A utility in Hawaii extracts water from deep wells to provide drinking water to customers. They use 3-phase electric motors to pump the water from the wells and out into the distribution system. The quality of the electrical service on the island is poor, however, with significant voltage fluctuations and unbalanced phases. The poor power quality and unbalanced phases was causing pump motors to burn out often within one year of installation, significantly short of the 15-20 useful lives of the motors.
The Problem of Phase Imbalance
High voltage and phase imbalance seriously impact the performance and useful lives of electric equipment, especially motors. Even slight imbalances of phases can cause motors to overheat and wear out much sooner than necessary. As seen in the table below, even a 1% phase imbalance increases temperatures and resistive losses, cutting the useful life of motors in half.
|% voltage unbalance||Winding temp (°C)||Resistive losses (% of total)||Efficiency reduction||Expected winding life (years)|
|2||140||35||1 – 2%||5|
|3||150||38||2 – 3%||2.5|
|4||160||40||3 – 4%||1.25|
|5||180||45||> 5%||< 1|
Because MicroPlanet’s patented products regulate with extreme speed (sub-cycle), efficiency (99.5% efficient), and accuracy (to within ½ volt of a set-point), our 3-phase products are designed to regulate each power phase independently. Because of the precision of our technology, our products can virtually eliminate phase imbalance, thus dramatically increasing both performance and the useful life of pump motors and other electric equipment.
Microplanet Technology Corp.
15530 Woodinville-Redmond Road NE
Suite B100 Woodinville, WA 98072