scholarly journals Improvement of Algorithm for Formation of Orthogonal Components of Input Quantities in Microprocessor Protection

2021 ◽  
Vol 64 (2) ◽  
pp. 95-108
Author(s):  
F. A. Romaniuk ◽  
Yu. V. Rumiantsev ◽  
V. Yu. Rumiantsev ◽  
I. V. Novash
Keyword(s):  
High Speed ◽  
Block Diagram ◽  
Short Circuit ◽  
Digital Device ◽  
Measuring Devices ◽  
Input Signals ◽  
Orthogonal Components ◽  
Mode Of Occurrence ◽  
Aperiodic Component ◽  
Microprocessor Protection

The use of orthogonal components (OC) underlies  the construction of measuring elements of  modern protection and automation devices. In most microprocessor-based protections, the orthogonal component of the input signal is extracted using a discrete Fourier transform (DFT). The DFT disadvantages are its low speed, which is more than one period of the fundamental frequency, as well as the sensitivity to the free aperiodic component, which creates significant conversion errors depending on the time constant of its decay. Such a settling time of the true output signal is often unacceptable for the design of high-speed measuring devices. The paper proposes to form the OC of the equivalent signal according to the values of the cosine and sine OC of the fundamental harmonic, formed using the DFT by multiplying them by the resulting correction factor. The developed algorithm for the formation of orthogonal components of input signals in microprocessor protections is characterized by high speed in transient modes and it has wide functionality. So, the proposed digital device for forming the orthogonal components of an equivalent signal, in comparison with digital filter based on the DFT, has an increased operating speed both in the mode of occurrence of a short circuit and during the decay of the monitored signal, while maintaining the same characteristics as in the DFT in other modes. A block diagram of the proposed digital device for forming the OC of an equivalent signal has been developed, all blocks of which can be implemented on a microelectronic and microprocessor element base. A digital model of the specified device has been developed in the dynamic modeling system MatLab-Simulink in accordance with the structural diagram. As a result of the calculations, a significant (up to two times) increase in the performance of the proposed digital device for forming the OC in transient modes has been established in comparison with the shapers based on the DFT.

scholarly journals Orthogonal Components Forming of the Microprocessor-Based Protection Input Signals

2020 ◽  
Vol 63 (4) ◽  
pp. 328-339 ◽  
Author(s):  
F. A. Romaniuk ◽  
V. Yu. Rumiantsev ◽  
Yu. V. Rumiantsev ◽  
V. S. Kachenya
Keyword(s):  
Fourier Transform ◽  
Discrete Fourier Transform ◽  
High Speed ◽  
Block Diagram ◽  
Short Circuit ◽  
Current Transformer ◽  
Secondary Current ◽  
Measuring Devices ◽  
Input Signals ◽  
Orthogonal Components

The use of orthogonal components (OS) is the main direction of determining information parameters in microprocessor relay protection and automation of electric power systems. Most of the measuring devices used in modern protection and automation devices can be implemented using known operating systems. Digital non-recursive frequency filters based on discrete Fourier transform are used for OS selection. The main disadvantage of these filters is their low performance that exceeds the period of industrial frequency. For the construction of high-speed measuring devices, this time of establishing the true output signal is often unacceptable. The article proposes to form the equivalent signal OS in microprocessor defenses based on the values of the cosine and sine axes of the main harmonic formed using a discrete Fourier transform, by multiplying them by a correction factor, which is a function of the values of the input signal amplitude and its main harmonic. The proposed algorithm for generating OS input signals in microprocessor defenses is characterized by high performance in transient modes and has wide functionality. A block diagram of an OS equivalent signal generator has been developed, all blocks of which can be implemented according to known schemes on a microelectronic and microprocessor element base. The OS shaper model is implemented in the MatLab-Simulink dynamic modeling environment. The model functioning was checked using two types of test actions, viz. a sinusoidal signal with a frequency of 50 Hz (idealized action) and a signal close to the real secondary current of a short-circuit current transformer. As a result of the performed calculations, a significant (up to two times) in the speed of the proposed method of OS formation in comparison with the formers based on the discrete Fourier transform, frequency properties of both formers being identical.

scholarly journals Formation of Orthogonal Components of Input Currents in Microprocessor Protections of Electrical Equipment

2021 ◽  
Vol 64 (3) ◽  
pp. 191-201
Author(s):  
F. A. Romaniuk ◽  
Yu. V. Rumiantsev ◽  
V. Yu. Rumiantsev ◽  
I. V. Novash
Keyword(s):  
Dynamic Properties ◽  
Electrical Equipment ◽  
Magnetic Core ◽  
Degree Of Saturation ◽  
Current Transformers ◽  
Input Action ◽  
Magnetic Cores ◽  
Orthogonal Components ◽  
Aperiodic Component ◽  
Microprocessor Protection

