Understanding Inverter Output Voltages for 230V Delta-Connected Motor in a 400V Network

Question

Hello A 230V delta-connected motor powered by an inverter, I wonder what it is like because our network has 400V interphase, a little bit not for such a motor. What output voltages do inverters have ??? Will there be a phase voltage of 130V behind the inverter and 230V between the phases so that...

kosmos99 · Answer

The inverter is reliably powered from one phase, i.e. 230V. The inverter output voltage depends on the set frequency.

Anonymous · Answer

Write what engine it is, preferably photos of the nameplate, because it can be interpreted in two ways. According to the rule U / f = const

Darom · Answer

Hello
The fact that inverters have a U / f strategy is obvious - it results from maintaining the correct flux.
It seems to me that the author wants to answer the question about the rated supply voltage of the inverter and the rated voltage of the motor. My guess is that the device will be connected to a 3x400V installation (standard in Poland) and the motor itself has 230V windings.
The author did not provide any data about the inverter. The inverter supply voltage (input voltage) must match the system voltage. As for the motor - most inverters (at least with which I have come across) have the option of entering the motor parameters, including the rated voltage.

kisses
- GIFT-

Anonymous · Answer

And from not exceeding the rated current when the impedance of the windings drops by lowering the frequency. The author also wrote: Which can be understood as the motor rated voltage is 230/400, so a delta connection would be dangerous.

djlukas · Answer

Or maybe the 87Hz technique is used here?

platinet64 · Answer

Lord Darom understood me more or less what was going on. Gentlemen, this is a topic as well as a more theoretical question, I want to understand the principle of operation of inverters. At 50Hz, could my motor work in a delta configuration like a 230V motor Triangle and our 400V interphase network, I have not read the answer if the inverter's (output) phase voltage would be, say, 130V, so that there was 230V between the phases so that this motor could the triangle work ??? is it as i understood my colleagues well about frequency regulation? well, what if I turn it up to 50 Hz will the voltage increase and I will not burn the engine ??? and even if I reduce the frequency, it will spin slower? Please explain the topic further ...

djlukas · Answer

If you set 230V 50Hz on the inverter in the motor parameters, the inverter will generate this much for this frequency.

Darom · Answer

Hello
Although I started and programmed a couple of inverters, I do not feel like a specialist in this field. There are a few professionals on the forum who have proved that they know very well about inverters and drives, but as you can see, they are not always available. There are many pages that cover this topic in depth.
In short, it looks like this:

You can see that the input (power) voltage of the inverter has little to do with the motor's supply voltage. Along the way, it is converted into direct current (DC) and back into alternating current (AC). The parameters of this alternating current result from the inverter settings and the signal controlling the rotation of the drive.
You can learn more on the website:
Link Building inverters

kisses
- GIFT-

platinet64 · Answer

Thank you gentlemen.

Krzysztof Kamienski · Answer

No. Only when the inverter is powered with 230 VAC, one or three-phase. Yes, but not enough to make a delta connection of the motor. It is correct . At 400 VAC power supply? Congratulations .

djlukas · Answer

Did your colleague hear about 87Hz?

jaro33 · Answer

And there are even inverters that do not have the correct voltage on the DC bus to get 400V for the motor.

The 1-phase inverter with 230V voltage controls a 400V star-connected motor (400V) and has almost four hundred
and it is true that such a situation should not be long-lasting because the motor and the inverter suffer.

This is the reverse of your case.

Krzysztof Kamienski · Answer

@ jaro33 Have a colleague heard about inverters with voltage doublers? Very popular in the USA. Powered by 120 VAC, they drive the 3x 220VAC motor. So who is suffering here?

jaro33 · Answer

I do not entirely agree. This is how the inverter has a system that allows you to power the motor with higher voltage. And I wrote that there are such solutions, but at the cost ... .. I can not even mention because I did not analyze this issue. But nothing is free in nature, and prices must be calculated. Only my opinion - maybe wrong. And besides, why inverters for 1-phase motors are much more expensive ??? Haven't read that anymore? to compare 865 and 346 is a big difference Anything you can do is just another thing like economics.

Darom · Answer

Hello
Today I had the opportunity to correct the settings of inverters that were installed a year ago. Due to the amount of space, the designer assumed an increase in the efficiency of small fans by increasing the rotational speed.

For example - this inverter can be ordered as single-phase 230V or three-phase 3x400V.
In the menu, I can choose a powered motor: 3 x 230V or 3 x 400V.
I have come across inverters that have a much wider motor rated voltage, for example from 3x230V to 3x660V.

kisses
- GIFT-

Understanding Inverter Output Voltages for 230V Delta-Connected Motor in a 400V Network

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