Fast Hybrid MPPT Technique for Photovoltaic Applications: Numerical and Experimental Validation

In PV applications, under mismatching conditions, it is necessary to adopt a maximum power point tracking (MPPT) technique which is able to regulate not only the voltages of the PV modules of the array but also the DC input voltage of the inverter. Such a technique can be considered a hybrid MPPT (HMPPT) technique since it is neither only distributed on the PV modules of the PV array or only centralized at the input of the inverter. In this paper a new HMPPT technique is presented and discussed. Its main advantages are the high MPPT efficiency and the high speed of tracking which are obtained by means of a fast estimate of the optimal values of PV modules voltages and of the input inverter voltage. The new HMPPT technique is compared with simple HMPPT techniques based on the scan of the power versus voltage inverter input characteristic. The theoretical analysis and the results of numerical simulations are widely discussed. Moreover, a laboratory test system, equipped with PV emulators, has been realized and used in order to experimentally validate the proposed technique

Fast Hybrid MPPT Technique for Photovoltaic Applications: Numerical and Experimental Validation

In PV applications, under mismatching conditions, it is necessary to adopt a maximum power point tracking (MPPT) technique which is able to regulate not only the voltages of the PV modules of the array but also the DC input voltage of the inverter. Such a technique can be considered a hybrid MPPT (HMPPT) technique since it is neither only distributed on the PV modules of the PV array or only centralized at the input of the inverter. In this paper a new HMPPT technique is presented and discussed. Its main advantages are the high MPPT efficiency and the high speed of tracking which are obtained by means of a fast estimate of the optimal values of PV modules voltages and of the input inverter voltage. The new HMPPT technique is compared with simple HMPPT techniques based on the scan of the power versus voltage inverter input characteristic. The theoretical analysis and the results of numerical simulations are widely discussed. Moreover, a laboratory test system, equipped with PV emulators, has been realized and used in order to experimentally validate the proposed technique

Variation of inflammatory indexes in patients with chronic abacterial prostatitis treated with an herbal compound/extract

Introduction: Inflammation is a highly prevalent finding in the prostate. Men with inflammation have higher IPSS score and increased prostate size. For men with prostatic inflammation, there is a significantly increased risk of developing acute urinary retention and the need of a surgical approach to the disease. Some laboratory tests (i.e. fibrinogen, C-reactive protein), can play a role in identifying patients at greatest risk of complications and adverse outcomes after surgery. There have been several experiences exploring the role of nutraceutical approach to the prostate inflammation. Aim of our study were to describe the variation in symptoms and inflammatory indexes in men affected by chronic abacterial prostatitis, treated with an herbal extract containing Curcuma Longa 500 mg, Boswellia 300 mg, Urtica dioica 240 mg, Pinus pinaster 200 mg and glycine max 70 mg. Materials and methods: A prospective multicenter study was conducted from February 2021 and March 2022. One hundred patients, with a diagnosis of Chronic Prostatitis were enrolled in a multicentric phase III observational study. They were treated with the herbal extract, one capsule per day, for 60 days. No placebo arm was included. In each patient, inflammatory indexes, PSA, prostate volume, IIEF-5, PUF, uroflowmetry (Qmax), IPSS-QoL, NIH-CPPS were registered and statistically compared at baseline and at the follow up visit. Results: The variation obtained on the inflammation indexes showed a global improvement after treatment, including the PSA reduction. We also recorded a significant improvement on IPSS-QoL, NIH-CPPS, PUF and Qmax scores. Conclusions: The herbal extract considered in our study may represent a promising and safe therapeutic agent leading to a reduction of inflammation markers, and could be used in the treatment of prostatitis and benign prostatic hyperplasia

Design and implementation of a hybrid MPPT technique based on the scan of the power vs voltage input characteristic of the inverter

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Design and implementation of a dynamic FPAA based photovoltaic emulator

In this paper, a new Photovoltaic (PV) emulator is presented and discussed. Its main feature is represented by the use of a Field Programmable Analog Array (FPAA) on which the desired current vs. voltage (I-V) PV characteristic can be implemented. The FPAA provides a suitable analog time varying reference signal for the output current control of a proper DC/DC converter whose output port emulates the PV I-V curve. The proposed emulator allows to track time varying irradiance values and therefore it allows also to emulate typical scenarios of automotive applications or involving fast time varying weather conditions (e.g. the ones which usually occur in tropical locations). Additional, not less important advantages of the proposed solution are the following ones: (1) no numerical interpolations and no storage of big amount of data in memory are required; (2) the FPAA is characterized by a great ease of reconfiguration and programming with respect to FPGA or DSP based implementations; (3) no DAC or ADC converters are needed; (4) not only uniform but also mismatching operating conditions can be easily emulated; (5) power sources different from PV sources can be easily emulated by using the same architecture. The presented experimental results allow to confirm the validity of the proposed FPAA based architecture

The Role of Multi-Staged Urethroplasty in Lichen Sclerosus Penile Urethral Strictures

Background: One-stage buccal mucosa graft urethroplasty (BMGU) is advised for non-obstructing, simple penile strictures due to lichen sclerosus (LS), while a multistage approach is preferred for most complex cases. Our study aims to evaluate long-term treatment outcomes and patient-reported outcomes (PROs) in patients undergoing multistage BMGU for LS-associated penile strictures. Methods: This is a retrospective analysis of prospectively collected data on multistage penile BMGU from 2001. All patients underwent a 2-stage (2St) or 3-stage (3St) BMGU with the final closure of the urethral plate. PROs were collected from a pre-defined questionnaire. Results: Twenty patients were successfully treated, while five experienced recurrence. If a first-stage Johanson was only performed, a 3St-BMGU was more likely, and higher treatment success was observed. A time course between the first and last stages shorter than 12 m was an independent predictor of treatment failure. Patients reported high overall satisfaction and urinary flow improvement. Sexual life was not significantly affected, while aesthetic appearance was the most affected dimension. Conclusions: Staged approaches have satisfactory treatment success rates, likely depending on the duration from the first to the last stage. PROs do not differ based on the number of stages performed, and overall satisfaction with the procedure is high