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Marine biofouling remains one of the key challenges for maritime industries, both for seafaring and stationary structures. Currently used biocide-based approaches suffer from significant drawbacks, coming at a significant cost to the environment into which the biocides are released, whereas novel environmentally friendly approaches are often difficult to translate from lab bench to commercial scale. In this article, current biocide-based strategies and their adverse environmental effects are briefly outlined, showing significant gaps that could be addressed through advanced materials engineering. Current research towards the use of natural antifouling products and strategies based on physio-chemical properties is then reviewed, focusing on the recent progress and promising novel developments in the field of environmentally benign marine antifouling technologies based on advanced nanocomposites, synergistic effects and biomimetic approaches are discussed and their benefits and potential drawbacks are compared to existing techniques.

Antifouling/antibacterial coating derived from a sustainable natural resource for biomedical devices have shown promising outcomes, especially in the prevention of bacterial growth. Herein, pulse-plasma chemical vapour deposition is used to fabricate antimicrobial coatings from Terpinen-4-ol, a tea tree oil-based precursor. In this manuscript, during RF plasma polymerisation, pulsed plasma is used to retain the pristine monomer structure in the developed stable coating and thereby enhance its antibacterial activity. The developed films have tunable physical and chemical properties. Diverse film surface properties were obtained by varying the plasma deposition parameters, mainly the deposition mode (pulse and continuous wave) and duty cycle. The role of film wettability on degree of bacterial attachment has been elucidated. Overall, the number of viable bacteria on all the deposited coatings (25–30%) were reduced to half with respect to the control (56%).

In industrial drives applications, fractional order controllers can exhibit phenomenal impact due to realization through digital implementation. Digital fractional order controllers have created wide scope as it possess the inherent advantages like robustness against the plant parameter variation. This paper provides brief design procedure of fractional order proportional-integral-derivative (FO-PID) controller through the indirect approach of approximation using constant phase technique. The new modified dynamic particle swarm optimization (IdPSO) technique is proposed to find controller parameters. The FO-PID controller is implemented using floating point digital signal processor. The building blocks are designed and assembled with all peripheral components for the 1.5 kW industrial DC motor drive. The robust operation for parametric variation is ascertained by testing the controller with two separately excited DC motors with the same rating but different parameters.

Single-phase to Three-phase Multilevel Matrix Converter ( $1\times 3 \ \mathrm{M}^{2}\mathrm{C}$ ) is presented in this paper. This converter connects a single-phase supply to a three-phase load directly with absence of any energy storage device (battery) or any heavy dc-link capacitor. The whole system promises the characteristics of the conventional matrix converter like balance operation and unity power factor (UPF). For analysis purpose a three-phase induction motor is modeled in simulation environment supplied by $1\times 3 \ \mathrm{M}^{2}\mathrm{C}$ >. The $1\times 3 \ \mathrm{M}^{2}\mathrm{C}$ > consists of source side current source rectifier (CSR), and load side three-phase three-level diode clamped inverter (3L-DCI). Complete modulation scheme to control the CSR and multilevel 3L-DCI in decoupled manner in order to simplify complexities of modulation of the $1\times 3 \ \mathrm{M}^{2}\mathrm{C}$ > is presented in this paper. The performance of $1\times 3 \ \mathrm{M}^{2}\mathrm{C}$ > driven three-phase induction motor is analyzed in MATLAB/Simulink environment and compared it with two level matrix converter with valid results are also given in the paper.

Sustainable marine antifouling strategies aim to minimize long term environmental impacts while effectively preventing surface colonization. In this study, we report upon a biodegradable antifouling coating for marine applications. In two stages, thin bilayers were produced using plasma-enhanced chemical vapor deposition of terpinen-4-ol, at applied powers of 100 W initially and then 10 or 25 W. The resulting coatings were characterized for solubility, surface energy, surface roughness and optical transmission. Both coatings exhibited similar solubility over the initial 14 days of observation, though structures deposited at 25 W were significantly more stable after 14 days. Coatings were smoother than the control surface upon which they were deposited and had higher hydrophobicity with transmission efficiencies >90% (400–1000 nm). Field assessments of the samples were carried out in Curralea Lake (Townsville, Australia) to assess their real world performance. Results indicate that the environmentally friendly coatings, terpinen-4-ol plasma polymer influenced antifouling. The proposed mechanism for this effect is the dissolution of the coating coupled with possible antimicrobial properties of the terpinen-4-ol. These results point to the potential usefulness of developing multilayer coatings for extended deployments.

This paper identifies possible topological reconfigurability of a T-type inverter for direct torque controlled (DTC) induction motor drives when an open-switch fault occurs. In open-switch fault, inverter current path is different than normal path. This causes undesirable inverter switching states. Since DTC is based on a voltage vector selection criterion, open-switch fault causes ambiguous torque control. Analysis of DTC drive under two different inverter open-switch fault conditions viz. half-bridge and neutral-point switch fault are presented. The operation of the inverter in DTC mode against faults is achieved by simple topological reconfiguration.

