Indian Journal of Science and Technology

Abstract

Objectives: The problem of instability in utilization of energy from PV system and harmonics injection due that is concerned here. The Analyzing of PV system and implementing with suitable techniques to attain permissible THD value is main objective of the work. Methods/Statistical Analysis: In this work for tracking maximum power perturb & observer method is employed. This PV system is integrated using Diode Clamped Multilevel Inverter (DCMLI), for this DCMLI APOD modulation technique is developed. PSA and PSO optimization methods are adopted for PI controller tuning which acts as voltage controller for DCMLI. As PSA is basic and local best optimization technique and PSO for its global best characteristics these methods are opted. Findings: The proposed closed loop system gives better control over open loop system. Tuning of the PI controller plays a crucial role in this closed loop system. In the applied heuristics tuning methods Particle Swarm Optimization (PSO) gives best THD control than Pattern Search Algorithm (PSA). The proposed techniques using PSO optimization is well suitable for PV system as the THD obtained by this is within standard acceptable limits. Actual existing systems like PV system with optimizations employed for MPPT’s or PV system with different multilevel topologies involves more complexity and less output quality than the proposed system. An integrated system is developed i.e. PV with suitable MPPT and multilevel inverter with advanced multilevel modulation tuned with heuristic optimization methods are proposed together for a standalone and also for grid application. Here the proposed system in the area of PV using optimization technique employed for multilevel inverter along with the multilevel modulation technique employed for the DCMLI plays an important role. Application/Improvements: The proposed system is developed based on voltage controller of multilevel inverter it can also be developed along with current controller system. The main objective of this work is to harmonic analysis a PV system with a multilevel inverter in standalone and grid connected mode using PSO and PSA optimization techniques.
Keywords: Diode Clamped Multilevel Inverter, Harmonic Analysis, MPPT Technique, Optimization Techniques, PV Array, Tuning of PI Controller