Control Strategy for Parallelly Operated Inverters to Achieve Proportionate Power Sharing

Authors

  • D. Anitha , D. Suchitra

Abstract

This paper examinesa control technique for parallel inverters operating in islanded mode.
Parallelly operated inverters have excellent regulation, high reliability and redundancy, which
make them suitable for Microgrid.A simple droop control technique (P/f, Q/V) is used to
achieveproportione active and reactive power sharing between the inverters. A simple droop
controller provides accurate real power sharing but the reactive power sharing is ineffective. The
challenge in reactive power sharing is due to variations in inverter terminal caused by parameter
dissimilarity among the connecting circuits. The parameter variations are compensated by adding
virtual impedance at the output of each inverter so that the terminal voltage at the parallel inverters
are equal. The virtual impedance along with droop controller has been effective in proportional
sharing of reactive power. A system with two parallel inverters is considered for the study. This
system has been implemented in MATLAB Simulink with droop controller and virtual impedance.
The simulated results proved that the real and reactive powers have been shared in proportion to
the rating of each inverter

Published

2020-10-15

Issue

Section

Articles