Labview-RedPitaya. Voltage signal delay , phase difference.

[MBA]

Hi!
I'm working with Labview and RedPitaya in order to measure Voltage and Current to calculate the instantaneous power that an elevator consumes while it is working in order to study how much of this power is active P and how much it's reactive Q.
I have to measure Voltage between line and neutral and multiply it and the current.

The problem is that the neutral is not accessible, so I have to measure line to line voltage and turn it into line to phase voltage.

In order to accomplish that I have to make two changes.
1) I have to /sqrt3. That I have already done without problem.
2)I have to set a phase difference of 30º, or a delay of the equivalent time (1.6666667 ms) to the voltage signal that is being acquired to turn it to line-neutral voltage.

I have tried to accomplish this last point by using a wait block in a while structure( see picture 1) , but it doesn't work properly when the voltage needs a loop, because the subVI is not running at the same speed when reading current and voltage after a delay as I see with the highlight option. And all the clock, wait or delay blocks that I have seen are supposed to work in a loop, not wired to a signal that an instrument is reading and acquiring.

generador de señaeles bucle desfase 1.666 ms.PNG

Is there any way to set this phase difference or an equivalent delay without a loop that affect only to the voltage signal read by channel ! 1 using a RedPitaya block ??

I have tried with the block ReadWaveform, but althoug it says that Trigger delay is set to zero ( in samples or in seconds) I don't know how to set a delay in milliseconds of 1.66667 that is what I need to make the conversion to line-neutral! (see picture 2)


Thanks in advance.

[redpitaya]

Hi,

Trigger delay is set in seconds.
just input 0.00166 seconds at it should work.
But I am not sure because with this you will delay the acquisition of both inputs simultaneously and you are on the same as without delaying.
You can set trigger channel (IN1 or IN2) and trigger delay but when trigger happens
acquisition is simultaneous.

You can delay your signal for 30 deg with multiplying your IN1 with reference sine in LabView.

Best