Difference between revisions of "I²t protection"
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| − | I²t protection is a motor overload protection method based on motor | + | I²t protection is a motor overload protection method based on motor thermal modeling. I²t is a kind of sensorless motor over temperature 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 | + | 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 motor burning. |
| − | I²t protection continuously estimates how much motor is dissipating heat | + | I²t protection continuously estimates how much motor is dissipating heat compared to its rated heat dissipation. At 100% of rated current, heat dissipation is at maximum sustainable level. Care need to be taken only when driving more current than rated current. |
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| + | 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 (peak) currents are allowed. | ||
[[Category:Technology]] | [[Category:Technology]] | ||
Revision as of 20:30, 18 April 2012
I²t protection is a motor overload protection method based on motor thermal modeling. I²t is a kind of sensorless motor over temperature 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 motor burning.
I²t protection continuously estimates how much motor is dissipating heat compared to its rated heat dissipation. At 100% of rated current, heat dissipation is at maximum sustainable level. Care need to be taken only 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 (peak) currents are allowed.
