This paper introduces a new window comparator circuit utilizing a new current conveyor and two diodes, operable at &#xb1;1.25&#x2009;V and capable of accurately detecting the voltage windows. Another modified circuit with distinct binary levels suited for automatic control applications is also suggested. Exhaustive simulation results showing detection of windows, as small as 50&#x2009;mV and as high as 1&#x2009;V, are included. Comparisons are further drawn with the traditional operational amplifier based circuit and the new circuit is found to benefit from the use of current-mode active element, namely, Extra-X Current Controlled Current Conveyor. The proposed theory is well supported through simulation results.

Sudhanshu Maheshwari

Current Conveyor Based Window Comparator Circuits

In the restructured environment, distributed generation (DG) is considered as a very promising option due to a high initial capital cost of conventional plants, environmental concerns, and power shortage. Apart from the above, distributed generation (DG) has also abilities to improve performance of feeder. Most of the distribution feeders have radial structure, which compel to observe the impact of distributed generations on feeder performance, having different characteristics and composition of time varying static ZIP load models. Two fuzzy-based expert system is proposed for selecting and ranking the most appropriated periods to an integration of distributed generations with a feeder. Madami type fuzzy logic controller was developed for sizing of distributed generation, whereas Sugeno type fuzzy logic controller was developed for the DG location. Input parameters for Madami fuzzy logic controller are substation reserve capacity, feeder power loss to load ratio, voltage unbalance, and apparent power imbalances. DG output, survivability index, and node distance from substation are chosen as input to Sugeno type fuzzy logic controller. The stochastic performance of proposed fuzzy expert systems was evaluated on a modified IEEE 37 node test feeder with 15 minutes characteristics time interval varying static ZIP load models.

Jagdish Prasad Sharma

H. Ravishankar Kamath

Fuzzy Logic Controller Based Distributed Generation Integration Strategy for Stochastic Performance Improvement

This paper presents a novel method of fault diagnosis by the use of fuzzy logic and neural network-based techniques for electric power fault detection, classification, and location in a power distribution network. A real network was used as a case study. The ten different types of line faults including single line-to-ground, line-to-line, double line-to-ground, and three-phase faults were investigated. The designed system has 89&#x25; accuracy for fault type identification. It also has 93&#x25; accuracy for fault location. The results indicate that the proposed technique is effective in detecting, classifying, and locating low impedance faults.

Oluleke O. Babayomi

Peter O. Oluseyi

Intelligent Fault Diagnosis in a Power Distribution Network

A Coplanar Waveguide (CPW) fed miniaturized ultra-wideband (UWB) tri-notch antenna with bandwidth enhancement is proposed. The antenna is prototyped for ultra-wideband (UWB) communication applications with bandwidth enhancement. By implementing asymmetric structure, the miniaturization in the antenna has been achieved with a very compact size of 22 &#xd7; 13 &#xd7; 1.5&#x2009;mm<sup>3</sup> making it suitable for USB dongle applications. The antenna is first simulated with partial rectangular ground plane which shows that operating bandwidth ranges from 3.1 to 10.6&#x2009;GHz. Then the antenna is measured and simulated by cutting the ground plane with specific geometry which shows that operating bandwidth now ranges from 3.1 to 20&#x2009;GHz which provides a wide usable fractional bandwidth of more than 150&#x25;. The antenna is then modified for tri-notch applications in order to reject worldwide interoperability for microwave access (WiMAX) band (3.3&#x2013;3.6&#x2009;GHz) and wireless local area network (WLAN) frequency bands (lower WLAN (5.15&#x2013;5.325) and upper WLAN (5.725&#x2013;5.825)&#x2009;GHz). Triple Band rejection capability has been achieved by introducing three complementary split ring resonators (CSRR) in the radiating patch.

MuhibUr Rahman

CPW Fed Miniaturized UWB Tri-Notch Antenna with Bandwidth Enhancement

Dynamic operating conditions along with contingencies often present formidable challenges to the power engineers. Decisions pertaining to the control strategies taken by the system operators at energy management centre are based on the information about the system&#x2019;s behavior. The application of ANN as a tool for voltage stability assessment is empirical because of its ability to do parallel data processing with high accuracy, fast response, and capability to model dynamic, nonlinear, and noisy data. This paper presents an effective methodology based on Radial Basis Function Neural Network (RBFN) to predict Global Voltage Stability Margin (GVSM), for any unseen loading condition of the system. GVSM is used to assess the overall voltage stability status of the power system. A comparative analysis of different topologies of ANN, namely, Feedforward Backprop (FFBP), Cascade Forward Backprop (CFB), Generalized Regression (GR), Layer Recurrent (LR), Nonlinear Autoregressive Exogenous (NARX), ELMAN Backprop, and Feedforward Distributed Time Delay Network (FFDTDN), is carried out on the basis of capability of the prediction of GVSM. The efficacy of RBFN is better than other networks, which is validated by taking the predictions of GVSM at different levels of Additive White Gaussian Noise (AWGN) in input features. The results obtained from ANNs are validated through the offline Newton Raphson (N-R) method. The proposed methodology is tested over IEEE 14-bus, IEEE 30-bus, and IEEE 118-bus test systems.

Akash Saxena

Ankit Kumar Sharma

Assessment of Global Voltage Stability Margin through Radial Basis Function Neural Network

Bitter coils are electromagnets used for the generation of extremely strong magnetic fields superior to 30 T. In this paper we calculate the mutual inductance and the magnetic force between Bitter disk (pancake) coil with the nonlinear radial current and the circular filamentary coil with the azimuthal current. The close form expressed over complete elliptic integrals of the first and second kind as well as Heuman’s Lambda function is obtained for this configuration either for the mutual inductance or for the magnetic force. The results of this method are compared with those obtained by the improved modified filament method for the presented configuration. All results are in an excellent agreement.

Slobodan Babic

Cevdet Akyel

Mutual Inductance and Magnetic Force Calculations for Bitter Disk Coil (Pancake) with Nonlinear Radial Current and Filamentary Circular Coil with Azimuthal Current

Our goal is to overview semiconductor mixers designed for good large signal performance. Twelve different mixers were compared utilizing pn diodes, bipolar transistors, and/or junction field effect transistors. The main aspect of comparison is the third-order intercept point (IP3), and both circuit analysis and measurement results have been considered. IP3 has been analyzed by the program AWR (NI AWR Design Environment) and measured by two-tone test (Keysight Technologies). We provide three ways of improvement of large signal performance: application of a diplexer at the RF port, reduction of DC currents, and exploiting a region of RF input power with infinite IP3. In addition to that, our contributions are several modifications of existing mixers and a new mixer circuit (as illustrated in the figures). It is widely believed that the slope of the third-order intermodulation product versus input power is always greater than that of the first-order product. However, measurement and analysis revealed (as illustrated in the figures) that the two lines may be parallel over a broad range of input power, thus resulting in infinite IP3. Mixer knowledge may be useful for a wide range of readers because almost every radio contains at least one mixer.

J. Ladv&#xe1;nszky

K. M. Osb&#xe1;th

Comparison of 6 Diode and 6 Transistor Mixers Based on Analysis and Measurement

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Advances in Electrical Engineering