-
Comparison of Series/Series and Parallel/Series Resonance Circuit in 1.5 kW Inductive Wireless Power Transfer for EV Applications
Bhukya Bhavsingh,
G. Suresh Babu,
B. Mangu
Issue:
Volume 11, Issue 1, February 2023
Pages:
1-14
Received:
15 December 2022
Accepted:
6 January 2023
Published:
30 January 2023
Abstract: Wireless power transfer system plays a key role in the present and future days, because of their upgraded comfort and safety and their merits of less green-house gas (GHG) emissions, cell phones, laptops and electric vehicle charging. In this paper, the basic two resonance circuits were analyzed using an inductive wireless power transfer (IWPT) system, at 1.5 kW, 120-mm, and 85 kHz resonance frequencies. It includes analyzing, designing, and comparing this resonance circuit to choose a suitable resonant circuit for the particular application of an IWPT system. The main analysis and comparison were: Mutual Inductance Effect (Misalignment), stresses on the components, Effect of mutual inductance on the efficiency, Effect of distance on the efficiency, Effect of frequency on the efficiency, Effect of the coupling coefficient (k) on the efficiency and transferred power, Effect of coupling coefficient (k) on the input impedance, Effect of distance on the coupling coefficient (k) and Mutual inductance, and both S/S and P/S circuits have same battery output dc power, current, voltage levels. Both resonance circuits designing formulas derived, electrical parameters are calculated for the given wireless power charger level reaches SAEJ2954 standards. In the end, both resonance circuits are verified through MATLAB simulation of the equivalent circuits.
Abstract: Wireless power transfer system plays a key role in the present and future days, because of their upgraded comfort and safety and their merits of less green-house gas (GHG) emissions, cell phones, laptops and electric vehicle charging. In this paper, the basic two resonance circuits were analyzed using an inductive wireless power transfer (IWPT) sys...
Show More
-
Effect of Water and Aerosols Absorption on Laser Beam Propagation in Moist Atmosphere at Eye-Safe Wavelength of 1.57 μm
Issue:
Volume 11, Issue 1, February 2023
Pages:
15-22
Received:
4 January 2023
Accepted:
25 January 2023
Published:
6 February 2023
Abstract: To realize optical wireless power transmission, atmospheric propagation of eye-safe wavelength (1.57μm) laser beams was theoretically investigated. Laser beams are affected by the presence of water vapor and aerosols which absorb and scatter the laser energy. The scattering coefficients of water molecules and aerosols were estimated to be about 6.3 × 10-7 and 5.6 × 10-5 m-1, respectively, at wavelength (λ0) of 1.57μm. Furthermore, the absorption coefficients of moist air at 30% relative humidity and aerosols were estimated to be about 6.16 × 10-3 and 2.52 × 10-5 m-1, respectively, at λ0 = 1.57μm. Then simulation of laser beam propagation in the moist atmosphere at λ0 = 1.57μm was performed using these coefficients. Under the condition of no wind, the beam intensity decreases rapidly with increasing the length z and the rate of decrease slows down as the beam radius (ω) increases. When zh is defined as the z where the normalized intensity is halved, the zh (= 25 m) at ω = 20 mm when input power P = 10 W is about three times longer than that (= 8 m) when P = 100 W. This result indicates that the thermal distortion of laser beams due to accumulated heat around the z axis becomes more conspicuous as the optical power increases. The effect of this thermal beam distortion can be weakened when the laser beam is subject to crosswinds. Under the condition of gentle uniform wind with wind velocity v = 5 m/s, propagation of laser beams with ω = 20 mm was studied when P = 100 W. The zh (= 105 m) when v = 5 m/s is about 13 times longer than that (= 8 m) when v = 0 m/s. Thus, under conditions of v = 5 m/s and 30% relative humidity, laser beams with P = 100 W and ω = 20 mm can propagate over 100 m without damaging the initial beam shape at λ0 = 1.57μm.
