deltaEnergy {DSWE}

Energy decomposition for wind turbine performance comparison

Description

Energy decomposition compares energy production from two datasets and separates it into turbine effects (deltaE.turb) and weather/environment effects (deltaE.weather).

Usage

deltaEnergy(
  data,
  powercol,
  timecol = 0,
  xcol,
  sync.method = "minimum power",
  imput = TRUE,
  vcol = NULL,
  vrange = NULL,
  rated.power = NULL,
  sample = TRUE,
  size = 2500,
  timestamp.min = 10
)

Arguments

data

A list of two data sets to be compared. A difference is always computed as (data2 - data1).

powercol

A numeric stating the column number of power production.

timecol

A numeric stating the column number of data time stamp. Default value is zero. A value other than zero should be provided when sync.method = 'time'.

xcol

A numeric or vector stating the column number(s) of power curve input covariates/features (environmental or weather variables are recommended).

sync.method

A string specifying data synchronization method. Default value 'minimum power'; other options include 'time' and 'random'.

imput

A boolean (TRUE/FALSE) indicating whether power imputation should be performed before calculating energy decomposition. The recommended and default value is TRUE. Change to FALSE when data have been preprocessed or imputed before.#' @param vcol A numeric stating the column number of wind speed. It is required when imput = TRUE.

vcol

A numeric stating the column number of wind speed.

vrange

A vector of cut-in, rated, and cut-out wind speed. Values should be provided when imput = TRUE.

rated.power

A numerical value stating the wind turbine rated power.

sample

A boolean (TRUE/FALSE) indicating whether to use sample or the whole data sets to train the power curve to be used for power imputation. Default value is TRUE. It is only used when imput = TRUE.

size

A numeric stating the size of sample when sample = TRUE. Default value is 2500. It is only used when imput = TRUE and sample = TRUE.

timestamp.min

A numerical value stating the resolution of the datasets in minutes. It is the difference between two consecutive time stamps at which data were recorded. Default value is 10.

Value

a list containing :

• deltaE.turb - A numeric,

• deltaE.weather - A numeric,

• deltaE.hat - A numeric,

• deltaE.obs - A numeric,

• estimated.energy - A numeric vector of the total energy calculated from each of f1(x2), f1(x1), f2(x2), f1(x2). If power is in kW, these values will be in kWh.

• data - A list of two datasets used to calculate energy decomposition, i.e. synchronized. When imput = TRUE, the power column is the result from imputation.

References

Latiffianti, E, Ding, Y, Sheng, S, Williams, L, Morshedizadeh, M, Rodgers, M (2022). "Analysis of leading edge protection application on wind turbine performance through energy and power decomposition approaches". Wind Energy. 2022; 1-19. doi:10.1002/we.2722.

Examples

data = list(data1[1:50,], data2[1:60,])
powercol = 7
timecol = 1
xcol = c(2:6)
sync.method = 'time'
imput = TRUE
vcol = 2
vrange = c(5,12,25)
rated.power = 100
sample = FALSE
Decomposition = deltaEnergy(data, powercol, timecol, xcol, sync.method, imput,
vcol, vrange, rated.power, sample)