formation mechanism and damping injection control of VSG. First, based on the energy composition and dynamic characteristics of VSG, the differential equations system of VSG is established and is transformed into the generalized Hamiltonian system. Second, the effects of the three parameters of VSG, the damping coefficient D, active power droop coefficient, and time constant of excitation TE on damping characteristics are researched from a dynamic perspective, and simulation research is carried out with an isolated microgrid. Lastly, the control design method of Hamiltonian structure corrections used to add the damping factor and design the equivalent control inject damping to improve the stability of the isolated microgrid. Research shows that the voltage and frequency stability of the isolated microgrid can be effectively improved by selecting three key parameters of VSG and damping injection control. The innovations of this paper are 1. The Hamiltonian model of the inverter is deduced and established by taking the inverter as a virtual generator. 2. Based on the Hamiltonian model, damping characteristics of inverter in the microgrid are studied. 3. Hamiltonian structure correction method is applied to the inverter, and equivalent damping injection is designed to improve the stability of the microgrid.

Highlights

  • Structure of Invertor UnitThe Udc is the output of energy storage unit, and can be regarded as a constant voltage source

  • Introduction published maps and institutional affilIt has become a standard configuration model that the DC storage unit and inverter are used to compensate for adjustment in a microgrid

  • The damping formation mechanism and damping injection control of virtual synchronous generator (VSG) are analyzed from the perspective of dynamics, and the isolated microgrid is constructed for simulation analysis

Read more

Summary

Structure of Invertor Unit

The Udc is the output of energy storage unit, and can be regarded as a constant voltage source. S1 –S6 are the power switching device that forms the three-phase bridge inverter circuit. When the invertor is regarded as VSG, the inductance of the bridge arm is regarded as the stator winding of the generator. L, R, Ia , and Ua are a phase reactance, resistance, current, and voltage of stator winding, respectively. Ea is the internal electric source of a phase of the generator, which can be expressed as E∠ φ, E is the internal electromotive force, φ is the phase angle L, R, Ia , and Ua are a phase reactance, resistance, current, and voltage of stator winding, respectively. ea is the internal electric source of a phase of the generator, which can be expressed as E∠ φ, E is the internal electromotive force, φ is the phase angle

Virtual Stator Unit
Virtual Excitation Unit
Rotor of VSG
Structure of VSG
Hamiltonian Function
Hamiltonian Model of VSG
L utin sin φ
Basic Theory
Damping Injection
Simulation System
Damping Characteristic Analysis
Damping Injection Control
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call