System Constraints part 6

<div dir="ltr" style="text-align: left;" trbidi="on"><span style="color: red; font-size: large;">Inequality Constraints</span><br /> <span style="font-size: large;">Network security constraints<br style="color: blue;" /><span style="color: blue;">Violation of constrains can take place subsequent to</span><br style="color: blue;" /><span style="color: blue;">abnormal conditions like a line outage, either</span><br style="color: blue;" /><span style="color: blue;">scheduled or forced, which affects the security of the</span><br style="color: blue;" /><span style="color: blue;">network</span><br style="color: blue;" /><span style="color: blue;">Sometimes a so called (x-1 study) is performed to</span><br style="color: blue;" /><span style="color: blue;">examine the reliability and security of the system</span><br style="color: blue;" /><span style="color: blue;">The x-1 study means that the network is studied with</span><br style="color: blue;" /><span style="color: blue;">outage of one branch at a time</span></span><br /> <br /> <span style="font-size: large;">Inequality Constraints<br /> <span style="color: red;">Transformer tap settings</span><br /> <span style="color: blue;">Sometimes, there is a possibility to change the</span><br style="color: blue;" /><span style="color: blue;">voltage in steps, i.e. to chose between different</span><br style="color: blue;" /><span style="color: blue;">values rather than varying the voltage smoothly</span><br style="color: blue;" /><span style="color: blue;">0 ≤ t ≤ tmax</span><br style="color: blue;" /><span style="color: blue;">For auto-transformers, tmax can be unity</span></span><br /> <br /> <div style="color: red;"><span style="font-size: large;"> Transformer tap settings</span></div><div style="color: blue;"><span style="font-size: large;"><br /> Phase shift-ing transformers have phase shift limits<br /> θmin ≤ θ ≤ θmax</span></div><br /> </div>

System Constraints part 6

Inequality Constraints Network security constraintsViolation of constrains can take place subsequent toabnormal conditions like a line outage, eitherscheduled or forced, which affects the security of …

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System Constraints part 5

<div dir="ltr" style="text-align: left;" trbidi="on"><div style="text-align: center;"><span style="font-size: large;"><a href="http://hayatei.blogspot.com/2010/12/system-constraints-part-4.html">System Constraints part 4</a></span></div><div style="text-align: center;"><br /> </div><div style="color: blue; text-align: center;"><br /> </div><div style="color: blue; text-align: center;"><span style="font-size: large;">Inequality Constraints</span></div><div style="color: blue; text-align: center;"><span style="font-size: large;"><br /> <span style="color: red;">Network security constraints</span></span></div><div style="color: blue; text-align: center;"><span style="font-size: large;"><br /> Violation of constrains can take place subsequent to<br /> abnormal conditions like a line outage, either<br /> scheduled or forced, which affects the security of the<br /> network<br /> Sometimes a so called (x-1 study) is performed to<br /> examine the reliability and security of the system<br /> The x-1 study means that the network is studied with<br /> outage of one branch at a time</span></div><div style="text-align: center;"><br /> </div></div>

System Constraints part 5

System Constraints part 4 Inequality Constraints Network security constraints Violation of constrains can take place subsequent to abnormal conditions like a line outage, either scheduled or forced, w…

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Buoyancy and Swimming

<div dir="ltr" style="text-align: left;" trbidi="on"><!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} p\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} v\:textbox {display:none;} </style> <![endif]--><!--[if !ppt]--><!--[endif]--> <br /> <div class="O"><div style="text-align: center;"> </div><div style="text-align: center;"><span style="font-family: "Times New Roman"; font-size: 111%;"><span style="left: -3.42%; position: absolute;">•</span></span><span lang="EN-US" style="color: red; font-family: "Times New Roman"; font-size: 20pt;">Buoyancy is why most people float.<span>  </span>Your body displaces water.<span>  </span>When the weight of the water you displace is more than your weight you float. </span></div><div style="color: red;"> </div><div style="color: red; text-align: center;"><span style="font-family: "Times New Roman"; font-size: 111%;"><span style="left: -4.1%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 20pt;">Because of buoyancy you weigh very little in water. </span></div><div style="color: red; text-align: center;"> </div><div style="color: red; text-align: center;"><span style="font-family: "Times New Roman"; font-size: 111%;"><span style="left: -3.55%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 20pt;">You can put most of your energy into movement because you need very little to </span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 20pt;">carry yourself</span></div><!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} p\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} v\:textbox {display:none;} </style> <![endif]--><!--[if !ppt]--><!--[endif]--> <div class="O" style="color: blue;"><span style="font-size: large;"><span lang="EN-US" style="font-family: "Times New Roman";">Who Needs Buoyancy?</span></span></div><div class="O" style="color: blue;"><span style="font-size: large;"><span lang="EN-US" style="font-family: "Times New Roman";"> </span></span></div><div class="O" style="color: blue;"><!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} p\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} v\:textbox {display:none;} </style> <![endif]--><!--[if !ppt]--><!--[endif]--> <div class="O"> <div><span style="font-family: "Times New Roman"; font-size: 156%;"><span style="left: -4.51%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 28pt;">Everyone needs buoyancy! </span></div><div><span style="font-family: "Times New Roman"; font-size: 156%; visibility: hidden;"><span style="left: -4.51%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 28pt;"> </span></div><div><span style="font-family: "Times New Roman"; font-size: 156%;"><span style="left: -4.18%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 28pt;">If you swim, boat, scuba dive, or float; you need </span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 28pt;">buoyancy!!! </span></div><div><span style="font-family: "Times New Roman"; font-size: 156%; visibility: hidden;"><span style="left: -4.51%; position: absolute;">•</span></span><span lang="EN-US" style="font-family: "Times New Roman"; font-size: 28pt;"> </span></div></div>  <span style="font-size: large;"><span lang="EN-US" style="font-family: "Times New Roman";"><br /> </span></span></div></div></div>

