High Efficiency Ferrite-Free Closed-Loop InductivelyCoupled Low Mercury Pressure Discharge UV Lamps

2020 ◽  
pp. 73-79
Author(s):  
Pavel V. Starshinov ◽  
Oleg A. Popov ◽  
Rimma A. Ilikeeva ◽  
Darya A. Bureeva ◽  
Igor V. Irkhin ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Closed Loop ◽  
High Efficiency ◽  
Gas Pressure ◽  
Induction Coil ◽  
Mercury Vapour ◽  
Buffer Gas ◽  
Inductively Coupled ◽  
Linear Resistance ◽  
Uv Lamps

Radiation and electrical characteristics of ferrite-free closed-loop inductively-coupled low mercury pressure UV lamps of 375 mm in length and 120 mm in width were experimentally studied. Discharges were excited at a frequency of 1.7 MHz and lamp RF power, Рlamp = (95–170) W. It was in quartz closed-loop tubes of 16.6 mm in inner diam. and of 815 mm in length, in the mixture of mercury vapour (7 х 10–3 mm Hg) with Ar (0.7 and 1.0 mm Hg) and with the mixture of 30 % Ne + 70 % Ar (0,7 and 1,0 mm Hg). The 3-turn induction coil made from litz wire with a low specific linear resistance (ρw = 1.4 x 10–4 Ohm/cm) was disposed on the lamp surface along the closed-loop tube perimeter. In lamps with buffer gas pressure of 1,0 mm Hg, the increase of lamp power from 95 to 150 W caused the decrease of induction coil power losses, Pcoil, from (6–7) W to (3–4) W. Also in these lamps increased induction coil power efficiency, ƞcoil = 1 – Pcoil/Plamp, from 92 % to 97 % and lamp UV radiation (λ = 254 nm) generation efficiency, ƞe, 254, from 57 % to 66 %. The decrease of buffer gas pressure from 1.0 to 0.7 mm Hg caused the decrease of ƞe, 254 by (10–20)%.

Power Losses in RF Inductor of Ferrite-Free Closed-Loop Inductively-Coupled Low Pressure Mercury Lamps

2020 ◽  
pp. 89-94 ◽  
Author(s):  
Ekaterina V. Lovlya ◽  
Oleg A. Popov
Keyword(s):  
Closed Loop ◽  
Low Pressure ◽  
Mercury Vapour ◽  
Plasma Power ◽  
Power Losses ◽  
Inductive Discharge ◽  
Inductively Coupled ◽  
Radial Inhomogeneity ◽  
Transformer Model ◽  
Rf Inductor

RF inductor power losses of ferrite-free electrode-less low pressure mercury inductively-coupled discharges excited in closed-loop dielectric tube were studied. The modelling was made within the framework of low pressure inductive discharge transformer model for discharge lamps with tubes of 16, 25 and 38 mm inner diam. filled with the mixture of mercury vapour (7.5×10–3 mm Hg) and argon (0.1, 0.3 and 1.0 mm Hg) at RF frequencies of 1, 7; 3.4 and 5.1 MHz and plasma power of (25–500) W. Discharges were excited with the help of the induction coil of 3, 4 and 6 turns placed along the inner perimeter of the closed-loop tube. It was found that the dependence of coil power losses, Pcoil, on the discharge plasma power, Ppl, had the minimum while Pcoil decreased with RF frequency, tube diameter and coil number of turns. The modelling results were found in good qualitative agreement with the experimental data; quantitative discrepancies are believed to be due skin-effect and RF electric field radial inhomogeneity that were not included in discharge modelling.

HIGH-GAIN/EFFICIENCY MULTISTAGE SWITCHED-CAPACITOR-VOLTAGE-MULTIPLIER DC–DC CONVERTER

2012 ◽  
Vol 21 (03) ◽  
pp. 1250023
Author(s):  
YUEN-HAW CHANG
Keyword(s):  
Power Efficiency ◽  
Closed Loop ◽  
Pulse Width Modulation ◽  
High Efficiency ◽  
Conversion Ratio ◽  
Switched Capacitor ◽  
Two Phase ◽  
Analysis And Design ◽  
Voltage Multiplier ◽  
Capacitor Voltage

A closed-loop interleaved multistage switched-capacitor-voltage-multiplier (mc × nc-stage SCVM) dc–dc converter is proposed by combining a variable-conversion-ratio (VCR) and pulse-width-modulation (PWM) control for low-power step-up conversion and high-efficiency regulation. In this SCVM, the power part is composed of two mc-stage SC cells (front) and two nc-stage SC cells (rear) in cascade, and these cells are operated by two-phase nonoverlapping clocks for an interleaved operation with voltage gain of mc × nc at most. This paper presents the VCR control to change the running stage number m,n and topological path for a more flexible and suitable gain level m × n (1 × 1, 2 × 1, 2 × 2, 3 × 1, 3 × 2, 3 × 3,…, mc × nc) according to the desired output so as to improve power efficiency, especially for the lower output. Besides, PWM is adopted not only to enhance output regulation for different outputs, but also to reinforce output robustness to source/loading variation. Further, some theoretical analysis and design include: SCVM model, steady-state analysis, conversion ratio, power efficiency, output ripple, stability, capacitance selection, and control design. Finally, the closed-loop SCVM is simulated, and the hardware is implemented and tested. All the results are illustrated to show the efficacy of the proposed scheme.

