EMO:How EMO models SFT constraints - Revision history

WoodsM: /* Estimating the constraint curves used by SPD */

2015-12-20T20:02:50Z

Estimating the constraint curves used by SPD

WoodsM: /* SFT constraint modelling in EMO */

2015-12-20T20:00:31Z

SFT constraint modelling in EMO

WoodsM: /* SFT constraint modelling in EMO */

2015-12-20T19:55:12Z

SFT constraint modelling in EMO

WoodsM: /* Estimating the constraint curves used by SPD */

2015-12-18T03:32:07Z

Estimating the constraint curves used by SPD

WoodsM: /* Estimating the constraint curves used by SPD */

2015-12-18T03:29:28Z

Estimating the constraint curves used by SPD

WoodsM: /* Estimating the constraint curves used by SPD */

2015-12-18T03:26:24Z

Estimating the constraint curves used by SPD

WoodsM: /* SFT constraint modelling in EMO */

2015-12-18T03:24:18Z

SFT constraint modelling in EMO

WoodsM: /* SFT constraint modelling in EMO */

2015-12-18T03:21:15Z

SFT constraint modelling in EMO

WoodsM: /* SFT constraint modelling in EMO */

2015-12-18T03:20:54Z

SFT constraint modelling in EMO

WoodsM: /* SFT constraint modelling in EMO */

2015-12-18T02:30:09Z

SFT constraint modelling in EMO

@@ Line 23: / Line 23: @@
 Up to version 5.2.13 estimates of the constraint curves were based on observing historical constraints (see [[EMO:Estimation From Historical Constraints|Estimation From Historical Constraints]])
-However from version 5.2.13 onwards the thermal characteristics of the circuit are used to calculate the thermal constraint curve.  This ensures that previously unconstrained lines may be modelled as effectively as possible.  The methods used to define and use the circuit's thermal characteristics are described in [[EMO:Use of line conductor information in SFT]]
+However from version 5.2.13 onwards the thermal characteristics of the circuit are used to calculate the thermal constraint curve.  This ensures that previously unconstrained lines may be modeled as effectively as possible.  It also requires the conductor type and configuration is entered into the model for each modeled line. The methods used to define and use the circuit's thermal characteristics are described in [[EMO:Use of line conductor information in SFT]]
 == SFT constraint modelling in EMO ==

@@ Line 28: / Line 28: @@
 [[File:ScreenShot SFT.PNG|1022px|thumb|none|Diagram 1.  SFT Protection factor trait in EMO]]
-Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  The SFT protection factor is one minus the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity.  For example if the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line.  The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW).  When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.
+Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  The SFT protection factor is one minus the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity.  For example if the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line.  The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW).  These two factors together with the maximum thermal capacity define a quadratic curve that we will call the 'estimated thermal constraint curve', this should be a close approximation of the physical SFT constraint in Diagram 1.
-The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.
+When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line. The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.
 {|
@@ Line 38: / Line 38: @@
 Where \(F'_{m}\) is the post-contingent flow on the protected line.
-To ensure the point \(( F_{m}\), \(F'_{m})\) does not lie outside the physical SFT constraint in Diagram 1 above, a linear constraint is added to the dispatch model as follows
+To ensure the point \(( F_{m}\), \(F'_{m})\) does not lie outside the estimated thermal constraint curve, a linear constraint is added to the dispatch model as follows
 {|
@@ Line 45: / Line 45: @@
 |}
-Where A is equal to the slope of the tangent line to the thermal constraint curve and C is the y-intersect of this line.  Once the exposed lines are identified and the related constraints are added to the model the dispatch is reiterated.  Eventually all relevant SFT constraints should be found and applied.
+Where A is equal to the slope of the tangent line to the estimated thermal constraint curve and C is the y-intersect of this line.  Once the exposed lines are identified and the related constraints are added to the model the dispatch is reiterated.  Eventually all relevant SFT constraints should be found and applied.

