Vector Diagram for Voltage and Current

**anandvh** · 01-10-2012, 02:12 PM

Does anyone have a code for plotting a vector diagram for voltage and current. The three phase voltages are 120 degrees apart. The current angles have to be plotted with respect to the corresponding voltage vector.

**pike** · 01-11-2012, 03:03 AM

Here is an old one that may do

3 Ph Current sine waves.xls

**anandvh** · 01-11-2012, 02:26 PM

Thanks Pike for your post. This is not exactly what I was looking for. I am attaching an excel file as an example. In sheet AC_Meter, all the electrical parameters are computed. Sheet1 contains a dummy of what the vector diagram should look like. The longer arms are the voltage vectors. These are always at 0, 120 and 240 degrees. In column F of sheet1, I compute the angle offset for the current vector with respect to the voltage vector. These are to be plotted as the smaller arms.

Is there any way that excel charting or vb programming can plot this diagram ?

Any help will be greatly appreciated.

**MrShorty** · 01-11-2012, 04:29 PM

Unfortunately, my knowledge of AC electricity is limited. What little I do remember is that it involved a bit of trigonometry and often used polar coordinates (and the subsequent conversions of polar to rectangular coordinates).

It looks like each vector is simply a line connecting the origin (0,0) with its endpoint. Can I assume you know how to calculate the coordinates of each endpoint? If you can calculate the coordinates of each endpoint, then you simply need to put them in a table, maybe like this:

vector 1
0 0
x1 y1
vector 2
0 0
x2 y2
vector 3
0 0
x3 y3...

Once you have some kind of table like that, you can simply plot each of those series on a scatter plot and you should get your vector diagram.

**pike** · 01-11-2012, 04:31 PM

Another old file which might be okVector Addition .xls

**anandvh** · 01-12-2012, 11:54 AM

Thanks MrShorty and Pike for your contributions. MrShorty's solution appears to be simpler to implement since all the angles are computed. Took a look at Pike's file. I will take some time to understand what has been done before attempting it. Thanks anyway for your assistance.