Patent ID: 6291958
Filing Date: 2001-09-18
Classification: G05D,H02H,H02P

Abstract:
A method for regulating a temperature of a motor in an electric machine having a controlled output, said method comprising the steps of:generating an error term defined by the difference between a predetermined reference temperature and a measured motor temperature;filtering said error term through a negative pass filter whereby said filtered error term is set to zero for a measured motor temperature that is less than or equal to said predetermined reference temperature;feeding said filtered error into a proportional-integral controller having a limited integrator, and proportional and integral gains;adding an output of the proportional-integral controller defined as u.sub.comp to said controlled output;filtering the sum of u.sub.comp and said controlled output through a positive pass filter;subtracting u.sub.comp from said controlled output;filtering the difference between u.sub.comp and said controlled output through a negative pass filter;summing the outputs of said positive pass filter and said negative pass filter to define an adjusted controlled output for preventing said motor temperature from rising above said predetermined reference temperature.