@@ Line 28: / Line 28: @@
 [[File:ScreenShot SFT.PNG|1022px|thumb|none|Diagram 1.  SFT Protection factor trait in EMO]]
-Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  The SFT protection factor is derived from the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity.  If the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line.  The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW).  When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.
+Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  The SFT protection factor is one minus the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity.  For example if the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line.  The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW).  When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.
 The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.

@@ Line 21: / Line 21: @@
 == Estimating the constraint curves used by SPD ==
-Up to version 5.2.13 estimates of the constraint curves were based on observing historical constraints (see [[From Historical Constraints|Estimation From Historical Constraints]])
+Up to version 5.2.13 estimates of the constraint curves were based on observing historical constraints (see [[EMO:Estimation From Historical Constraints|Estimation From Historical Constraints]])
 However from version 5.2.13 onwards the thermal characteristics of the circuit are used to calculate the thermal constraint curve.  This ensures that previously unconstrained lines may be modelled as effectively as possible.  The methods used to define and use the circuit's thermal characteristics are described in [[EMO:Use of line conductor information in SFT]]

@@ Line 23: / Line 23: @@
 Up to version 5.2.13 estimates of the constraint curves were based on observing historical constraints (see [[From Historical Constraints|Estimation From Historical Constraints]])
-However from version 5.2.13 onwards the thermal characteristics of the circuit are used to calculate the thermal constraint curve.  This ensures that previously unconstrained lines may be modelled as effectively as possible.
+However from version 5.2.13 onwards the thermal characteristics of the circuit are used to calculate the thermal constraint curve.  This ensures that previously unconstrained lines may be modelled as effectively as possible.  The methods used to define and use the circuit's thermal characteristics are described in [[EMO:Use of line conductor information in SFT]]
 == SFT constraint modelling in EMO ==

← Older revision		Revision as of 03:24, 18 December 2015
Line 43:		Line 43:
	\|}		\|}

−	Where A is equal to the ~~protection factor on~~ the ~~protected~~ line. Once the exposed lines are identified and the related constraints are added to the model the dispatch is reiterated. Eventually all relevant SFT constraints should be found and applied.	+	Where A is equal to the slope of the tangent line to the thermal constraint curve and C is the y-intersect of this line. Once the exposed lines are identified and the related constraints are added to the model the dispatch is reiterated. Eventually all relevant SFT constraints should be found and applied.

← Older revision		Revision as of 03:21, 18 December 2015
Line 27:		Line 27:

	Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively). The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO. The SFT protection factor is derived from the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity. If the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line. The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW). When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.		Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively). The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO. The SFT protection factor is derived from the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity. If the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line. The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW). When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.
		+
	The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.		The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.

@@ Line 26: / Line 26: @@
 [[File:ScreenShot SFT.PNG|1022px|thumb|none|Diagram 1.  SFT Protection factor trait in EMO]]
-Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  Setting the SFT protection factor to a high number will tend to relax any constraints on that line.
+Among the traits shown for a circuit in EMO is the SFT protection factor, SFT protection factor curvature and SFT threshold (shown here under the columns "'''SFT PF'''", "'''SFT PFQ'''", "'''SFT Threshold'''" respectively).  The SFT protection factor and curvature will determine the nature of the SFT constraints generated by EMO.  The SFT protection factor is derived from the estimated slope of the thermal constraint curve at the point it passes through the point of maximum thermal capacity.  If the slope at that point is such that 0.05 MW extra capacity is available for every 1 MW the flow is below the maximum thermal capacity then the SFT protection factor will be 1.05. Setting the SFT protection factor to a high number will tend to relax any constraints on that line.  The SFT protection factor curvature is the rate at which this slope changes as the the powerflow is reduced (per 100MW).  When making a dispatch with Auto-SFT on EMO will search for lines that may be overloaded by an outage in another line.  The effect of an outage at the contingent line (C) on the power flow on the protected line (M) can be estimated as a proportion of the flow on C being transferred to M.
 {|