I'm not certain I know what the requirement is, but I doubt it has to do with reversing the direction of rotation.

The main thing that comes to mind is that some home owners and businesses now have solar panels on their roofs (or wind turbines) that generate DC current that is converted to AC by an inverter which connects to their power main. Often, it will supply less than the building uses, so they just draw less power from the power company. But if they produce more power than they use, the power can actually flow back out the service entrance.

I understand that some places have laws that require power companies to buy excess power produced in this way, but others disallow the practice. Either way, the building's power meter would have to detect that power is flowing out instead of in so the customer isn't charged as if they were consuming it.

The other thing that comes to mind is a motor-generator set. When I was in the Navy many years ago, we had motor-generator sets that would convert AC power to DC and vice-versa. It was just two motors on one shaft. We would either supply power to the AC machine so it would generate DC power, or supply DC power to generate AC power. It would inherently and automatically switch back and forth depending on the relative bus voltages. But the rotation was always in the same direction.

Now that solid state rectifiers and inverters are so capable, I doubt there's much demand for those any more. And I'm not sure how your relay would fit in anyway.

TakkyKun

Hello, I'm an EE student and study in 3rd year. I'd receive an assignment about "Reverse Power Relay". My objective is to create a device which can detect a Watt hour Meter that connect to DC Generator & Moter. This device will alert if the reverse of power exceed its limit. But I still have some question

1. What might be the cause of the reverse direction of DC motor & Generator rotation ?
2. What happen if DC motor & generator rotate in an opposite direction ?

If anyone feel free to help me out, you can post your comment here or mail me to <REMOVED BY ADMIN>

Thank you 😀)

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