Third Order Integral Terminal Sliding Control for DC-DC Converter Voltage Stability

In DC bus, constant power loads (CPLs) are connected in DC distribution networks (DCDNs) which causes the system instability due to the negative impedance properties of CPLs. To ensure system stability, a third-order integral terminal sliding mode controller (3-ITSMC) is proposed using an improved quick-reaching law. In this proposed control scheme, an improved reaching law is used to mitigate chattering from the system and tackles the underlying issue of the non-minimum phase in DC-DC boost converters (DDBCs). Through the Lyapunov stability theory, 3-ITSMC controller can ensure the stability of the entire system which is the main aim of this proposed 3-ITSMC. The performance of the proposed control scheme is validated through the simulation investigations implemented in MATLAB/Simulink under major fluctuations demonstrating that it enhances the stability of DCDNs in every aspect as compared to the existing sliding mode controllers. After the simulation, the tracking error of 3-ITSMC is 20% for DC voltage variation. Additionally, for the variations in CPLs’ power, the tracking error of 3-ITSMC is 18%.