functions.ac.power: AC power in the time and frequency domain

In renpow: Renewable Power Systems and the Environment

Description

Calculates and plots AC power in the domain and phasors. Includes complex number calculations.

Usage

inst.pow.calc(x, freq = 60, nc = 2)
inst.pow.plot(x, rms = FALSE, freq = 60, nc = 2)
inst.pow.leg(ang, lab, ym, w, units, pf)
complex.pow.calc(xc, dig = 2, res = TRUE)
complex.pow.plot(cp)
complex.pow.tri(cp)
pf.corr(P, V, pf, pfc, w = 377, dig = 2)
pf.corr.tri(xpfc)

Arguments

x	list of voltage and current phasors
freq	frequency in Hz
nc	number of cycles to calculate and/or plot
rms	logical to decide to plot the rms value
ang	angles for legend
lab	label for legend
ym	magnitude for legend
w	angular frequency for legend and for pf correction
units	units for legend
pf	power factor for legend of inst.pow.leg or to be corrected by pf.corr
xc	list with voltage, current, and phase angle
dig	number of digits to round complex power
res	logical to print results of complex power
cp	output of complex power; a list
P	real power for pf correction
V	voltage for pf correction
pfc	target power factor
xpfc	output of pf.corr; a list

Details

inst.pow.calc calculates time domain isntantaneous power given current and voltage phasors. Its output is passed to inst.pow.plot. inst.pow.plot produces time domain plots given current and voltage phasors. It uses inst.pow.leg to display legend

Value

w	angular frequency in rad/s
vm	array of magnitude
ang	array of angle
pf	power factor
pavg	average power
t	time sequence
v.i	matrix with voltage and current as a function of time
p	instantaneous power or power as a function of time
units	units for complex power result
S	apparent power
theta	phase angle
P	real power
Q	reactive power
pf	power factor
prnt	string to print results
cp	complex power output of pf.corr
cpc	complex power after correction
y	Voltage,current, and corrected params

Note

Functions used in Chapter Chapter 8 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

# power resistor
vm=170; R=10
x <- list(c(vm,0),c(vm/R,0))
inst.pow.plot(x)

# power capacitor
w <- 377; v.s <- c(170,0)
C=1000*10^-6
# current response
i.res <- c(v.s[1]*(w*C),v.s[2]+90)
x <- list(v.s,i.res)
inst.pow.plot(x)

# calc complex power
V.s=c(170,10); Z.p=c(10,20)
I.p <- div.polar(V.s,Z.p)
V <- V.s[1]/sqrt(2); I <- I.p[1]/sqrt(2)
theta <- V.s[2]-I.p[2] 
cp <- complex.pow.calc(list(V,I,theta))

# pf correction
P=5; V=240; I=40; pfc=0.9
pf <- P*1000/(V*I)
# call pf correction function
pfcorr <- pf.corr(P,V,pf,pfc)
# visualize
pf.corr.tri(pfcorr)

renpow documentation built on May 1, 2019, 6:49 p.m.