*7.3. Load Switching*

An event of load switching is realized by switching off the load connected at node 671 at 4th cycle and again switched on at 8th cycle. Voltage and current signals recorded at node 650 are processed to obtain the FI using WD-index and ALN-index as illustrated in Figure 16. It is inferred from Figure 16 that FI has lower values compared to the threshold during the event of switching off and on the load. Hence, it is established that the algorithm is effective for the discrimination of load switching event from the faulty events.

**Figure 16.** Fault index with event of load switching.

### **8. Performance of Protection Scheme**

This section presents brief comments on the results and comparison of results with the existing algorithms.

#### *8.1. Brief Discussion of Results*

Results discussed in the Sections 4–7 show that the algorithm introduced in this paper is effective in providing protection against different types of faults to the hybrid grids where conventional generator, wind power plant, solar energy plant, loads, OH lines, UG cables, capacitors, transformers, measuring devices and switches are available. This is effective only if both voltage and current signals are used. It will not work when either current or voltage signals are used individually. This algorithm is fast and accurately identifies as well as classifies all types of faults during different scenarios such as presence of high level noise, different fault incidence angles, high fault impedance, different sampling frequencies, different locations of the RE generators, and different fault locations. The algorithm is effective for protection of the high voltage networks up to voltage levels of 765 kV which comprises of thermal plants, hydro plants, nuclear plants, wind generators integrated to network at different nodes, solar generators integrated to network at different nodes, feeding agriculture (induction motors) loads, domestic loads and industrial loads. However, for ring systems the protection scheme has to be installed at both ends of the line. Results also show that algorithm is effective in discriminating the faulty and operational events.
