Welcome Guest ( Log In | Register ) is such a construct allowed? Options daniel@ka Jun 18 2010, 01:00 PM Post #1 Member  Group: Members Posts: 23 Joined: 3-June 08 Member No.: 11,399 CODE     model R        pin p,n;        parameter resistance R0;    equation        p.v - n.v = p.i * R0;        p.i + n.i = 0;    end R;        model ground        pin n;    equation        n.v = 0;    end ground;        model V        pin p,n;        parameter voltage V0;    equation        p.v - n.v = V0;        p.i + n.i = 0;    end V;        model circuit_working        V V1(V0 = 1);        R R1(R0 = 1);        ground gnd;    equation        connect(V1.p, R1.p);        connect(V1.n, R1.n);        connect(V1.n, gnd.n);              end circuit_working;    model circuit_not_working        V V1(V0 = 1);        R R1(R0 = 1);        pin n;    equation        n.v = 0;                connect(V1.n, n);        connect(V1.p, R1.p);        connect(V1.n, R1.n);    end circuit_not_working;this is very similar to my previous problemI think it is obvious what the code should doIn my opinion both variants are equivalent in terms of mathematical description(I am using the openmodelica 3.0)I would like to ask somebody to try this example in dymola (as I do not have access to it)and to report the results.Regards, Daniel   daniel@ka Jun 17 2010, 10:45 PM Post #2 Member  Group: Members Posts: 23 Joined: 3-June 08 Member No.: 11,399 Hello @all,CODE    type voltage = Real(final unit = "V");    type current = Real(final unit = "A");    type resistance = Real(final unit = "V/A", final min = 0);    connector pin        voltage v;        flow current i;    end pin;        model R        pin p,n;        parameter resistance R0;    equation        p.v - n.v = p.i * R0;        p.i + n.i = 0;    end R;    model circuit        R R1(R0(max = 1e9) = 1);        pin p, n;    equation        p.v - n.v = 10 "Volt";        connect(p, R1.p);        connect(n, R1.n);        n.v = 0;        p.i + n.i = 0;    end circuit;what I am trying is to implement a voltage source within the circuitthis may not be wise but I want to understand what happens if onegoes this path.CODE>> instantiateModel(elec.circuit)"fclass elec.circuitReal R1.p.v(unit = "V");Real R1.p.i(unit = "A");Real R1.n.v(unit = "V");Real R1.n.i(unit = "A");parameter Real R1.R0(unit = "V/A", min = 0.0, max = 1000000000.0) = 1.0;Real p.v(unit = "V");Real p.i(unit = "A");Real n.v(unit = "V");Real n.i(unit = "A");equation  R1.p.v - R1.n.v = R1.p.i * R1.R0;  R1.p.i + R1.n.i = 0.0;  p.v - n.v = 10.0;  n.v = 0.0;  p.i + n.i = 0.0;  (-n.i) + R1.n.i = 0.0;n.v = R1.n.v;  (-p.i) + R1.p.i = 0.0;p.v = R1.p.v;  p.i = 0.0;  n.i = 0.0;end elec.circuit;"we have 2 pins within R and 2 pins within the circuit, which makes 8 variables in totalall but the last two equations (n.i=0; p.i=0) can also be found in the previous codeI guess that all flow-prefixed variables will implicitly(?) create such 0-equationsbut should not this be the case when the pins (p and n) were left unconnected?It would be nice if someone could provide some advice.Regards, Daniel   1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
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