24. Substation is a critical aspect of power grid and serves many functions. However, one of the following is not one of its functions:(1%) а.Step up or step down of power voltage; b. Interconnect transformers for voltage adjustments; c. Switcher between connecting lines; d. Prevent power system from water damages.

Fig: 1

Fig: 2

Fig: 3

Fig: 4

Fig: 5