Array Module Research Articles

Quality Control Using Ultrasonic Phased Array Inspection of Components Produced by Directed Energy Deposition in Ti6Al4V Alloy

Additive manufacturing (AM) is rapidly becoming a viable manufacturing method for industrial metallic parts. This is related to the benefits achieved, such as reducing material wastage, an increase in design freedom and weight savings. But, to guarantee the highquality of the components produced, the non-destructive methods of inspection need to be optimised or developed. In this study, a Ti6Al4V 3D coupon was produced by the Laser Wire Directed Energy Deposition process (w-DED-LB), in which artificial holes of different diameters simulating defects were machined. To validate the quality control method after production by means of Ultrasonic Phased Array Techniques, the component was inspected using the Gekko equipment from Eddyfi Technologies, through the methodologies of the phased-array conventional mode and the Total Focusing Method (TFM). The probe used was a 5L64-64X7-NW1-P-5-OM, with a 5.0 MHz frequency system with 64 elements, with dimensions of length 64 mm, width 7 mm, and pitch of 1.0 mm. The results obtained showed that the TFM mode provides better detection of the defects, resolution, and measurement capabilities when compared with the conventional phased array mode.

A Maximum Power Tracker for Photovoltaic Module Arrays Based on the Improved Perturbation and Observation Method

A Maximum Power Tracker for Photovoltaic Module Arrays Based on the Improved Perturbation and Observation Method

Design Methodology of Off-Grid PV Solar Powered Systems for Rural Areas in Ecuador

Renewable technologies are a modern, clean form of energy with a very low environmental impact. They can become a viable option for energy generation, especially in rural areas of Ecuador, where the scarce access to electricity service limits the development possibilities of these areas. Solar energy is the resource used by off grid photovoltaic generation systems, which are used exclusively in rural areas because the installation of the electrical grid is costly or technically complex. In the Matlab/Simulink environment, off grid photovoltaic systems have been designed, which are composed of an array of photovoltaic modules, charge controllers, storage systems and single-phase inverters that together will allow knowing the behavior of electric power generation through solar photovoltaic energy. In addition, a maximum power point tracking (MPPT) algorithm was developed to obtain the peak power of the photovoltaic array and a discrete integral proportional control was incorporated for the charging and discharging of the batteries. Finally, a sizing tool was designed and developed through Excel Macros and Visual Basic, which facilitated the input of the different parameters and the obtaining of the results for the implementation of the photovoltaic systems.

A Novel Approach for Apple Freshness Prediction Based on Gas Sensor Array and Optimized Neural Network.

Apple is an important cash crop in China, and the prediction of its freshness can effectively reduce its storage risk and avoid economic loss. The change in the concentration of odor information such as ethylene, carbon dioxide, and ethanol emitted during apple storage is an important feature to characterize the freshness of apples. In order to accurately predict the freshness level of apples, an electronic nose system based on a gas sensor array and wireless transmission module is designed, and a neural network prediction model using an improved Sparrow Search Algorithm (SSA) based on chaotic sequence (Tent) to optimize Back Propagation (BP) is proposed. The odor information emitted by apples is studied to complete an apple freshness prediction. Furthermore, by fitting the relationship between the prediction coefficient and the input vector, the accuracy benchmark of the prediction model is set, which further improves the prediction accuracy of apple odor information. Compared with the traditional prediction method, the system has the characteristics of simple operation, low cost, reliable results, mobile portability, and it avoids the damage to apples in the process of freshness prediction to realize non-destructive testing.

