Hej,

If you have a DC voltage of 800V, you can operate your converter in grid-tied operation. It can control the active and reactive power flow. In practice, you just need to size your grid filter and choose your switching frequency in a manner to satisfy the required current harmonic and THD requirements.

In comparison to a 400V DC link, you do not need a boost converter.

Hi,

On the face it, the idea sounds perfectly valid. I want to add a few points you can add to your checklist before proceeding.

Practical implications:

1) you have no power converter interface, you are saving on a lot of devices, but there is no intermittent energy storage element, like an inductor or capacitor. This means all the harmonic currents flow from your battery directly, which can have considerable ESR. You may want to consider putting a DC link capacitor, after looking at the ESR numbers for battery and caps, and comparing the cost advantage.

2) You mentioned bidirectional converter. When you run the inverter on a battery, you automatically assume that the battery voltage is stiff and can sink or source power. So you can bidirectional power flow in this case directly from the battery. However, beware that you might accidentally pump active power into the battery overcharging it beyond the rated limits. Just a suggestion. Please have a look at the numbers and make sure the scenario never occurs in your application. Again, having a DC link cap, and using diodes, you can ensure unidirectional power flow from battery if necessary.

Dear Anton Kersten and Rahul Dewani ,

Thanks for your valuable suggestions. Both the answers clarify my query.