scholarly journals Equivalent circuit and calculation of unbalanced power in three-wire three-phase linear networks

2017 ◽  
Author(s):  
Rafael Montoya-Mira ◽  
José M. Diez ◽  
Pedro A. Blasco ◽  
Rafael Montoya
Keyword(s):  
Equivalent Circuit ◽  
Linear Networks ◽  
Three Phase

scholarly journals Faults diagnosis in stator windings of high speed solid rotor induction motors using fuzzy neural network

2021 ◽  
Vol 12 (1) ◽  
pp. 597
Author(s):  
Ahmed Thamer Radhi ◽  
Wael Hussein Zayer
Keyword(s):  
Neural Network ◽  
Equivalent Circuit ◽  
High Speed ◽  
Fuzzy Neural Network ◽  
Induction Motors ◽  
Stator Winding ◽  
Three Phase ◽  
Fuzzy Neural ◽  
Diagnosis Method ◽  
Faults Diagnosis

The paper deals with faults diagnosis method proposed to detect the inter-turn and turn to earth short circuit in stator winding of three-phase high-speed solid rotor induction motors. This method based on negative sequence current of motor and fuzzy neural network algorithm. On the basis of analysis of 2-D electromagnet field in the solid rotor the rotor impedance has been derived to develop the solid rotor induction motor equivalent circuit. The motor equivalent circuit is simulated by MATLAB software to study and record the data for training and testing the proposed diagnosis method. The numerical results of proposed approach are evaluated using simulation of a three-phase high-speed solid-rotor induction motor of two-pole, 140 Hz. The results of simulation shows that the proposed diagnosis method is fast and efficient for detecting inter-turn and turn to earth faults in stator winding of high-speed solid-rotor induction motors with different faults conditions

The Poynting Vector and the New Theory of a Transformer. Part 11. Three-Phase Three-Core Transformers without a Neutral Wire

2021 ◽  
Vol 1 (1) ◽  
pp. 23-34
Author(s):  
Mansur A. SHAKIROV ◽  
Keyword(s):  
Equivalent Circuit ◽  
Single Phase ◽  
Poynting Vector ◽  
Magnetic Circuit ◽  
Phase Zone ◽  
Field Patterns ◽  
Three Phase ◽  
Short Circuits ◽  
The Difference ◽  
Mathematical Relations

A topological equivalent circuit for a three-phase three-core transformer reflecting the spatial structure of its magnetic system is developed. Owing to this approach, it became possible to represent the magnetic fluxes of the magnetic circuit’s all main sections and the apertures for each of three phases directly in the circuit in the absence of the windings’ neutral wires. The circuit is constructed by stitching together the anatomical circuit models of single-phase transformers obtained in the previous parts with taking into account the relationships between the fluxes at the junctions of the phase zones in iron. Its validity is confirmed by the rigor nature of the physical and mathematical relations for idealized transformers with infinite magnetic permeability of iron and simplified magnetic field patterns, which corresponds to the generally accepted approach with neglecting the magnetization currents. The difference lies in the fact that the developed model takes into account the heterogeneity of magnetization in different parts of the magnetic circuit with allocating more than 30 sections in the iron and apertures. The transition to the model of a real three-core transformer is carried out by adding four nonlinear transverse magnetization branches in each extreme phase zone and eight branches in the central phase zone to the idealized equivalent circuit. It is shown that in cases of winding connections without neutral wires, there is no flux of the Poynting vector in interphase zones in any unbalanced mode. In this case, the problems connected with the occurrence of fluxes exceeding the no-load fluxes under the conditions of symmetric and asymmetric short circuits, as well as the occurrence of buckling fluxes in these modes in the region outside the transformer iron, are solved.

scholarly journals Open-Loop Single-Phase Space State Model and Equivalent Circuit of a Non-Conventional Three-Phase Inverter

