I am not able to determine why the voltage of this circuit climbs to 10^6 volts then just drop to 0 . This is a modification of the voltage regulator from industry examples.
model SFDI_voltageRegulator "Buck converter and Zener regulator comparison."
extends Modelica.Icons.Example;
parameter Modelica.SIunits.Resistance r1 = 16 "Resistance for the load";
parameter Modelica.SIunits.Capacitance c1(displayUnit = "uF") = 4e-006 "Capacitance of the buck converter capacitor";
parameter Modelica.SIunits.Capacitance c2(displayUnit = "uF") = 4e-006 "Capacitance of the buck converter capacitor 2";
parameter Modelica.SIunits.Inductance l1(displayUnit = "mH") = 0.02 "Inductance of the buck converter inductor";
parameter Modelica.SIunits.Time T(displayUnit = "ms") = 5e-005 "Time for one period";
parameter Real D = 12 / 24 "Duty-ratio";
parameter Modelica.SIunits.Voltage vin = 24 "Input voltage into the buck converter";
Modelica.Electrical.Analog.Sources.ConstantVoltage voltage_BuckConverter(V = vin) annotation(Placement(visible = true, transformation(origin = {-116.682, 5}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
Modelica.Electrical.Analog.Basic.Resistor load_BuckConverter(R = r1) annotation(Placement(visible = true, transformation(origin = {126.766, -5}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
Modelica.Electrical.Analog.Basic.Capacitor capacitor_BuckConverter(C = c1) annotation(Placement(visible = true, transformation(origin = {3.376, 5}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
Modelica.Electrical.Analog.Basic.Inductor inductor_BuckConverter(L = l1) annotation(Placement(visible = true, transformation(origin = {-16.624, 25}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Basic.Ground ground_BuckConverter annotation(Placement(visible = true, transformation(origin = {-82.533, -52.959}, extent = {{-10, -10}, {10, 10}}, rotation = -720)));
Modelica.Blocks.Sources.BooleanPulse booleanPulse(period = T, width = D * 100) annotation(Placement(visible = true, transformation(origin = {-107.893, 75}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Ideal.IdealDiode idealDiode_BuckConverter(Vknee = 0.04, T = 308.15) annotation(Placement(visible = true, transformation(origin = {-36.624, 5}, extent = {{-10, -10}, {10, 10}}, rotation = -270)));
Modelica.Electrical.Analog.Ideal.IdealClosingSwitch idealClosingSwitch annotation(Placement(visible = true, transformation(origin = {-76.624, 25}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Basic.Capacitor capacitor_BuckConverter1(C = c2) "Second capacitor" annotation(Placement(visible = true, transformation(origin = {60, 0}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
Modelica.Electrical.Analog.Semiconductors.Diode diode annotation(Placement(visible = true, transformation(origin = {93.172, -16.641}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
Modelica.Electrical.Analog.Basic.Resistor resistor(R = 300) "Lead light resistor" annotation(Placement(visible = true, transformation(origin = {93.422, 10}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
equation
connect(voltage_BuckConverter.n, ground_BuckConverter.p) annotation(Line(visible = true, origin = {-100, -34.49}, points = {{-16.682, 29.49}, {-17.074, -0.51}, {17.074, -0.51}, {17.467, -8.469}}, color = {0, 0, 255}));
connect(capacitor_BuckConverter.n, voltage_BuckConverter.n) annotation(Line(visible = true, origin = {-51.624, -30}, points = {{55, 25}, {55, -5}, {-65.058, -5}, {-65.058, 25}}, color = {0, 0, 255}));
connect(capacitor_BuckConverter.n, idealDiode_BuckConverter.p) annotation(Line(visible = true, origin = {-14.88, -32.25}, points = {{18.256, 27.25}, {17.5, -2.75}, {-22.5, -2.75}, {-21.744, 27.25}}, color = {0, 0, 255}));
connect(load_BuckConverter.n, voltage_BuckConverter.n) annotation(Line(visible = true, origin = {-41.695, -30}, points = {{168.461, 15}, {168.39, -5}, {-75, -5}, {-74.987, 25}}, color = {0, 0, 255}));
connect(voltage_BuckConverter.p, idealClosingSwitch.p) annotation(Line(visible = true, origin = {-106.663, 21.667}, points = {{-10.019, -6.667}, {-10.019, 3.333}, {20.039, 3.333}}, color = {0, 0, 255}));
