Electrical and Electronics

Polymeric insulating materials are increasingly being used in outdoor and radiation environments such as space, nuclear power plants etc. It is well known that polymeric materials used for electrical insulations may suffer from tracking. It is necessary to form a credible database about the tracking resistance of different polymeric insulating materials and their behaviour under ac/dc voltage stresses as affected by the radiation. The investigations here show that, the DC resistance to tracking of all the materials investigated were significantly lower than that for AC. It is therefore necessary to formulate separate standards for tracking under DC voltage stresses. Also, the test results show that Silicone rubber and High Density Poly Ethylene samples are reliable for radiation environments.

In this paper a resource efficient SVPWM algorithm having low computational overheads, is proposed. This can be used for Three Phase voltage source inverter to supply variable voltage and variable frequency to three phase ac drives. This technique has the advantages such as lower switching losses, higher output voltage for the same dc bus voltage, and better harmonic performance. Conventional scheme is theoretically simple, the implementation is difficult especially with the advance of switching frequency (low sampling period). The complicated procedures will result in long processing time and extensive computational resources. Using this resource efficient SVPWM algorithm, the conventional SVPWM is decomposed into fast integer operations entirely by using an intermediate vector, which will properly counteract the redundant calculations of the remaining procedures. Since it can be implemented without any multiplier or divider, the fast algorithm is especially suitable for field programmable gate array applications. It ensures lower hardware resource usage, and at the same time, operates faster. Also the Field Programmable Gate Arrays (FPGAs) offer high computational ability and flexibility due to their parallel execution and reconfigurable hardware. Hence the scheme suggests the implementation of a resource efficient algorithm for SVPWM generation using FPGA and obtains higher sampling rates with minimal use of hardware resources Hence a modified SVPWM algorithm is developed by using intermediate vectors and the transformed mathematical equations, from the conventional SVPWM algorithm. This modified algorithm is then implemented using VHDL, downloaded on XILINX Spartan 2E kit XC3S200E and the waveforms were observed on the oscilloscope.

A small size low profile microstrip patch antenna with different shape configuration like L, U and E- shape is presented here. Slot insertion causes size reduction which increases the bandwidth and return loss. So here we will see the performance of bandwidth enhancement and return loss by graphical analysis of different value. This paper reviews the performance analysis of compact and small planar monopole antenna with symmetrical L and U- shaped slots for wireless local area network (WLAN) and worldwide Interoperability for microwave access (WiMAX) (2014). Circularly polarized arrowhead shaped slotted microstrip antenna (2014), small UWB Planar Monopole Antenna with Added GPS/GSM/WLAN Bands (2012). Application of characteristic mode to commonly used circular polarized U-slot and E-shaped patch antenna (2012). Bandwidth enhancement of a polarization reconfigurable antenna with stair slots on the ground (2014). This paper also discusses the technology incorporated in order to bring about the required change in terms of improved performance. The performances of the antenna are compared along with measured and simulated result.

Mobile communication is currently one of the major services that are developing at a rapid pace.4G (also known as beyond 3G) is a term used to describe the next complete evolution in wireless communications. A 4G system will be able to provide a comprehensive Internet Protocol solution where voice, data and streamed multimedia services can be provided to users on an "anytime, anywhere" basis, and at higher data rates than previous generations. This implies that roaming between different networks must be automatic and transparent to the user. The international telecommunications regulatory and standardization bodies are working for commercial deployment of 4G networks roughly in the 2012–2015 time scale.

This paper describes a QRS detector system to be implemented using 0.35µm CMOS technology which is used in biomedical applications. The proposed system uses fuzzy logic controller and several analog circuits for detecting QRS complexes and separating these parts from the rest of ECG signal. Simulation results using HSPICE that verify the functionality of system are presented.

Multilevel inverter technology has emerged recently as a very important alternative in the area of high-power system. They give low harmonics, smaller distortion even at low switching frequencies and has low commutation loss but they suffers from complexity problem requiring large number of power devices and complex control algorithm. This paper presents some important topologies like diode-clamped(neutral -point clamped), capacitor-clamped (flying capacitor), and cascaded multicell inverter with separate dc sources and comparison between these topologies is done on the basis of total loss and estimated cost of each topology .Other emerging topology and modulation schemes are also discussed along with their advantages.

In this paper we describes and analyzes the Zone Routing Protocol (ZRP),which is a hybrid mobile ad-hoc protocol which fragments the network into overlapping routing zones, allowing for the use of independent protocols within and between the zones. ZRP performance better than other protocols ,but increase network load by use of useless control packets and decrease of network performance.

A design and development of a simple monopole antenna based on metamaterial resonators for multiband operation is presented. The antenna operates in the frequency range of 2.97 GHz to 4.25GHz, 4.6 GHz to 5.24 GHz, 7.15 GHz to 10.41GHz, with impedance bandwidth of 35.45%, 13.01% and 37.13%, respectively. The split ring resonators (SRR) acts as metamaterial resonators which are embedded on the planar monopole that resonates for multiple frequency bands. The antenna shows the good impedance matching and radiation performance. The measured result is agreed well with the simulated result. The proposed antenna finds their application in the different wireless communications such as Wi-MAX, Wi-Fi and Satellite Communication.

A general framework for the development of a new generation of PM Linear Oscillating Machine (PMLOM) using FE magnetic analysis suitable for short strokes is described in this paper. A microcontroller based IGBT inverter is developed for the control of thrust and oscillation frequency. The PMLOM can perform precision oscillation task with relatively low power dissipation. The use of powerful permanent magnet material such as Neodymium-Iron-Boron alloys has greatly improved the performance of the machine. The forces for aluminium mover embedded with rare earth permanent magnets are determined analytically and the results are validated extensively by comparison with finite element analyses.

ABSTRACT In this paper induction motor speed controlling using FOC with genetic algorithm tuned hybrid PID plus fuzzy controller is discussed. Tuning of PID plus fuzzy speed controller by GA improves static and dynamic performance of FOCIM. Nonlinear induction motor modeling is modeled as linear model for optimization of controller gains. Matlab/Simulink based simulations are carried out with different cases to check efficiency of proposed controller. These results are compared with conventional trial and error method to check improvement in peak overshoot and response time. Keywords: FOCIM (Field Oriented Control Induction Motor), Genetic Algorithm, Fuzzy, mutation, crossover.