Fuzzy logic gain-tuned adaptive second-order GI-based multi-objective control for reliable operation of grid-interfaced photovoltaic system

• Published in: IET generation, transmission & distribution Vol. 12; no. 5; pp. 1153 - 1163
• Main Authors: Vedantham, Srinivas, Kumar, Shailendra, Singh, Bhim, Mishra, Sukumar
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 13.03.2018
• Subjects: adaptive control; adaptive DC bus voltage; automatic protection scheme; dynamic grid conditions; four wire system; fuzzy control; fuzzy logic gain‐tuned adaptive control scheme; fuzzy logic integrator gain‐tuned improved second‐order generalised integrator; grid currents balancing; grid‐side faults; invertors; load current; load current fundamental component extraction; maximum power extraction; neutral current; non‐linear frequency error variation; photovoltaic power systems; point of common coupling voltage; power factor correction; power generation control; power generation reliability; PV array; PV inverter; Research Article; second‐order GI‐based multiobjective control scheme; smooth system operation; steady‐state grid conditions; switching losses; total harmonic distortions; weak distribution grids; automatic protection scheme; load current; weak distribution grids; dynamic grid conditions; PV inverter; power generation control; total harmonic distortions; point of common coupling voltage; smooth system operation; fuzzy control; invertors; power factor correction; maximum power extraction; power generation reliability; PV array; load current fundamental component extraction; grid-side faults; neutral current; photovoltaic power systems; adaptive control; fuzzy logic integrator gain-tuned improved second-order generalised integrator; steady-state grid conditions; adaptive DC bus voltage; grid currents balancing; non-linear frequency error variation; second-order GI-based multiobjective control scheme; four wire system; fuzzy logic gain-tuned adaptive control scheme; switching losses
• ISSN: 1751-8687; 1751-8695
• DOI: 10.1049/iet-gtd.2017.0958

This study presents the fuzzy logic integrator gain-tuned improved second-order generalized integrator (GI) for a double-stage grid-interfaced photovoltaic (PV) system. The proposed system includes the functionalities of feeding active power to the grid, power factor correction, grid currents balancing and system isolation under grid side faults. Moreover, the smooth system operation is ensured under weak distribution grids where grid voltage is subject to huge diversions. Furthermore, automatic protection scheme for the system under grid-side faults is also established with the proposed algorithm for increased reliability. The fuzzy-tuned GI provides advantages of efficient and effective extraction of load current fundamental component under steady-state and dynamic grid conditions. The non-linear frequency error variation is compensated here using fuzzy logic-based self-tuning integrator gain of the controller. The controller is improved to mitigate the possible DC component in the load current. The neutral current in the loads is nullified by using a four wire system. The adaptive DC bus voltage helps to minimize the switching losses and prevents unexpected tripping of the PV inverter. The system is experimentally verified using a prototype built in the laboratory.