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In this article, the linear dynamic analysis of AC generators modeled as RLC circuits with periodically time-varying inductances via Floquet’s theory is considered. Necessary conditions for the dynamic stability are derived. The harmonic balance method is employed to predict the transition curves and stability domains. An approximate expression for the Floquet form of solution is constructed using Whittaker’s method in the neighborhood of transition curves. Numerical verifications for the obtained theoretical results are considered. In accordance with the experimental results, a satisfactory agreement is relatively achieved with the closed experimental literature of the problem.

Inverters with Quasi-Z-Source Networks (QZSN) provide DC-DC boosting and DC-AC conversion in a single stage. It offers reduced cost, complexity, and volume compared with the classical two-stage conversion system, which is composed of a boost converter followed by a Voltage-Source-Inverter (VSI). Further, QZSI provides superior conversion characteristics for single-stage grid-connected photovoltaic transformerless systems. However, the absence of galvanic isolation in these systems makes it possible to allow leakage current through these systems' parasitic capacitances due to the high-frequency Common-Mode Voltage (CMV) generated by the Pulse Width Modulation (PWM) nature of the inverter output voltages. As a result of this current, critical safety issues may arise with PV systems. Many PWM techniques have been presented in recent years for QZSIs. This paper is intended to provide a comprehensive analysis and review study of the characteristics of most of these PWM techniques in terms of CMV and leakage currents. In this study, closed-form equations have been derived to determine the effective CMV and leakage current analyses for all modulation techniques. Analytical and simulation approaches are used to identify schemes with the lowest CMV and current leakage effects. Moreover, the experimental setup is presented by applying the Simple-Boost Modified Space Vector Modulation (SB-MSVM) technique. [ABSTRACT FROM AUTHOR]

One of the obstacles of using the fuel cells in remote areas is the absence of hydrogen infrastructure to supply the required fuel to the unit. However, this can be solved by producing hydrogen on-site from water electrolysis. In this paper, the sizing of a stand-alone hybrid PV/PEMFC system to supply electric power for remote residential areas is discussed. The PV system is used to supply the required electric power to a water electrolyzer. The cost of energy (COE) of the hybrid PV/PEMFC system is compared with previous works by the authors for the same residential system when supplied by two individual power sources as two alternatives. The first one is a stand-alone photovoltaic system (SAPV), while the other one is a stand alone PEMFC system. The analysis results will help to define the most economic alternative to supply electricity for remote areas.