Nomex® Electrical Insulation: Dual Temperature Aging Cells

Dual temperature aging cells are used to simulate aging of insulation used in liquid immersed transformers and Hybrid Electric Vehicle traction motors. Like the actual applications, the system allows the insulation on the conductor to be aged at a higher temperature than the surrounding fluid. This avoids overheating the fluid during accelerated aging which changes the degradation mechanism. The transformer simulation cells completely submerge the magnet wire in the fluid. To simulate the partially submerged windings in a Hybrid Electric Vehicle motor, half of the wing is in the fluid and the other half is in the gas phase above the fluid. The computer monitors and controls the conductor and fluid temperatures separately. After aging, the insulation can be evaluated electrically and mechanically. In addition, the fluid is evaluated electrically and chemically for degradation.