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Grid Interactive Single Stage Solar Powered Water Pumping System Utilizing Improved Control Technique
摘要： This paper proposes a single stage grid interactive solar powered switched reluctance motor (SRM) driven water pumping system with an efficient control technique. The control of proposed system provides the proficient maximum power point technique (MPPT) tracking and motor drive control with bidirectional power flow between the photovoltaic (PV) array and single phase grid. It has harmonics components elimination, improved dynamic performance and a DC offset rejection capability compared to other control. A PV feed-forward term is also incorporated in developed control to enhance the dynamic performance of the system and to minimize the size of DC link capacitor with improved MPPT performance. The novel scheme of fundamental switching of SRM drive over its maximum operational time (when the grid is present) makes system efficient and reliable. An improved perturb and observe (P&O) based maximum power point tracking (MPPT) algorithm is used in this system to minimize the undesirable losses in a PV array specially under varying insolation levels. The proposed control is tested on a developed prototype and its suitability is authenticated through simulated and test results under various conditions.
关键词： MPPT,Bidirectional Power Flow,Water Pump,Switched Reluctance Motor,VSC,PV Array,Power Quality
更新于2025-09-23 15:23:52
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Novel High Gain, High Efficiency DC–DC Converter Suitable for Solar PV Module Integration With Three-Phase Grid Tied Inverters
摘要： This paper proposes a novel configuration for high gain, high efficiency dc–dc converter comprising a single switch, two intermediate capacitors, and a coupled inductor for low voltage solar PV module fed applications. The high voltage gain is achieved by charging the intermediate capacitors through the coupled inductor in parallel and discharging in series. In a two winding coupled inductor, considered in the presented work, maximum two intermediate capacitors can be integrated with the secondary winding. A passive lossless clamped circuit is also provided in the converter, which recovers the leakage energy to improve the efficiency and alleviate large voltage spike. The structure of the circuit is such that the power device voltage stress is reduced thereby increasing the efficiency. The maximum power point tracking at various irradiation levels is implemented in the proposed converter. Laboratory prototype of a 300-W system with 30–45-V input and 700-V output was built to validate the theoretical claims. All the detailed analysis, simulation, and experimental waveforms are presented. A maximum converter efficiency of around 95% is achieved.
关键词： maximum power point tracking (MPPT),switched capacitor,solar PV,coupled inductor,dc micro-grid,step-up,high efficiency,3-φ inverter,low voltage,high gain,dc–dc converters
更新于2025-09-23 15:22:29
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All-fiber passively Q-switched erbium-doped laser with Cr <sup>2+</sup> :ZnSe nanocrystals saturable absorber
摘要： We experimentally demonstrate an all-fiber Q-switched erbium-doped laser using polyvinyl alcohol-based Cr2+:ZnSe nanocrystals (NCs) as saturable absorbers (SAs). The Cr2+:ZnSe NCs were produced by femtosecond laser ablation, and were spherical, with an average radius of about 107 nm. The nonlinear saturable absorption was characterized with a saturable optical intensity of 20 MW cm?2 and a modulation depth of ～24%. By placing the SA inside an erbium-doped fiber (EDF) laser cavity, a stable 3.152 μs pulse with a repetition rate of 34.452 kHz centered at 1564 nm was achieved, when pumped at the maximum pumping power of 300 mW. The maximum pulse energy reached 33 nJ and the signal-to-noise ratio was 48 dB. The results indicate that Cr2+:ZnSe NCs are promising for the development of a stable all-fiber passively Q-switched EDF laser.
关键词： Cr2+: ZnSe nanocrystals,passively Q-switched,all-fiber laser
更新于2025-09-23 15:21:01
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High-peak-power and narrow-linewidth Q-switched Ho:YAG laser in-band pumped at 1931 nm
摘要： We describe a high-peak-power, narrow-linewidth Q-switched Ho:YAG laser at 2097 nm wing-pumped by a high power and high brightness Tm:fiber source at 1931.5 nm. The laser was wavelength locked and spectrum narrowed utilizing a volume Bragg grating as the input coupler, resulting a linewidth (FWHM) of less than 0.1 nm. At 22.7 W of incident pump power, stable pulses of 5.5 mJ pulse energy and 17.5 ns of pulse duration have been generated at repetition frequency of 1 kHz, corresponding to peak power of 314.3 kW.