ElectrodeLess FerriteFree ClosedLoop InductivelyCoupled Fluorescent Lamp

2018 ◽  
pp. 140-142 ◽  
Author(s):  
Oleg A. Popov ◽  
Pavel V. Starshinov ◽  
Victoriya N. Vasina
Keyword(s):  
Closed Loop ◽  
Copper Wire ◽  
Glass Tube ◽  
Luminous Flux ◽  
Induction Coil ◽  
Mercury Vapour ◽  
Plasma Power ◽  
Fluorescent Lamp ◽  
Power Losses ◽  
Pressure Discharge

Electrode-less ferrite-free inductivelycoupled low pressure discharge was excited in the mixture of mercury vapour (~10–2 Torr) and argon (0.1 Torr) at a frequency of 2.0 MHz and lamp RF powers of (150–202) W with the help of a 6turn induction coil. The discharge lamp of rectangular shape (50 cm in length and 7 cm in height) employed a closed-loop glass tube of 30 mm in diam. Tube walls inner surface was coated with three-color phosphor (Тcc = 3100 K, Ra = 80). The induction coil made from silver-coated copper wire (ρw = 2.2x10–3 Ohm/cm) was disposed on the atmospheric side of tube walls, along closed-loop lamp tube perimeter. As plasma power, Ppl, grew from 127W to 180 W, coil power losses practically were unchanged, Pcoil = (25–22) W. Lamp luminous flux, Фv, grew with plasma power from 10430 lm (Ppl =127 W) to 13500 lm (Ppl =180 W), while plasma efficacy, ηpl = Фv/Ppl, decreased from 82 to 75 lm/W, and lamp efficacy ηV = Фv/(Ppl + Pcoil) decreased from 70 to 67 lm/W.

Inductor and Plasma Characteristics of Ferrite-Free Inductively-сoupled Amalgam Ultraviolet Lamps with Closed-loop Small Diameter Discharge Tubes

Vestnik MEI ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. 98-111
Author(s):  
Oleg A. Popov ◽  
◽  
Pavel V. Starshinov ◽  
Rimma A. Ilikeeva ◽  
Darya A. Bureeva ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Closed Loop ◽  
Unit Length ◽  
Small Diameter ◽  
Mercury Vapor ◽  
Induction Coil ◽  
Buffer Gas ◽  
Plasma Power ◽  
High Efficient ◽  
Radiation Generation

The electrical and radiation characteristics of innovative high-efficient 254-nm wavelength ultraviolet (UV) radiation sources employing ferrite-free inductively-coupled low-pressure discharges excited in closed-loop quartz tubes are experimentally studied. The discharge was excited using a 3-turn induction coil at a frequency of 1.7 MHz and lamp power equal to 90-160 W in a mixture of mercury vapor at a pressure of around 0.01 mmHg and buffer gas (Ar, a mixture of 30%Ne+70%Ar) at pressures of 0.7 and 1.0 mmHg in a closed tube 16.6 mm in diameter and 815 mm long. The coil turns made of multiconductor wire (Litz wire) with a low per unit length resistivity of 0.00014 Ωm/cm and 1.5 mm in diameter were arranged over the discharge tube perimeter. It was found that, as the lamp power was increased, the power loss in the induction coil wire decreased from 7-9 to 3-4 W, and the coil efficiency increased from 92 to 98%. In lamps filled with buffer gas at a pressure of 1.0 mmHg, the maximal plasma UV radiation generation efficiencies equal to 68% and 66%, respectively, were achieved at plasma power levels of 105-155 W. The decrease of buffer gas pressure to 0.7 mmHg entails a drop of lamp UV radiation generation efficiency by 10-20% and a shift of its maximum values to the zone of lower plasma power values.

HIGH-EFFICIENCY 2-STAGE MULTIPHASE SWITCHED-CAPACITOR CONVERTER VIA VARIABLE-PHASE AND PWM CONTROL

2010 ◽  
Vol 19 (08) ◽  
pp. 1753-1780
Author(s):  
YUEN-HAW CHANG
Keyword(s):  
Power Efficiency ◽  
Closed Loop ◽  
High Efficiency ◽  
Dynamic Error ◽  
Output Regulation ◽  
Switched Capacitor ◽  
Voltage Gain ◽  
Variable Phase ◽  
Analysis And Design ◽  
Switched Capacitor Converter

