Difference between revisions of "I²t protection"
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| − | I²t protection is a motor overload protection method based on motor thernal | + | I²t protection is a motor overload protection method based on motor thernal modeling. I²t is a kind of sensorless motor overtemperature protection. |
==Protection mechanism== | ==Protection mechanism== | ||
Motor heat generation is typically dominated by resistive heat dissipation. The heat dissipation of resistance is proportional to flowing current in power of two. I²t algorithm assumes resistive dissipation being the only heat source of motor which is good enough estimate to prevent motorn burning. | Motor heat generation is typically dominated by resistive heat dissipation. The heat dissipation of resistance is proportional to flowing current in power of two. I²t algorithm assumes resistive dissipation being the only heat source of motor which is good enough estimate to prevent motorn burning. | ||
Revision as of 15:10, 18 April 2012
I²t protection is a motor overload protection method based on motor thernal modeling. I²t is a kind of sensorless motor overtemperature protection.
Protection mechanism
Motor heat generation is typically dominated by resistive heat dissipation. The heat dissipation of resistance is proportional to flowing current in power of two. I²t algorithm assumes resistive dissipation being the only heat source of motor which is good enough estimate to prevent motorn burning.
I²t protection continuously estimates how much motor is dissipating heat and estimates motor temperature. At motor rated current heat dissipation is at maximum sustainable level and care must be taken when driving more current than rated current. I²t algorithm will simply limit output current to rated current level if algorithm calculates that motor temperature is already at maximum. If calculated temperature is below maximum, then higher currents are allowed.