Study on Meta-heuristics techniques for shade dispersion to enhance GMPP of PV array systems under PSCs

Reconfiguring the photovoltaic modules in an array is one option for reducing the influence of partial shadowing circumstances, which shows the shade dispersion property on the entire photovolatic array. This paper proposes a novel meta-heuristic optimization technique named Vommi that resolves the reconfiguration process of shaded modules in a photovoltaic array. Using the proposed objective function, the major goal of this unique optimization technique is to maximize the power extracted from the shaded PV array during shading conditions. The proposed meta-heuristic Vommi optimization algorithm is compared to conventional total cross-tied, and particle swarm optimization algorithm-based configurations in terms of power at the global maximum power point, improved fill factor, power losses, execution ratio, etc. The global maximum power point of the Vommi optimization algorithm configuration delivers such as 990 W, 1283 W, 1181 W, and 1173 W, which are higher than conventional approaches during all four partial shodowing circumstances and smoother power-voltage characteristics..

Optimization of Module Partition Based on the Weighted Clustering Method for a Wideband Irregular Subarrayed Array

In wideband beam scanning with module-level time delay and subarray-level phase shifting methods in irregular subarrayed planar arrays, obtaining the optimal module partition is a critical challenge. In this paper, we propose a module partition optimization method based on the weighted clustering method. Firstly, we demonstrate that pattern matching is equivalent to the subarray-level excitation matching principle. Then we transform the complex optimization model into a real clustering optimization framework based on the second-order Taylor approximation, which reduces the computational complexity. Next the weighted clustering method is proposed to reduce the matching error by modifying the membership rule and cluster center of K-means clustering, ultimately obtaining the optimized module partition scheme. Additionally, we propose a minimum module quantity estimation method to explore the relationship between array bandwidth and module quantity. The proposed methods are applicable to both uniform and non-uniform weighting cases. The effectiveness and potential of the proposed method are verified by different numerical experiments and comparison of state-of art method.

Power losses in PV arrays of field-aged modules

Most of studies are focused mainly on performance degradation analysis of solar cell or categorizing PV failure modes concerning solely climate or cell-technology. However, the impact of degradation modules on output power of PV arrays remains somewhat unclear and has not been reported so far. Therefore, main task of the present work is to get a general view of mismatch effect on PV arrays output for aged panels. Photovoltaic current-voltage characteristics of the 10 individual modules at Research Unit in Renewable Energies in Saharan Medium were measured and recorded. Measurements are based on the analysis of mismatch losses due to series and parallel connection of aged PV modules. Degradation data and the analysis of the I-V characteristics indicate that the tested modules have suffered in the hot desert. Both of visual and electrical degradation data reaffirm the direct relation between observed physical degradation and output power drop. Results and analysis of the I-V characteristics and degradation data indicate that Power losses in crystalline PV modules are also due to mismatch in the I-V characteristics of these modules. The paper provides many findings that can be beneficial in further studies on design of aged PV array and development of a crystalline silicon PV module and can enable the manufacturers to prevent premature failure in desert climates.

An Adaptive Maximum Power Point Tracker for Photovoltaic Arrays Using an Improved Soft Computing Algorithm

This paper presents an improved version of the firefly algorithm (FA) by which a maximum power point (MPP) tracker was developed to track down the global maximum power point (GMPP) of a partially shaded photovoltaic module array (PVMA). As the first step, our team developed a high-voltage step-up converter where a coupled inductor was used to store the energy so that the duty cycle can be reduced so as to raise the voltage gain. The single-peaked P-V output characteristic curve of a PV array turns out to contain multiple peaks when the array is partially shaded. As a consequence, conventional MPP trackers occasionally track down a local maximum power point (LMPP), instead of the desired GMPP, and the output power of the array falls accordingly. Therefore, an improved version of the FA is proposed as a way to ensure that the GMPP can be tracked down in a more efficient way. Using the Matlab software, the MPP tracking performance of the proposed tracker was finally simulated in five scenarios. As it turned out, the proposed converter provided a high voltage gain at a relatively low duty cycle, and the improved version of the FA outperformed the original in terms of tracking time.

