Lead Compensators

Lead compensators

There are many ways to realize continuous-time (or analog) lead compensators, such as electronic networks using operational amplifiers, electrical RC networks, and mechanical spring-dashpot systems. Compensators using operational amplifiers are frequently used in practice.

Figure 1 shows an electronic circuit using operational amplifiers. The transfer function for this circuit is given by

         Fig: 1 Lead network                                                                             Fig: 2 Pole-zero configurations: (a) lead network; (b) lag (a) (b) network

From the equation of the transfer function, we see that this network is a lead network if R₁C₁ > R₂C₂, or α < 1. It is a lag network if R₁C₁ < R₂C₂. The pole-zero configurations of this network when R₁C₁ > R₂C₂ and R₁C₁ < R₂C₂ are shown in Figure 2 (a) and (b), respectively.