Behaviour of single-phase self-excited induction generator during short-circuit at terminals

2018 ◽  
Vol 37 (5) ◽  
pp. 1815-1823
Author(s):  
Krzysztof Makowski ◽  
Aleksander Leicht
Keyword(s):  
Output Voltage ◽  
Design Methodology ◽  
Single Phase ◽  
Short Circuit ◽  
Voltage Regulation ◽  
Circuit Model ◽  
Field Analysis ◽  
Induction Generator ◽  
Content Type ◽  
Current Drop

PurposeThe purpose of this paper is to present analysis of short-circuit transients in a single-phase self-excited induction generator (SP-SEIG) for different capacitor topologies.Design/methodology/approachThe paper presents field analysis of the short-circuit problem in the SP-SEIG on the base of two-dimensional field-circuit model of the generator.FindingsThe carried-out field computations of the tested SP-SEIG show that the self-excited induction generator is intrinsically protected from the results of sudden short-circuit, as output voltage and current drop rapidly to zero. Short-circuit is a problem when a series capacitor is used to improve output voltage regulation. Experimental results show that re-excitation of the generator is possible after the short-circuit is removed.Originality/valueThe originality of the paper is the presented analysis of short-circuit transients at terminals of SP-SEIG. A finite elements method-based field circuit model was used. The simulation results were validated by the measurements conducted on a laboratory test setup.

Analysis of self-excitation and performance characteristics of a single-phase self-excited induction generator by field-circuit method

2016 ◽  
Vol 35 (1) ◽  
pp. 200-224 ◽  
Author(s):  
Krzysztof Makowski ◽  
Aleksander Leicht
Keyword(s):  
Single Phase ◽  
The Self ◽  
Performance Characteristics ◽  
Field Analysis ◽  
Induction Generator ◽  
Proper Solution ◽  
Content Type ◽  
Initial Voltage ◽  
Terminal Voltage ◽  
And Performance

Purpose – The purpose of this paper is to present analysis of an influence of rotor slots opening on self-excitation process, terminal voltage and performance characteristics of the single-phase self-excited induction generator (SPSEIG). Design/methodology/approach – The paper presents field analysis of the self-excitation problem in the SPSEIG and performance characteristics on the base of two-dimensional field-circuit model of the generator. Findings – The carried out field computations of the tested SPSEIG with closed rotor slots showed that only an initial voltage across the excitation capacitor of about nominal value (230 V) causes successful self-excitation of the generator. It was also proved that the suitable opening of the rotor slots, beside remnant flux density in the rotor core, facilitates self-excitation in the generator. Since in working applications initially charging of the capacitor to almost nominal voltage may cause a problem, therefore employment of semi-closed rotor slots in the SPSEIG would be proper solution. Originality/value – The conducted simulations, validated by laboratory tests showed that not only suitable excitation capacitor capacitance and rotor speed are needed to obtain desired terminal voltage of the generator, but also suitable initial voltage across the capacitor in auxiliary stator winding is very important and necessary for reliable self-excitation of the single-phase induction generator with closed rotor slots. The employment of semi-closed rotor slots in the SPSEIG makes the self-excitation more effective.

Investigation on the shaft voltage generation of large synchronous turboalternators

2020 ◽  
Vol 39 (5) ◽  
pp. 1145-1156
Author(s):  
Kevin Darques ◽  
Abdelmounaïm Tounzi ◽  
Yvonnick Le-menach ◽  
Karim Beddek
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Short Circuit ◽  
Element Model ◽  
Stator Winding ◽  
Content Type ◽  
Voltage Generation ◽  
The Impact ◽  
Investigation Process ◽  
Circulating Currents

Purpose This paper aims to go deeper on the analysis of the shaft voltage of large turbogenerators. The main interest of this study is the investigation process developed. Design/methodology/approach The analysis of the shaft voltage because of several defects is based on a two-dimensional (2D) finite element modeling. This 2D finite element model is used to determine the shaft voltage because of eccentricities or rotor short-circuit. Findings Dynamic eccentricities and rotor short circuit do not have an inherent impact on the shaft voltage. Circulating currents in the stator winding because of defects impact the shaft voltage. Originality/value The original value of this paper is the investigation process developed. This study proposes to quantify the impact of a smooth stator and then to explore the contribution of the real stator winding on the shaft voltage.

Influence of shape and material of rotor bars on performance characteristics of single-phase self-excited induction generators

2019 ◽  
Vol 38 (4) ◽  
pp. 1235-1244 ◽  
Author(s):  
Aleksander Leicht ◽  
Krzysztof Makowski
Keyword(s):  
Single Phase ◽  
General Purpose ◽  
Performance Characteristics ◽  
Induction Generator ◽  
Content Type ◽  
Operating Range ◽  
Induction Generators ◽  
Stable Operating ◽  
Rotor Cage ◽  
And Performance

Purpose The purpose of the paper is to present an analysis of an influence of shape and material of rotor bars on the process of self-excitation and performance characteristics of single-phase, self-excited induction generator (SP-SEIG). Design/methodology/approach The presented analysis is based on the results of transient simulations of SP-SEIG performed with the use of field-circuit model of the machine. Four various shapes of the rotor bars and two different conductor materials were investigated. The results for the base model with rounded trapezoidal rotor slots were validated by measurements. Findings An improvement of the performance characteristics – the extension of the stable operating range of the generator – was obtained for rectangular copper rotor bars. The improvement is the result of strong skin effect in the squirrel rotor cage. Application of round rotor slots results in shorter time of voltage build-up during the self-excitation of the generator caused by less apparent deep bar effect in round bars. Originality/value The originality of the paper is the application of the copper rotor cage in the single-phase, self-excited induction generator. Its use is beneficial, as it allows for extension of the range of stable operating range. The results may be used for designing new constructions of the single-phase, self-excited induction generators, as well as the constructions based on general purpose single-phase induction motors.

