within ;model control_unit

// Control unit: all PID used in the control strategy + first value used to start the cycle simulations

// Control unit inputs for evaporative temperature control Modelica.Blocks.Interfaces.RealInput Mdot "Set point signal Evap. Temp." annotation (Placement(transformation(extent={{-98,14}, {-74,38}}, rotation=0), iconTransformation(extent={{-100,6},{-86,20}}))); Modelica.Blocks.Interfaces.RealInput T_hf_su "Present Value of Evap. Temp." annotation (Placement(transformation(extent={{-98,40}, {-74,64}}, rotation=0), iconTransformation(extent={{-100,30},{-86,44}}))); Modelica.Blocks.Interfaces.RealInput p_su_exp "Elec. Frequency initial values" annotation (Placement(transformation(extent={{-98,-22}, {-74,2}}, rotation=0), iconTransformation(extent={{-100,-42},{-86,-28}}))); Modelica.Blocks.Interfaces.RealOutput CS_freq "Control Signal of the electrical frequency" annotation (Placement( transformation(extent={{92,54},{130,92}}), iconTransformation(extent={{84,26}, {104,46}})));

components.PID PID_expander( PVmax=70, PVmin=-70, CSmin=16.7, CSmax=83.3, PVstart=0, CSstart=0.5, steadyStateInit=true, Ti=3, Kp=-5) annotation (Placement(transformation(extent={{20,62},{46,82}})));

// Frequency controlling PID parameters parameter Real Kp_freq=2 "Elec. freq.PID Proportional gain (normalised units)"; parameter Modelica.SIunits.Time Ti_freq "Elec. freq.PID Integral time"; parameter Modelica.SIunits.Time Td_freq=0 "Elec. freq.PID Derivative time"; parameter Real Nd_freq = 1 "Elec. freq.PID Derivative action up to Nd / Td rad/s"; parameter Real Ni_freq = 1 "Elec. freq.PID Ni*Ti is the time constant of anti-windup compensation"; parameter Real b_freq = 1 "Elec. freq.PID Setpoint weight on proportional action"; parameter Real c_freq = 0 "Elec. freq.PID Setpoint weight on derivative action"; parameter Real PVmin_freq "Elec. freq.PID Minimum value of process variable for scaling"; parameter Real PVmax_freq

"Elec. freq.PID Maximum value of process variable for scaling"; parameter Real CSmin_freq "Elec. freq.PID Minimum value of control signal for scaling"; parameter Real CSmax_freq "Elec. freq.PID Maximum value of control signal for scaling"; parameter Real PVstart_freq = 0.5 "Elec. freq.PID Start value of PV (scaled)"; parameter Real CSstart_freq = 0.5 "Elec. freq.PID Start value of CS (scaled)";

components.PID PID_pump( PVmin=0, PVmax=70, CSmin=0.01, PVstart=5, CSstart=0.55, steadyStateInit=true, Kp=-0.7, Ti=6, CSmax=1) annotation (Placement(transformation(extent={{20,0},{46,22}}))); Modelica.Blocks.Interfaces.RealInput T_su_exp "Set point signal Overheating" annotation (Placement(transformation(extent={{-98,-52}, {-74,-28}}, rotation=0), iconTransformation(extent={{-100,-18},{-86,-4}}))); Modelica.Blocks.Interfaces.RealInput p_cd "Present Value of Overheating" annotation (Placement(transformation(extent={{-98,68}, {-74,92}}, rotation=0), iconTransformation(extent={{-100,54},{-86,68}}))); Modelica.Blocks.Interfaces.RealOutput CS_Xpp "Control signal of the pump capacity ratio" annotation (Placement( transformation(extent={{92,-10},{130,28}}), iconTransformation(extent={{84,-30}, {104,-10}})));

// Pump capacity ratio contrlling PID parameters parameter Real Kp_Xpp "Xpp PID Proportional gain (normalised units)"; parameter Modelica.SIunits.Time Ti_Xpp "Xpp PID Integral time"; parameter Modelica.SIunits.Time Td_Xpp=0 "Xpp PID Derivative time"; parameter Real Nd_Xpp = 1 "Xpp PID Derivative action up to Nd / Td rad/s"; parameter Real Ni_Xpp = 1 "Xpp PID Ni*Ti is the time constant of anti-windup compensation"; parameter Real b_Xpp = 1 "Xpp PID Setpoint weight on proportional action"; parameter Real c_Xpp = 0 "Xpp PID Setpoint weight on derivative action"; parameter Real PVmin_Xpp "Xpp PID Minimum value of process variable for scaling"; parameter Real PVmax_Xpp "Xpp PID Maximum value of process variable for scaling"; parameter Real CSmin_Xpp "Xpp PID Minimum value of control signal for scaling"; parameter Real CSmax_Xpp "Xpp PID Maximum value of control signal for scaling"; parameter Real PVstart_Xpp = 0.5 "Xpp PID Start value of PV (scaled)"; parameter Real CSstart_Xpp = 0.5 "Xpp PID Start value of CS (scaled)";

Modelica.Blocks.Sources.Constant DELTAT_SP(k=10) annotation (Placement(transformation(extent={{-52,10},{-40,22}})));

