Frequency response of motor drive loads in microgrids

Daniel Joseph Ryan, Hugh Duffy Torresan, Reza Razzaghi, Behrooz Bahrani

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)


Islanded microgrids require power reserve with fast primary-frequency response to operate stably. Primary-frequency response from generators or batteries incurs high costs. Alternatively, primary-frequency responsive loads reduce costs by allowing generators and batteries to operate more flexibly. In industrial microgrids, which comprise a significant portion of the microgrid market, electrical motors are a significant portion of the total load. However, existing demand response mechanisms are not suitable for motor loads in microgrids. In this article, a novel grid-supporting motor drive controller is proposed. This controller can be retrofitted to motor drive loads to provide fast primary-frequency response. A reduced-order analytical model of the motor drive load is derived, which can be directly integrated into system-wide frequency stability studies. Additionally, the primary-frequency response time of the motor drive is assessed, analytically and through EMT simulation, and is less than 100 ms, which is comparable to large battery energy storage systems. Finally, the behaviour of a microgrid system that includes two large motor drive loads is assessed during various large disturbances through EMT simulation.

Original languageEnglish
Pages (from-to)1197-1206
Number of pages10
JournalIEEE Transactions on Energy Conversion
Issue number2
Publication statusPublished - Jun 2021


  • demand response
  • droop operation
  • load modelling
  • Microgrids
  • power system control
  • power system dynamics
  • variable speed drive

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