scholarly journals Estimation of Equivalent Circuit Parameters of Single-Phase Transformer by Using Chaotic Optimization Approach

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1697 ◽  
Author(s):  
Martin Ćalasan ◽  
Danilo Mujičić ◽  
Vesna Rubežić ◽  
Milovan Radulović
Keyword(s):  
Parameter Estimation ◽  
Equivalent Circuit ◽  
Single Phase ◽  
Classical Method ◽  
Short Circuit ◽  
Average Error ◽  
Optimization Approach ◽  
Power Load ◽  
Equivalent Circuit Parameters ◽  
Output Characteristics

This paper deals with parameter estimation of single-phase transformer equivalent circuit by using Chaotic Optimization Approach (COA). Unknown transformer equivalent circuit parameters need to be accurately estimated for the best possible matching between the measured and the estimated transformer output characteristics (for example, output power—load resistance characteristic). Unlike literature approaches which apply different estimation techniques and are based either on the nameplate data or the load data obtained from experiments, in this paper the use of COA is evaluated on both types of input data. For two single-phase transformers, different with respect to machine power and voltage levels, the COA-based parameter estimation is compared to various literature techniques as well as to classical method based on open-circuit and short-circuit tests. The results show that COA outperforms other approaches in terms of average error between the measured and the estimated values of the primary current, secondary current and secondary voltage at full load, or between the measured and the estimated output characteristics. The effectiveness of COA is additionally confirmed through its application on laboratory 2kVA, 220 V/110 V, 50 Hz single-phase transformer.

Augmented Short-Circuit Test for the Measurement of Transformer Equivalent-Circuit Parameters with Large Series Branch Impedances

2010 ◽  
Vol 47 (1) ◽  
pp. 86-93
Author(s):  
Saurabh Kumar Mukerji ◽  
Moleykutty George
Keyword(s):  
Equivalent Circuit ◽  
High Voltage ◽  
Single Phase ◽  
Short Circuit ◽  
Large Series ◽  
Test Results ◽  
Voltage Supply ◽  
Short Circuit Test ◽  
Equivalent Circuit Parameters

An augmented short-circuit test is described for the determination of equivalent-circuit parameters of single-phase transformers with large series-branch impedances. This test may be conducted at rated currents with the transformer connected to a reduced voltage supply. Thus harmonics in current and voltage waves are negligible. This test is therefore free from harmonics-associated errors. Based on test results, phasor equations are found which give formulae for the equivalent-circuit parameters with series-branch impedance split into low- and high-voltage components.

scholarly journals A Study on a Single-Phase HTS Transformer with a Cylindrical Central Iron Core

2018 ◽  
Vol 228 ◽  
pp. 03001
Author(s):  
Meiying Yin ◽  
Yong Zhao ◽  
Zhuyong Li ◽  
Xingmei Li ◽  
Wenzhao Yin ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Liquid Nitrogen ◽  
Single Phase ◽  
Short Circuit ◽  
Liquid Nitrogen Temperature ◽  
Iron Core ◽  
The Past ◽  
In Series ◽  
New Type ◽  
Load Tests

During the past decade, a number of high temperature superconducting (HTS) transformer prototypes have been designed, and the majority of them are full-core transformers and air-core transformers. However, in this study, we proposed a new type of HTS transformer, where the iron core is different in that the limbs and connecting yokes are absent. To investigate the performance of this type of HTS transformer, we design and fabricate a single-phase HTS partial core transformer prototype using the secondary generation (2G) HTS GdBCO wires. The iron core is at room temperature, and the windings are immersed in liquid Nitrogen. The structures of primary and secondary windings are three layers connected in series and nine double pancakes connected in parallel, respectively. Fundamental characteristics are obtained by standard short-circuit, no-load and load tests in liquid Nitrogen temperature of 77 K. In addition, an equivalent circuit of the HTS transformer is proposed to analyze the characteristic of the transformer. The calculated values based on the equivalent circuit are consistent with that of experiment. The detailed results about the design of the HTS partial-core transformer, the experiment, and the equivalent circuit are presented and discussed in this study.

scholarly journals A Method to Determine the Equivalent Circuit Parameters of Single-Phase Induction Motor

1994 ◽  
Vol 30 (4) ◽  
pp. 476-478
Author(s):  
Yoshitomo OKADA ◽  
Kouji OBAYASHI ◽  
Thoru HOSOKAWA ◽  
Hao FENG ◽  
Kimio YAMASHITA
Keyword(s):  
Equivalent Circuit ◽  
Induction Motor ◽  
Single Phase ◽  
Equivalent Circuit Parameters

scholarly journals Determination of Equivalent Circuit Parameters of a Solid Rotor Asynchronous Electric Machine

2019 ◽  
Vol 9 (2) ◽  
pp. 1880-1885
Keyword(s):  
Mathematical Model ◽  
Equivalent Circuit ◽  
High Speed ◽  
Short Circuit ◽  
Initial Approximation ◽  
Electric Machine ◽  
Least Square ◽  
Algebraic Equations ◽  
Current Frequency ◽  
Equivalent Circuit Parameters

The article deal with the determining the equivalent circuit parameters of a solid rotor asynchronous electric machine. To solve the problem, we determined the structure and parameters of a mathematical model using known geometric relationships and parameters of used materials. The least square method is used to determine the equivalent circuit parameters of an unlaminated-rotor asynchronous electric machine. The magnetic field distribution is calculated when the stator winding is supplying with a sinusoidal current and under short-circuit conditions. The imaginary part of the stator phase inductance versus stator current frequency when the rotor is fixed is calculated using the field theory. This dependence is approximated. The system of algebraic equations determining the approximation parameters is non-linear. The Levenberg-Marquardt method provides solution convergence of the equation system when using two or more loops on the rotor. The selection of the initial approximation largely determines the convergence of the solution made by the iterative method. The preliminary studies showed that the use of simplified scheme of the substitution of an asynchronous electric machine with one contour on the rotor is suitable as an initial approximation of parameters. The numerical solution of the equations determined the approximation parameters. The equivalent circuit parameters of high-speed electric generator with solid asynchronous rotor was made as an example of using of the approach under consideration. We need to use three loops on the rotor in the mathematical model of the asynchronous electric machine to take into account the effect of current displacement in solid rotor.

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