RESUMEN
This paper is an attempt to provide a dual-source inverter, an intelligent inverter topology that links two isolated DC sources to a single three-phase output through single-stage conversion. The converter is designed to be utilized in hybrid photovoltaic fuel cell systems, among other renewable energy applications. The proposed dual-source inverter employs a single DC-AC converter, as opposed to conventional dual-source hybrid inverters which make use of several input DC-DC modules to obtain the voltage formed across the inverter's input DC-link. In the proposed topology, the semiconductor count is low, which leads to improved efficiency, cost, complexity, and reliability. The proposed topology makes use of two impedance networks connected by transformers, diodes, and capacitors. The regulation of the electrical power generated by primary sources and the independence of the converter on key factors like voltage and frequency are essential parameters in multi-input converters. This feature becomes highly prominent when the control algorithm is implemented by conventional processors. Viewed from this perspective, the control method described in this paper is worthy of consideration. The research work describes a 220-W/50 Hz prototype that employs Simple Boost-SPWM. Experimental results verify the analyses and corroborate the satisfactory performance of the suggested converter.
RESUMEN
BACKGROUND: Nowadays, magnetic nanoparticles (MNPs) have received much attention because of their enormous potentials in many fields such as magnetic fluid hyperthermia (MFH). The goal of hyperthermia is to increase the temperature of malignant cells to destroy them without any lethal effect on normal tissues. To investigate the effectiveness of cancer therapy by magnetic fluid hyperthermia, Fe0.5Zn0.5Fe2O4 nanoparticles (FNPs) were used to undergo external magnetic field (f=515 kHz, H=100 G) in mice bearing implanted tumor. METHODS: FNPs were synthesized via precipitation and characterized using transmission electron microscopy (TEM), vibrating sample magnetometer, and Fourier transform infrared. For in vivo study, the mice bearing implanted tumor were divided into four groups (two mice per group), namely, control group, AMF group, MNPs group, and MNPs&AMF group. After 24 hours, the mice were sacrificed and each tumor specimen was prepared for histological analyses. The necrotic surface area was estimated by using graticule (Olympus, Japan) on tumor slides. RESULTS: The mean diameter of FNPs was estimated around 9 nm by TEM image and M versus H curve indicates that this particle is among superparamagnetic materials. According to histological analyses, no significant difference in necrosis extent was observed among the four groups. CONCLUSION: FNPs are biocompatible and have a good size for biomedical applications. However, for MFH approach, larger diameters especially in the range of ferromagnetic particles due to hysteresis loss can induce efficient heat in the target region.
RESUMEN
As the output power of a microgrid with renewable energy sources should be regulated based on the grid conditions, using robust controllers to share and balance the power in order to regulate the voltage and frequency of microgrid is critical. Therefore a proper control system is necessary for updating the reference signals and determining the proportion of each inverter in the microgrid control. This paper proposes a new adaptive method which is robust while the conditions are changing. This controller is based on a modified sliding mode controller which provides adapting conditions in linear and nonlinear loads. The performance of the proposed method is validated by representing the simulation results and experimental lab results.
