OpenModelica错误:可扩展连接器数组-确定过多的系统

Question

谁能告诉我为什么下面的modelica代码在OpenModelica 1.12.0上会产生错误？如果我去掉最后两个连接方程式，它会工作得很好。

class A
  Conn cc[3];
  Real a(start=0,fixed=true);
  Real b(start=0,fixed=true);
  Real c(start=0,fixed=true);
equation
  der(a) = 1;
  der(b) = 2;
  der(c) = 3;
  connect(a,cc[1].v);
  connect(b,cc[2].v); // Remove this to make it work
  connect(c,cc[3].v); // Remove this to make it work
end A;

可扩展连接器cc为空：

expandable connector Conn
end Conn;

上面的代码在OpenModelica 1.12.0上产生错误：

[1] 15:07:44 Symbolic Error
Too many equations, over-determined system. The model has 6 equation(s) and 4 variable(s).

[2] 15:07:44 Symbolic Warning
[A: 11:3-11:21]: Equation 5 (size: 1) b = cc[2].v is not big enough to solve for enough variables.
  Remaining unsolved variables are: 
  Already solved: b
  Equations used to solve those variables:
    Equation 2 (size: 1): der(b) = 2.0

[3] 15:07:44 Symbolic Warning
[A: 12:3-12:21]: Equation 6 (size: 1) c = cc[3].v is not big enough to solve for enough variables.
  Remaining unsolved variables are: 
  Already solved: c
  Equations used to solve those variables:
    Equation 3 (size: 1): der(c) = 3.0

基本上，我希望有一个可扩展的连接器数组，我可以根据需要添加不同类型的变量。

编辑2018年8月8日

关于我只能将“连接器”连接到一个可扩展的连接器，实际上我看到modelica规范3.4文档说：

All components in an expandable connector are seen as connector instances even if they are not declared as 
such [i.e. it is possible to connect to e.g. a Real variable].  

似乎我可以在OpenModelica中将实数变量连接到一个可扩展的连接器，但是在JModelica中我得到了一个错误：

Error at line 13, column 11, in file 'A.mo':
  Connecting to an instance of a non-connector type is not allowed

我也可以在OpenModeica中将实变量连接到普通的(不可扩展的)连接器，但在JModelica中同样不允许这样做。因此，工具对语言规范的解释是不同的！

Answer 1

您不能将Real variables连接到可扩展连接器，它需要是连接器。但不知何故，这也不起作用，似乎是一个bug。工作原理(在OM和Dymola中测试)如下：

class Expandable
  expandable connector Conn
    Real v[3];
  end Conn;

  connector RealOutput = output Real "'output Real' as connector";

  Conn cc;
  RealOutput a(start=0,fixed=true);
  RealOutput b(start=0,fixed=true);
  RealOutput c(start=0,fixed=true);
equation 
  der(a) = 1;
  der(b) = 2;
  der(c) = 3;
  connect(a,cc.v[1]);
  connect(b,cc.v[2]);
  connect(c,cc.v[3]);
end Expandable;