This paper presents the implementation of fractional order PID (FO-PID) controller using hardwired modules of constant phase element (CPE). A new approach of phase shaping by slope cancellation of asymptotic phase plots for zeros and poles within the given bandwidth is realized. Analog circuits, which exhibit analog fractional-order integrator and fractional-order differentiator, are used for building the FO-PID controller. The design procedure is developed to obtain the optimal pole---zero pairs and respective "Fractance" components to realize for any value of fractional differ-integrator. These CPE elements give minimum error tolerance over the set phase value by using commercially available (R---C) components and Op-Amps. The pole---zero location in the root locus plot with constant asymptotic angle under various feed-forward gains is achieved with these analog integrodifferential circuits of the FO-PID. The iso-damping feature of the controller is practically demonstrated. A comparative performance is demonstrated under various settings of feed forward gains, which indicate the constant overshoot with FO-PID against the conventional PID. These circuits are developed and implemented with a DC motor emulator to confirm the designed performance of the controller.

If the common-mode voltage in the induction motor drive is not eliminated, it may cause failure of motor bearings and malfunctioning of the electrical equipment associated with the drive. This article proposes the modified direct torque control technique to control the induction motor fed by three-level inverter, commonly called a neutral-point-clamped inverter. The selective voltage vectors in three-level inverter determine elimination of the common-mode voltage. The classic three-level direct torque control based on selection of 6-full, 6-half, and 2-zero voltage vectors out of available 27 is modified so that the 6-intermediate voltage vectors and a zero voltage vector are employed. A comparative investigation with another three-level direct torque control method which reduces both common-mode voltage and torque ripple is also carried out. These methods are compared with classic two-level direct torque control method in context of common-mode voltage, torque ripple, current total harmonic disto...

This paper presents a Direct Torque Control (DTC) strategy for the five-phase induction motor driven by a three-level five-phase inverter in order to improve the performance of the five-phase induction motor. In the proposed DTC technique, only 22 voltage vectors out of 243 available voltage vectors in a three-level five-phase inverter are selected and are divided in 10 sectors each with a width of 36˚. The four different DTC combinations (DTC-I, II, III and IV) for a three-level five-phase induction motor drive are investigated for improving the performance of five-phase induction motor. All four of the DTC strategies utilize a combination of the same large and zero voltage vectors, but with different medium voltage vectors. Out of these four techniques, DTC-II gives the best performance when compared to the others. This DTC-II technique is analyzed in detail for improvements in the performance of five-phase induction motor in terms of torque ripple, x-y stator flux and Total Harmonics Distortion (THD) of the stator phase current when compared to its two-level counterparts. To verify the effectiveness of the proposed three-level five-phase DTC control strategy, a DSP based experimental system is build. Simulation and experimental results are provided in order to validate the proposed DTC technique.

This paper present the finite-state predictive power control (FS-PPC) for the interlinking converter in the micro-grid. The proportional-integral (PI) based controllers are dynamically slower for the sudden changes in the power reference values. The phase lock loop (PLL) is essential requirement for such algorithms. The FS-PPC has faster dynamic response as compare to PI based controller in tracking the reference values. The FS-PPC is proposed to control the power flow between the DC and AC micro-grids. The developed control provides the constant switching frequency operation for the interlinking converter which reduces the ripples and total harmonic distortion of the grid current in order to follow the grid codes. Simulation results are provided for the validity of the control algorithm.

Nanocomposites offer attractive and cost-effective thin layers with superior properties for antimicrobial, drug delivery and microelectronic applications. This work reports single-step plasma-enabled synthesis of polymer/zinc nanocomposite thin films via co-deposition of renewable geranium essential oil-derived polymer and zinc nanoparticles produced by thermal decomposition of zinc acetylacetonate. The chemical composition, surfaces characteristics and antimicrobial performance of the designed nanocomposite were systematically investigated. XPS survey proved the presence of ZnO in the matrix of formed polymers at 10 W and 50 W. SEM images verified that the average size of a ZnO nanoparticle slightly increased with an increase in the power of deposition, from approximately 60 nm at 10 W to approximately 80 nm at 50 W. Confocal scanning laser microscopy images showed that viability of S. aureus and E.coli cells significantly reduced on surfaces of ZnO/polymer composites compared to pristine polymers. SEM observations further demonstrated that bacterial cells incubated on Zn/Ge 10 W and Zn/Ge 50 W had deteriorated cell walls, compared to pristine polymers and glass control. The release of ZnO nanoparticles from the composite thin films was confirmed using ICP measurements, and can be further controlled by coating the film with a thin polymeric layer. These eco-friendly nanocomposite films could be employed as encapsulation coatings to protect relevant surfaces of medical devices from microbial adhesion and colonization.