Buoyancy and Swimming

v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} p\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} v\:textbox {display:none;} •Buoyancy is why most p…

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System Constraints part 4

<div dir="ltr" style="text-align: left;" trbidi="on"><a href="http://hayatei.blogspot.com/2010/12/system-constraints-part-3.html"><span style="font-size: large;">System Constraints part 3</span></a><br /> <br /> <div style="color: red;"><span style="font-size: large;">Inequality Constraints</span></div><br /> <span style="color: blue; font-size: large;"><br /> Running spare capacity constraints</span><br /> <span style="color: blue; font-size: large;"><br /> To ensure the existence of enough spinning reserve to </span><br /> <br /> <span style="color: blue; font-size: large;">overcome any emergency situation</span><br /> <span style="color: blue; font-size: large;"><br /> The generation should guarantee a minimum spare capacity </span><br /> <br /> <span style="color: blue; font-size: large;">in addition to load demand and power losses</span><br /> <span style="color: blue; font-size: large;"><br /> Pg > PLoad + Ploss</span><br /> <span style="color: blue; font-size: large;"><br /> This difference, i.e. spare capacity, is defined according to</span><br /> <br /> <span style="color: blue; font-size: large;"> economic issues and technical aspects like the ramping rates</span><br /> <br /> <span style="color: blue; font-size: large;"> of the generators</span><br /> <br /> <br /> <div style="text-align: center;"><b><span style="color: red; font-size: large;"> Transmission line constraints</span></b></div><div style="color: blue; text-align: center;"><b><span style="font-size: small;"><br /> </span></b></div><div style="color: blue;"><b><span style="font-size: small;"> There is a thermal capability of each transmission line that defines the allowed flow of </span></b></div><div style="color: blue;"><br /> </div><div style="color: blue;"><b><span style="font-size: small;">active and reactive power</span></b></div><div style="color: blue;"><b><span style="font-size: small;"><br /> The transmitted power is limited as follows</span></b></div><div style="color: blue;"><b><span style="font-size: small;"><br /> PT.L ≤ PT.L,max</span></b></div><div style="color: blue;"><b><span style="font-size: small;"><br /> Where PT.L,max is the maximum loading capacity of the transmission line System</span></b></div></div>

System Constraints part 4

System Constraints part 3 Inequality Constraints Running spare capacity constraints To ensure the existence of enough spinning reserve to  overcome any emergency situation The generation should guaran…

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System Constraints part 3

<div dir="ltr" style="text-align: left;" trbidi="on"><span style="font-size: large;"><a href="http://hayatei.blogspot.com/2010/12/system-constraints-part-2.html">System Constraints part 2</a></span><br /> <br /> <br /> <div style="text-align: center;"><span style="font-size: large;"><span style="color: red;">Inequality Constraints</span></span></div><div style="color: blue; text-align: center;"><span style="font-size: large;"><br /> </span></div><span style="font-size: large;"><span style="color: blue;">Voltage constraints</span></span><br /> <span style="font-size: large;"><span style="color: blue;"> </span><br style="color: blue;" /><span style="color: blue;">The upper limit of phase angles is defined</span><span style="color: blue;"> regarding the </span></span><br /> <br /> <span style="font-size: large;"><span style="color: blue;">transient stability of power systems</span><span style="color: blue;"> On the other hand, the </span></span><br /> <br /> <span style="font-size: large;"><span style="color: blue;">lower limit of the angles is</span><span style="color: blue;"> defined taking into account </span></span><br /> <br /> <span style="font-size: large;"><span style="color: blue;">achieving an efficient</span><span style="color: blue;"> utilization of transmission facility</span><span style="color: blue;"> </span></span><br /> <span style="font-size: large;"><span style="color: blue;">  </span></span><br /> <span style="font-size: large;"><span style="color: blue;">Typical operating angle of transmission line lies</span></span><br /> <span style="font-size: large;"><span style="color: blue;"> </span><br style="color: blue;" /><span style="color: blue;">between 30° - 45°</span></span><br /> <br /> <div style="color: blue;"><span style="font-size: large;"><br /> </span></div><div style="color: blue;"><span style="font-size: large;"><br /> Voltage constraints</span></div><div style="color: blue;"><span style="font-size: large;"><br /> Vmin ≤ Vn ≤ Vmax</span></div><div style="color: blue;"><span style="font-size: large;"><br /> δ min ≤ δ n ≤ δ max</span></div><div style="color: blue;"><span style="font-size: large;"><br /> Where: is the magnitude of node angle with an angle of dn at</span></div><div style="color: blue;"><br /> </div><div style="color: blue;"><span style="font-size: large;"> node n</span></div><br /> </div>

System Constraints part 3

System Constraints part 2 Inequality Constraints Voltage constraints  The upper limit of phase angles is defined regarding the  transient stability of power systems On the other hand, the  lower limit…

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