RTDS Implementation of the Optimal Design of Grid-connected Microgrids Using Particle Swarm Optimization

Abstract

The  dynamic  nature  of  the  distribution  network challenges  the  stability  and  control  of  the  microgrid.  In  this paper,   a   simplified   simulation   model   of   an   inverter-based microgrid  in  the  grid-connected  mode  is  implemented  in  real-time   on   a   Real-Time   Digital   Simulator   (RTDS®).   The simulation is performed fast because RTDS works in continuous sustained real-time. All components such as the inverter bridge, LC  filter,  coupling  inductor  and  grid  are  modeled  using  their physical  representation  in  standard  library  blocks.  The  inverter bridge  is  modeled  by  the  assumption  of  ideal  sources.  Optimal design  of  the  LC  filter,  PI  controllers,  and  damping  resistance obtained   using   particle   swarm   optimization   (PSO)   in   the optimal nonlinear model of the grid-connected microgrid is used in the simulation model. Nonlinear time domain simulation has been  carried  out  to  assess  the  effectiveness  of  the  proposed controllers  under  disturbance.  The  results  show  satisfactory performance   with   efficient   damping   characteristics   of   the microgrid    considered    in    this    study.    Additionally,    the effectiveness  of  proposed  approach  for  optimizing  different parameters  and  its  robustness  have  been  confirmed  through  the nonlinear  time  domain  simulations.  The  performance  of  this controller has been verified in simulation using a RTDS.