There are some factors that are hurting the potential of variable speed HVAC systems that need to be addressed by the HVAC industry. For example, variable speed HVAC systems and measurement instruments have been traditionally developed to handle electrical input power supplies that are simple sine waves. With the development of low cost solid state power devices and integrated circuits, many variable speed motor concepts have gone into production. Many of these, such as the capacitor filter type inverter, draw current from the line that have extremely high harmonic content. It is important to measure this power or energy accurately in order to determine HVAC efficiency, design and develop standards. It is also important for the purpose of separating losses in the development of more efficient HVAC systems to be able to measure accurately the power into the motor leads as well as the AC power delivered to the electronic drive.

Principal Investigator: Hamid Toliyat, Texas A&M University

Conducted: September 1999 - December 2001

Sponsored by: TC 8.11, Electric Motors and Motor Control.