Abstract: To realize optical wireless power transmission, atmospheric propagation of eye-safe wavelength (1.57μm) laser beams was theoretically investigated. Laser beams are affected by the presence of water vapor and aerosols which absorb and scatter the laser energy. The scattering coefficients of water molecules and aerosols were estimated to be about 6.3...
Show More
-
Design and Implementation of a Digital Control System for Lead Acid Battery Charging
Marie Danielle Fendji,
Franck Mbah Kimbong,
Ioannis Tsipouridis,
Pierre Tsafack
Issue:
Volume 11, Issue 1, February 2023
Pages:
23-33
Received:
10 January 2023
Accepted:
1 February 2023
Published:
14 February 2023
Abstract: Ensuring a long battery life and satisfactory performance requires accurate charging cycles. There are three phases to the charge cycle - Constant Current Charge, Constant Voltage Charge, and Float Charge. It is usual that lead acid battery users complain about fast degrading performance because most the low cost commercially available lead Acid Battery chargers provides only single-stage charging phase which is that of constant-voltage charging phase. To ensure long service life and good performance, it is of paramount importance that all charging modes are respected. This said it is clear that the battery charger should have a certain degree of controllability over voltage and current quantities through-out the charging process. In this paper, we designed and built a lead acid battery charger to use in conjunction with a synchronous buck converter topology. After implementing and testing the system, we obtained good results in both the quantitative and qualitative analysis of the implemented system tested, a 12 V- 7000mAh battery. With the help of a MCU-based digital control system containing two different control transfer functions - constant current Feedback Control and Constant Voltage Feedback Control monitoring the charging process proved possible without any overshoot. The prototype showed us an efficiency rating of 86.60%, the maximum error level was recorded at 0.05V, and there were no problems related to overshoot or transient response when testing our prototype which worked flawlessly.
Abstract: Ensuring a long battery life and satisfactory performance requires accurate charging cycles. There are three phases to the charge cycle - Constant Current Charge, Constant Voltage Charge, and Float Charge. It is usual that lead acid battery users complain about fast degrading performance because most the low cost commercially available lead Acid Ba...
Show More
-
A Model Based LCL-Type Grid Connected Converter Under Balanced and Unbalanced Faults in a Micro-Grid Distributed Generation
Issue:
Volume 11, Issue 1, February 2023
Pages:
34-42
Received:
17 February 2023
Accepted:
7 March 2023
Published:
16 March 2023
Abstract: This research was conducted to verify the significance of the LCL-filter on the grid current and the impact of variable fault resistance values on the reactive power genereated in a grid-tied inverter. The stability of LCL-type grid connected inverter with capacitor current feedback in active damping state was evaluated in this paper. The effects of balanced and unbalanced grid faults on the active and reactive power was studied through simulation at different fault resistance values of 0.00025Ω and 2.5Ω. The FFT waveforms showed that THD values of 48.56% and 38.45% were achieved for the grid voltage at 0.00025Ω and 2.5Ω fault resistance while THD values of 9.50% and 4.41% were obtained for the grid current at a varied current feedback coefficient (KCP) of 4.75 and 14.75. Simulation results also showed that a very negligible real and reactive power was gained with a zero grid voltage within the fault zone at 0.00025Ω fault resistance. At a 2.5Ω fault resistance, a voltage sag was produced which accounted for the transient response in the real power generated and reactive power absorbed during the fault period. The result obtained from the root-locus plot showed that the loci for the derived LCL-filter current transfer function intersected at +j 8.734 and -j 8.734 which makes the system marginally stable All simulation procedures were realized in MATLAB/SIMULINK 2015.
Abstract: This research was conducted to verify the significance of the LCL-filter on the grid current and the impact of variable fault resistance values on the reactive power genereated in a grid-tied inverter. The stability of LCL-type grid connected inverter with capacitor current feedback in active damping state was evaluated in this paper. The effects o...
Show More
