Performance comparison of PI and PI-fuzzy controller for grid-connected fuel cell inverter system

This paper presents the modeling, simulation, and performance evaluation of a hybrid proton exchange membrane fuel cell (PEMFC) with an energy storage system utilized in a grid-connected distributed generation (DG) system. To control the fuel cell/battery grid-side voltage source inverter (VSI), the conventional voltage-mode and currentmode control schemes with improved proportional-integral (PI)-fuzzy controller for both inner current and outer voltage control loops have been developed. The proposed PI-fuzzy controller has the advantage of fuzzy control while maintaining the simplicity and robustness of the PI controller. The space-vector pulse width modulation technique has been applied to the VSI control to generate a sinusoidal waveform. A comparison has been made between the PI-fuzzy controller and the PI controller in the VSI in terms of the generated total harmonic distortion (THD). The results showed that by applying PI-Fuzzy controller, the voltage and current THD are reduced to 0.40 % and 3.77 %, respectively compared to 0.43 % voltage THD and 14.08 % current THD using the conventional PI controller

Suitability of Demand Response Program Equipped with Solar Energy in UTHM

Demand Response Program (DRP) is a program developed in western country to cater high load demand.  This system enhance the quality of the current smart grid system. This program encourage two-ways interaction between the consumer and the utility provider. The consumers are required to reduce their load consumption upon request by the utility provider, thus avoiding them from paying for the high load demand. However, the current design of DRP is seem to put the user at disadvantages. Thus, deployment of the new practice equipped with renewable energy sources will make the system more user- friendly. As DRP prove to be beneficial in many terms, this project is conducted to find DRP relevancy to be implemented in Universiti Tun Hussein Onn Malaysia (UTHM). According to the electrical consumption data disclosed by Facility Management Division, the power consumed by UTHM is remarkably high especially during 11.00am to 12.00 pm. Thus, DRP is being proposed to be put into practise during this period. Nonetheless, it is not economically wise to implement the program to the whole campus. Therefore, three buildings with the most power consumption had been chosen for this study. They are the library, Faculty of Civil and Environmental Engineering (FKAAS) building and Faculty of Technology and Vocational Education (FPTV) building. The building power consumption and economic evaluation had been analysed using HOMER simulation. From the analysis, the combination of FPTV and FKAAS had been chosen for DRP implementation. The reason are, these buildings have superiority over the library in term of reliability and effectiveness. In terms of economy, it is almost equivalent to each other

Covid-19 and pregnancy, childbirth, and breastfeeding: The interim guidance of the italian national institute of health

This summary is based on the 2nd edition of the "Interim guidance on pregnancy, childbirth, breastfeeding and care of infants (0-2 years) in response to the COVID-19 emergency. Update of the INIH COVID-19 Report n. 45/2020", published on 5 February 2021.

Fabrication of a wearable antenna with defected ground structure on a flexible TPU-polyester substrate

Abstract This work presents a patch antenna with defected ground structure (DGS) on flexible materials for wearable applications. It is fed a 50 Ω inset feed and designed for operation at 2.45 GHz on a thermoplastic polyurethane-polyester fabric substrate. The DGS are integrated to ensure a compact design and improved bandwidth, efficiency, and gain. Simulations indicated that the antenna bandwidth is enhanced from 28.4 MHz without DGS to 79.3 MHz. Besides that, its gain is also improved from 2.01 dBi without DGS to 3.62 dBi and efficiency from 30% to 74%. Both antenna designs are fabricated and measured and provide good results and performance with efficiency greater than 50%

Compact wideband wearable antipodal Vivaldi antenna for 5G applications

Abstract In this paper, a compact wearable antipodal Vivaldi antenna resonating at 3.5 GHz is proposed for 5G n77 and n78 bands. It is designed on a flexible polyester substrate with a dielectric constant (ɛ r ) of 2 and loss tangent (tan δ) of 0.005. The antenna parameters were optimized via parametric analyses using CST software with a size of 33 × 33 mm² (length × width). The antenna is evaluated in terms of reflection coefficient (S 11 ), gain, efficiency, radiation pattern and surface current density and its reflection coefficient is verified with measurement. This antenna attained a maximum simulated gain of 4.17 dBi and an efficiency of 98.18 % in the resonating band

Dual band circular patch flexible wearable antenna design for sub-6 GHz 5G applications

Abstract In this paper, a dual band wearable antenna for 5G applications that resonates at 3.63 GHz and 4.95 GHz covering sub-6 GHz 5G-NR bands such as n48, n77, n78, and n79 is presented. The antenna consists of slotted circular ring patch as radiating element, polyester as wearable substrate, and a partial ground plane on the bottom. The designed antenna is sized at 55×46×0.4 mm³, achieving a bandwidth of 300 MHz from 3.50 to 3.80 GHz and a bandwidth of 160 MHz from 4.86 to 5.02 GHz. Besides, the antenna shows realized gain of 4.2 dBi at 3.63 GHz and 5.78 dBi at 4.95 GHz, whereas efficiency is found 90.5 % and 82.3 % respectively