LOAD FREQUENCY CONTROL OF POWER SYSTEM WITH NON-LINEARITIES

Abstract

Modern large-scale power systems comprise numerous interconnected distribution, generation, and transmission units spread across each corner of the globe. Due to random load demands happening throughout the particular day, atmospheric effects, variation in system parameters, modeling mismatches, and physical limitations in the power system, managing the frequency of a power system through Load Frequency Control (LFC) is a significant task. This work initially discussed numerous advantages of using LADRC over conventional PID controllers. A review of LADRC as a control approach was then studied. The LFC problem is numerically formulated considering both single-area and multi-area power systems. Various non-linearities that affect power system stability and may cause low-frequency oscillations were discussed. A describing function(DF) analysis is used to study stability analysis when non-linearities are considered. Critical load demand is calculated using DF analysis, which might be helpful to future reviewers in judging the disturbances responsible for oscillations in the power system. Using LADRC as a control scheme, existing simulations are shown in single and multiarea power systems. Then, a realistic IEEE 39 bus New England Test system is analyzed. Based on this, a single area is taken from the three-area system for DF analysis. Various tuning parameters of LADRC are proposed under this test system to observe various advantages of LADRC, such as excellent disturbance rejection capability, suppressing noise disturbance, and reference tracking.