The maximum phase shift that can be obtained by using a

The maximum phase shift that can be obtained by using a lead compensator with transfer function
G_C(s) = 4(1 + 0.15s) is equal to
(1 + 0.005s)

For phase-shift only		1 + 0.15 s		is important.
		1 + 0.005 s

It is identified that T = 0.05 and aT = 0.15
⇒ a = 3
Maximum phase shift is given by φ_m such that

tan φ_m =	a - 1	=	3 - 1	=	1
	2 √a		2 √3		√3

∴ φ_m = 30°

G_C(s) =	4(1 + 0.15s)	is equal to
	(1 + 0.005s)