The analytical assessment of 5.05 kWp grid tied photovoltaic plant performance on the system level has been carried out in this study. The solar PV plant has been installed on the roof of the block-A of the Darshan Institute of Engineering and Technology, Rajkot. India. The Darshan Institute of Engineering and Technology has been monitoring and recording all the parameters of 5.05 kWp grid tied solar PV power plant for 3 years. This paper helps in study of the performance and consistency of this system. The final yield, reference yield and performance ratio are observed to vary from 2.96 h/d to 5.43 h/d, 4.22 h/d to 7.29 h/d and 68%–83% respectively. The global in-plane solar radiation at the city of Rajkot is 2212 kWh/m 2 /annum. The average annual measured energy yield of the plant is found to be 1636 kWh/kWp. The total estimated system losses due to irradiance angle, temperature, module quality, array and cell mismatch, AC/DC wiring, MPPT, soiling and dirt, and inverter are found to be 26%. As a whole, the location, soiling pattern, design of PV and maintenance of solar PV system are the primary reasons of energy variability and system energy production.

A simplified space vector pulse width modulation (SVPWM) is proposed for a three-level five-phase inverter. The proposed method generates the duty cycle of the three-level inverter switches based on dwell times of the two-level inverter and carrier index. The proposed method automatically determines the eligible vectors, region, and switching sequence of optimized five vectors based on the modulation index. Out of 243 available vectors, 113 most eligible vectors are used for generation of desired voltage reference in main subspace, while zeroing the average voltage in the auxiliary subspace by using the proper switching sequence. This method also uses the redundant vectors in each subcycle thus balances the dc-link capacitor voltages and no additional algorithm or techniques are needed to balance the dc-link capacitor voltage. The identification of the reference location with the carrier index using the signum function simplifies the algorithm implementation. Thus, the proposed method eases the implementation of optimum five vectors to a greater extent. Based on only changing the carrier index, the proposed method can be easily extended for any multiphase multilevel (5, 7,…, n) inverter. The simulation and hardware results of the three-level five-phase inverter validate the proposed simplified method.

The aim of paper is to employ digital fractional order proportional integral derivative (FO-PID) controller for speed control of buck converter fed DC motor. Optimal pole-zero approximation method in discrete form is proposed for realization of digital fractional order controller. The stand-alone controller is implemented on embedded platform using digital signal processor TMS320F28027. The five tuning parameters of controller enhance the performance of control scheme. For tuning of the controller parameters, dynamic particle swarm optimization technique is employed. The proposed control scheme is simulated on MATLAB and verified by experimental results. Performance comparison shows better speed control of separately excited DC motor with the realized digital FO-PID controller than that of the integer order PID controller.

Plasma processing, e.g., functionalisation and deposition of antibacterial coatings, is often used to enhance surface properties of biomaterials. Plasma is, however, a non-uniform active medium, and the result of processing depends on the nature of both the plasma and the substratum. Here we show that when an antibacterial coating (i.e., polyterpenol) is plasma polymerised onto four types of titanium substrata that differ in their micro- and nano-scale topography (but not the bulk chemistry), the distribution of functional groups, e.g., OH and C O, in the polymer across the surface differs sufficiently, and so does the antibacterial activity of the resulting material system. While the addition of a coating hinders biofilm formation by Staphylococcus aureus and Pseudomonas aeruginosa, the bactericidal effect is significantly stronger in polymers deposited onto surfaces possessing lower degrees of nanoscale roughness, e.g., substrata after mechanical and chemical polishing. The reduced antibacterial efficacy of polymers on substrata with greater surface roughness (e.g., on mechanically polished or lotus leaf-like surfaces) is attributed to a greater extent of thickness non-uniformity and heterogeneity in the functional group distribution across the surface. These findings suggest that the magnitude and distribution of topographical features of the substratum should be considered when designing plasma-enabled surface modification strategies.

This paper presents a new open-loop speed estimation method for a three-phase induction motor drive. The open-loop speed estimators available in literature have the advantage of reduced computational stress over the observers but they share a common limitation of being largely dependent on flux and machine parameters. They involve integrations and differentiation in the algorithm that leads to serious error in estimation when subject to different operating conditions. The proposed estimator is based on synchronous speed tracking and is cost-effective. It is immune to any variation in machine parameters and noise. The synchronous speed is computed from stator frequency which is estimated on-line using the stator current signals. A unique, non-adaptive method for estimation of stator frequency within one-sixteenth of time period is also proposed to enhance the speed of estimation. Computer simulation and experimentation on a 2.2 kW Field oriented controlled induction motor drive is carried out to verify the performance of proposed speed estimator. The results show excellent response over a wide range of rotor speed in both directions including low speed and under different operating conditions. This confirms the effectiveness of the proposed method.