The methods used in the microprocessor protection of electrical equipment for forming orthogonal components of input currents ensure their reliable isolation after changing the mode followed by one or more periods of the fundamental frequency. This is due to the inertia of the functional elements, in particular, digital frequency filters, as well as the saturation of the steel magnetic cores of current transformers. To increase the speed of the selection of orthogonal components of the input currents, it is proposed to form them as equivalent ones in terms of the cosine and sine components obtained using digital Fourier filters by multiplying by the resulting coefficient. The method that has been developed for determining the specified coefficient provides compensation for the delay caused by the inertia of digital filters, as well as the saturation of the steel of magnetic cores of current transformers. The proposed method of forming orthogonal components is highly effective in the modes of strong saturation of the magnetic core with a complex input action in the presence of an aperiodic component with a large damping time constant. The evaluation of the efficiency of the proposed method was performed using a complex digital model implemented in the dynamic modeling environment MatLab-Simulink. As a result of the performed studies, it was found that in the absence of saturation of the magnetic core of current transformers, as well as in the presence of a small and medium degree of saturation, the proposed method for forming equivalent orthogonal components of input currents has dynamic properties close to the ones of those that had been previously proposed. With a strong saturation of the magnetic core of current transformers, the speed of obtaining reliable values of these components is increased by 1.5–2 times.

scholarly journals Methods of Forming Orthogonal Components of Input Signals for Relay Protection

2019 ◽  
Vol 62 (1) ◽  
pp. 5-14 ◽  
Author(s):  
F. A. Romaniuk ◽  
М. S. Loman ◽  
V. S. Kachenya
Keyword(s):  
Fundamental Frequency ◽  
Digital Filter ◽  
Sampling Frequency ◽  
Transient Phenomena ◽  
Advantages And Disadvantages ◽  
Input Signals ◽  
Orthogonal Components ◽  
Sine Signal ◽  
Aperiodic Component ◽  
The Mathematical Model

The existing frequency digital filters for allocation of the fundamental frequency of a sine signal are considered and their advantages and disadvantages are noted. Preference is given to the combined digital filter. The existing methods of determining the orthogonal components of a sine signal are analyzed and their disadvantages are pointed out. It is concluded that most of the existing methods for determining orthogonal components are sensitive to the fundamental frequency deviation of the sine signal. This is due to the fact that the deviation of the frequency alters the angle of one sample. The method for solving this problem has been proposed. The essence of the method is the dynamic recalculation of the angle of one sample depending on the calculated frequency. The mathematical model for research of ways of formation of orthogonal components is presented. The model includes transient generator taking into account the aperiodic component, combined digital filter and the methods of formation of orthogonal components under study. The method of transient phenomena formation that takes into account the aperiodic component is described. Coefficients of combined digital filter for sampling frequency of 1200 Hz are given. One of the implementations of the proposed method of formation of orthogonal components in the programming language MatLab is presented. One of the more popular methods and the proposed method acted as the formers of orthogonal components under study. The final part of the article presents the results of the research, as well as their analysis.

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

2019 ◽  
Vol 62 (5) ◽  
pp. 403-412 ◽  
Author(s):  
F. A. Romaniuk ◽  
V. Yu. Rumiantsev ◽  
I. A. Novash ◽  
Yu. V. Rumiantsev
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Electrical Equipment ◽  
Current Transformer ◽  
Secondary Current ◽  
Measuring Element ◽  
Two Factors ◽  
Orthogonal Components ◽  
Current Measuring ◽  
Harmonic Components

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.

Two-Phase Short Circuit in the Power Grid Powered by a Transformer with a Y/Δ-11 Winding Connection

2020 ◽  
pp. 25-30
Author(s):  
Aleksandr S. Serebryakov ◽  
Vladimir L. Osokin ◽  
Sergey A. Kapustkin
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Relay Protection ◽  
Electric Circuit ◽  
Operational Reliability ◽  
Research Purpose ◽  
Industrial Complex ◽  
Two Phase ◽  
Short Circuit Currents ◽  
Secondary Winding

The article describes main provisions and relations for calculating short-circuit currents and phase currents in a three-phase traction transformer with a star-triangle-11 connection of windings, which feeds two single-phase loads in AC traction networks with a nominal voltage of 25 kilovolts. These transformers provide power to the enterprises of the agro-industrial complex located along the railway line. (Research purpose) The research purpose is in substantiating theoretical equations for digital intelligent relay protection in two-phase short circuits. (Materials and methods) It was found that since the sum of instantaneous currents in each phase is zero, each phase of the transformer works independently. We found that this significantly simplifies the task of analyzing processes with a two-phase short circuit. In this case, the problem of calculating short-circuit currents in the traction network can be simplified by reducing it to the calculation of an ordinary electric circuit with three unknown currents. (Results and discussion) The article describes equations for calculating short-circuit resistances for one phase of the transformer when connecting the secondary winding as a star or a triangle. The currents in the phases of the transformer winding at short circuit for the star-triangle-11 and star-star-with-ground schemes are compared. It was found that when calculating short-circuit currents, there is no need to convert the secondary winding of the traction transformer from a triangle to a star. (Conclusions) It was found that the results of the research can be used in the transition of relay protection systems from electromagnetic relays to modern high-speed digital devices, which will increase the operational reliability of power supply systems for traction and non-traction power consumers.