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 744
Author(s):  
Vinícius Melo ◽  
Alexandre Melo ◽  
Walbermark Santos ◽  
Jussara Fardin ◽  
Lucas Encarnação
Keyword(s):  
Equivalent Circuit ◽  
Direct Current ◽  
Single Phase ◽  
Green Energy ◽  
State Model ◽  
Phase Inverter ◽  
Three Phase ◽  
Space State ◽  
Phase Models ◽  
Three Phase Inverter

Recently, many non-conventional three-phase inverters, topologies for green energy source grid-connection systems, and electric drives have been proposed. Simplifying the inverter circuit is crucial to analyze and solve their models in order to design them. The main goal of the study is centered on obtaining a single-phase equivalent circuit and space state model from non-conventional three-phase inverters based on bidirectional direct current–direct current (DC–DC) Buck-Boost topology using isolated gate bipolar transistors (IGBT). From just one phase of the three-phase inverter, the single-phase equivalent circuit was obtained by means of Kirchhoff’s laws. The equivalent circuit operation steps were presented in order to obtain the space state model. Finally, the equivalent circuit was simulated, and experimental results with a 200 W three-phase inverter feeding a resistive, inductive, and capacitive loads were performed to confirm the theoretical and simulation analyses. The results show the state space dynamic behavior variables of single-phase and three-phase models are quite similar. Therefore, it can be concluded that the proposed circuit can be used with property to represent equivalent single-phase models of non-conventional three-phase inverters.

Research on Differential-Mode Conducted EMI of Three-Phase PWM Rectifier AC Side

2011 ◽  
Vol 130-134 ◽  
pp. 3289-3292
Author(s):  
Ke Xin Wei ◽  
Rui Xia Duan ◽  
Bin Liang
Keyword(s):  
Equivalent Circuit ◽  
Frequency Band ◽  
Circuit Diagram ◽  
Pwm Rectifier ◽  
Differential Mode ◽  
Three Phase ◽  
Source Voltage ◽  
Mode Interference ◽  
Interference Mechanism ◽  
Conducted Emi

Taking three phase PWM rectifier as the research object, according to interference mechanism of the rectifier bridge, this paper describes the equivalent circuit of AC side differential mode interference and calculates the interference source voltage and differential mode interference voltage of the three phase PWM rectifier AC side in 150KHz-30MHz frequency band. Then we analyze the model of the equivalent circuit diagram using the Saber software and verify the validity of the model and the accuracy of the calculation through experiments.

scholarly journals A Novel Three Phase to Seven Phase Conversion Technique Using Transformer Winding Connections

2017 ◽  
Vol 7 (5) ◽  
pp. 1953-1961
Author(s):  
M. Tabrez ◽  
P. K. Sadhu ◽  
A. Iqbal
Keyword(s):  
Equivalent Circuit ◽  
Power Density ◽  
Experimental Approach ◽  
Phase Conversion ◽  
Three Phase ◽  
Higher Power ◽  
Transformer Winding ◽  
Present Design ◽  
Transformer Design ◽  
Scheme Analysis

This paper proposes a novel multiphase transformer connection scheme which converts three phase balanced AC input to seven phase balanced AC output. Generalized theory to convert a three phase utility supply into any number of phases is presented. Based on the proposed generalized principle, a three phase to seven phase power converting transformer design is presented with connection scheme, analysis and simulation and experimental results of the proposed three phase to seven phase conversion transformer. The proposed transformer in this paper is analyzed and compared with the connection scheme for seven phase available in the literature. The connection scheme is found to have higher power density, lower core area and lower core requirement as compared to the available connection scheme of the same rating. Impedance mismatching between different phases of the transformer is observed in the three phase to seven phase transformer available in the literature. As this mismatching introduces error in study of per phase equivalent circuit diagrams as well as imbalance in voltage and currents. The present design also addresses the impedance mismatching issue and reduces mismatching in the proposed transformer design. A prototype of the proposed system is developed and waveforms are presented. The proposed design is verified using simulation and validated using experimental approach.

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