Method of changing an operation mode of a frequency converter based on temperature conditions, and a frequency converter having a changeable mode of operation based on temperature conditions
First Claim
1. A method in connection with a frequency converter, the frequency converter being arranged for periodic recurrent use, wherein the method comprises steps of:
- determining and storing in a memory a magnitude of an average temperature rise of a power semiconductor in the frequency converter, caused by one loading period;
determining a temperature limit from the determined temperature rise and a highest allowed temperature of the power semiconductor;
determining the temperature of the power semiconductor in the frequency converter; and
changing the operation mode of the frequency converter by reducing a torque limit on-line when the temperature of the power semiconductor exceeds the temperature limit when transferring to a loading period,wherein the determining of the magnitude of the average temperature rise caused by one loading period comprises;
(i) determining the magnitude of the temperature before the start of the loading period;
(ii) determining the magnitude of the temperature after the loading period;
(iii) calculating the difference of the determined temperatures; and
(iv) repeating steps (i)-(iii) and calculating the mean of the differences of the determined temperatures.
2 Assignments
0 Petitions
Accused Products
Abstract
A method in connection with a frequency converter and a frequency converter, the frequency converter being arranged for periodic recurrent use. The method comprises steps for generating and storing in a memory an average heating of a power semiconductor of the frequency converter, caused by one loading period, determining a temperature limit from the generated heating and the highest allowed temperature of the power semiconductor, determining the temperature of the power semiconductor in the frequency converter, and changing the operation mode of the frequency converter when the temperature of the power semiconductor exceeds the temperature limit when transferring to a loading period.
-
Citations
10 Claims
-
1. A method in connection with a frequency converter, the frequency converter being arranged for periodic recurrent use, wherein the method comprises steps of:
-
determining and storing in a memory a magnitude of an average temperature rise of a power semiconductor in the frequency converter, caused by one loading period; determining a temperature limit from the determined temperature rise and a highest allowed temperature of the power semiconductor; determining the temperature of the power semiconductor in the frequency converter; and changing the operation mode of the frequency converter by reducing a torque limit on-line when the temperature of the power semiconductor exceeds the temperature limit when transferring to a loading period, wherein the determining of the magnitude of the average temperature rise caused by one loading period comprises; (i) determining the magnitude of the temperature before the start of the loading period; (ii) determining the magnitude of the temperature after the loading period; (iii) calculating the difference of the determined temperatures; and (iv) repeating steps (i)-(iii) and calculating the mean of the differences of the determined temperatures. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A frequency converter comprising several semiconductors and being arranged for periodic recurrent use, wherein the frequency converter comprises:
-
means for determining and storing a magnitude of an average temperature rise of a power semiconductor in the frequency converter, caused by one loading period, means for determining a temperature limit from the determined temperature rise and a highest allowed temperature of the power semiconductor, means for determining the temperature of the power semiconductor in the frequency converter, and means for changing the operation mode of the frequency converter by reducing the torque limit on-line when the temperature of the power semiconductor exceeds the temperature limit when transferring to a loading period, wherein the means for determining of the magnitude of the average temperature rise caused by one loading period comprises; means for determining the magnitude of the temperature before the start of the loading period; means for determining the magnitude of the temperature after the loading period; and means for calculating the difference of the determined temperatures.
-
Specification