Investigation of the Low Voltage Ride-Through of Inverter Using Virtual Inertia Methods in Microgrid

Abstract

Inverter based Distributed Energy Resources lack the inertia and damping features of synchronous generators dominated traditional power system. The growing penetration of renewable energy technologies coupled with their inherent intermittency also constitute grid instability challenge due to insignificant inertia and damping. The virtual inertia machine methods for the control of inverter based Distributed Energy Resources present the required inertia support that mimics the dynamic performance of a typical synchronous generator. These control methods provide excellent improvement in the stability of the grid. Several studies and implementations have been carried out on providing virtual inertia support for inverters in steady-state and under balanced grid voltage, however there is a need to investigate the dynamic performances during voltage sags occasioned by faults and other grid transients. Due to the low overvoltage and overcurrent tolerance capabilities of inverters, this investigation is important to observe the inverter transient behavior while ensuring the protection of constituent power electronic switches. Consequently, this work carried out an investigation to assess the two methods of Virtual Inertia Machine in ensuring the inverter sustained grid connection in compliance with grid codes, fault current limitation and fault recovery.