Multiphysical computation of the structural bending in a bottom-drive VCM

2016 ◽  
Vol 35 (5) ◽  
pp. 1617-1624
Author(s):  
Salatiel García-Moreno ◽  
Manuel Bandala-Sánchez
Keyword(s):  
Design Methodology ◽  
Short Circuit ◽  
Mechanical Reinforcement ◽  
Content Type ◽  
Normal Forces ◽  
Variable Capacitance ◽  
Original Analysis ◽  
Electromechanical Effects ◽  
Rotor Poles ◽  
Supporting Ring

Purpose This paper intends to lay a background knowledge towards the feasibility of developing a bottom-drive variable capacitance micromotor (VCM) using a surface micromachining process (SMP). The purpose of this paper is to determine the possibility of neglecting the bending of the rotor plates caused by the electrostatic normal forces when deploying a set of mechanical supports. Design/methodology/approach A multiphysics simulation approach is considered in order to analyse the coupled electromechanical effects in a steady state and to evaluate if the proposed geometries are useful to reduce the bending of the plates. Findings A surfaced micromachined bottom-drive VCM requires mechanical reinforcement in order to eliminate the risk of an electrical short circuit caused by the deformation in the rotor plates. The combination of an external supporting ring and anchored structural ribs on top of the rotor poles is sufficient to neglect the deformation in the poles of the rotor. Originality/value An original analysis with the objective of setting a background in the development of a bottom-drive electrostatic micromotor using a SMP is presented.

Novel step-down topologies of star-connected autotransformer

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
JiaRong Wang ◽  
Bo He ◽  
XiaoQiang Chen
Keyword(s):  
Design Methodology ◽  
Voltage Regulation ◽  
Content Type ◽  
Harmonic Reduction ◽  
Modeling Analysis ◽  
Step Down ◽  
The Mathematical Model ◽  
Practical Implications ◽  
Theoretical Results ◽  
Equivalent Capacity

Purpose This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Two new symmetrical step-down topologies of star-connected autotransformers are proposed in this paper. Taking the equivalent capacity as the main parameter, the obtained topologies are modeled and analyzed in detail. Design/methodology/approach This paper adopts the research methods of design, modeling, analysis and simulation verification. First, the star-connected autotransformer is redesigned according to the design objective of symmetrical step-down topology. In addition, the mathematical model of two topologies is established and a detailed theoretical analysis is carried out. Finally, the theoretical results are verified by simulation. Findings Two symmetrical star-connected autotransformer step-down topologies are designed, the winding configurations of the corresponding topology are presented, the step-down ranges of these three topologies are calculated and the influence of step-down ratio on the equivalent capacity of autotransformer are analyzed. Through analysis, the target step-down topologies are obtained when the step-down ratio is [1.1, 5.4] and [1.1, 1.9] respectively. Research limitations/implications Because the selected research object is only a star-connected autotransformer, the research results may lack generality. Therefore, researchers are encouraged to further study the topologies of other autotransformers. Practical implications This paper includes the implications of the step-down ratio on the equivalent capacity of autotransformers and the configuration of transformer windings. Originality/value The topologies designed in this paper enable star-connected autotransformer in the 12-pulse rectifier to be applied in step-down circumstances rather than situations of harmonic reduction only. At the same time, this paper provides a way that can be used to redesign the autotransformer in other multi-pulse rectifier systems, so that those transformers can be used in voltage regulation.

The perceptually-inspired model of tactile texture sensor based on the inverse-magnetostrictive effect

2019 ◽  
Vol 46 (3) ◽  
pp. 345-350
Author(s):  
Lili Wan ◽  
Bowen Wang ◽  
Xiaodong Wang ◽  
Wenmei Huang ◽  
Ling Weng
Keyword(s):  
Surface Texture ◽  
Output Voltage ◽  
Design Methodology ◽  
Surface Microstructure ◽  
Sensor Output ◽  
Texture Characteristic ◽  
Content Type ◽  
Microstructure Characteristics ◽  
Texture Properties ◽  
Output Characteristics

Purpose The purpose of this study is to develop an output model to extract surface microstructure characteristics of different objects, so as to predict the response of the output voltage obtained from tactile texture sensor. Design/methodology/approach The model is based on the consideration of the inverse-magnetostrictive effect, the flexure mode, the linear constitutive equations and the strain principle. Findings This research predicts and investigates the effect of the texture properties on the tactile texture sensor output characteristics. Originality/value The surface texture characteristic is regarded to be important information to evaluate and recognize the object.

Characteristics Analysis and Simulation of Self-Excited Single-Phase Induction Generator

2014 ◽  
Vol 577 ◽  
pp. 474-477
Author(s):  
Wen Yeau Chang
Keyword(s):  
Steady State ◽  
Close Agreement ◽  
Single Phase ◽  
Equivalent Circuit Model ◽  
Voltage Regulation ◽  
The Self ◽  
Induction Generator ◽  
Iterative Approach ◽  
Two Phase ◽  
Characteristics Analysis

This paper presents steady-state characteristics analysis of a self-excited single-phase induction generator (SPIG) which supplies an isolated load. The self-regulated characteristics of a SPIG by connecting external capacitors are examined. The system consisting of both shunt and series capacitors in short shunt and long shunt connections to improve voltage regulation of SPIG has been analyzed. Based on two-phase symmetrical components equivalent circuit model, a fast iterative approach to simulate the operated state of a SPIG is developed. To demonstrate the effectiveness of the proposed approach, the approach has been tested on a practical motor-driven SPIG. Very close agreement between experimental and simulated results has been obtained.

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