800 Gbit/s QSFP-DD Transceiver Based on Thin-Film Lithium Niobate Photonic Integrated Circuit

800G Ethernet is expected to be the dominant solution for the next generation inter- and intra-data-center connections. To boost the transmission capacity to 800Gb/s, utilizing multi-level pulse amplitude modulation (PAM) transmitting format and adopting multiple lanes are competitive solutions. In this paper, we demonstrate a PAM4-modulated 800G QSFP-DD transceiver integrated with two 4×100G thin-film lithium niobate (TFLN) DR4 modulator chips. The DR4 modulator chips have a 13.5 dB insertion loss (including the inherent 3 dB modulation loss and 6 dB splitting loss) and one DR4 chip requires one 17 dBm light source. The EO response has a 40 GHz bandwidth at 2.3 dB and the electric reflection keeps below -12 dB. The eight channels of 800G transceiver have a clear open eye patterns at 1.5 Vpp driving voltage under 53.125 Gbaud PAM-4 modulation with all the ERs above 4.03 dB and TDECQ's below 2.13 dB. The sensitivity of the receiver is around -8.6 dBm after 2 km and back-to-back transmission with the BER of all the channels below the DR4 forward error correcting threshold. It is demonstrated that our 800G QSFP-DD transceiver meets 400GBASE-DR4 standards and packaging requirements simultaneously. This is the first time that 4×100G DR4 modulator array based on TFLN and 800G QSFP-DD transceiver based on TFLN are reported to the best of our knowledge.

Overall Design and Power Generation Calculation of Photovoltaic System in Shanyin meteorological station

Based on the data of Shanyin meteorological station and Solargis database, this paper evaluates the local solar energy resources, and carries out the overall scheme design and power generation estimation of the feasibility study stage of the 50MW photovoltaic power generation project in Shanyin county. After analysis, it is proposed to select crystalline silicon solar modules for the project. The specification of polycrystalline silicon solar modules is 305wp, and the specification of monocrystalline silicon solar modules is 315wp. It is recommended to adopt fixed installation for the photovoltaic module array. In addition, the component support of the project is fixed with an installation angle of 35°. 500mx inverter is selected for the project because of its high cost performance ratio. Based on the above work, the total power generation in 25 years is calculated.

A mm-Wave Frequency Modulated Transmitter Array for Superior Resolution in Angular Localization Supporting Low-Latency Joint Communication and Sensing

Joint sensing-and-communication is envisioned to play a major role in emerging mm-Wave wireless systems to perform rapid tracking of wireless nodes for reliable wireless communication and ubiquitous distributed sensing. Phased arrays are essential to realize high array gains and enhance the communication distance. However, their pencil sharp beams require precise localization and tracking of wireless nodes to maintain beam alignment and reliable communication, especially in mobile wireless links. In parallel, array-based mm-Wave radars require large arrays for precise angular resolution that is fundamentally limited by the form factor and power consumption of the radar systems. We propose a frequency modulated array (FMA) transmitter (Tx) to convert locations/positions to timing information, which supports dual-modes for joint sensing-and-communication: rapid and precise full field-of-view (FoV) receiver (Rx) localization in the Tx/Rx localization mode for wireless communication and target angular detection in its radar mode. Exploiting its unique joint space-time-frequency dependent signals, the FMA distinguishes spatial signatures far below its array 3-dB beamwidth, i.e., achieving super-resolution and can simultaneously localize multiple Rx nodes or detect multiple targets in “one-shot.” Moreover, FMA only adds minimal circuit/computation overhead on traditional multi-in multi-out (MIMO) arrays. A proof-of-concept 28-GHz four-element multi-mode FMA Tx array is implemented in a 45 nm CMOS silicon on insulator (SOI) process. Over-the-air (OTA) measurements with Rx nodes in the communication-mode or reflectors in radar-mode demonstrate the four-element FMA Tx array operations and achieve a full-FoV coverage with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt;$</tex-math> </inline-formula> 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> –4 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> accuracy in angular localization with a 10 ns timing resolution (i.e., 100 MHz digital clock in Rx). Sensing aided communication is demonstrated to create sharp and secure constellation decomposition array (CDA) 64 quadratic-amplitude modulation (QAM) beams toward target Rx at low rms error vector magnitude (EVM) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&lt;$</tex-math> </inline-formula> 5.33% using the sensed data from FMA based Rx localization scheme.