In many photovoltaic (PV) energy conversion systems, nonisolated DC-DC converters with high voltage gain are desired. The PV exhibits a nonlinear power characteristic which greatly depends on the environmental conditions. Hence in order to draw maximum available power various algorithms are used with PV voltage/current or both as an input for the maximum power point tracking (MPPT) controller. In this paper, golden section search (GSS) based MPPT control and its application with three-level DC-DC boost converter for MPPT are demonstrated. The three-level boost converter provides the high voltage transfer which enables the high power PV system to work with low size inductors with high efficiency. The balancing of the voltage across the two capacitors of the converter and MPPT is achieved using a simple duty cycle based voltage controller. Detailed simulation of three-level DC-DC converter topology with GSS algorithm is carried out in MATLAB/SIMULINK platform. The validation of the proposed system is done by the experiments carried out on hardware prototype of 100 W converter with low cost AT’mega328 controller as a core controller. From the results, the proposed system suits as one of the solutions for PV based generation system and the experimental results show high performance, such as a conversion efficiency of 94%.

Pulse width modulated adjustable speed drives used in industries lead to significant advantages in terms of performance, size, and efficiency. But, the output voltage and the current waveforms become non-sinusoidal leading to an increase in voltage and thermal stresses. This results into accelerated insulation aging and premature failure of the motors. With multiple stresses, the life models for insulating materials become complex and ambiguous. This article presents the fuzzy logic application to derive an electrothermal life model to investigate the synergic effects of voltage and thermal stresses on intrinsic aging of inverter-fed induction motor insulation. Three parameters, viz. voltage stress factor, waveform slope stress factor, and spike frequency factor, are proposed to describe the insulation stresses for pulse width modulated voltages. These parameters are computed from the experimental results at different switching frequencies and are used in fuzzy logic-based life estimation algorith...

Strategies that confine antibacterial and/or antifouling property to the surface of the implant, by modifying the surface chemistry and morphology or by encapsulating the material in an antibiotic-loaded coating, are most promising as they do not alter bulk integrity of the material. Among them, plasma-assisted modification and catechol chemistry stand out for their ability to modify a wide range of substrates. By controlling processing parameters, plasma environment can be used for surface nano structuring, chemical activation, and deposition of biologically active and passive coatings. Catechol chemistry can be used for material-independent, highly-controlled surface immobilisation of active molecules and fabrication of biodegradable drug-loaded hydrogel coatings. In this article, we comprehensively review the role plasma-assisted processing and catechol chemistry can play in combating bacterial colonisation on medically relevant coatings, and how these strategies can be coupled with the use of natural antimicrobial agents to produce synthetic antibiotic-free antibacterial surfaces.

The dual-inverter fed open-end winding configuration can be categorized as a new breed of multi-level converters. The structure is simple and offers a lot of advantages. However, the development of suitable PWM schemes is more complicated, due to the availability of a large number of switching states and existence of the multiple two-dimensional planes. An overview of attempts to develop suitable modulation techniques for the dual-inverter fed five-phase machine drives recognizes that progress has been made over the past few years. This paper presents a performance comparison of three PWM schemes of the dual-inverter fed five-phase, open-end winding motor drives. The quality of the phase output voltages are compared and the adequate analyses are provided. The simulation results show that the Carrier Based Phase Disposition (PD) PWM scheme enables generation of the most excellent output voltage among the three PWM schemes. The Total Harmonics Distortion (THD) of the output voltages generated by the carrier based PWM scheme reduces by 65% and 15% on average compared to the THD of the output voltages produced by the URS PWM scheme and the decomposition PWM scheme respectively.

The microwave dielectric properties of CeO(2) nanoparticles (0.5, 1.0 & 1.5wt%) doped Mg(2)(TiO(4)(MTO) ceramics have been investigated at cryogenic temperatures. The XRD patterns of the samples were refined using the full proof program reveal the inverse spinel structure without any secondary phases. The addition of CeO(2) nanoparticles lowered the sintering temperature with enhancement in density and grain size as compared to pure MTO ceramics. This is attributed to the higher sintering velocity of the fine particles. Further, the microwave dielectric properties of the MTO ceramics were measured at cryogenic temperatures in the temperature range of 6.5-295 K. It is observed that the loss tangent (tanδ) of all the samples increased with temperature. However, the CeO(2) nanoparticles doped MTO ceramics manifested lower loss tangents as compared to the pure MTO ceramics. The loss tangents of the pure and MTO ceramics doped with 1.5 wt% of CeO(2) nanoparticles measured at 6.5K are found to be 6.6x10^-5 and 5.4x10^-5, respectively. The addition of CeO(2) nanoparticles did not cause any changes on the temperature stability of the MTO ceramics at cryogenic temperatures. On the other hand, the temperature coefficient of the permittivity increased with rise in temperature and with the wt% of CeO(2) nanoparticles. The obtained lower loss tangent values at cryogenic temperatures can be attributed to the decrease in both intrinsic and extrinsic losses in the MTO ceramics.

