Morris Ezra

ABSTRACT The amount of small-scaled renewable energy sources is anticipated to increase on the low-voltage distribution networks for the improvement of energy security and reduction of greenhouse gas emission. Malaysia has a high solar irradiance level that is ideal for photovoltaic (PV) systems. However, the growth of the PV systems on the low-voltage distribution networks can create a number of technical issues such as voltage rise, voltage unbalance, and reversed power flow. Usually, these issues happen with little fluctuations. However, these issues tend to fluctuate very rapidly in Malaysia because this region has a very low clear sky index. A large amount of clouds often passes over the country, hence making the incident solar irradiance to be highly scattered and fluctuating. Therefore, the power output of the PV systems fluctuates substantially. To ensure an effective operation of the distribution networks with the PV systems, a novel fuzzy control method is developed and implemented to govern the operation of an energy storage system consisting of a bidirectional inverter coupled with lead-acid batteries. The fuzzy controlled energy storage system is able to mitigate the fluctuating voltage rises and voltage unbalances on the networks by actively manipulating the flow of real power between the networks and the batteries. To verify the effectiveness of this fuzzy control method, an experimental network integrated with 7.2-kW photovoltaic systems was set up. A number of case studies are performed to show that the proposed fuzzy control system is able to mitigate fluctuating voltage rises and voltage unbalances under the highly intermittent power output of the PV systems.

ABSTRACT This study aims a method of testing the Bounded Input Bounded Output (BIBO) stability of recursive 2-Dimensional (2-D) digital filters using the method for computation of variance or 2-D complex integrals. In the case when the non-essential singularities of the second kind (NSSK) are present, a method is given to determine whether the filter is l1 stable. The method seems to be very simple for lower order filters and even for higher order filters.

Electric vehicle (EV) is an innovation that is used to overcome the impact of the environment in this 21st century. The details of Electric vehicle must be analyzed in order to understand the pros and cons about the technology. The main component of an EV is its battery which is called as the green car battery. In this paper, various factors such as the environmental impact analysis of green batteries, comparison between various fuel types, and regional concern are discussed.

This paper mainly discusses the technique used to reduce sidelobes for polyphase pulse compression codes. A brief explanation is given on pulse compression and range resolution. Binary, ternary, quinquenary, multilevel and Barker codes are also discussed. The details of polyphase pulse compression code that comprises Frank code, Extended Frank code, P3 and P4 codes are described. The basic theory on

The observed received signal vector r=[r0, r, rN>1]' (1) containing Np observed samples, is modeled as Гк=£/'Л/+И* (2) 1=0 = fpt+nt , k = 0 ,N>I where the superscript t denotes vector or matrix transpose. f=[f„,fi fL]' (3) is the discrete T-spaced channel response Na=L+l (4) is the ...

ABSTRACT The principle motivation of this research work is to develop environmental-friendly polymer electrolytes utilizing corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-allyl-3-methylimidazolium chloride ([Amim] Cl) by solution casting technique. The highest ionic conductivity value was achieved for the composition CS:LiTFSI:[Amim] Cl (14 wt. %:6 wt. %:80 wt. %) which exhibits the ionic conductivity value of 5.68 × 10−2 S cm−1 at 40 °C with the activation energy of 4.86 kJ mol−1. This sample possess high concentration of amorphous phase coupled with greater presence of conducting cations (lithium, Li+ and imidazolium, [Amim]+) as depicted by the dielectric loss tangent plot. The conductivity–temperature plots were found to obey Arrhenius rule in which the conductivity mechanism is thermally assisted. The melting temperature of polymer electrolyte decreases with increase in [Amim] Cl content. This is attributed to the good miscibility of [Amim] Cl in CS:LiTFSI matrix inducing structural disorderliness. Reference to the TGA results it is found that the addition of [Amim] Cl diminishes the heat-resistivity whereas enhancement in the thermal stability occurred at the initial addition and declines with further doping of [Amim] Cl.

ABSTRACT 'Green' polymer electrolytes were fabricated from corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-allyl-3-methylimidazolium chloride, [Amim] Cl by solution casting method. This communication covers the influence of different proportions of [Amim] Cl concentration in plasticising the CS: LiTFSI matrix in term of the degree of co-ordination, ionic conductivity and relative viscosity. The possible dipole-dipole interaction between the chemical constituents was confirmed based on the Fourier transform infrared analysis. The highest ionic conductivity of 4.18 x 10(-4) S m(-1) was achieved at room temperature for the composition of CS : LiTFSI : [Amim] Cl (14 wt-% : 6 wt-% : 80 wt-%). The incorporation of environmental-friendly [Amim] Cl in the polymer electrolyte is significantly important in improving the ionic conductivity by increasing the amorphous morphology that consequently improves the ion transport mechanism. The highest conducting sample possesses the lowest relative viscosity with the value of 3.98 attributed to the greater structural disorderliness.

... 70–71. [9] Y. Hou, Y. Gu, S. Zhang, F. Yang, H. Ding and Y. Shan. J. Mol. Liq., 143 (2008), pp. 154–159. [10] HR Jhong, DSH Wong, CC Wan, YY Wang and TC Wei. Electrochem. Commun., 11 (2009), pp. 209–211. [11] J. Zhang, T. Wu, S. Chen, P. Feng and X. Bu. Angew. ...

