Dragonfly algorithm-based optimization for selective harmonics elimination in cascaded H-bridge multilevel inverters with statistical comparison

Harmonics worsen the quality of electrical signals, hence, there is a need to eliminate them. The test objects under discussion are single-phase versions of cascaded H-bridge (CHB) multilevel inverters (MLIs) whose switching angles are optimized to eliminate specific harmonics. The Dragonfly Algorithm (DA) is used to eradicate low-order harmonics, and its statistical performance is compared to that of many other optimization techniques, including Particle Swarm Optimization (PSO), Accelerated Particle Swarm Optimization (APSO), Differential Evolution (DE), and Grey Wolf Optimization (GWO). Various scenarios of the algorithms’ search agent population for inverters with seven, nine, and eleven levels of output voltages are comprehensively addressed in this research. No algorithm shows total dominance in every scenario. The DA is least impacted by the change in dimensions of the narrated problem

An MPPT technique for unshaded/shaded photovoltaic array based on transient evolution of series capacitor

For maximum power point (MPP) application, the transient evolution of capacitor can be exploited to examine the power-voltage (P-V) characteristics of a photovoltaic (PV) array. This method is simple and inexpensive. In addition, it can be implemented on any array size whether un-shaded or partially shaded. This paper presents a new MPPT technique that scans the P-V curve of PV array with a series capacitor (Cscan) through a unique H-bridge architecture. The proposed technique employs a simple algorithm, which controls the H-bridge to scan the P-V curve in two sequences: (1) during charging of capacitor, and (2) during discharging of capacitor. The proposed MPPT neither requires the isolation of PV array from load nor executes power loss during checking of P-V curve. The effects of input capacitor (Cin) of converter during scanning of P-V curve are comprehensively discussed, and then the correct sizing of Cscan according to array size is explained with a design example. A comparative analysis of different MPPTs in the context of tracking ability, dynamic, and steady state efficiencies is presented. This analysis highlights the advantage of proposed technique over other MPPTs. Finally, the fundamental operation of proposed MPPT is verified through experimental results

MPPT technique based on improved evaluation of photovoltaic parameters for uniformly irradiated photovoltaic array

In this article, a new maximum power point tracking (MPPT) method is proposed. The proposed MPPT is in principle, a hybrid version of open circuit voltage (Voc), short-circuit current (Isc) and perturb & observe (P&O) techniques. Improved relations are derived in this paper on the basis of which the proposed MPPT operates. These are: voltage and current relations of PV which correspond to MPP, duty cycle function of converter to set PV operating point at MPP, criterion to measure the varying weather conditions and limits criteria to evaluate the steady weather conditions. All these relations are incorporated in the control architecture of the proposed technique, which contains three loops: E-MPP loop, R-MPP loop and S-loop. The proposed MPPT and past-proposed methods are tested through computer aided simulations and experimental prototype under dynamic and steady weather conditions. The comparative analysis between the MPPTs indicates that the proposed technique outperforms other MPPTs by a significant margin. Previous article in issu