The voltage fluctuations caused by rapid industrial load change have been a major concern for supply utilities, regulatory agencies and customers. This paper gives a general review about how to examine/assess voltage flicker and methods followed in measuring the flickers due to rapid changing loads and means for its mitigation. It discusses the effects on utilities conditions, compensators response time and compensator capacity of flicker mitigation. A comparison between conventional mitigation techniques and the state-of-art mitigation techniques are carried out. It is shown in many cases that the state-of-art solution provides higher performance compared with conventional mitigation techniques. However, the choice of most suitable solution depends on characteristics of the supply at the point of connection, the requirement of the load and economics.

In this paper, the direct torque control (DTC) for a three-level five-phase inverter-fed five-phase induction motor is proposed to improve the low-speed performance. The classical DTC scheme (DTC-I) is modified in order to minimize the demagnetization effect during a low-speed operation. According to the modification, the voltage vector space plane is divided into 20 sectors, each of sector 18°. For odd number of sectors, ${{\pm 36^\circ }}$ displaced intermediate voltage vectors, and for even number of sectors, ${{\pm 36^\circ }}$ displaced main voltage vectors are selected instead of classic ${{\pm 72^\circ }}$ displaced voltage vectors. The zero voltage vectors are omitted in the proposed DTC scheme (DTC-II) for the low-speed operation. The DTC-II scheme reduces the demagnetization effect during a low-speed region at the cost of increase in the torque ripple due to avoiding zero voltage vectors. As the speed ramps up, the ${{\pm 72^\circ }}$ displaced voltage vectors are selected through a seven-level torque comparator and are divided into ten sectors. Therefore, in the medium and the higher speed region, the torque ripple is reduced by using the seven-level torque comparator. Simulation and experimental results are presented in order to validate the DTC-II method.

This paper presents an integrated high power battery charging topology by incorporating a split three phase induction motor for electric vehicle. In charging/vehicle to grid mode, stator winding is used as an inductive filter between grid and converter. During this operation, the rotor of machine is kept in stationary position as rotating magnetic field is cancelled out due to built-in nature of split phase stator winding. Therefore, mechanical locking is not required. Proposed configuration works under unity power factor operation. Through the reconfiguration of stator winding, same motor is used as three phase induction motor for traction purpose. Simulation results for proposed concept are provided for both charging and vehicle to grid mode.

Ageing population and a multitude of neurological and cardiovascular illnesses that cannot be mitigated by medication alone have resulted in a significant growth in the number of patients that require implantable electronic devices. These range from sensors, gastric and cardiac pacemakers, cardioverter defibrillators, to deep brain, nerve, and bone stimulators. Long-term implants present specific engineering challenges, including low energy consumption and stable performance. Resorbable electronics may offer excellent short-term performance without the need for surgical removal. However, most electronic materials have poor bio- and cytocompatibility, resulting in immune reactions and infections. This paper reviews the current situation and highlights challenges for future advancements.

Studies on innovation point towards the need for both in-house research and development (R&D) capabilities along with collaborations with external organisations or linkages with other firms, universities and research institutes. The argument is that innovation is not just a firm specific factor but requires support from several other factors which in turn involves developing linkages with various actors/institutions as sources of resources and/or knowledge for innovation. This paper presents findings from an exploratory study about the Malaysian biofuel sector as an innovation system. Instead of using the neo-classical approach and proposing policy interventions based on traditional market failure rationale (Bergek et al., 2008a), the functional analysis of the technological innovation systems (TIS) approach is used to analyse the biofuel sector in Malaysia to help reveal the strengths and weaknesses in terms of its fulfillment of seven critical functions which are necessary for the generation and commercialization of a product. In addition an attempt is made to reveal the inducement and blocking mechanisms affecting the Malaysian biofuel TIS and the seeking of improved poor functionality. These functional aspects of the Malaysian biofuel sector are analysed in different phases of its development to gain an understanding of the different institutions and their functions at different phases of the development of the innovation system.

In this paper, author proposed an Anti-windup FO-PI controller based on integral state predictor for speed control of variable speed motor drive. Controller gains are tuned by FOMCON toolbox using Nelder-Mead optimization topology where, initial range of controller gains are taken from stabilization curve. Performance of proposed topology and various anti-windup topology are evaluated and compared based on control effort, set-point tracking and performance indices such as ISE and IAE for both IO-PI and FO-PI controller. Result shows that proposed methodology provides smooth landing to its steady-state, when system comes from saturation to linear region with less control effort.