Modelica.Blocks.Sources.Constant const_pump(k=0.5539) annotation (Placement(transformation(extent={{34,-26},{46,-14}}))); Modelica.Blocks.Sources.Constant const_exp(k=50) annotation (Placement(transformation(extent={{34,34},{46,46}}))); components.DELTAT dELTAT annotation (Placement(transformation(extent={{-60,-34},{-40,-14}}))); components.Tev_SP tev_SP annotation (Placement(transformation(extent={{-60,54},{-40,74}}))); components.Init init(length=10, t_init=20) annotation (Placement(transformation(extent={{-20,-8},{0,12}}))); components.Init init1(length=8, t_init=10) annotation (Placement(transformation(extent={{-20,54},{0,74}}))); components.Init init2(t_init=4, length=3) annotation (Placement(transformation(extent={{70,2},{84,16}}))); components.Init init3(t_init=6, length=3) annotation (Placement(transformation(extent={{70,66},{84,80}})));equation connect(DELTAT_SP.y, PID_pump.SP) annotation (Line( points={{-39.4,16},{4.3,16},{4.3,15.4},{20,15.4}}, color={0,0,127}, smooth=Smooth.None)); connect(p_su_exp, dELTAT.P) annotation (Line( points={{-86,-10},{-68,-10},{-68,-17.4},{-59.8,-17.4}}, color={0,0,127}, smooth=Smooth.None)); connect(T_su_exp, dELTAT.T) annotation (Line( points={{-86,-40},{-68,-40},{-68,-28.2},{-60,-28.2}}, color={0,0,255}, smooth=Smooth.None)); connect(p_cd, tev_SP.p_cd) annotation (Line( points={{-86,80},{-74,80},{-74,70.6},{-60,70.6}}, color={0,0,127}, smooth=Smooth.None)); connect(T_hf_su, tev_SP.T_hf_su) annotation (Line( points={{-86,52},{-74,52},{-74,65.2},{-60,65.2}}, color={0,0,127}, smooth=Smooth.None)); connect(Mdot, tev_SP.Mdot) annotation (Line( points={{-86,26},{-68,26},{-68,59.8},{-60,59.8}}, color={0,0,127}, smooth=Smooth.None)); connect(init1.y, PID_expander.PV) annotation (Line( points={{0.8,64.2},{14.4,64.2},{14.4,68},{20,68}}, color={0,0,127}, smooth=Smooth.None)); connect(init3.y, CS_freq) annotation (Line( points={{84.56,73.14},{94.4,73.14},{94.4,73},{111,73}}, color={0,0,127}, smooth=Smooth.None)); connect(init2.y, CS_Xpp) annotation (Line( points={{84.56,9.14},{95.4,9.14},{95.4,9},{111,9}}, color={0,0,127}, smooth=Smooth.None)); connect(init.y, PID_pump.PV) annotation (Line( points={{0.8,2.2},{13.4,2.2},{13.4,6.6},{20,6.6}}, color={0,0,127}, smooth=Smooth.None)); connect(dELTAT.DELTAT, init.u2) annotation (Line( points={{-39.6,-21},{-28,-21},{-28,6},{-22,6}}, color={0,0,127},

smooth=Smooth.None)); connect(dELTAT.Tsat, init1.u2) annotation (Line( points={{-39.6,-25},{-32,-25},{-32,68},{-22,68}}, color={0,0,127}, smooth=Smooth.None)); connect(const_pump.y, init2.u1) annotation (Line( points={{46.6,-20},{62,-20},{62,6.34},{68.6,6.34}}, color={0,0,127}, smooth=Smooth.None)); connect(const_exp.y, init3.u1) annotation (Line( points={{46.6,40},{60,40},{60,70.34},{68.6,70.34}}, color={0,0,127}, smooth=Smooth.None)); connect(tev_SP.Tev, init1.u1) annotation (Line( points={{-39.4,65.2},{-36,65.2},{-36,60.2},{-22,60.2}}, color={0,0,127}, smooth=Smooth.None)); connect(DELTAT_SP.y, init.u1) annotation (Line( points={{-39.4,16},{-36,16},{-36,-1.8},{-22,-1.8}}, color={0,0,127}, smooth=Smooth.None)); connect(tev_SP.Tev, PID_expander.SP) annotation (Line( points={{-39.4,65.2},{-36,65.2},{-36,76},{20,76}}, color={0,0,127}, smooth=Smooth.None)); connect(PID_expander.CS, init3.u2) annotation (Line( points={{46.78,72},{58,72},{58,75.8},{68.6,75.8}}, color={0,0,127}, smooth=Smooth.None)); connect(PID_pump.CS, init2.u2) annotation (Line( points={{46.78,11},{58.39,11},{58.39,11.8},{68.6,11.8}}, color={0,0,127}, smooth=Smooth.None)); annotation ( uses(Modelica(version="3.2")), Diagram(coordinateSystem(preserveAspectRatio=true, extent={{-100,-100},{100, 100}}), graphics), Icon(coordinateSystem(preserveAspectRatio=true, extent={{-100,-100},{100, 100}}), graphics={Rectangle( extent={{-96,74},{88,-54}}, lineColor={0,0,0}, fillColor={215,215,215}, fillPattern=FillPattern.Solid), Text( extent={{-68,50},{56,12}}, lineColor={255,0,0}, lineThickness=0.5, fillColor={255,0,0}, fillPattern=FillPattern.Solid, textString="Control"), Text( extent={{-70,22},{60,-16}}, lineColor={255,0,0}, lineThickness=0.5, fillColor={255,0,0}, fillPattern=FillPattern.Solid, textString="Unit")}));end control_unit;