MXene/perovskite-based bionic human odor sensor array with machine learning

Human identification is crucial in many fields. However, it is challenging to achieve instant and accurate human identification through body odors. In this work, an in-situ growth strategy was utilized to establish a gas-sensitive nanocomposite material library with MXene and perovskite. A plug-and-play bionic sensor array module based on the material library was manufactured and assembled into an instant detection platform (IDP). Machine learning (ML) algorithms were introduced to assist IDP in identifying human odors. Due to its unique Schottky Barrier structure, the material library exhibited higher performance and responded 37 % ∼ 70 % higher than initial MXene. IDP was applied to detect the odors of volunteers’ breaths and clothes with an accuracy rate of 69.2 % and 51.1 %, respectively, with the assistance of ML. In all, an instant, convenient, and accurate human identification prototype machine was fabricated, providing a general solution for more complex application scenarios.

Maximum Power Point Tracking of Photovoltaic Module Arrays Based on a Modified Gray Wolf Optimization Algorithm

In this study, a modified gray wolf optimization algorithm (GWOA) was proposed to facilitate the maximum power point tracking (MPPT) of photovoltaic module arrays (PMAs). To increase the voltage conversion ratio and achieve a voltage boost through reduced duty cycles, a high-voltage step-up converter with a coupled inductor was used to replace the conventional energy storage inductor. To achieve global MPPT, the iteration parameters of the proposed GWOA were adjusted according to the slope of the PMA power–voltage (P–V) curve. According to the simulation results, the modified GWOA is more effective in MPPT than the perturbation and observation algorithm and conventional GWOA when multiple peaks appear in the P–V curve of a shaded PMA. In addition, the modified GWOA exhibits an improved tracking speed response and steady-state response.

An Maximum Power Point Tracker of Photovoltaic Module Arrays Based on Improved Firefly Algorithm

In this paper, an improved firefly algorithm (FA) was proposed for application on photovoltaic module arrays (PVMAs) with partial modules under shading so that the maximum power point tracking (MPPT) could be implemented. Firstly, a new model of high voltage step-up converter was developed for executing the MPPT of the PVMA. For the energy storage inductor of the developed converter, the architecture of the coupled inductor was adopted so that the converter switch did not need to operate under an excessive duty cycle, which could increase the voltage gain and reduce the ripple of the output voltage at the same time. To prevent shading on the partial modules within the PVMA and generate more than one peak on the power-voltage (P-V) output characteristic curve, where the conventional MPPT could only track the local maximum power point (LMPP) and reduce the output power of the PVMA, the maximum power tracker, based on the improved FA, was proposed in this paper. Such a tracker could perform an automatic online adjustment on the FA iteration parameters, according to the slope of the P-V output characteristic curve, for the PVMA and, at the same time, perform at 0.8 times of the maximum power point (MPP) voltage for the module array under standard test condition (STC), serving as the initial tracking voltage for implementing the global maximum power point tracking (GMPPT). Lastly, the actual test results were applied to verify that the proposed converter indeed contained a high voltage step-up and low-ripple output voltage. The improved FA could also track GMPP faster and further improve the power-generating efficiency of the PVMA.

Green quality by design HPLC approach for the simultaneous determination of Bilastine and Montelukast

For the simultaneous estimation of two co-formulated antihistaminic drugs (Bilastine and Montelukast), a novel and eco-friendly reversed-phase HPLC approach with both diode array and fluorescence detection modes was designed. Rather than using the routine methodology, the Quality by Design (QbD) approach was adopted to speed up the method development and to test robustness of the method. To evaluate the effect of variable factors on chromatographic response, a full factorial design was used. The chromatographic separation was performed using isocratic elution on the C18 column. The mobile phase consists of 92% methanol, 6% acetonitrile, and 2% phosphate buffer with 0.1 (v/v) triethylamine adjusted to pH 3, it was pumped at a flow rate of 0.8 mL/min with an injection volume of 20 μL. The developed stability indicating HPLC approach was used to assess the stability of montelukast (MNT). It was subjected to a variety of stress conditions, including hydrolytic (acid–base), oxidative, thermal, and photolytic stress conditions. All of these conditions were found to have relevant degradation pathways. Under the described experimental conditions, MNT degradation followed pseudo-first-order kinetics. The kinetic parameters of its degradation (rate constant and t1/2) were calculated and a proposal for the degradation pathway was postulated.