In this paper a simplified Centre aligned Space Vector Pulse Width Modulation (SVPWM) using voltage dispersion is proposed for a two-level n-phase inverter having odd number of phase. The conventional SVPWM algorithm for calculating the dwell time requires Clarke transformation, sector identification, identification of large and middle vectors in each sector and assigning dwell time to it. In the proposed dispersion Space Vector PWM (d-SVPWM), dwell time is calculated based on sorting the sampled amplitude of reference voltage without any complex process like Clarke transformation, sector identification. In this paper five-phase inverter is taken as an example case of multi-phase inverter. The simulation and hardware results of five-phase inverter are presented and this validates the performance of proposed algorithm. In short the proposed algorithm is another way to implement SVPWM for n-phase inverter in a much simplified manner.

Photovoltaic Systems are gaining importance rapidly. The performance of the photovoltaic system is hugely dependant on atmospheric conditions. The performance evaluation of the PV systems before on site installation is costly and time consuming. Also, MPPT techniques play a vital role in photovoltaic systems, however on site testing of MPPT techniques is somehow difficult. A PV simulator can be used in replacement of PV arrays for the performance evaluation of the complete system alongwith MPPT accurately in the laboratory. This paper presents the PV simulator based on real-time execution of the PV array mathematical model. The PV model is simulated in LabVIEW and interfaced to the real world through a data-acquisition system. The simulator is further used to test the performance of MPPT techniques under uniform radiation as well as non-uniform radiation. The performance of new Golden Section Search(GSS) technique is evaluated using the proposed simulator. The comparative performance of the GSS technique with conventional MPPT techniques is presented to prove its capability. The dynamic operating tests under various shading pattern are demonstrated with PV emulator to ascertain the efficacy of the MPPT technique.

The speed control of the DC motor fed through buck-converter is generally employed with conventional integer order PID. The closed loop speed control of these drives are prone to deteriorate in their performance over a period of time. This paper proposes the fractional order (FO) PID speed controller with DC motor. The feasibility of more tuning parameters enhances the performance. Oustaloup's approximation method is used to approximate the fractional order differentiator and integrator. This controller performances are tested in the simulation mode.

The main aim of this paper is to design PID control PWM module using field programmable gate array (FPGA) technology. FPGA based realization offers high speed, complex functionality, consume less power, and provides parallel processing. In this paper, we have implemented PID control PWM module on programmable logic design software Quartus II and verified on DE0 Nano Board (Cyclone IV FPGA family of company Altera). Signal Tap II analyzer and RTL viewer are used for analyzing and debugging the design. For Proper timing constraint and clock arrangement, Time Quest analyzer is used. The simulation and hardware results shows that implementation with FPGA has some advantages such as flexible design, high reliability and high speed.

This paper deals speed control of a Permanent Magnet Brushless Direct Current (PMBLDC) Motor using Fractional Order PID (FO-PID) controller tuned with different algorithms for PMBLDC motor. The inherent advantages of the FO-PID over conventional are its added fractions variables. The FO-PID controller is a generalized form of PID controller in which order of integration (I) and differentiation is any real number. It is shown that the proposed controller, which has five independent parameters (Kp, Ki, Kd, λ, μ) to tune, provides a powerful framework to control PMBLDC motor. The gain of PID controller is obtained by conventional methods of Ziegler-Nicholas (ZN), Cohen Coon (CC) and Amstron-Hagglund (AH). The Oustaloup's method is used to approximate the fractional order. Integration (s-λ) and differentiation (sμ) order is tuned using Nelder-Mead (NM), Interior point (IP) and Active set (AS) algorithm. The controller analysis is presented with the plant to ascertain the performance of the PMBLDC motor. Improvement in transient performance of the system using FO-PID controller is observed in the comparative results.

In the micro-grid network, it is especially difficult to support the critical load without uninterrupted power supply. The proposed micro-wind energy conversion system with battery energy storage is used to exchange the controllable real and reactive power in the grid and to maintain the power quality norms as per International Electro-Technical Commission IEC-61400-21 at the point of common coupling. The generated micro-wind power can be extracted under varying wind speed and can be stored in the batteries at low power demand hours. In this scheme, inverter control is executed with hysteresis current control mode to achieve the faster dynamic switchover for the support of critical load. The combination of battery storage with micro-wind energy generation system (μ WEGS), which will synthesize the output waveform by injecting or absorbing reactive power and enable the real power flow required by the load. The system reduces the burden on the conventional source and utilizes μ WEGS and battery storage power under critical load constraints. The system provides rapid response to support the critical loads. The scheme can also be operated as a stand-alone system in case of grid failure like a uninterrupted power supply. The system is simulated in MATLAB/SIMULINK and results are presented.

