I²t protection - Revision history

Tero K at 22:51, 19 October 2017

2017-10-19T22:51:26Z

Tero K at 22:31, 19 October 2017

2017-10-19T22:31:31Z

Tero K at 13:25, 7 February 2015

2015-02-07T13:25:26Z

WikiAdmin at 12:19, 3 May 2012

2012-05-03T12:19:25Z

WikiAdmin at 20:39, 18 April 2012

2012-04-18T20:39:14Z

WikiAdmin at 20:32, 18 April 2012

2012-04-18T20:32:59Z

WikiAdmin at 20:30, 18 April 2012

2012-04-18T20:30:45Z

Tero K at 15:10, 18 April 2012

2012-04-18T15:10:46Z

Tero K: Created page with "I²t protection is a motor overload protection method based on motor thernal time constant. ==Protection mechanism== Motor heat generation is typically dominated by resistive ..."

2012-04-18T15:09:25Z

Created page with "I²t protection is a motor overload protection method based on motor thernal time constant. ==Protection mechanism== Motor heat generation is typically dominated by resistive ..."

New page

I²t protection is a motor overload protection method based on motor thernal time constant.
==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.

[[Category:Technology]]

@@ Line 12: / Line 12: @@
 ==Parameters==
-When configuring I²t protection, only one [[GDtool]] parameter needs to be set:
+[[File:i2t.JPG|thumb|Granity will display the actual current limitation reason in the Testing tab. In this example the limit reason is I²t protection, so drive has dropped Actual current limit to the value of MCC parameter.]]When configuring I²t protection, only one [[GDtool]] parameter needs to be set:
 ;Motor time constant
 :Time in seconds how long it takes motor temperature rise to 63% from idle temperature to maximum allowed temperature when motor is driven continuously with 100% of rated current. If unsure, use low values (<500 seconds) to have error in safe direction.
@@ Line 18: / Line 18: @@
 *[[Motor peak and continuous current limits]]
 *[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of I²t method]
-[[Category:Technology]]
 [[Category:Glossary]]

@@ Line 5: / Line 5: @@
 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.
+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. In other words:
+* Current/torque setpoint is internally clamped to a user defined {{Param|MMC}} if I²t calculation shows temperature rise to be less than motor's maximum safe level
 [[File:Currentlimits graph i2t.png|800px]]

@@ Line 5: / Line 5: @@
 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.
 ==Parameters==
 When configuring I²t protection, only one [[GDtool]] parameter needs to be set:
@@ Line 11: / Line 15: @@
 :Time in seconds how long it takes motor temperature rise to 63% from idle temperature to maximum allowed temperature when motor is driven continuously with 100% of rated current. If unsure, use low values (<500 seconds) to have error in safe direction.
 ==See also==
 *[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of I²t method]
 [[Category:Technology]]
 [[Category:Glossary]]

← Older revision		Revision as of 12:19, 3 May 2012
Line 13:		Line 13:
	*[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of I²t method]		*[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of I²t method]
	[[Category:Technology]]		[[Category:Technology]]
		+	[[Category:Glossary]]

@@ Line 6: / Line 6: @@
 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.
+==Parameters==
 ==See also==
-*[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of "I squared T" method]
+*[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of I²t method]
 [[Category:Technology]]

← Older revision		Revision as of 20:32, 18 April 2012
Line 7:		Line 7:
	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.		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.

		+	==See also==
		+	*[http://www.copleycontrols.com/motion/pdf/IsqT.pdf Copley Controls explanation of "I squared T" method]
	[[Category:Technology]]		[[Category:Technology]]

@@ Line 1: / Line 1: @@
-I²t protection is a motor overload protection method based on motor thernal modeling. I²t is a kind of sensorless motor overtemperature protection.
+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 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 motor 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.
+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.
 [[Category:Technology]]