Numerical Validation of a Thermal ROM of a Hydroelectric Generator Scale Model

A thermal reduced order model (ROM) of a scale model of a hydroelectric generator was created in this study. To do so, thermal simulations of the rotor solid domain were performed (with different heat losses and ambient air temperatures) by applying the convection heat transfer coefficients obtained from a separate CHT simulation to the rotor surfaces. A response surface was then created from the numerical database and a thermal ROM model was built to instantaneously predict rotor pole temperatures under any desired operating condition. Comparison of the pole temperature rise predicted by the ROM model with those computed by a CHT model under the same operating conditions demonstrated that maximum error of the ROM model was less than 3% with constant pole heat loss and less than 4% with temperature-dependent pole heat loss. Consequently, this modeling approach is quite promising and it sets the basis for a future transient thermal model that could be used to monitor the temperature of hydroelectric generator components in real time to prevent damage due to overheating.