Feedforward adaptive phase-locked loop for process control systems

This paper presents the application of feedforward adaptive phase-locked loop (feedforward adaptive PLL) for process control systems. The feedforward controller whose gain is less than one, is added to the adaptive PLL in order to improve the response at transient state. The experimental result in controlling the first order lag process shows that the speed of the response is faster than the response of the adaptive PLL process control system. The proposed process control system has also the properties of tracking, fast load disturbance rejection and stability for the process parameter change.