Revolutionary building approach for maximal photovoltaic system results to improve maximum power point tracking in solar inverter

¹ Department of EEE, Institute of Aeronautical Engineering, Hyderabad
² Vel Tech Multi Tech Dr. Rangarajan Dr. Sakunthala Engineering College, Chennai - 62
³ Department of Mechanical Engineering, Veltech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, Chennai - 600062
⁴ Department of Computer Science and Engineering, Hyderabad Institute of Technology and Management, Hyderabad
⁵ Department of Electronics and Communication Engineering, Mohan Babu University (Erstwhile Sree Vidyanikethan Engineering College), Tirupati - 517102, Andhra Pradesh, India
⁶ Department of Computer Science and Engineering, Koneru Lakshmaiah Education Foundation, Vaddeswaram, Guntur Dist., Andhra Pradesh - 522302, India
⁷ Information Technology, Kings Engineering College, Sriperumbudur 602117, India

^* Corresponding author: sridharp35@gmail.com

Abstract

Due to the inherent frequency ripple in single-phase photovoltaic (PV) grid-connected solar inverters, the Maximum Power Point Tracking (MPPT) will inevitably be affected. To improve the MPPT performances, a passive LC power decoupling circuit with a Robust Sliding-Mode Control (RSMC) is proposed in this article. The frequency pulsation on the DC link is effectively canceled with the passive LC decoupling path. Thus, the MPPT accuracy is significantly enhanced, and the utilization of a small DC-link capacitor becomes possible. The resonance between the LC circuit and the main DC-link capacitor appears, which can be damped through an active damping method. The proposed RSMC offers good steady-state, dynamic performance (voltage fluctuation and settling time), and the robustness of the DC-link voltage, which is also beneficial to MPPT control in terms of high accuracy and fast dynamics. The systematic design of RSMC is presented, and a detailed parameter optimization design of the LC decoupling circuit is discussed. Experimental tests are performed on a 2.5-kW single-phase grid-connected solar inverter, and the results validate the effectiveness of the proposed strategy.