The hour ahead load forecasting is used for the reliable and proactive operation of the power system. The hour ahead load forecasting is a one type of Short Term Load Forecasting (STLF). The mostly STLF is used for the spinning reserve capacity, unit commitment and maintenance planning in the power system. In this paper the Linear Regression (LR) and the Artificial Neural Network (ANN) are used to study the STLF. In the ANN feed forward network is used for the hourly load forecasting. One fast training algorithm the Levenberg-Marquardt Back Propagation (LMBP) is used to train the neural network. The neuron model is trained using the historical load data of Indian distribution system. The sensitivity of the weather data for the STLF is verified. Both the techniques the LR and the ANN are compared according to the Mean Absolute Error (MAE) and the Mean Absolute Percentage Error (MAPE). The accuracy of the ANN technique for the STLF with the weather data is proved for the residential and the industrial feeder.

The integration of the wind generator into the grid connected system becomes a challenge. The major problem is to have a dynamic reactive power support along with the controlled real power support from the source. In this paper a control algorithm is proposed to maintain the unity power factor of the source supply with no reactive power support from the source. The static compensator ( STATCOM ) is connected at a point of common coupling (PCC) with a battery energy storage system (BESS).The STATCOM and energy storage is interfaced with wind generating system, supporting the real and reactive power and also maintain the stable voltage at PCC and support the grid. The effectiveness of the proposed scheme relieves the main supply source from the reactive power demand of the load and the induction generator. The reactive power compensation by STATCOM with bang-bang controller with hysteresis based technique maintains the dynamic stability of the grid and matches the operating behavior of grid system. This scheme is simulated with a MATLAB/SIMULINK in power system block set, having interface of induction generator and non-linear load at PCC and performance is evaluated.

In this article, an improved integrated battery energy storage system (BESS) controller for distributed energy system is presented. The BESS is integrated in parallel with the full wave bridge converter into the distributed energy system network. In a normal operating mode, the BESS serves as a power conditioner as well as an active power filter in a distributed power system network. This work presents BESS controller which is designed for regulating the state of charge of the batteries and also to manage the active power in a distributed power system network. The off peak load energy is used to recover the batteries’ state of charge through the BESS controller. In this BESS controller, the constant current–constant voltage (CC–CV) mode is used and it helps to keep the batteries’ state of charge conditions for improving the reliability of the distributed power system system. This control strategy is incorporated into the main converter. The controller helps in managing the phase, amplitude and waveform of the current and voltage on the distributed power system network. The controller ensures the power quality and also assists in improving the power factor with respect to the utility for the intermittent distributed generation as well as the load. In this article, the test results of a prototype system are presented, which validates the proposed controller strategy of BESS in a distributed power system network.

The proposed wind energy conversion system with battery energy storage is used to exchange the controllable real and reactive power in the grid and to maintain the power quality norms as per International Electro-technical commission IEC-61400-21 at the point of common coupling. The generated wind power can be extracted under varying wind speed and can be stored in the batteries at low power demand hours. In this scheme, inverter control is executed with hysteresis current control mode to achieve the faster dynamic switchover for the support of grid. The combinations of battery storage with wind energy generation system, which will synthesizes the output waveform by injecting or absorbing reactive power and enable the real power flow required by the load. The system reduces the burden on the conventional source and utilizes WEGS and battery storage power under load constraints. The system provides rapid response to support the grid. The scheme can also be operated as a stand-alone system in case of grid failure like a uninterrupted power supply. The system is simulated in MATLAB and results are presented.

Injection of the wind power into an electric grid affects the power quality. The performance of the wind turbine and thereby power quality are determined on the basis of measurements and the norms followed according to the guideline specified in International Electro-technical Commission standard, IEC-61400. The influence of the wind turbine in the grid system concerning the power quality measurements are-the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation and these are measured according to national/international guidelines. The paper study demonstrates the power quality problem due to installation of wind turbine with the grid. In this proposed scheme STATic COMpensator (STATCOM) is connected at a point of common coupling with a battery energy storage system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the real power source under fluctuating wind power. The STATCOM control scheme for the grid connected wind energy generation system for power quality improvement is simulated using MATLAB/SIMULINK in power system block set. The effectiveness of the proposed scheme relives the main supply source from the reactive power demand of the load and the induction generator. The development of the grid co-ordination rule and the scheme for improvement in power quality norms as per IEC-standard on the grid has been presented.

