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Battery management system for microgrid applications
(2018-07-02)
Prompinit, Krisada
;
Khomfoi, Surin
This paper describes the operation and control methodology for a Battery Energy Storage System (BESS) designed to mitigate the negative impacts of lithium-ion energy storage. The Battery Monitoring System (BMS) provides real time status data of the battery's parameters such as current voltage and temperature in order to prevent energy storage deterioration.The data will be sent through CAN-bus that allows microcontrollers and other devices to communicate with each other in applications without a host computer. Including, energy provision.
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Experimental studies on power control microwave ablation in vitro animal tissues with microwave percutaneous coagulator
(2013-12-01)
Chaichanyut, M.
;
Lertprasert, P.
;
Tungjitkusolmun, S.
Microwave coagulation therapy (MCT) has been used mainly for the treatment of small-size tumors. The operating frequency is 2450 MHz for the present MCT. In this paper, we analyzed the heating characteristics (temperature distributions patterns, lesion on size and etc.) of an applicator composed of thin microwave antenna. The configurations of thin microwave monopole antennas were considered: Coaxial Quarter Conductor Antennas (CQCA). Experimental protocol was composed by a radiation system and a thermometry system. We apply the microwave power during experiments was 10W, 20W, 40W and 80W which microwave power all case will vary the duration time for ablation were 60s 120s 240s and 480s respectively; Thermal sensors were placed next to the antenna at 1mm, a large number of experiments on porcine liver are carried out, the temperature distribution within the liver are measured and illustrated, for cases of different injected microwave power and ablation time. From our experimental results, if we considered the region where temperature exceeds 50°C, the threshold for successful hepatic ablation. The CQCA has lesion size was larger, with a lesion width of approximately 20 mm. In addition, the ablation areas in cases of different input microwave powers are measured also. All these results indicate the potential validity of this system on medical treatment of liver cancer of human body. © 2013 IEEE.
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Connectivity of ad hoc wireless networks: An alternative to graph-theoretic approaches
(2010-04-01)
Panichpapiboon, Sooksan
;
Ferrari, Gianluigi
;
Tonguz, Ozan K.
Connectivity in wireless ad hoc and sensor networks is typically analyzed using a graph-theoretic approach. In this paper, we investigate an alternative communication-theoretic approach for determining the minimum transmit power required for achieving connectivity. Our results show that, if there is significant multipath fading and/or multiple access interference in the network, then graph-theoretic approaches can substantially underestimate the minimum transmit power required for connectivity. This is due to the fact that graph-theoretic approaches do not take the route quality into consideration. Therefore, while in scenarios with line-of-sight (LOS) communications a graph-theoretic approach could be adequate for determining the minimum transmit power required for connectivity, in scenarios with strong multipath fading and/or multiple access interference a communication-theoretic approach could yield much more accurate results and, therefore, be preferable. © Springer Science+Business Media, LLC 2009.
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Analysis of a half-bridge inverter for a small-size induction cooker using positive-negative phase-shift control under ZVS and NON-ZVS operation
(2007-12-01)
Achara, P.
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Viriya, P.
;
Matsuse, K.
This paper presents a detailed analysis of circuit operation under ZVS and NON-ZVS conditions in a high-frequency half-bridge inverter for a small-size and low-voltage induction cooker, using the principle of positivenegative phase-shift control over a wide control range both in positive and negative directions. A variety of modes of circuit operation with the voltage and current equations during phase-shift power control under the operating conditions of ZVS and NON-ZVS are analyzed as a first step and the output voltage and current waveforms are obtained by MATLAB program. These waveforms will be analyzed by Fourier analysis which can lead further to the calculation of ac output power P<inf>0</inf>, dc input power P<inf>d</inf>, and hence the conversion efficiency η of the half-bridge inverter. The analysis results shows that the control ranges of ac output power P<inf>0</inf> and dc input power P<inf>d</inf> are limited by the occurrence of NON-ZVS operating condition, which changes according to the switching frequency f<inf>s</inf>. © 2007 IEEE.