ABSTRACT The degree of crystallinity in the matrix formed by cellulose acetate (CA) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) were reduced by embedding with deep eutectic solvent (DES) which is a type of ionic mixture synthesized from choline chloride and urea in a specific ratio. The fabrications of thin films were done by solution casting technique. The sample with composition of CA:LiTFSI:DES (28 wt%:12 wt%:60 wt%) appears as the highest conducting sample with the calculated value of 2.61 9 10(-3) S cm(-1) at ambient temperature. This high conducting sample possesses low relative viscosity so as to have high ion fluidity of 0.19. SEM micrographs were used to study the structural alternation that took place in the presence of DES at different ratio in the polymer electrolytes matrix. The dielectric loss tangent plot reveals the low relaxation time for high conducting sample which has immense movements of lithium conducting ion (Li(+)). The enhancement in the ionic conductivity of the DES plasticized samples with temperature obeys Arrhenius rule.

Acknowledgment: This work is supported by the Korea Ministry of Science and Technology through the National Research Laboratory (NRL) and Dual Use Technology Project. ... 0 IEE 2003 Electronics Letters Online No: 20030519 DOI: IO.I049/el:20030519 Du Chang Heo, Jin Dong Song, ...

ABSTRACT Transparent thin film polymer electrolytes were prepared by solvent casting technique with the doping of environmental-friendly ionic liquid, 1-allyl-3-methylimidazolium chloride ([Amim] Cl) into the matrix formed by cellulose acetate (CA) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The ionic conducting nature of this system improves significantly from the order of 10−7–10−2 S cm−1 upon increasing doping of [Amim] Cl content till a maximum of 4.68 × 10−2 S cm−1 is attained for the composition CA:LiTFSI:[Amim] Cl (14:6:80 wt%). The improving trend in ionic conductivity results from the bond weakening between the connecting atoms in the crystalline region that induces to the increase in amorphous counterpart fractions in the CA matrix. This observation was proved via the accountancies in the reduction of relative viscosity, root mean square value and increase in void as increase in [Amim] Cl doping. The resultant phase conversion hence permits immense lithium ion (Li+) fluidity along the polymer backbone and assisting the improvement in ionic conductivity. The thin film polymer electrolyte is found to be elastic in the presence of crystalline fraction and radically deforms upon the chains diffusion into the amorphous fraction. The linear curvatures of the Arrhenius plot justify the conductivity improvement as via the increasing frequency of Li+ ions hopping as the temperature increases. The increasing addition of [Amim] Cl diminishes both the heat-resistivity and thermal stability of CA:LiTFSI:[Amim] Cl matrix.

... S. Ramesh a , Corresponding Author Contact Information , E-mail The Corresponding Author , R. Shanti b , Ezra Morris b. ... Jhong et al., 2009 HR Jhong, DS Wong, HC Wan, CY Wang and YTC Wei, A novel deep eutectic solvent-based ionic liquid used as electrolyte for dye ...

Polymer electrolytes were developed by solution casting technique utilizing the materials of cellulose acetate (CA), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and deep eutectic solvent (DES). The DES is synthesized from the mixture of choline chloride and urea of 1:2 ratios. The increasing DES content well plasticizes the CA:LiTFSI:DES matrix and gradually improves the ionic conductivity and chemical integrity. The highest conducting sample was identified for the composition of CA:LiTFSI:DES (28 wt.%:12 wt.%:60 wt.%), which has the greatest ability to retain the room temperature ionic conductivity over the entire 30 days of storage time. The changes in FTIR cage peaks upon varying the DES content in CA:LiTFSI:DES prove the complexation. This complexation results in the collapse of CA matrix crystallinity, observed from the reduced intensity of XRD diffraction peaks. The DES-plasticized sample is found to be more heat-stable compared to pure CA. Nevertheless, the addition of DES diminishes the CA:LiTFSI matrix's heat-resistivity but at the minimum addition the thermal stability is enhanced.

ABSTRACT In the process of designing digital recursive filters to satisfy a given magnitude response. the designer may end up with an unstable filter. This unstable filter can be stabilized using methods such as Planar Least Sqare Inverse technique, Complex Ceptrum Method etc. The Planar Least Square Inverse technique is supposed to preserve the desired magnitude response which is found to be not true in all cases. Hence a new method of designing recursive filters using the improved genetic optimization algorithm is presented in this paper. The optimally designed filter will be stable and will have a magnitude response almost similar to the desired magnitude response.

ABSTRACT In the process of designing digital recursive filter to satisfy a given magnitude response, the designer may end up with an unstable filter. This unstable filter can be stabilized using methods such as Planar Least Square Inverse (PLSI) technique, Complex Ceptrum Method etc. The Planar Least Square Inverse technique is supposed to preserve the desired magnitude response which is found to be not true in all cases. Hence a new method of designing stable recursive filters using PLSI technique and particle swarm optimization algorithm is presented in this paper. The optimally designed filter will have a magnitude response almost similar to the desired magnitude response.

This paper presents a particle swarm optimization (PSO)-based neuro-sliding mode controller for the transient stability enhancement of multimachine power systems with unified power flow controller (UPFC). The UPFC is modeled as controllable loads. These controllable ...