Performance of various magnetic core models in comparison with the laboratory test results of a ferroresonance test on a 33 kV voltage transformer

Electric Power Components and Systems

2010

Iron losses strongly influence ferroresonance behavior of power transformers. While a jump-up is the characteristic of the non-linear magnetizing branch, the jump-down phenomenon can only be described when losses or loads are considered. In this article, the impact of core losses (constant resistance or non-linear resistancce) on the turning points of the bifurcation diagram of a ferroresonance circuit is investigated by a developed 2-D bifurcation diagram. The sensitivity of solutions with respect to the circuit parameters are analyzed and discussed. It is shown that the left-side turning point is more affected by the non-linear core loss model than the right side is. Based on the developed method, an operational guideline for the range of values of the load that avoids the jump between steady-state solutions and ferroresonance overvoltages with different source voltage amplitudes is provided. The results obtained by analytical approach are compared with time domain simulations.

Section: Steady-state Bifurcation Diagramssupporting

confidence: 60%

“…It is seen that the core loss non-linearity has far less of an effect on the right-side turning point. In fact, as recognized in [20,21], the right-side turning point is more greatly affected by hysteresis than core loss non-linearity.…”

Section: Steady-state Bifurcation Diagramsmentioning

confidence: 98%

Impact of Core Loss Non-linearity on Stability Domain of Ferroresonance

Electric Power Components and Systems

2010

“…Simulated waveforms closely match the measured waveforms [19]. Transformer models with different core loss models were not able to predict the first bifurcation point precisely because it is more affected by hysteresis and its minor loops [17,18]. Figure 8 shows the core loss measured and simulated by different core loss models during increasing and decreasing source voltage amplitude.…”

Section: Time-domain Bifurcation Diagrammentioning

confidence: 81%

“…The sampling rate of the DAC is 100 kHz. The ferroresonance is considered a low-frequency phenomenon, and the harmonic content of the voltage and current does not exceed 2 kHz [17]. Therefore, the sampling rate of 100 kHz is high enough for recording the signals.…”

Section: Ferroresonance Laboratory Test Circuit and Its Elementsmentioning

confidence: 99%

“…angular frequency widely used [1][2][3][4][5]. It was found that such a modeling approach produces significant errors in predicting first and second turning points of bifurcation diagram [17][18][19]. A 2D bifurcation diagram based on the shooting method of non-linear dynamics was developed in [20] to predict areas at risk of ferroresonance over-voltages.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Harmonic Balance Based Stability Domain Analysis of Period-1 Ferroresonance

Electric Power Components and Systems

2011

In an attempt to find regions at risk of ferroresonance, different timedomain simulations and analytical approaches were investigated on a one-phase laboratory transformer. A 2D bifurcation diagram based on a one-term harmonic balance method has been developed. It was shown that increase of core losses during over-voltages significantly affects the stability domain of period-1 ferroresonance. Time-domain simulations show that a static core loss model as a function of the maximum flux of the transformer predicts the second bifurcation point with enough accuracy. This modeling approach was incorporated in harmonic balance analysis. A comparison has been made between analysis and measurements.

Numerical and experimental analysis of core loss modeling for period-1 ferroresonance

Euro. Trans. Electr. Power

2010

Iron losses strongly influence ferroresonance behavior of power transformers. Core losses have a great importance on the lower limit of the voltage source interval where a fundamental ferroresonance regime exists. This paper is concerned with comparing analytical nonlinear core loss models implemented to fundamental ferroresonance studies. A simple singlephase model is used to represent the case of ferroresonance between a transformer and a capacitor. Comparisons are made between the analytical methods and corresponding experimental results. Simulation results show that estimation of the core losses with enough accuracy determines the second bifurcation point, whatever the core loss model is.