关键词： narrow-linewidth,Q-switched Ho:YAG laser,volume Bragg grating,1931.5 nm,high-peak-power
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Bombay, India (2019.3.29-2019.3.31)] 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Soft-Switching High Step-Up Active Clamp Coupled Inductor-Based Converter for Grid-Tied Solar Photovoltaic Applications
摘要： The Renewable energy source like solar Photovoltaic is desired to be worked at low voltages. For grid-tied applications, it requires high voltage conversion which results in a reduced efficiency. In this work, zero-voltage switching (ZVS) based dc-dc converter with high step-up active clamped coupled inductor is presented for grid-tied solar photovoltaic applications. For achieving high conversion ratio switched capacitor cell is inserted to coupled inductor secondary winding. With this combination, the difficulties of leakage inductance are overcome. The active clamp circuit is incorporated to overwhelm the voltage spikes across the switches and also to implement the ZVS operation for switching devices. Simulation results for the proposed dc-dc converter are presented with the theoretical analysis.
关键词： coupled inductor,soft-switching,switched capacitor cell,Active clamp
更新于2025-09-23 15:21:01
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A hybrid output multiport converter for standalone loads and photovoltaic array integration
摘要： Multiport converters (MPCs) are relatively recent power converter structures, which bestow the merits such as the omission of redundant power stages, centralized control, compact packaging, enhanced efficiency, improved reliability, and so on and have larger potential in domestic applications. They have the ability to amalgamate energy sources such as photovoltaic (PV) sources and battery storages, and can accommodate hybrid (ac and dc) domestic loads (bulbs, fans, induction stoves, and electric bike chargers). Hence, they can replace the conventional off-line uninterruptible power supplies, which are habitually used in domestic applications. The unique feature of MPCs is the ability to transfer the power between multiple sources and loads concurrently/independently. This article proposes cascaded sources switched tapping multi-level DC-link inverter (CSSTMLDCLI) involved hybrid loads MPC, which can integrate PV sources and feed above mentioned hybrid domestic loads. The involved novel seven level multilevel inverter structure, the CSSTMLDCLI has reduced component count to offer a high quality ac output, while the dc output is synthesized by a forward converter structure. The working principle of the CSSTMLDCLI along with the systematic design procedure is presented. The validity and effectiveness of the proposed converter are ratified through both MATLAB? Simulink R2016a simulation and the experimentation for a typical solar, battery, and grid supported domestic power backup. The system is managed for a lesser energy purchase using a developed minimal grid usage energy management system, which is implemented using ALTERA QUARTUS II 12.0SP2, field-programmable gate array processor.
关键词： hybrid load MPC (HLMPC),photovoltaic (PV),cascaded sources switched tapping multilevel DC-link inverter (CSSTMLDCLI),multilevel inverters (MLI),pulse width modulation (PWM),multiport converters (MPC)
更新于2025-09-23 15:21:01
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Prospective Study of Q Switched Alexandrite Laser 755a?ˉnm and V Beam Pulsed Dye Laser 595a?ˉnm in Dermatofibroma
摘要： Pulsed dye and carbon dioxide lasers have been applied in dermato?broma with clinical improvement. We treated 23 dermato?bromas two times at a 4-week interval with Q-Switched alexandrite laser 755 nm (7.5 J/cm2, 3 mm, 50 ms). V Beam pulsed dye laser with a wavelength of 595 nm was used for the residual erythema (10-11 J/cm2, 7 mm, 1.5 ms). A partial attenuation of brown colour was observed in 9 patients and complete disappearance of brown colour in 14 patients. Patient satisfaction was very high. Fifteen patients felt a decrease in hardening of dermato?broma after treatment. A pigment network in dermoscopy was observed in all patients before treatment and no one after treatment. A combined treatment using both V Beam pulsed dye laser and Q-Switched alexandrite laser may be a therapeutic option to reduce the aesthetic effect of dermato?broma with a high patient satisfaction and good cosmetic outcomes.
