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Chroma Bidirectional DC Power Supply Operation [VIDEO]

Increasing developments in renewable energies along with the rapid growth of electric vehicles are motivating the commercialization of distributed energy sources in micro grids. The same goes for the bidirectional design of power conversion devices. These devices are motivating battery applications to achieve higher efficiencies, higher voltage conversion, and higher power densities. With that said, design and test engineers are looking to replicate these characteristics from battery simulators with bidirectional DC power capabilities for their product development.

The Chroma 62000D not only provides source and load modes, but offers a bidirectional switch-mode that enables two-quadrant operation providing both DC power and regenerative DC loading. The absorbed energy feeds back to the grid with an efficiency of up to 93%. The regenerative load modes includes constant current, constant voltage, and constant power and can simulate the battery for testing battery connected charging devices. Where conventional methods required both DC power supply and regenerative DC load, one single Chroma 62000D can fulfill both charging and discharging tests in one unit.

Now let’s go ahead and take a look at the 62000D. As you can see, we have several items under the Measurement and Setup function. They are the main menu, mode indicator, additional settings, lock button, display mode, rotary knob input mode, on/off indicator, mode menu, parameter settings, and measurement value.

For this demonstration, we will be using two 62000D units. The unit below will simulate a device under test for each mode. As I mentioned earlier, the 62000D has 3 modes: source, load, and two-quadrant source and load mode.

Let’s look at source mode first. In source mode, the load setting will be grayed out and cannot be set.
Let’s simulate a DC/DC converter as the DUT. Spec will be 380V, the current limit of source is 15A, and the Load is 5A. So, first, we set the voltage to 400V and the current to 15A. Then press the ON button.

You can see the mode indicator on 62000D is displaying source mode. And DUT’s mode indicator is showing the load mode. Here shows the CV/CC mode.

Let’s say we increase the DUT’s current to 10A. The 62000D remains in CV mode and the current is being regulated at about 10A. Now let me show you CC mode by increasing the DUT’s current limit to 20A. You can see the 62000D popped right into CC mode. The current is being regulated at the set current limit, 15A, but now the voltage dropped down to 380V.

Now let’s switch to Load mode. Notice the source settings are now grayed out. Here, we are simulating a Fuel Cell stack as the DUT and the specs are 380V, current limit of source is 15A, and the Load is 20A. We set the current limit of the load to 10A and then press the ON button.

The mode indicator is now showing load mode.
It can lower the load current directly by changing the current limit.

Finally, let’s select the two-quadrant source and load. As you can see, both source and load settings are available. This time we are simulating a Bidirectional On-Board Charger as the DUT with the specs of 380V, current limit of source is 15A, and the load is 10A. Therefore, we set the 62000D to 400V output, the load current at 20A, and the source current at 15A.

As you can see, because the output voltage setting is higher than DUT, the 62000D is in source mode. Let’s see what happens if the output voltage is lower than DUT by decreasing the 62000D’s voltage to 370V. You can see the current drops to around -15A.

And the 62000D can carries out the source and load transition with a seamless switch. This feature is great for power conversion systems or motor driver testing as well.

And there you have it. Still, there are many powerful functions and features in this programmable bidirectional DC power supply. To find out more about the 62000D, feel free to contact us or visit our website. Thanks for watching.

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