Joint Feature Selection of Power Load in Time Domain and Frequency Domain Based on Whale Optimization Algorithm

Table 1

Description of time domain features and frequency domain features.

	Features	Computing formula
Time domain features	Mean value
	Root mean square
	Square root amplitude
	Absolute mean
	Skewness
	Kurtosis
	Variance
	Maximum value
	Minimum value
	Peak-to-peak value
	Waveform index
	Peak index
	Pulse index
	Margin index
	Skewness index
	Kurtosis index
Frequency domain features ()	Frequency mean
	Frequency standard deviation
	Dispersion or concentration of spectrum
		Frequency center
		Root mean square frequency
		Index of position change of main frequency band

Where represents the sampling value of power parameters of electrical equipment in one day, represents the length of power data ( in this paper), and represents the frequency calculated by discrete Fourier transform (DFT).