**3. WT applications in power systems**

In the main stream literature, wavelets were first applied to power system in 1994 by Robertson (Robertson et al., 1994) and Ribeiro (Ribeiro, 1994). From this year, the number of publications in this area has increased. The most popular wavelet analysis applications in power systems are as following:


## Power system transients

224 Advances in Wavelet Theory and Their Applications in Engineering, Physics and Technology

In view of the fact that WPT generates large number of nodes it increases the computational burden. In DWT only approximations are further decomposed thus reducing the level of

In the main stream literature, wavelets were first applied to power system in 1994 by Robertson (Robertson et al., 1994) and Ribeiro (Ribeiro, 1994). From this year, the number of publications in this area has increased. The most popular wavelet analysis applications in

Fig. 2. Decomposition tree for DWT

Fig. 3. Decomposition tree for WPT

power systems are as following:

 Forecasting in power systems Power system measurement Power system protection

 Power quality Partial discharges

decomposition and thereby computational attempts.

**3. WT applications in power systems** 

Fig. 4 shows the percentage of 196 IEEE papers based in each area (Source: search on IEEE Explore). One can conclude that most research are carried in the field of power quality and power system protection.

Fig. 4. Percentage of wavelet articles in different areas of power system

Next sections present a general description of wavelet applications in the selected areas of power systems.
