Stages of building a physical model

We will use the library blocks to build the model. Physical Modeling from the section Fundamental Components/Electrical:

You can find the block you need by searching in the library or entering its name in the search field that appears when you double-click on the canvas.

To add a block to the model, drag it with the mouse from the block library. Place them on the canvas in the correct order and connect them as they are connected in a real electrical circuit.:

Immediately after adding the blocks, they have default values. To change the settings, double-click on the block or right-click and select Options:

Ammeter Current Sensor outputs current to port I, voltmeter Voltage Sensor — the voltage in the port is V. These signals can be connected to Terminator from the library Basic/Receivers and enable recording.

For more information about building models in Engee, see Building a model.

Before the simulation, you need to choose a solver suitable for physical models. Usually, implicit solvers are used: Rosenbrock23, Rodas4, RadauIIA5, QNDF, ImplicitEuler, Trapezoid, TRBDF2, KenCarp4. They require fewer steps than explicit ones.

A physical model can include multiple networks. Each network (linked block diagram) requires one block Solver Configuration, which sets the parameters of the solver.

In this example, the parameters of the Solver Configuration block can be left by default.

After selecting the solver, all that remains is to select the simulation time and run the simulation.

Let’s see the results in the window signal visualization . The graphs show how when charging a capacitor, the current decreases exponentially, and the voltage across it increases.

There are several ways to create a physical model in Engee, and the choice depends on your task and the required implementation.

The easiest and most effective way is to use ready-made blocks from the library. physical modeling. This is a classic approach: use the necessary physical blocks (like the resistor and capacitor in the example above) and connect them into a physical model. All the necessary equations are already embedded inside these blocks and do not require debugging.

If a suitable block is not available in the physical library, then you can describe its behavior yourself by creating your own physical component using Engee physical modeling language. The language allows you to describe an arbitrary physical model (physical variables, equations, laws, and relationships), and Engee figures out how to calculate it itself.

To visually see the difference between the approaches, study the demo model.: DC motor. In it, the same system is implemented in two ways: using ready-made blocks. Engee libraries and through a physical component created in a physical modeling language. When comparing the simulation results, it can be seen that both approaches produce identical results, which confirms the validity of using a physical component on a par with the physical blocks of the Engee library. At the same time, the component code is easy to read due to the simple syntax, and in some tasks this approach may be more convenient than classical modeling through physical blocks.

Thus, the Engee physical modeling language is not just a tool for creating individual components, but also a powerful tool for describing complex physical systems. At the same time, the code remains readable, which is extremely important when working with complex models.