关键词： Q Switched alexandrite,Laser,Dermato?broma,Dermoscopy,V Beam pulsed dye
更新于2025-09-23 15:21:01
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TiOxNy Thin Film Sputtered on a Fiber Ball Lens as Saturable Absorber for Passive Q-Switched Generation of a Single-Tunable/Dual-Wavelength Er-Yb Double Clad Fiber Laser
摘要： The use of titanium oxynitride (TiOxNy) thin ?lms as a saturable absorber (SA) element for generation of passive Q-switched (PQS) laser pulses, from a linear cavity Er-Yb double-clad ?ber (EYDCF) laser, is demonstrated. Additionally, the deposition of the material as a thin ?lm covering a ?ber micro-ball lens (MBL) structure is reported for the ?rst time. The TiOxNy coating is deposited by a direct current (DC) magnetron-sputtering technique. The MBL is inserted within the laser cavity in a re?ection con?guration, alongside a re?ecting mirror. As a result, the coated ?ber MBL simultaneously acts as a SA element for PQS laser pulses generation and as an interference ?lter for wavelength selection and tuning of the generated laser line. Tunable single-laser emission in a wavelength range limited by dual-wavelength laser generation at 1541.96 and 1547.04 nm is obtained. PQS laser pulses with a repetition rate from 18.67 to 124.04 kHz, minimum pulse duration of 3.57 μs, maximum peak power of 0.359 W, and pulse energy of 1.28 μJ were obtained in a pump power range from 1 to 1.712 W.
关键词： Q-switched ?ber lasers,titanium oxynitride,DC magnetron sputtering,?ber micro-ball lens,saturable absorber materials
更新于2025-09-23 15:21:01
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ultra-fine tuning
摘要： Researchers from Xi’an University of Technology in China, alongside researchers from the ENSEIRB and the IERF in France, propose an auto-tuning network for a phased-array high intensity focused ultrasound (HIFU) system based on a variable synchronous switched capacitor. The novel system is capable of automatically compensating for the reactive power and impedance drifts, caused by temperature fluctuations and manufacturing errors, in circuit transducers and complies with magnetic resonance imaging (MRI) compatibility regulations.
关键词： phased-array,variable synchronous switched capacitor,high-intensity focused ultrasound,HIFU,Auto-tuning network,MRI compatibility
更新于2025-09-23 15:21:01
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Face and neck rejuvenation using an improved non-ablative fractional high power 1064-nm Q-switched Nd:YAG Laser: clinical results in 16 women
摘要： Objective: To evaluate the safety and efficacy of a specific treatment protocol using a new and improved non-ablative fractional high-power 1064-nm Q-switched Nd:YAG laser for face and neck rejuvenation. Methods: Sixteen women, aged 30 to 60 years old, were selected to undergo three consecutive treatment sessions with this new laser at maximum energy (2,400 mJ/pulse, Clear Lift laser?-Harmony XL-Pro, Alma Lasers Ltd.). Face and neck were treated in eight patients, respectively. Each treatment used the same protocol. The efficacy was evaluated by the therapist (TS), the patient (PS), and two separate independent experts who were blind to the study (E1 and E2). Results: According to E1 and E2, the mean reduction in signs of skin aging on a Global Esthetic Improvement Scale was 30-40%. Using a 0–10 points scale, TS and PS mean (range) satisfaction rates were 9.0 (8–10); 9.2 (6–10) for the face and 8.7 (8–10); 8.0 (3–10), for the neck, respectively. The procedure was practically painless, no significant adverse effects were observed, and the patients returned to their daily and work activities without downtime. Conclusion: This laser was safe and effective for face and neck minimally invasive rejuvenation, with excellent results using our usual routine use conditions.
关键词： fractionated laser,resurfacing,Q-Switched Nd:YAG laser,Skin rejuvenation,non-ablative laser
更新于2025-09-23 15:19:57