An energy buffer for controllable input impedance of constant power loads

Manuel Gutierrez, Peter A. Lindahl, Arijit Banerjee, Steven B. Leeb

Research output: Contribution to journalArticlepeer-review


Power electronic circuits often regulate load power and present a constant power profile to the utility or other electrical source. These constant power loads therefore exhibit a negative incremental input impedance and pose stability challenges when present in either dc or ac systems. This paper presents an energy buffer power converter for a constant power LED lighting load that presents a controllable input impedance to the electrical source. The use of an energy buffer allows the converter to independently control input and output power. The input power is controlled to resemble a resistive load, ensuring that the device exhibits a positive incremental input impedance over short-term input disturbances. Simultaneously, the output power is held constant through high-bandwidth regulation. The control scheme balances the power flow in the long term. Experimental results are presented that demonstrate independence between input and output performance, as well as long-term power balance.

Original languageEnglish (US)
Article number8633442
Pages (from-to)2910-2921
Number of pages12
JournalIEEE Transactions on Industry Applications
Issue number3
StatePublished - May 1 2019


  • Energy storage
  • light-emitting diodes
  • negative resistance devices
  • power converter
  • stability

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering

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