Merge pull request #28168 from ffarha/next

Adding maximum rate of change of control value in PIDTransientControl

framework/include/controls/PIDTransientControl.h

@@ -51,6 +51,8 @@ class PIDTransientControl : public Control
   const Real _maximum_output_value;
   /// Limiting minimum value for the output of the PID controller
   const Real _minimum_output_value;
+  /// Limiting maximum value for the rate of change of output of the PID controller
+  const Real _maximum_change_rate;
   /// Integral of the error
   Real _integral;
   /// Saved value of the integral at the beginning of a timestep, to recover from a failed solve

framework/src/controls/PIDTransientControl.C

@@ -54,7 +54,12 @@ PIDTransientControl::validParams()
   params.addParam<Real>("minimum_output_value",
                         -std::numeric_limits<Real>::max(),
                         "Can be used to limit the minimum value output by the PID controller.");
-
+  params.addRangeCheckedParam<Real>(
+      "maximum_change_rate",
+      std::numeric_limits<Real>::max(),
+      "maximum_change_rate>0",
+      "Can be used to limit the absolute rate of change per second of value "
+      "output by the PID controller.");
   return params;
 }
 
@@ -71,6 +76,7 @@ PIDTransientControl::PIDTransientControl(const InputParameters & parameters)
     _reset_integral_windup(getParam<bool>("reset_integral_windup")),
     _maximum_output_value(getParam<Real>("maximum_output_value")),
     _minimum_output_value(getParam<Real>("minimum_output_value")),
+    _maximum_change_rate(getParam<Real>("maximum_change_rate")),
     _integral(0),
     _integral_old(0),
     _value_old(0),
@@ -147,7 +153,14 @@ PIDTransientControl::execute()
     if (_dt > 0)
       value += _Kder * delta / _dt;
 
-    value = std::min(std::max(_minimum_output_value, value), _maximum_output_value);
+    // If the maxmimum rate of change by the pid is fixed
+    if (_maximum_change_rate != std::numeric_limits<Real>::max())
+    {
+      value = std::min(std::max(_value_old - _dt * _maximum_change_rate, value),
+                       _value_old + _dt * _maximum_change_rate);
+    }
+    else
+      value = std::min(std::max(_minimum_output_value, value), _maximum_output_value);
 
     // Set the new value of the postprocessor
     if (isParamValid("parameter"))

test/tests/controls/pid_control/gold/abs_max_rate_change.csv

@@ -0,0 +1,22 @@
+time,integral,left_boundary_average
+0,0,0
+1,0.74999999857139,0.5
+2,1.0000000000087,1
+3,1.2500000001768,1.5
+4,1.5000000010787,2
+5,1.7500000000994,2.5
+6,1.9999999994641,3
+7,2.2499999992713,3.5
+8,2.5000000007506,4
+9,2.2499999995544,3.5
+10,1.9999999993692,3
+11,1.7500000011553,2.5
+12,1.4999999993654,2
+13,1.2500000006843,1.5
+14,1.0125000007242,1.0249999996979
+15,1.1493749988583,1.2987499986277
+16,1.3862812505461,1.7725625007516
+17,1.5497484377364,2.0994968754729
+18,1.5984344530613,2.1968689065483
+19,1.5711259338526,2.1422518677051
+20,1.5232741330385,2.046548266139

test/tests/controls/pid_control/tests

@@ -19,6 +19,14 @@
       recover = false
       cli_args = 'Outputs/file_base=min_max_limits Controls/integral_value/maximum_output_value=4.0 Controls/integral_value/minimum_output_value=2.0 Executioner/nl_abs_tol=1e-12 Executioner/end_time=10'
       detail = 'allowing the Proportional Integral Derivative control to have limits for its maximum and minimum output,'
+    []
+    [abs_max_rate_change]
+      type = 'CSVDiff'
+      input = 'pid_control.i'
+      csvdiff = 'abs_max_rate_change.csv'
+      recover = false
+      cli_args = 'Outputs/file_base=abs_max_rate_change Controls/integral_value/maximum_change_rate=0.5 Executioner/nl_abs_tol=1e-12'
+      detail = 'allowing the Proportional Integral Derivative control to have limits for its absolute maximum rate of change of control variable,'
     []    
     [basic_postprocessor]
       type = 'CSVDiff'