Dymola：使用非线性求解器初始化区域供热网络模拟

Question

我一直在Dymola建模和模拟一些简单的区域供热网络，并且在初始化过程中经常遇到错误。

我们正在模拟的系统包括

生产者：两个压力边界 - 源和汇。通过PI控制源处的压力，其确保源压力使得消费者的最小压差大于或等于某个设定值。
消费者：他们有一个PI控制阀和一个固定返回温度的热交换器。阀控制质量流量，随后控制热流以在任何给定时间匹配消费者负载。
管道：具有热损失的动态热水力模型和考虑延迟的空间分布。矢量化端口和混合体积用于减少非线性方程。

下图是该网络的一个大大简化的版本（此处发生相同的错误）消费者模型如下所示：和生产者：

在初始化期间，发生以下错误：

        ERROR: Failed to solve non-linear system using Newton solver.
    To get more information: Turn on Simulation/Setup/Debug/Nonlinear solver diagnostics/Details
    Solution to systems of equations not found at time = 0
       Nonlinear system of equations number = 3
       Infinity-norm of residue = 118280
       Iteration is not making good progress.
       Accumulated number of residue       calc.: 389
       Accumulated number of symbolic Jacobian calc.: 5
       Last values of solution vector:
    L.PI.gainPID.y = 0
       Last values of residual vector:
    { -118280 }
Trying to solve non-linear system using global homotopy-method.
... loading "data" from "C:/Users/Sim1/Desktop/Keith Dymola Files/GrazReininghaus_UseCase/PythonScriptsforTranslation/Reininghaus.txt"
ERROR: Failed to solve non-linear system using Newton solver.
To get more information: Turn on Simulation/Setup/Debug/Nonlinear solver diagnostics/Details
Solution to systems of equations not found at time = 0
   Nonlinear system of equations number = 1
   Infinity-norm of residue = 2.22814E+018
   Iteration is not making good progress.
   Accumulated number of residue       calc.: 101
   Accumulated number of symbolic Jacobian calc.: 9
   Last values of solution vector:
M.port_a.m_flow = 0.000485868
N.valveLinear.dp = -55.8243
O.valveLinear.dp = -135.618
P.valveLinear.dp = 550.474
I.port_a.m_flow = 3.20321E-010
C.port_a.m_flow = 2.19343E-011
D.port_a.m_flow = 0.00208272
E.valveLinear.dp = 371.552
L.port_a.m_flow = -7.10982E-012
J.valveLinear.dp = 243.085
K.port_a.m_flow = 1.924E-005
   Last values of residual vector:
{ 6.60393E+013, -1.14781E+018, -1.05438E+018, -2.58754E+016, -111988,
  -1.56817E+010, 16024.9, 3.14411E+007, 3.99781E+008, 3.14412E+007,
  -15012.9 }

Error: could not solve simplified initialization for homotopy method.
Error: could not solve simplified initialization for homotopy method.
FixInitials:Init

组件A，B，C e.t.c是网络中的消费者。我正在使用Radau IIa 5阶解算器，tol = 1e-06。消费者阀门inittype中的PI控制器仅与integrtor状态集成，生产者中的PI初始化为输出值。我尝试过使用网络中质量流量和压降的各种标称值，以及PI控制器中的初始值，但始终返回相同的形式ERROR。模型通过了错误检查，但在初始化时总是失败。

我想知道是否有人有调试这种非线性系统的经验，如果有的话，关于如何初始化这些模型的一些技巧将对调试过程有很大帮助。