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This paper aims to deal with a modified-based approach for the evaluation of the steady state performances of three-phase self-excited induction generator (SEIG) feeding single-phase load.

Using the symmetrical components method, the proposed approach is based on a modified model of unbalanced three-phase SEIG, which is formulated similarly to the well-known model of balanced three-phase SEIG. Owing to this modified model, the determination of the SEIG operating point amounts to the resolution of two semi-decoupled nonlinear equations for two unknowns; the magnetizing reactance and the per-unit frequency. A simple resolution method based on an iterative two-step technique is used. The results obtained by the proposed approach are compared with those given by a conventional approach and are validated experimentally.

The proposed approach is as accurate as the conventional approach. Further, for the same accuracy degree, the proposed approach permits to speed up the resolution when compared to the conventional approach, as only few iterations are required for the convergence. The proposed approach was also successfully used for the steady state analysis of SEIG under generalized unbalanced loading conditions.

The determination of the operating point of the generator is based on a modified model of the generator and a simple iterative resolution method. The calculation technique can be implemented on low resource controller to provide online voltage control of the SEIG.

The paper contains two main originalities. The first one consists in a modified formulation of the SEIG model under unbalanced loading conditions. The modified formulation permits the use of the well-known model of balanced three-phase SEIG. Unlike previous ones reported in the literature, the proposed model does not require tedious algebraic manipulations. The second originality is the use of two-step technique to solve the equations, which permits to avoid laborious mathematical derivations and manipulating high-order polynomials.

The purpose of this paper is to discuss two evaluation methods of single pole auto-reclosing process effectiveness in HV transmission lines. Secondary arc current and recovery voltage results obtained by load flow calculation are compared to the results obtained by the time domain simulations. Moreover, a nonlinear secondary arc implementation is presented.

A computer simulation studies were performed using DIgSILENT PowerFactory® software to analyse phenomena during single phase to earth short circuit and during single pole circuit breaker opening. Possibilities of electric arc extinction for different earthing solutions of shunt reactors were examined.

The authors indicate, that precise representation of secondary electric arc in power system studies could lead to different conclusion than analysis carried out on simplified arc models. Recommendations for line construction (i.e. earthing reactor installation) and line operation (i.e. prolongation of dead time during auto-reclosing) based on time domain simulations are less restrictive than resulting from the traditional steady-state calculation approach.

An implementation of mathematical model of nonlinear secondary arc for DIgSILENT PowerFactory® software is presented. The model could be used during the process of design of HV transmission line, to assess its proper operation, to calculate dead time during single pole reclosing or to evaluate the necessity of installing additional earthing reactors.

A low power flip-flop circuit is designed for energy-efficient devices. Digital sequential circuits are in huge demand because every processor has most of the parts of digital circuit. The sequential circuits consist of a basic data storing element, a latch is used to store single bit data. The flip-flop takes a sufficient portion of the total chip area and overall power consumption as well. This study aims to the low power energy-efficient applications like laptops, mobile phones and palmtops.

This paper proposes a new type of flip-flop that consists of the only 16 transistors with a single-phase clock. The flip-flop has two blocks, master and slave latch. In this design, the authors have focused on only master latch, which includes a level restoring circuit. It is used to help the master latch in data retention process. The latch circuit has two inverters in back-to-back arrangement. The proposed flip-flop is implemented on 65 nm complementary metal oxide semiconductor technology using Cadence Virtuoso environment and compared with other reported flip-flops.

The proposed flip-flop architecture outperformed the peak percentage, i.e. 79.25% as compared to transmission gate flip-flop and a minimum of 20.02% compared to 18 T true single phase clocking (TSPC) improvement in terms of power. It also improved C to Q delay and power delay product. In addition, by reducing the number of transistors the total area of the proposed flip-flop is reduced by a minimum of 13.76% with respect to 18TSPC and existing flip-flop. For reliability checking the Monte Carlo simulation is performed for thousand samples and it is compared with the recently reported 18TSPC flip-flop.

This work is tested by using a test circuit with a load capacitor of 0.2 fF. The proposed work uses a new topology to work as master-slave. Power consumption of this technique is very less and it is best suitable for low power applications. This circuit is working properly up to 2 GHz frequency.

This paper aims to propose a simplified model of vanadium redox flow batteries (VRBs) for VRB energy storage system (ESS) design considering the operational characteristics of VRB, and a VRB ESS, considering the low terminal voltage of VRB, was presented.

