Smart grid models in Acumen

Anita has started collecting and documenting models of several smart grid components. The main goal is to be able to simulate smart micro-grids by connecting several of these component models. This collection of models can also be used to compare Acumen to other tools such as Simulink and Modelica.

Some interesting components for smart grids are illustrated below. The figure shows an electric motor connected to a voltage source which is, in turn, regulated by a PI controller in a current feedback loop. The desired current output is the square signal h(t). The corresponding Acumen code can be found below. This example illustrates how different electromechanical components, sensors and controllers may be modeled individually and connected to form a micro grid.



class RLcircuit(R, L)
  private i = 0; i' = 0; v = 0; e = 0; end
  i' [=] (v - e - R*i) / L;
end

class ElectricMotor(Jeq, kE, kT, TL)
  private i = 0; wm = 0; wm' = 0; e = 0; end
  wm' [=] (kT*i - TL) / Jeq;
  e     [=] wm*kE;
end

class PIcontroller(kP, kI, kPWM)
  private h = 0; int_h = 0; int_h' = 0; i = 0; int_i = 0; int_i' = 0; v = 0; end
  int_i'  [=] i;
  int_h' [=] h;
  v       [=] kPWM*(kP*(h - i) + kI*(int_h - int_i));
end

class Main(simulator)
  private
    motor      = create ElectricMotor(0.0002, 0.1, 0.1, 0);
    circuit     = create RLcircuit(4, 2);
    controller = create PIcontroller(50, 100, 6);
    mode = 1; t = 0; t' = 1;
  end
 
  t' [=] 1;
  controller.i [=] circuit.i;
  circuit.v     [=] controller.v;
  circuit.e    [=] motor.e;
  motor.i      [=] circuit.i;

  simulator.timeStep [=] 0.001;
  simulator.endTime  [=] 1;

  switch mode
    case 1
    controller.h [=] 0;
    if t >= 0.1 mode = 2; end

    case 2
    controller.h [=] 10;
    if t >= 0.2 mode = 3; end

    case 3
    controller.h [=] 0;
  end

end











--
Anita Pinheiro Sant'Anna