Dynamic Modeling of Shipboard AC/DC Interconnected Microgrids and Attenuation of Transient States Caused by Pulsating Load Changes
Subject Areas : مهندسی برق و کامپیوتر
Mostafa Zamani
1
,
Arash Dehestani Kolagar
2
*
,
Mahdi Mossayebi
3
,
Mohammad Reza Alizadeh Pahlavani
4
1 - Faculty of Elec. and Com. Eng., Malek Ashtar University of Technology, Tehran,
2 - Faculty of Electrical & Computer Engineering, Malek Ashtar University of Technology, Iran
3 - Faculty of Elec. and Com. Eng., Malek Ashtar University of Technology, Tehran,
4 - Faculty of Elec. and Com. Eng., Malek Ashtar University of Technology, Tehran,
Keywords: Disturbance resulting from load switching, microgrid stability, pulsed load switching, microgrid dynamic modeling.,
Abstract :
AC/DC microgrids of modern vessels have undergone significant changes due to the increase of high-power loads and the development of energy storage systems. In this paper, the extracted microgrid model is the main model developed in the dq reference frame, and the simulation results show the dynamic effect caused by any instability between the AC and DC subsystems of the microgrid. Thus, according to the results of the simulations, the microgrid AC/DC subsystems will have different transient characteristics in case of disturbances such as short circuit, switching of high-power loads, and occurrence of electric arc, which lead to the instability of the microgrid. The ability of the microgrid to maintain stability largely depends on the damping of electromechanical oscillations by the controllers in the AC/DC microgrid, which makes the study and design of these controllers very important. In order to attenuate the transient states of the DC subsystem, the PI closed-loop controller is used in the energy storage system to control the duty cycle of the IGBT switches in the DC/DC converter. The results show that with the appropriate design of the controller of the energy storage system, the transient states in the DC subsystem, in case of instabilities caused by the load pulse changes, are significantly reduced and attenuate the transient states of the microgrid. In this article, the second Lyapunov method is used to evaluate the stability of AC/DC microgrid.