Comparative assessment of digital filters for microprocessorbased relay protection

Романюк, Ф. А.; Rumiantsev, V. Yu.; Новаш, И. В.; Rumiantsev, Yu. V.; Boiko, Oleksandr

doi:10.15199/48.2016.07.28

Cited by 3 publications

(1 citation statement)

References 4 publications

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“…The main parameters of a digital signal are: the sampling rate -the number of samples per fundamental frequency period and the sampling period -time between two adjacent samples [9].…”

Section: Introductionmentioning

confidence: 99%

Current Transformer Saturation Detection Method Based on Artificial Neural Network

Rumiantsev

2023

Izv. vysh. ucheb

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When current transformer is saturated, mainly due to the presence of an exponentially decaying DC component in the fault current, its secondary current has a distinctive distorted waveform which significantly differs from its primary (true) waveform. It leads to an underestimation of the secondary current value calculated by the relay protection compared to its true value. Thus, in its turn, results in trip time delay or even in a relay protection devices operation failure, since its settings and algorithms are calculated and designed on the assumption that the secondary current waveform is sinusoidal and proportional to the primary. And since, when using classical electromagnetic current transformer, it is impossible to exclude the possibility of its saturation, the detection of such abnormal condition is an urgent technical problem. The article proposes to use an artificial neural network for this purpose, which, together with the traditional method of saturation detection based on adjacent secondary current samples comparison, allows implementing a fast and reliable current transformer saturation detector. The article details the stages of the practical implementation of such an artificial neural network. The MATLAB-Simulink environment was used for assess the proposed saturation detector operation. The experiments that had been performed confirmed that proposed method provides fast and accurate saturation detection within the wide range of the power system and current transformer parameters change.

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“…The main parameters of a digital signal are: the sampling rate -the number of samples per fundamental frequency period and the sampling period -time between two adjacent samples [9].…”

Section: Introductionmentioning

confidence: 99%

Current Transformer Saturation Detection Method Based on Artificial Neural Network

Rumiantsev

2023

Izv. vysh. ucheb

View full text Add to dashboard Cite

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Matlab-Simulink Based Information Support for Digital Overcurrent Protection Test Sets

Новаш¹,

Романюк²,

Румянцев³

et al. 2017

Izv. vysh. ucheb

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The implementation of information support for PC-based and hardware-software based sets for digital overcurrent protection devices and their models testing using MatLab-Simulink environment is considered. It is demonstrated that the mathematical modeling of a part of the power system – viz. of the generalized electric power object – could be based on rigid and flexible models. Rigid models implemented on the basis of mathematical description of electrical and magnetic circuits of a power system can be considered as a reference model for the simulation results that have been obtained with the aid of another simulation system to be compared with. It is proposed to implement flexible models for generalized electric power object in the MatLabSimulink environment that includes the SimPowerSystems component library targeted to power system modeling. The features of the parameters calculation of the SimPowerSystems component library blocks that the power system model is formed of are considered. Out of the Simulink standard blocks the models of a wye-connected current transformers were composed as well as the digital overcurrent protection, missing in the component library. A comparison of simulation results of one and the same generalized electric power object implemented in various PC-based software packages was undertaken. The divergence of simulation results did not exceed 3 %; the latter allows us to recommend the MatLab-Simulink environment for information support creation for hardware-software based sets for digital overcurrent protection devices testing. The structure of the hardware-software based set for digital overcurrent protection device testing using the Omicron CMC 356 has been suggested. Time to trip comparison between the real digital protection device МР 801 and the model with the parameters which are exactly match the parameters of the prototype device was carried out using the identical test inputs. The results of the tests demonstrated a close coincidence of results (the divergence of not more than 8 %), that confirms the possibility of using the suggested hardware-software based test set during the development and debugging of new digital relay protection devices.

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Technique of Performance Improvement of the Microprocessor-Based Protection Measuring Element

et al. 2019

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The technique is proposed to improve the performance of the measuring element of microprocessor-based protection and its implementation is considered at the software level. Two factors mainly influence on the performance of the measuring elements of microprocessorbased protection of electrical installations. The first one is associated with the appearance of aperiodic and harmonic components in the measured signals due to transients and nonlinearity of the electrical installation elements, and the second–with the inertia of information processing algorithms, in particular–with analog and digital filtering. This leads to the fact that the signal determining time at the output of the measuring element is delayed to unacceptable values that in some cases makes the high-speed protection of electrical equipment ineffective. To solve this problem, it is proposed to form the output signal of the measuring element in the form of special equivalent signals, which are a function of the pre-calculated correction factor and orthogonal components of the controlled signal. In the MatLab-Simulink dynamic modeling environment a mathematical model of the developed measuring element has been implemented, as well as a model of the elements of the power system. Checking the functioning of the model of the measuring element was carried out with the use of 2 types of test effects, viz. a sinusoidal signal with a frequency of 50 Hz (idealized effect), as well as a signal close to the real secondary current of the current transformer in case of short circuit. Computational experiments carried out in relation to the current measuring element using harmonic and close-to-real test effects made it possible to reveal a significant (up to 2 times) increase in the performance of the proposed measuring element as compared to existing ones based on the implementation of the discrete Fourier transform.

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Comparative assessment of digital filters for microprocessorbased relay protection

Cited by 3 publications

References 4 publications

Current Transformer Saturation Detection Method Based on Artificial Neural Network

Current Transformer Saturation Detection Method Based on Artificial Neural Network

Matlab-Simulink Based Information Support for Digital Overcurrent Protection Test Sets

Technique of Performance Improvement of the Microprocessor-Based Protection Measuring Element

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