|
| 1 | +using ModelingToolkit, OrdinaryDiffEq |
| 2 | + |
| 3 | +t = only(@variables(t)) |
| 4 | +D = Differential(t) |
| 5 | +""" |
| 6 | +A simple linear resistor model |
| 7 | +
|
| 8 | + |
| 9 | +""" |
| 10 | +@component function Resistor(; name, R=1.0) |
| 11 | + systems = @named begin |
| 12 | + p = Pin() |
| 13 | + n = Pin() |
| 14 | + end |
| 15 | + vars = @variables begin |
| 16 | + v(t), [guess=0.0] |
| 17 | + i(t), [guess=0.0] |
| 18 | + end |
| 19 | + params = @parameters begin |
| 20 | + R = R, [description = "Resistance of this Resistor"] |
| 21 | + end |
| 22 | + eqs = [ |
| 23 | + v ~ p.v - n.v |
| 24 | + i ~ p.i |
| 25 | + p.i + n.i ~ 0 |
| 26 | + # Ohm's Law |
| 27 | + v ~ i * R |
| 28 | + ] |
| 29 | + return ODESystem(eqs, t, vars, params; systems, name) |
| 30 | +end |
| 31 | +@connector Pin begin |
| 32 | + v(t) |
| 33 | + i(t), [connect = Flow] |
| 34 | +end |
| 35 | +@component function ConstantVoltage(; name, V=1.0) |
| 36 | + systems = @named begin |
| 37 | + p = Pin() |
| 38 | + n = Pin() |
| 39 | + end |
| 40 | + vars = @variables begin |
| 41 | + v(t), [guess=0.0] |
| 42 | + i(t), [guess=0.0] |
| 43 | + end |
| 44 | + params = @parameters begin |
| 45 | + V = 10 |
| 46 | + end |
| 47 | + eqs = [ |
| 48 | + v ~ p.v - n.v |
| 49 | + i ~ p.i |
| 50 | + p.i + n.i ~ 0 |
| 51 | + v ~ V |
| 52 | + ] |
| 53 | + return ODESystem(eqs, t, vars, params; systems, name) |
| 54 | +end |
| 55 | + |
| 56 | +@component function Capacitor(; name, C=1.0) |
| 57 | + systems = @named begin |
| 58 | + p = Pin() |
| 59 | + n = Pin() |
| 60 | + end |
| 61 | + vars = @variables begin |
| 62 | + v(t), [guess=0.0] |
| 63 | + i(t), [guess=0.0] |
| 64 | + end |
| 65 | + params = @parameters begin |
| 66 | + C = C |
| 67 | + end |
| 68 | + initialization_eqs = [ |
| 69 | + v ~ 0 |
| 70 | + ] |
| 71 | + eqs = [ |
| 72 | + v ~ p.v - n.v |
| 73 | + i ~ p.i |
| 74 | + p.i + n.i ~ 0 |
| 75 | + C * D(v) ~ i |
| 76 | + ] |
| 77 | + return ODESystem(eqs, t, vars, params; systems, name, initialization_eqs) |
| 78 | + end |
| 79 | + |
| 80 | + @component function Ground(; name) |
| 81 | + systems = @named begin |
| 82 | + g = Pin() |
| 83 | + end |
| 84 | + eqs = [ |
| 85 | + g.v ~ 0 |
| 86 | + ] |
| 87 | + return ODESystem(eqs, t, [], []; systems, name) |
| 88 | + end |
| 89 | + |
| 90 | + @component function Inductor(; name, L=1.0) |
| 91 | + systems = @named begin |
| 92 | + p = Pin() |
| 93 | + n = Pin() |
| 94 | + end |
| 95 | + vars = @variables begin |
| 96 | + v(t), [guess = 0.0] |
| 97 | + i(t), [guess = 0.0] |
| 98 | + end |
| 99 | + params = @parameters begin |
| 100 | + (L = L) |
| 101 | + end |
| 102 | + eqs = [ |
| 103 | + v ~ p.v - n.v |
| 104 | + i ~ p.i |
| 105 | + p.i + n.i ~ 0 |
| 106 | + L * D(i) ~ v |
| 107 | + ] |
| 108 | + return ODESystem(eqs, t, vars, params; systems, name) |
| 109 | + end |
| 110 | + |
| 111 | +""" |
| 112 | +This is an RLC model. This should support markdown. That includes |
| 113 | +HTML as well. |
| 114 | +""" |
| 115 | +@component function RLCModel(; name) |
| 116 | + systems = @named begin |
| 117 | + resistor = Resistor(R=100) |
| 118 | + capacitor = Capacitor(C=0.001) |
| 119 | + inductor = Inductor(L=1) |
| 120 | + source = ConstantVoltage(V=30) |
| 121 | + ground = Ground() |
| 122 | + end |
| 123 | + initialization_eqs = [ |
| 124 | + inductor.i ~ 0 |
| 125 | + ] |
| 126 | + eqs = [ |
| 127 | + connect(source.p, inductor.n) |
| 128 | + connect(inductor.p, resistor.p, capacitor.p) |
| 129 | + connect(resistor.n, ground.g, capacitor.n, source.n) |
| 130 | + ] |
| 131 | + return ODESystem(eqs, t, [], []; systems, name, initialization_eqs) |
| 132 | +end |
| 133 | +"""Run model RLCModel from 0 to 10""" |
| 134 | +function simple() |
| 135 | + @mtkbuild model = RLCModel() |
| 136 | + u0 = [] |
| 137 | + prob = ODEProblem(model, u0, (0.0, 10.0)) |
| 138 | + sol = solve(prob) |
| 139 | +end |
| 140 | +@test SciMLBase.successful_retcode(simple()) |
| 141 | + |
| 142 | +@named model = RLCModel() |
| 143 | +@test length(ModelingToolkit.get_initialization_eqs(model)) == 1 |
| 144 | +syslist = ModelingToolkit.get_systems(model) |
| 145 | +@test length(ModelingToolkit.get_initialization_eqs(syslist[1])) == 0 |
| 146 | +@test length(ModelingToolkit.get_initialization_eqs(syslist[2])) == 1 |
| 147 | +@test length(ModelingToolkit.get_initialization_eqs(syslist[3])) == 0 |
| 148 | +@test length(ModelingToolkit.get_initialization_eqs(syslist[4])) == 0 |
| 149 | +@test length(ModelingToolkit.get_initialization_eqs(syslist[5])) == 0 |
| 150 | +@test length(ModelingToolkit.initialization_equations(model)) == 2 |
| 151 | + |
| 152 | +u0 = [] |
| 153 | +prob = ODEProblem(structural_simplify(model), u0, (0.0, 10.0)) |
| 154 | +sol = solve(prob, Rodas5P()) |
| 155 | +@test length(sol[end]) == 2 |
| 156 | +@test length(equations(prob.f.initializeprob.f.sys)) == 0 |
| 157 | +@test length(unknowns(prob.f.initializeprob.f.sys)) == 0 |
0 commit comments