Performance Analysis of Active/Reactive Power Control of a Grid Following Voltage Source Inverter using Sliding Mode Control

Due to the high penetration of renewable energy and the presence of dynamic loads, uncertainties and disturbances in the electricity network have increased significantly. Consequently, the active and reactive power requirements of the network fluctuate rapidly. The conventional control architecture of the grid following voltage source inverter (VSI) is based on proportional-integral (PI) controllers. Even though PI controllers are more reliable, they are less robust against sudden system variations, leading to slower response time and overshoots that may adversely affect the network’s power quality. The proposed control architecture includes sliding mode control (SMC) at the outer active and reactive power control layer and PI controller at the inner current control layer, offering a more robust inverter for larger grid applications. Initially, the main drawback of SMC, known as “chattering,” is discussed, and a boundary layer approach is introduced to minimize this issue. Subsequently, the performance of the SMC method is compared to that of conventional controllers. The proposed SMC controller shows better reference tracking performance and better robustness against disturbances.