According to the designed topology of VRB ESS and the simplified model of VRB, a small perturbation analysis method was used to establish the transfer function of VRB ESS, and the controller parameters of VRB ESS under constant charging and discharging current were designed.

Test results have demonstrated that this designed VRB ESS has fast response, small overshoot, strong adaptation and high steady precision, which strongly verified the reasonable design.

This simplified model of VRB can be suitably used for VRB ESS design. This designed VRB ESS realized the bidirectional power flow of VRB and AC grid. In this designed VRB ESS, phase-shifted full-bridge converter and a single-phase inverter were used and VRB was charged and discharged under constant current.

The paper presents a topology of VRB ESS which can realize the bidirectional power flow of VRB and AC grid. Considering the complexity of VRB model, a simplified model of VRB was proposed for the controller parameters design of VRB ESS, and this method can be used in application.

The purpose of this paper is to present, a novel boost‐active clamp bridge single stage high‐frequency zero voltage soft‐switching‐pulse width modulation (ZVS‐PWM) inverter, which converts the utility frequency AC power into high‐frequency AC power with an embedded controller. This single stage high‐frequency inverter is composed of a single‐phase diode bridge rectifier, a non‐smoothing filter, a boost‐active clamp bridge type ZVS‐PWM high‐frequency inverter, and an induction‐heated load with planar type litz wire working coil assembly. Also, the paper discusses how to extend the soft‐switching operation ranges and improve power conversion efficiency.

The proposed converter is simulated and it is implemented using embedded controller.

It was found that the single stage high‐frequency induction heating (IH) inverter using boosted voltage function can eliminate the DC and low‐frequency components of the working coil current and reduce the power dissipation of the circuit components and switching devices.

The paper shows that the PWM HF inverter is preferred for IH, since it has reduced switching losses and switching stresses. The paper can be extended to PC‐based wireless control, which can be part of a distributed control system in major industrial heating systems.

Statistics show that selecting the best investment program based on both cost and effectiveness can avoid financial losses. However, investment evaluation of a power transformer is full of uncertainty as it is hard to obtain accurate and useful cost-effectiveness results. Therefore, the purpose of the paper is to establish an investment evaluation model.

The cost-effectiveness evaluation model in this study used grey correlation analysis for the power transformer selection based on life cycle cost (LCC). Indices of cost and effectiveness factors were chosen to form a three-level index system including quantitative and qualitative factors. Evidential reasoning was applied to quantify the qualitative indexes. Grey correlation analysis was applied to select the best investment program.

The results from this study show that the proposed approach is effective and offers a new approach to evaluating transformer investment.

The model was applied to an investing decision-making problem of the transformer in a new substation in Wuhan, China.

It is very important to select the best transformer program in the candidate investment programs because the investment program decides almost 70 percent of the LCC of the power transformer.

WITH two of its 40,000 kW generators having recently been brought into operation, the new Roxburgh power station on South Island, which is New Zealand's largest, having a potential capacity of 320,000 kW, incorporates a number of interesting lubrication features.

AN ancient fable tells of strong brothers destined to great things. But one lay quietly, in his youth, applying goose grease to his muscles while the others disported among themselves in contest of strength. When the day of trial came it was the lone one, Atlas, who took the weight of the world upon his shoulders. The Greeks were neither fools nor strangers to work study.

A Selection of Equipment of Use in the Production and Maintenance of Aircraft, Missiles, Space Vehicles and their Components The Cycatron is the latest addition to the range of stud welding equipment manufactured by Crompton Parkinson (Stud Welding) Ltd. This is a capacitor‐discharge unit which enables studs up to and including 1 in. diameter to be applied safely to any gauge section of sheet metal down to 26 gauge in steel or 20 gauge in aluminium or aluminium alloy. A range of completely new applications is therefore brought within the scope of stud welding techniques. The unit, which is portable, is mounted on undergear consisting of two large diameter rubber tyred wheels at the rear and two steel feet at the front, designed to give the cabinet stability when not actually being moved.

Details of Electrical and Electronic Apparatus and Applications in the Maintenance and Operation of Aircraft, Missiles and Space Vehicles. A completely new, compact airborne navigation computer has been designed by The Mareoni Co. to enable long‐range aircraft to navigate to within a few miles of any destination throughout the world—an automatic track guidance system that needs no aids or reference from ground stations.