Reduced-Order Structure-Preserving Model for Parallel-Connected Three-Phase Grid-Tied Inverters

Brian Johnson, Victor Purba, Saber Jafarpour, Francesco Bullo, Sairaj Dhople

Research output: Contribution to conferencePaper

35 Scopus Citations

Abstract

Next-generation power networks will contain large numbers of grid-connected inverters satisfying a significant fraction of system load. Since each inverter model has a relatively large number of dynamic states, it is impractical to analyze complex system models where the full dynamics of each inverter are retained. To address this challenge, we derive a reduced-order structure-preserving model for parallel-connected grid-tied three-phase inverters. Here, each inverter in the system is assumed to have a full-bridge topology, LCL filter at the point of common coupling, and the control architecture for each inverter includes a current controller, a power controller, and a phase-locked loop for grid synchronization. We outline a structure-preserving reduced-order inverter model with lumped parameters for the setting where the parallel inverters are each designed such that the filter components and controller gains scale linearly with the power rating. By structure preserving, we mean that the reduced-order three-phase inverter model is also composed of an LCL filter, a power controller, current controller, and PLL. We show that the system of parallel inverters can be modeled exactly as one aggregated inverter unit and this equivalent model has the same number of dynamical states as any individual inverter in the system. Numerical simulations validate the reduced-order model.
Original languageAmerican English
Number of pages7
DOIs
StatePublished - 2017
Event2017 IEEE 18th Workshop on Control and Modeling for Power Electronics (COMPEL) - Stanford, California
Duration: 9 Jul 201712 Jul 2017

Conference

Conference2017 IEEE 18th Workshop on Control and Modeling for Power Electronics (COMPEL)
CityStanford, California
Period9/07/1712/07/17

Bibliographical note

See NREL/CP-5D00-68202 for preprint

NREL Publication Number

  • NREL/CP-5D00-70295

Keywords

  • dynamic states
  • grid connected inverters
  • interfaces
  • inverter
  • LCL
  • system load

Fingerprint

Dive into the research topics of 'Reduced-Order Structure-Preserving Model for Parallel-Connected Three-Phase Grid-Tied Inverters'. Together they form a unique fingerprint.

Cite this