AC waves and plots {renpow}

AC in the time and frequency domain

Description

Calculates and plots AC sinusoidal waves in the time domain and phasors. Includes complex number calculations.

Usage

waves(x, f = 60, nc = 2)
ac.plot(v.t, v.lab = "v(t)", v.units = "V", y.lab = "v(t)[V]", rms = FALSE)
phasor.plot(v.p, v.lab = "V", v.units = "V", lty.p = NULL)
polar(rec)
recta(pol)
mult.polar(x1,x2)
div.polar(x1,x2)
horiz.lab(nw, ym, tmax, ymax, units, yrms, rms)
wave.leg(nw, ang, lab, ym, w, units)
phas.leg(np, mag, ang, lab, units, lty.p)
gridcir(rmax)
sinplot(xlab, ylab)
arc(mag, ang)
rot.fig(vp,v.lab="wt")
admit(Z.r)
vector.phasor(V, I)

Arguments

x

AC variable given as a list of arrays. Each array contains two entries: magnitude and phase

f

Frequency in Hz, default 60 Hz

nc

Number of cycles to calculate and plot, default 2 cycles

v.t

Values of AC variable at time intervals calculated using waves

v.lab

Label for variable in time domain plot or phasor plot; time domain would typically include (t) and phasor would be upper case; also specifies label for angle in rot.fig

v.units

Units for variable in time domain plot or phasor plot; time domain would typically include (t) and phasor would be upper case

y.lab

Label for y axis composed of variable label and units

rms

Logical for whether the RMS value is added to the plot

v.p

Phasors to plot

lty.p

set of line types for plot and type of line for legend

rec

argument to polar array of rectangular coord

pol

argument to rect: array of magnitude and angle

x1, x2

complex numbers to multiply or divide by mult.polar and div.polar

nw

number of waves to assign horizontal lines

ym

magnitude array

tmax

max x axis value

ymax

max y axis value

units

units for lines and for legend

yrms

rms value to be used in y axis

ang

angle of waves or phasors

lab

label for legend

w

angular frequency for legend

np

number of phasors for legend

mag

magnitude of waves or phasors

rmax

max extent of polar grid for gridcir

xlab

xaxis label for sinplot

ylab

yaxis label for sinplot

vp

voltage for rot fig

Z.r

impedance in rectangular form

V

Voltage

I

Current

Details

Waves is first used to calculate values for time and the variable. Then the object creted by wave is used by ac.plot. Functions polar() and recta() allow polar and rect conversion specifying phasors as arrays. Function mult.polar and div.polar are used for multiplication and division of phasors. Function horiz.lab plots horizontal lines with labels for magnitude and rms. Used mostly by other renpow functions. Function wave.leg and phas.leg write out waves and phasors for legend. Used mostly by other renpow functions. Function gridcir draws a polar grid. Used mostly by other renpow functions. Function arc draws an arc from 0 degrees to a phasor line specified by mag and ang. Used mostly by other renpow functions. Function admit calculates admittance given the impedance in rectagular form. Function vector.phasor specifies volatge and current phasors for plotting.

Value

Function waves:

w

angular frequency

t

time values

nw

number of waves

ym

magnitude values

ang

ang

y

values

yrms

rms values

Note

Functions used in Chapter 5, 8, and 10 of Acevedo (2018)

Author(s)

Miguel F. Acevedo [e-mail]

References

Acevedo, M.F. 2018. Introduction to Renewable Electric Power Systems and the Environment with R. Boca Raton, FL: CRC Press. (ISBN 9781138197343)

Irwin, J.D. and R.M. Nelms. 2011. Basic Engineering Circuit Analysis. 11th edition. 2011: Wiley.

See Also

Power electronics functions ac.plot.rect, rectifier, inverter

Examples

# from Chapter 5
# one wave show phase angle
x <- list(c(170,30)); v.t <- waves(x); ac.plot(v.t)

# two waves different magnitude and phase
x <- list(c(170,0),c(160,30)); v.t <- waves(x);
v.lab <- c("v1(t)","v2(t)"); v.units <- rep("V",2)
ac.plot(v.t,v.lab,v.units)

# one phasor
v.p <- list(c(170,10)); phasor.plot(v.p)

# phasors phase difference
v.units <- rep("V",2)
v.lab <- c("V1","V2")
# V1 leads V2
v.p <- list(c(170,70),c(170,50))
phasor.plot(v.p,v.lab,v.units)

# rect to polar
polar(c(2,1))
# polar to rect
recta(c(2,45))
# multiplication
x <- polar(c(1,2))
y <- polar(c(2,3))
mult.polar(x,y)

# from Chapter 8
# nodal analysis
Y1 <- 1/(5+5i); Y2 <- 1/(5+5i); Y3 <- 1/(10+10i) 
Y <- matrix(c(Y1+Y2,-Y2,-Y2,Y3+Y2),ncol=2,byrow=TRUE)
Is <- c(1+0i,0+0i)
Vn <- solve(Y,Is)
VpIp <- vector.phasor(Vn,Is)
phasor.plot(VpIp$VI, c("V1","V2","Is1","Is2"),
           c("V","V","A","A"),lty.p=c(2,2,1,1))