Add serial_inductor

Author: YingboMa

Diff for: test/models/electrical_components.jl renamed to examples/electrical_components.jl

@@ -8,13 +8,13 @@ function Pin(;name)
     ODESystem(Equation[], t, [v, i], [], name=name, defaults=[v=>1.0, i=>1.0])
 end
 
-function Ground(name)
+function Ground(;name)
     @named g = Pin()
     eqs = [g.v ~ 0]
     ODESystem(eqs, t, [], [], systems=[g], name=name)
 end
 
-function ConstantVoltage(name; V = 1.0)
+function ConstantVoltage(;name, V = 1.0)
     val = V
     @named p = Pin()
     @named n = Pin()
@@ -26,7 +26,7 @@ function ConstantVoltage(name; V = 1.0)
     ODESystem(eqs, t, [], [V], systems=[p, n], defaults=Dict(V => val), name=name)
 end
 
-function Resistor(name; R = 1.0)
+function Resistor(;name, R = 1.0)
     val = R
     @named p = Pin()
     @named n = Pin()
@@ -40,7 +40,7 @@ function Resistor(name; R = 1.0)
     ODESystem(eqs, t, [v], [R], systems=[p, n], defaults=Dict(R => val), name=name)
 end
 
-function Capacitor(name; C = 1.0)
+function Capacitor(;name, C = 1.0)
     val = C
     @named p = Pin()
     @named n = Pin()
@@ -70,3 +70,15 @@ function Inductor(; name, L = 1.0)
           ]
     ODESystem(eqs, t, [v, i], [L], systems=[p, n], defaults=Dict(L => val), name=name)
 end
+
+function connect_pins(ps...)
+    eqs = [
+           0 ~ sum(p->p.i, ps) # KCL
+          ]
+    # KVL
+    for i in 1:length(ps)-1
+        push!(eqs, ps[i].v ~ ps[i+1].v)
+    end
+
+    return eqs
+end

Diff for: examples/rc_model.jl

@@ -0,0 +1,17 @@
+include("electrical_components.jl")
+
+R = 1.0
+C = 1.0
+V = 1.0
+@named resistor = Resistor(R=R)
+@named capacitor = Capacitor(C=C)
+@named source = ConstantVoltage(V=V)
+@named ground = Ground()
+
+rc_eqs = [
+          connect_pins(source.p, resistor.p)
+          connect_pins(resistor.n, capacitor.p)
+          connect_pins(capacitor.n, source.n, ground.g)
+         ]
+
+@named rc_model = ODESystem(rc_eqs, t, systems=[resistor, capacitor, source, ground])

Diff for: examples/serial_inductor.jl

@@ -0,0 +1,16 @@
+include("electrical_components.jl")
+
+@named source = ConstantVoltage(V=10.0)
+@named resistor = Resistor(R=1.0)
+@named inductor1 = Inductor(L=8.0e-9)
+@named inductor2 = Inductor(L=2.0e-9)
+@named ground = Ground()
+
+eqs = [
+       connect_pins(source.p, resistor.p)
+       connect_pins(resistor.n, inductor1.p)
+       connect_pins(inductor1.n, inductor2.p)
+       connect_pins(source.n, inductor2.n, ground.g)
+      ]
+
+@named ll_model = ODESystem(eqs, t, systems=[source, resistor, inductor1, inductor2, ground])

Diff for: test/components.jl

@@ -1,7 +1,7 @@
 using Test
 using ModelingToolkit, OrdinaryDiffEq
 
-include("models/rc_model.jl")
+include("../examples/rc_model.jl")
 
 sys = structural_simplify(rc_model)
 @test !isempty(ModelingToolkit.defaults(sys))
@@ -31,3 +31,13 @@ sol = solve(prob, Tsit5())
 @test sol[resistor.v] == sol[source.p.v] - sol[capacitor.p.v]
 #using Plots
 #plot(sol)
+
+include("../examples/serial_inductor.jl")
+sys = structural_simplify(ll_model)
+u0 = [
+      inductor1.i => 0.0
+      inductor2.i => 0.0
+      inductor2.v => 0.0
+     ]
+prob = ODEProblem(sys, u0, (0, 10.0))
+sol = solve(prob, Rodas4())

Diff for: test/models/rc_model.jl

@@ -1,6 +1,6 @@
 using ModelingToolkit, AbstractTrees, Test
 
-include("models/rc_model.jl")
+include("../examples/rc_model.jl")
 
 io = IOBuffer()
 print_tree(io, rc_model)