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Erlang capacity analysis with imperfection power control and overlay of multiclass CDMA on TDMA system
(2004-09-27)
Kaewbunsong, Pitak
;
Sheevasuvit, Fusak
This paper presents the Erlang capacity analysis in blocking probability equation of CDMA. The Imperfection in reverse link is due to the power control in multiclass transmission service to users and the overlay of TDMA system. Here we use Gaussian and Lognormal models to estimate the Erlang. The Imperfection in power control will be modeled as a Lognormal random variable. The standard deviation of this variable depends on the mobile velocity the branch number of receiver, and the measured power between mobile communicating and base station. The overlay of TDMA system used in this case is base on the GSM standard. The numerical results show that the Erlang capacity decrease when we use overlay of spectrum frequency and imperfect power control on system.
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Blocking probability of the reverse link cellular CDMA system
(2002-01-01)
Kumpairee, C.
;
Kimpan, C.
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Pin-Ngern, O.
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Hemmakorn, N.
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Noppanakeepong, S.
The blocking probability of the reverse link cellular CDMA system is presented. Gaussian and lognormal approximation are the methods for determination of blocking probability. In the analysis in this paper, the parameter for the number of resolvable paths over a Rayleigh multipath fading channel is presented. In addition, we also show the effect of power control errors.
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Effect of multipath fading on the Erlang capacity of imperfect power control in cellular CDMA system
(2002-01-01)
Omsin, S.
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Manyanon, A.
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Kimpan, C.
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Pin-Ngern, O.
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Noppanakeepong, S.
This paper presents an approach to the evaluation of the reverse link capacity of a cellular CDMA system, which is based on using Gaussian and lognormal approximations. We include the fading channel multipath intensity profile (MIP) shape factor in the Erlang capacity formula. Imperfect power control and Rayleigh multipath fading channels are considered.
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Capacity analysis of forward-link in DS-CDMA cellular system with power control
(2002-01-01)
Longpichai, S.
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Rattanakoch, W.
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Kidakorn, P.
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Kimpan, C.
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Pin-Ngern, O.
In this paper, we analyze the forward-link capacity of a cellular DS-CDMA system, especially the effects of power control, path loss exponent (γ) and orthogonality factor (f<inf>0</inf>) of multipath propagation on the system. The problem of finding an optimum power control factor (n) is evaluated. According to n, the proper threshold distance is estimated for optimum performance. With these factors, the numerical results show that the capacity is reduced by changing f<inf>0</inf> from 0.7 to 0.2 and γ from 5 to 3.
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Outage probability, throughput and delay analysis of cellular DS-CDMA system in the presence of correlated signal and interference
(2002-01-01)
Rattanakoch, W.
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Kimpan, C.
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Pin-Ngern, Ouen
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Noppanakeepong, S.
In this paper, we evaluate the performance of a cellular DS-CDMA system, by taking into account the correlation between signal and interference, to determined outage probability, throughput and delay for the reverse link with power control error. The numerical results show that when the correlation is considered the outage probability decreased, the throughput value increased, that is, the performance can be achieved.
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Outage probability of the overlapped carriers allocation scheme with imperfect power control in DS-CDMA
(2002-01-01)
Techotchawan, A.
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Leepila, R.
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Kimpan, C.
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Thitimajshima, P.
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Noppanakeepong, S.
The outage probability is investigated in cellular FD/CDMA (frequency division/code division multiple access) in terms of the SNR under the overlapped carrier allocation scheme in the reverse link of a cellular radio system, which is based on using Gaussian and lognormal approximations, respectively. In numerical results, the bandlimited pulse generated by raised cosine pulse shaping filters (SRRC) of the transmitted signal is investigated and compared in conventional FD/CDMA and OC-CDMA (overlapping carrier CDMA) for the outage probability. It is also shown that the outage probability can be improved by overlapping of carriers.

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