Phase and Polarization Digitally Modulated Array Using Reconfigurable DR Element: Proposal, Design, and Verification

The proposal, design, and verification of a phase and polarization digitally reconfigurable / modulated array using the reconfigurable dielectric resonator (DR) elements are developed in this paper. Different from the conventional phased arrays and reconfigurable antennas, the radiated electromagnetic (EM) wave can be flexibly controlled by simultaneously modulating its phase and polarization. To realize phase switching, a clever 1-bit phase shifter (0° / 180°) is introduced in the element design. The polarization states are controlled by integrating the switch-loaded feeding structure. And a compact 2-bit polarization tuner (0°-LP, 90°-LP, RHCP, and LHCP) is finally realized. Since every element can realize 1-bit phase and 2-bit polarization switching, the far-field beams and polarization types of the array format can be arbitrarily modulated by designing the coding sequence. To verify the proposed working principle, a compact reconfigurable metasurface-loaded DR element, and a four-element digitally reconfigurable linear array are implemented, respectively. The overlapped -10 dB impedance and 3 dB axial ratio bandwidths are 2.35-2.55 GHz (12.5 %) and 2.42-2.48 GHz (2.4 %), respectively (Covering 2.40 GHz WIFI / BT band). More importantly, it can achieve 16 different beam & polarization modes. The proposed antennas exhibit a low-cost, compact size, good bandwidth, and flexible radiation modulation capacity. They are promising candidates for future smart antennas to manipulate and control electromagnetic (EM) waves.

Three-Dimensional Active Incoherent Millimeter-Wave Imaging

A new 3-D active incoherent millimeter-wave (3-D AIM) imaging method is introduced in this article. By utilizing a sparse interferometric receive array and pulse modulation in the transmitted noise signals we demonstrate far-field incoherent imaging in three dimensions. Interferometric image formation is based on the spatio-temporal incoherence of the signals emitted by or scattered from the imaging scene. To support this, we use active noise transmission from multiple independent transmitters which provide incoherent illumination in space (azimuth and elevation) and time. Two-dimensional (azimuth-elevation) image formation in this manner only requires statistical knowledge of the waveforms, greatly simplifying the imaging system. In this work, we modulate the transmitted waveforms to impart range-dependent information that can be used to also obtain range, supporting imaging in three dimensions. We modulate a Gaussian pulse onto the noise waveforms and apply incoherent pulse integration to provide sufficient spatio-temporal decorrelation of the signals. We introduce a new 3-D Fourier image formation algorithm, provide imaging simulations, and include experimental image reconstructions from a 38 GHz millimeter-wave imaging system. Video-rate 3-D imagery of a moving target is presented to demonstrate the feasibility of the approach for real-time 3-D imaging applications.

Large-Scale Terahertz Sensor Array Module With Antenna-Coupled Microbolometers on Glass Substrate With Sigma–Delta ADC Readout ASIC

We describe the design, fabrication and demonstration of a terahertz sensor array module, designed to operate over 250-350GHz. The antenna coupled microbolometer was fabricated on a glass substrate with an integrated array of pixel switches and row multiplexing circuitry implemented with LTPS (Low Temperature PolySilicon) thin film transistors. While other microbolometer arrays have been reported for the upper Terahertz bands, we focus on lower frequencies where adequate semiconductor sources are available potentially enabling important medical and security applications. The devices were fabricated in a Gen 3.5 flat panel manufacturing facility implementing what we call Large Area MEMS Platform (LAMP) surface micromachining process, providing a path to low-cost manufacturing. Individual pixels were defined on a 0.7mm pitch across an array of 128x128 pixels in this first demonstration. Since flat panel fabrication capabilities use large, single-shot reticle masks and large glass substrates, physically larger arrays can be manufactured without mask stitching. An ROIC (readout integrated circuit) was demonstrated to support the THz sensor panel with 648 input channels, each providing an independent sigma delta ADC with excellent uniformity and 12 effective number of bits. An early demonstration of the sensor array is described, imaging a metallic knife hidden in a cardboard envelope.