connect(inductor_BuckConverter.n, load_BuckConverter.p) annotation(Line(visible = true, origin = {82.303, 18.333}, points = {{-88.927, 6.667}, {44.463, 6.667}, {44.463, -13.333}}, color = {0, 0, 255}));
connect(inductor_BuckConverter.p, idealDiode_BuckConverter.n) annotation(Line(visible = true, origin = {-33.291, 21.667}, points = {{6.667, 3.333}, {-3.333, 3.333}, {-3.333, -6.667}}, color = {0, 0, 255}));
connect(booleanPulse.y, idealClosingSwitch.control) annotation(Line(visible = true, origin = {-73.624, 49.333}, points = {{-23.269, 25.667}, {-3, 25.667}, {-3, -17.333}}, color = {255, 0, 255}));
connect(inductor_BuckConverter.p, idealClosingSwitch.n) annotation(Line(visible = true, origin = {-46.624, 25}, points = {{20, 0}, {-20, 0}}, color = {0, 0, 255}));
connect(inductor_BuckConverter.n, capacitor_BuckConverter.p) annotation(Line(visible = true, origin = {3.376, 21.667}, points = {{-10, 3.333}, {0, 3.333}, {0, -6.667}}, color = {0, 0, 255}));
connect(capacitor_BuckConverter1.p, inductor_BuckConverter.n) annotation(Line(visible = true, origin = {37.792, 20}, points = {{22.208, -10}, {22.208, 5}, {-44.416, 5}}, color = {0, 0, 255}));
connect(capacitor_BuckConverter1.n, ground_BuckConverter.p) annotation(Line(visible = true, origin = {-11.267, -35.74}, points = {{71.267, 25.74}, {71.267, 0.74}, {-71.267, 0.74}, {-71.266, -7.219}}, color = {0, 0, 255}));
connect(resistor.p, inductor_BuckConverter.n) annotation(Line(visible = true, origin = {60.073, 23.333}, points = {{33.349, -3.333}, {33.349, 1.667}, {-66.697, 1.667}}, color = {0, 0, 255}));
connect(resistor.n, diode.p) annotation(Line(visible = true, origin = {93.297, -3.481}, points = {{0.125, 3.481}, {0.125, -0.16}, {-0.125, -0.16}, {-0.125, -3.16}}, color = {0, 0, 255}));
connect(diode.n, ground_BuckConverter.p) annotation(Line(visible = true, origin = {5.319, -34.9}, points = {{87.852, 8.259}, {87.852, -0.1}, {-87.852, -0.1}, {-87.852, -8.059}}, color = {0, 0, 255}));
annotation(experiment(StopTime = 5, __Wolfram_SynchronizeWithRealTime = false), __Wolfram(openClass = BuckConverter, useDocumentationTemplate = false), __Wolfram(PlotSet(plots = {Plot(name = "LoadVoltageBuckConvertervsZenerRegulator ", preferred = true, subPlots = {SubPlot(curves = {Curve(x = time, y = load_BuckConverter.v), Curve(x = time, y = load_Zener.v)})}), Plot(name = "BuckConverterBehavior", subPlots = {SubPlot(curves = {Curve(x = time, y = load_BuckConverter.v), Curve(x = time, y = load_Zener.v)}, range = Range(xmin = 0.007985104552499202, xmax = 0.008516085813714526, ymin = 11.9518475877193, ymax = 12.13411793372319)), SubPlot(curves = {Curve(x = time, y = booleanPulse.y)}, range = Range(xmin = 0.007985104552499202, xmax = 0.008516085813714526, ymin = auto, ymax = auto))})})), uses(Modelica(version = "3.2.1")), Documentation(info = "<html><!--WSMINSERTIONTAGSTART BuckConverter.ExampleModel -->
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</div><div class=\"header\"> </div><h1>Buck Converter</h1><div class=\"contenttable\">
<span class=\"contenttableheader\">CONTENTS:</span><br/>
<table class=\"contenttabletable\"><tr><td><a href=\"#\" onClick=\"document.getElementById('headerTag_Introduction').scrollIntoView(); return false;\"><span class=\"hacek\">ˇ</span> Introduction</a></td><td><a href=\"#\" onClick=\"document.getElementById('headerTag_Dynamics').scrollIntoView(); return false;\"><span class=\"hacek\">ˇ</span> Dynamics</a></td></tr><tr><td><a href=\"#\" onClick=\"document.getElementById('headerTag_Simulation').scrollIntoView(); return false;\"><span class=\"hacek\">ˇ</span> Simulation</a></td><td></td></tr></table></div><a id=\"headerTag_Introduction\" class=\"target\"> </a>
<h2>Introduction</h2>
<p class=\"\">
Using a linear DC?to?DC regulator is one of the simplest ways to reduce the voltage of a DC supply. However, as linear regulators work by converting excess power to heat, they are highly inefficient and inconvenient to use in many applications. A common alternative to reduce DC voltage is instead to use a buck converter. In this example, we study the difference in efficiency between a buck converter and a simple (linear) Zener regulator when converting a supply voltage of 24 V to an output voltage of 12 V.