A closed-loop scheme of 2-stage multiphase switched-capacitor (MPSC) converter is proposed by combining variable-phase control (VPC) and pulse-width-modulation (PWM) technique for low-power DC-DC step-up conversion and high-efficiency output regulation. In this MPSC, there are 2 voltage doublers in series for boosting voltage gain up to 4 at most. Here, VPC is suggested to improve power efficiency, especially for the lower output voltage. It realizes a variable multiphase operation by changing MPSC topological path for more suitable level of voltage gain (4x/3x/2x/1x) according to the desired output. Besides, PWM is adopted for better output regulation not only to compensate dynamic error, but also to reinforce robustness against source/loading variation. Further, the theoretical analysis and design include: MPSC model, steady-state analysis, power efficiency, conversion ratio, ripple percentage, capacitance selection, stability, and control design. Finally, the closed-loop MPSC is simulated, and the hardware implementation is realized and tested. All the results are illustrated to show the efficacy of the proposed scheme.

Electrical Characteristics of the High-frequency Induction Coil for Low Pressure Discharge in Ferrite-free Closed-loop Tubes

Vestnik MEI ◽  
2021 ◽  
pp. 95-104
Author(s):  
Ekaterina V. Lovlya ◽  
◽  
Oleg A. Popov ◽  
Ilya A. Oshurkov ◽  
◽  
...  
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Tube Diameter ◽  
Induction Coil ◽  
Spatial Inhomogeneity ◽  
Design Parameters ◽  
Mercury Vapour ◽  
Driving Frequency ◽  
Plasma Power ◽  
Field Frequency

The effect the high-frequency field frequency and lamp design parameters have on the performance characteristics of the inductor of a ferrite-free inductively-coupled closed-loop tube is studied within the framework of a transformer model. The discharge was excided in tubes with diameters equal to 16, 25 and 38 mm in a mixture of mercury vapour (~ 0.01 mm Hg) and argon (0.6 mm Hg) at driving frequencies equal to 1.7, 3.4 and 8.5 MHz and plasma power equal to 25–200 W by means of an induction coil containing 1, 2 and 3 turns, and placed over the closed-loop tube inner perimeter. It has been found that the dependences of inductor high-frequency current and voltage, and power loss in the coil wire on the discharge plasma power have a minimum, which shifts toward lower power levels with increasing the driving frequency and discharge tube diameter. The minimal values of coil current, voltage, and power losses decrease with increasing the driving frequency, tube diameter and number of coil turns. The prediction results are in satisfactory qualitative agreement with the experimental data; the mismatches are supposedly due to the assumptions adopted in the model, according to which the skin effect and electric field spatial inhomogeneity were not taken into account.

Electric and Radiation Characteristics of Ferrite-free Closed-loop Inductively-coupled Mercury Discharge UV-lamps

Vestnik MEI ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 87-97
Author(s):  
V. Starshinov ◽  
◽  
Oleg A. Popov ◽  
Igor V. Irkhin ◽  
Viktoriya N. Vasina ◽  
...  
Keyword(s):  
Closed Loop ◽  
Radiation Characteristics ◽  
Inductively Coupled ◽  
Uv Lamps

A High Efficiency Induction Coil

1915 ◽  
Vol 80 (2086supp) ◽  
pp. 412-414
Author(s):  
Louis B. Laruncet
Keyword(s):  
High Efficiency ◽  
Induction Coil

The Characteristics of a Ferrite-free Closed-loop Inductively-coupled Low-pressure Mercury Discharge Lamp

Vestnik MEI ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 89-96 ◽  
Author(s):  
Oleg A. Popov ◽  
◽  
Pavel V. Starshinov ◽  
Viktoriya N. Vasina ◽  
◽  
...  
Keyword(s):  
Closed Loop ◽  
Low Pressure ◽  
Inductively Coupled ◽  
Discharge Lamp

scholarly journals High-efficiency method for recycling lithium from spent LiFePO4 cathode

2020 ◽  
Vol 9 (1) ◽  
pp. 1586-1593
Author(s):  
Tingting Yan ◽  
Shengwen Zhong ◽  
Miaomiao Zhou ◽  
Xiaoming Guo ◽  
Jingwei Hu ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
High Efficiency ◽  
Optical Emission ◽  
Extraction Process ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Moisture Analysis ◽  
Lifepo4 Cathode ◽  
Solid Liquid

Abstract The extraction of Li from the spent LiFePO4 cathode is enhanced by the selective removal using interactions between HCl and NaClO to dissolve the Li+ ion while Fe and P are retained in the structure. Several parameters, including the effects of dosage and drop acceleration of HCl and NaClO, reaction time, reaction temperature, and solid–liquid ratio on lithium leaching, were tested. The Total yields of lithium can achieve 97% after extraction process that lithium is extracted from the precipitated mother liquor, using an appropriate extraction agent that is a mixture of P507 and TBP and NF. The method also significantly reduced the use of acid and alkali, and the economic benefit of recycling is improved. Changes in composition, morphology, and structure of the material in the dissolution process are characterized by inductively coupled plasma optical emission spectrometry, scanning electron microscope, X-ray diffraction, particle size distribution instrument, and moisture analysis.

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