Cable Simulation using Ansys 2D Extractor and Simplorer

Hi, this is Mark with Ozen Engineering, and in this video I'll demonstrate how to simulate a cable using ANSYS 2D Extractor and use it in a circuit simulation using ANSYS Simplorer. Let's first look at a couple of examples that show how these simulations work.

Here we see a model of an armored multi-conductor cable. It's used in a three-phase electric power system with an induction machine as the load. The detailed cable geometry is first simulated using the electromagnetic field solvers in 2D Extractor.

This gives an accurate frequency response that can be described in terms of distributed RLCG parameters or the equivalent S-parameters.

Then the results from the cable simulation are dynamically linked into the system schematic, and this includes the power source, high voltage transformers, and the electromechanical load.

The cable results are represented by a reduced order model, which allows the system to simulate the current voltage, and allows the system simulation to run very quickly.

In this example, the simulation is predicting the effects of a transient short-circuit fault condition on one of the power system phases. A second example of how these types of accurate cable models can be used is the design of AC drive systems.

In this simulation, which is courtesy of Rockwell Automation, a shielded VFD cable with four power conductors and two braking conductors is first characterized as a short circuit fault. The AC drive systems are designed to predict the current voltage and the current voltage.

This is used in the simulation of AC drive systems. In this simulation, which is courtesy of Rockwell versus frequency using 2D Extractor.

Then the cable results are linked into the system model, and that includes the three-phase source, the VFD drive with the rectifier and inverter, and the motor load. This approach gives good agreement between the simulation and measurement for the voltage and the current waveforms.

So the first step is to create the cable model. This is done in the same environment as the circuit model, which is the ANSYS electronics desktop. So once we have a 2D Extractor blank design open, we can go to the 2D Extractor toolkit menu, cable modeling, and choose automotive cable bundle.

This is an easy way to define the geometry of the cable. You can also import it from a DXF file, or you can create it by drawing it inside the 2D Extractor window.

And in this case, we can define the number of wires, the type of insulation, the thickness of insulation, and the properties of the jacket. So we can define these individually using this menu. You can export and import predefined combinations or configurations for your cables.

I've already done that, so I'll import one of those now.

And for this purpose, we have three wires that are AWG 8. They have cross-linked polyethylene insulation material, and we have the same three conductors, and we have the same connector for the ground, and I've got a 60 mil thick XLPE jacket material.

So we click on draw, and this creates the geometry for our cross section. It automatically assigns material properties, as you can see here. The next step for the 2D Extractor model is to assign all the conductors as either signal or grounds.

So we can select wire one through three, right-click and say assign conductor, make it separate signal lines, and that will create wires one, two, and three, which are all signal lines. We can take wires four, five, and six, which are ground references.

We can assign conductor, assign that as a reference ground, click OK. So now we have a reference ground. And so our last step before we can solve this model is to assign a ground. So I'm going to set up a frequency sweep and a solution for the parameters that we're interested in.

So I'll switch over to a model that I've already solved, and I have an analysis set up. It goes up to 30 megahertz and asks for RL and CG solutions.

And one thing in the frequency sweep is you want to include enough detail in terms of the frequencies and the number of frequencies in the sweep so that we have good resolution across the band.

And we also have enough frequency bandwidth, to represent the rise time of the signals that will be used in the transient simulation in Simplorer. So in this case, I'm going up to 30 megahertz from DC up to 30 megahertz.

And we also want to select interpolating sweep, which will be much faster than running a discrete sweep.

So after we have the solution results, we can plot the distributed parameters, the RLCG matrix, can plot the self terms as well as the mutual terms for the resistance, inductance, and the capacitance. So we plotted that on a logarithmic scale.

You can see the self term for a conductor, wire one, also the mutual resistances over to wire three and wire two. That increases as we expect. And here we see the inductances, the self inductances and the mutual inductances of the wires.

And we also see the capacitances of each wire, the self and mutual capacitances across the frequency band. We can also plot the mesh. The solution is adaptively created in terms of the mesh that's used for the frequency band and for the results.

The finite element solution can plot the mesh for each CG and RL solution. We can also plot the fields from the solution, plot the magnetic flux density, plot the electric field. We can animate these so we can see the solutions as a function of the excitations.

If we go to edit sources, we can change for both CG and RL solutions. We can change the magnitude and the phase of the signals in each wire. So the next step is to take the cable model and to dynamically link it into the schematic in Simplorer. So we can do that by going to a schematic view.

This is a Simplorer window, which is also in the electronics desktop. If we wanted to add a Simplorer blank schematic, we could add that. We can add that across the top here in Simplorer.

And I've added one that has all the components that we need for the system simulation except for the RLCG component from a cable. So we have the load over on the right. We have an RL load. We have a voltage probe for the source and for the load. And we have a trapezoidal pulse waveform.

It's a periodic source with amplitude of 200 volts, period of 300 microseconds. And a rise time of 100 nanoseconds and a fall time of 100 nanoseconds. So that will serve as our input pulse for the system. And it's very simple to add in the component that we're just modeling as the cable.

We can go to add component and go down to Q3D, dynamic component. And we want to add the state space model. And this will create a reduced order model for use in the circuit. We can choose between S parameters or RLGC parameters.

And we'll choose RLGC parameters, which is the recommended approach for this model. And we will click the depth. And for now, we'll put 250 meters as the length of the cable. We can drag and drop that into the schematic and wire that up.

We'll use one of the wires for the simulation and the others have a 1 mega ohm resistor to ground for the other components. And we'll use the other wire for the conductors. The only thing you need to do at this point is to add the analysis for transient setup.

We're running a 600 microsecond simulation. And we're setting this step time for that between 5 nanoseconds and 10 nanoseconds. And the important thing about setting the step time is you want to capture good resolution for the rise time. So we're going to get 5 to 10 seconds.

And we're going to get 5 to 10 samples for the rise time. So once we have the results of the circuit model, we can look at the results of the waveform. We can do this under the results. We can plot from the volt meters, source, and the load waveforms.

And here we have the red waveform, which is the source input pulse. You can see a period of 300 microseconds, a couple of repetitions of that waveform. And then in the blue, we can see the ringing response. At the load, through 250 meters of the cable.

So using this approach, we can look at different types of cables, different types of circuits, different types of load conditions, and see the transient responses for the circuit of interest.

So I hope this video was helpful in showing how to perform cable and circuit simulations using 2D Xtractor and Simplorer. If you like videos like this, please subscribe to the channel and give a thumbs up to the video. Thank you and have a great day. Thank you.