Experimental Investigation on the Energy Performance of Variable Frequency Drives in HVAC Systems

K. Kiamehr, S. Shahahmadi, Gang Wang, L. Song

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Variable frequency drives (VFDs) are widely applied on induction motors that drive fans and pumps in heating, ventilation and air conditioning systems. Under partial loads, VFDs not only adjust frequency to reduce motor speed and mechanical output power (load) but also adjust voltage to reduce motor electrical input power. The ratio of voltage to frequency affects the motor efficiency. On the other hand, VFDs not only consume energy, but also create harmonics, which can cause additional motor energy losses and interfere with sensitive electronic equipment. So far, not enough studies have been done to identify the motor losses and the effects of harmonics on system energy consumption. The purpose of this paper is to experimentally investigate the additional energy loss resulted by VFDs and the optimal ratio of voltage to frequency of VFDs. First the energy consumption with different voltage-frequency ratio settings under different loads is measured on the same system to identify the optimal voltage-frequency ratio. Then the additional energy loss is identified by comparing power difference of a chilled water system with and without a VFD. The measurement results show that the VFD results in 2.5% energy loss and the optimal voltage-frequency ratio is not always the flux optimization mode.

Original languageEnglish (US)
Title of host publicationAEI 2017
Subtitle of host publicationResilience of the Integrated Building - Proceedings of the Architectural Engineering National Conference 2017
PublisherAmerican Society of Civil Engineers (ASCE)
Pages432-439
Number of pages8
ISBN (Electronic)9780784480502
StatePublished - Jan 1 2017
EventArchitectural Engineering National Conference 2017: Resilience of the Integrated Building, AEI 2017 - Oklahoma City, United States
Duration: Apr 11 2017Apr 13 2017

Other

OtherArchitectural Engineering National Conference 2017: Resilience of the Integrated Building, AEI 2017
CountryUnited States
CityOklahoma City
Period4/11/174/13/17

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ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Architecture

Cite this

Kiamehr, K., Shahahmadi, S., Wang, G., & Song, L. (2017). Experimental Investigation on the Energy Performance of Variable Frequency Drives in HVAC Systems. In AEI 2017: Resilience of the Integrated Building - Proceedings of the Architectural Engineering National Conference 2017 (pp. 432-439). American Society of Civil Engineers (ASCE).