Fluttering Amplitude Amplification by Utilizing Flapping Moment in Flutter-Driven Triboelectric Nanogenerator

2021 ◽  
Author(s):  
Yi Zhang ◽  
Ka Chung Chan ◽  
Sau Chung Fu ◽  
Christopher Yu Hang Chao
Keyword(s):  
Flow Velocity ◽  
High Speed ◽  
Aerodynamic Force ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Energy Output ◽  
Small Scale ◽  
Triboelectric Nanogenerator ◽  
Peak Value

Abstract Flutter-driven triboelectric nanogenerator (FTENG) is one of the most promising methods to harvest small-scale wind energy. Wind causes self-fluttering motion of a flag in the FTENG to generate electricity by contact electrification. A lot of studies have been conducted to enhance the energy output by increasing the surface charge density of the flag, but only a few researches tried to increase the converting efficiency by enlarging the flapping motion. In this study, we show that by simply replacing the rigid flagpole in the FTENG with a flexible flagpole, the energy conversion efficiency is augmented and the energy output is enhanced. It is found that when the flag flutters, the flagpole also undergoes aerodynamic force. The lift force generated from the fluttering flag applies a periodic rotational moment on the flagpole, and causes the flagpole to vibrate. The vibration of the flagpole, in turn amplifies the flutter of the flag. Both the fluttering dynamics of the flags with rigid and flexible flagpoles have been recorded by a high-speed camera. When the flag was held by a flexible flagpole, the fluttering amplitude and the contact area between the flag and electrode plates were increased. The energy enhancement increased as the flow velocity increased and the enhancement can be 113 times when the wind velocity is 10 m/s. The thickness of the flagpole was investigated. An optimal output of open-circuit voltage reaching 1128 V (peak-to-peak value) or 312.40 V (RMS value), and short-circuit current reaching 127.67 μA (peak-to-peak value) or 31.99 μA (RMS value) at 12.21 m/s flow velocity was achieved. This research presents a simple design to enhance the output performance of an FTENG by amplifying the fluttering amplitude. Based on the performance obtained in this study, the improved FTENG has the potential to apply in a smart city for driving electronic devices as a power source for IoT applications.

Short Circuit Modelling and Simulation of 2×25 kV High Speed Railways

2008 ◽  
Author(s):  
Luigi Battistelli ◽  
Mario Pagano ◽  
Daniela Proto ◽  
Arturo Amendola ◽  
Luigi Candurro ◽  
...  
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Modelling And Simulation ◽  
Circuit Modelling

Control of Bump Morphology in Lead Free Solder Plating for Higher Density Packaging

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001643-001669
Author(s):  
Koji Tatsumi ◽  
Kyouhei Mineo ◽  
Takeshi Hatta ◽  
Takuma Katase ◽  
Masayuki Ishikawa ◽  
...  
Keyword(s):  
High Speed ◽  
Flip Chip ◽  
New Technologies ◽  
Short Circuit ◽  
Lead Free Solder ◽  
Cu Pillar ◽  
Fine Pitch ◽  
Different Shapes ◽  
Free Solder ◽  
High Density Packaging

Solder bumping is one of the key technologies for flip chip connection. Flip chip connection has been moving forward to its further downsizing and higher integration with new technologies, such as Cu pillar, micro bump and Through Silicon Via (TSV). Unlike some methods like solder printing and ball mounting, electroplating is a very promising technology for upcoming finer bump formation. We have been developing SnAg plating chemical while taking technology progress and customers' needs into consideration at the same time. Today, we see more variety of requests including for high speed plating to increase the productivity and also for high density packaging such as narrowing the bump pitch itself and downsizing of the bump diameter. To meet these technical needs, some adjustments of plating chemical will be necessary. This time we developed new plating chemicals to correspond to bump miniaturization. For instance, our new SnAg chemical can control bump morphology while maintaining the high deposition speed. With our new plating chemicals, we can deposit mushroom bumps that grow vertically against the resist surface, also this new chemicals work effectively to prevent short-circuit between mushroom bumps with fine pitch from forming. In addition, we succeeded in developing high speed Cu pillar plating chemicals that can control the surface morphology to create different shapes. We'd like to present our updates on controlling bump morphology for various applications.

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