In this paper, an improved proportional integral stator resistance estimation for a direct torque controlled induction motor is proposed. This estimation method is based on an on-line stator resistance correction regarding the variations of the stator current estimation error. In fact, the input variable of the PI estimator is the stator current estimation error. The main idea is to tune accurately the stator resistance value relatively to the evolution of the stator current estimation error gradient to avoid the drive instability and ensure the tracking of the actual value of the stator resistance. But there is an unavoidable steady state error between the filtered stator current modulus and its estimated value from the dq model of the machine which is due to pseudo random commutations of the inverter switches. An offset has been introduced in order to overcome this problem, for different speed command values and load torques. Simulation results show that the proposed estimator was able to successfully track the actual value of the stator resistance for different operating conditions

Strategies that confine antibacterial and/or antifouling property to the surface of the implant, by modifying the surface chemistry and morphology or by encapsulating the material in an antibiotic-loaded coating, are most promising as they do not alter bulk integrity of the material. Among them, plasma-assisted modification and catechol chemistry stand out for their ability to modify a wide range of substrates. By controlling processing parameters, plasma environment can be used for surface nano structuring, chemical activation, and deposition of biologically active and passive coatings. Catechol chemistry can be used for material-independent, highly-controlled surface immobilisation of active molecules and fabrication of biodegradable drug-loaded hydrogel coatings. In this article, we comprehensively review the role plasma-assisted processing and catechol chemistry can play in combating bacterial colonisation on medically relevant coatings, and how these strategies can be coupled with the use of natural antimicrobial agents to produce synthetic antibiotic-free antibacterial surfaces.

A simple method for the design of ultra-wideband antennas in planar format is presented. This method is demonstrated for a high-dielectric-constant substrate material, which allows for a considerable antenna size reduction. Simulations are performed using Ansoft's High-Frequency Structure Simulator (HFSS) for antennas assuming DuPont951 (er = 7.8) and RT6010LM (er = 10.2) substrates. For the 1-mm-thick DuPont951, the designed antenna with 22 X 28 mm dimensions features a 10-dB return-loss bandwidth from 2.7 GHz to more than 15 GHz. For the 0.64-mm-thick RT6010LM a 20 X 26 mm antenna exhibits a 10-dB return loss bandwidth from 3.1 to 15 GHz. Both antennas feature nearly omnidirectional properties across the whole 10-dB return-loss bandwidth. The validity of the presented UWB antenna design strategy is confirmed by measurements performed on a prototype developed on RT6010LM substrate.

The distribution feeders often get overloaded under peak power demands. This situation is generally countered by load shedding, which leads to financial losses to utilities and individual users. The compensation of real/reactive power not only provides the voltage profile improvement but also ensures the sustain power to the consumers. This paper presents the new control algorithm to support the real and reactive load power demand by integrating energy storage (ES). The efficiency functions co-relates to the thermal limit and storage energy availability. For a given radial feeder this control algorithm ensures the unity power factor on source side which provides relief in reactive power support from the source. The energy saving due to loss reduction and reliability of supply for critical load justify the additional energy storage investment. This algorithm is implemented with the energy storage system along with the DSTATCOM. The performance of the controller is observed using MATLAB/SIMULINK.

This paper proposes Proportional Resonant (PR) controller implementation with double update mode digital PWM for grid connected single phase inverter. Digital implementation of PR compensator to track the sinusoidal current reference is also presented. A distinctive advantage of PR controller over conventional Proportional Integral (PI) controller for disturbance rejection capability and lower steady state error is achieved. Model of double update digital PWM is analysed and implemented through DSP. The advantage of modulation delay reduction in proposed digital PWM in double update mode improves the closed loop performance. The PR controllers are tuned to suppress the lower order harmonics. Design of the controllers and their tuning methodology is elaborated and analysed through simulation in MATLAB. Phase Lock Loop (PLL) elimination in grid synchronization and removal of switching noise component in sampled signals is demonstrated. The experimental results of 100W grid connected inverter with the PR digital controller implementation through TMS320F28027 are validated for the proposed control scheme.

Integration of the renewable source in the distribution network under varying load profile is a daunting task. This paper presents the PV system with battery energy storage to improve the distribution network utilization. The load profile of the distribution systems demands the reactive/real power support to maintain the voltage profile and better efficiency in the power utilization. The addition, instantaneous injectable real/reactive power is made available through PV and battery energy storage through D-STATCOM interface. Always power from renewable source availability and load demand in the distribution network are mismatching. The intermittent energy storage with batteries not only resolves this mismatching but also supports the operational efficacy of distribution infrastructure. This operation is proposed through control algorithm based on the battery capacity support in real/reactive power demand by the load. This ensures the negligible reactive power from the source under near unity power factor operation of the distribution feeder. This relief provides the additional capacity availability on the existing distribution network. This improvement in the utilization justifies the investment on the batteries. The typical distribution operation under different operating conditions is simulated with the proposed control scheme. The results are verified with its cost analysis on urban feeder.

In current era, efficient control of electrical machines is highly desirable. For better control, one cannot go ahead without power electronics. There are various machines currently serving in industries, e.g., AC, DC, etc. To make available the desired power supply for the machines, rectifiers and inverters, etc. are used. There is large number of rectification techniques and some new techniques are still being developed. In this paper, the author compares various topologies for power supply conditioning, specially focusing on rectification process, with help of MATLAB/SIMULINK model simulations.