</p><a id=\"headerTag_Dynamics\" class=\"target\"> </a>
<h2>Dynamics</h2>
<p class=\"\">
A buck converter is a switched-mode power supply that uses a <a href=\"modelica://Modelica.Electrical.Analog.Ideal.IdealClosingSwitch\">switch</a>, a <a href=\"modelica://Modelica.Electrical.Analog.Ideal.IdealDiode\">diode</a>, an <a href=\"modelica://Modelica.Electrical.Analog.Basic.Inductor\">inductor</a>, and a <a href=\"modelica://Modelica.Electrical.Analog.Basic.Capacitor\">capacitor</a> to convert direct current voltage from a higher to a lower level. When the switch is turned off, the inductor current freewheels through the diode. When the switch is turned on, the inductor current increases and doesnt pass through the diode.
</p><a id=\"headerTag_Simulation\" class=\"target\"> </a>
<h2>Simulation</h2>
<p class=\"\">
To simulate the model, perform this step:
</p><ul><li>Click the <span class=\"dialogelement\">Simulate</span> button in the top toolbar <img src=\"./BuckConverter/DocumentationFiles/simulate.png\" alt=\"\"/>.</li></ul><h3>Plot the results</h3>
<p class=\"\">
When the simulation is done, a stored plot will automatically be displayed:
</p><p class=\"\">
<img src=\"./BuckConverter/DocumentationFiles/plot.png\" alt=\"\"/>
</p><h3>Zoom</h3>
<p class=\"\">
The switch is continuously being opened and closed by the <a href=\"modelica://Modelica.Blocks.Sources.BooleanPulse\">boolean pulse</a> supplied to it. This happens so fast that it is hard to discern from the graph.
</p><p class=\"\">
Zoom in on the graph to explore the ripple caused by the buck converter. To do this, perform the following steps
</p><ul><li>In the <span class=\"dialogelement\">Plot Window</span>, position your mouse cursor around 13 V on the Y-axis and 0.009 s.</li><li>Draw a small box around the plots (see picture) by clicking and dragging your mouse cursor. When you release the button, you will zoom in on the selected area</li><li>To return to the original view, right click anywhere in the <span class=\"dialogelement\">Plot Window</span> and select <span class=\"dialogelement\">Rescale</span>.</li></ul><p class=\"\">
<img src=\"./BuckConverter/DocumentationFiles/resize.png\" alt=\"\"/>
</p><h3>Change Parameters</h3>
<p class=\"\">
Changing parameters for the simulation can be done rapidly in Simulation Center. The <span class=\"variablename\">D</span> parameter determines the duty-ration of the buck converter. This is determined by the relative duration between the closed/on period and the open/off period. The standard value for this parameter is 0.5 which means that 50% of the time, the switch will be closed and the voltage source will be connected to the circuit. The resulting voltage over the load will be 50% of the input voltage.
</p><p class=\"\">
Try changing the duty-ration of the converter, <span class=\"variablename\">D</span> and see how this affects the controller:
</p><ul><li>Switch to the <span class=\"dialogelement\">Parameter</span> tab to the left in the Experiment Browser.</li><li>Scroll down to the <span class=\"variablename\">D</span> parameter and change its value to 0.75 by typing into the box to the right of the parameter.</li><li>Simulate again by following the steps in the Simulation section to see the effects of your changes.</li></ul><p class=\"\">
You should now see the graph below, note that the Zener regulator is not affected by the parameter change above:
</p><p class=\"\">
<img src=\"./BuckConverter/DocumentationFiles/plot2.png\" alt=\"\"/>
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end SFDI_voltageRegulator;