Technical modelling of solar photovoltaic water pumping system and evaluation of system performance and their socio-economic impact

Water is a precious resource for agriculture and most of the land is irrigated by tube wells. Diesel engines and electricity-operated pumps are widely used to fulfill irrigation water requirements; such conventional systems are inefficient and costly. With rising concerns about global warming, it is important to choose renewable energy source. In this study, SPVWPS has been optimally designed considering the water requirement, solar resources, tilt angle and orientation, losses in both systems and performance ratio. A PVSyst and SoSiT simulation tools were used to perform simulation analysis of the designed solar photovoltaic WPS. After designing and performance analysis, farmers were interviewed during fieldwork to assess socioeconomic impacts. In the result section, performance of PV system is analyzed at various tilt angles and it is established that system installed at a 15° tilt angle is more efficient. The annual PV array virtual energy at MPP of designed photovoltaic system is 33342 kWh and the annual energy available to operate the WPS is 23502 kWh. Module array mismatch and ohmic wiring losses are 374.16 kWh and 298.83 kWh, respectively. The total annual water demand of the selected site is 80769 m³ and designed SPWPS pumped 75054 m³ of water, supplying 92.93% of the irrigation demand. The normalized values of the effective energy, system losses, collection losses and unused energy in the SPVWP system are 2.6 kW/kWp/day, 0.69 kW/kWp/day, 0.72 kW/kWp/day and 0.48 kW/kWp/day, respectively. The annual average performance ratio of the proposed system is 74.62%. The results of the interviews showed that 70% of farmers are extremely satisfied with the performance of SPVWPS and 84% of farmers indicated that they did not incur any operating costs. The unit cost of the SPWPS is 0.17 €/kWh, which is 56.41% and 19.04% less expensive than the cost of diesel and grid electricity.

An Improved Photovoltaic Module Array Global Maximum Power Tracker Combining a Genetic Algorithm and Ant Colony Optimization

In this paper, a hybrid optimization controller that combines a genetic algorithm (GA) and ant colony optimization (ACO) called GA-ACO algorithm is proposed. It is applied to a photovoltaic module array (PVMA) to carry out maximum power point tracking (MPPT). This way, under the condition that the PVMA is partially shaded and that multiple peaks are produced in the power-voltage (P-V) characteristic curve, the system can still operate at the global maximum power point (GMPP). This solves the problem seen in general traditional MPPT controllers where the PVMA works at the local maximum power point (LMPP). The improved MPPT controller that combines GA and ACO uses the slope of the P-V characteristic curve at the PVMA work point to dynamically adjust the iteration parameters of ACO. The simulation results prove that the improved GA-ACO MPPT controller is able to quickly track GMPP when the output P-V characteristic curve of PVMA shows the phenomenon of multiple peaks. Comparing the time required for tracking to MPP with different MPPT approaches for the PVMA under five different shading levels, it was observed that the improved GA-ACO algorithm requires 19.5~35.9% (average 29.2%) fewer iterations to complete tracking than the mentioned GA-ACO algorithm. Compared with the ACO algorithm, it requires 74.9~79.7% (average 78.2%) fewer iterations, and 75.0~92.5% (average 81.0%) fewer than the conventional P&amp;O method. Therefore, it is proved that by selecting properly adjusted values of the Pheromone evaporation rate and the Gaussian standard deviation of the proposed GA-ACO algorithm based on the slope scope of the P-V characteristic curves, a better response performance of MPPT is obtained.