Phase Selector Research Articles

Development of an Automatic Phase Selector for Nigerian Power Utility Customers

Power utility customers in a developing country like Nigeria have constituted a habit of changing the electricity supply line from an unavailable or unstable phase to the most available or stable phase. The category of customers involved in this character are those on single phase power supply. However, this act is being carried out manually at the meter point using the cut-out fuses. This attitude results in phase unbalances, overheating electrical equipment including feeder pillars, transformer coils, network faults, and overall system instability. Thus, this paper presents the development of an Automatic Phase Selector for Nigerian Power Utility Customers. The device automatically selects an available phase from the three-phase power supply lines. The research comprises designing an automatic phase selector circuit, simulation of the designed circuit, programming code development in C- Language for the microcontroller, construction of the designed circuit, and carrying out tests on completed work done to ascertain the effectiveness of the developed system. The system operation involved a three-phase supply from the closest distribution network of the power utility company which is connected to a three-in-one gang switch while the switching ON and OFF of their static switches represent phase-off in an ideal situation. The operational results of this system are presented in the form of the truth table which indicates that the affected customer would not have a power supply only when the 3-phases are under voltage or overvoltage or unavailable. This implies that one of the three phases that meet the three criteria would be switched ON. A pure sine wave was used as input into the Optocoupler and the output waveform of the rectified pulsating signal is separately displayed. This output waveform is very clean and noiseless. Finally, the system when practically tested with an unbalanced three-phase supply, worked perfectly enhancing the flexibility of operating an Automatic Phase selector and hence avoiding manual switching of the phase selector which has been attributed to changing of cut-out fuses and associated stress as well as having a user-friendly phase selector.

Adaptive faulty phase selector for microgrids including battery energy storage stations

Battery energy storage stations (BESSs) hold promising market potential within microgrids, serving as a complementary solution to mitigate fluctuations in renewable distributed generations and providing backup power during microgrid outages or emergencies. However, the distinct fault signatures of BESSs, compared to conventional synchronous generator (SG)-based sources, can result in misoperation of the widely-used superimposed current magnitude (SCM)-based faulty phase selector (FPS), which has received limited attention in previous research. Moreover, the variable operation modes of the microgrid further deteriorate the working condition of the SCM-based FPS. As a consequence, the potential misidentification of faulty phase(s) in the presence of BESS violates the selective phase tripping requirements in existing microgrids. To achieve precise selection of faulty phase(s), this paper proposes a novel FPS based on the generalized magnitude ratio (GMR). Firstly, the proposed FPS applies a compensation method to SCM and extends it to the superimposed voltage magnitude (SVM), mitigating the adverse impacts caused by the unbalanced sequence impedance of BESS. Subsequently, the GMR, which integrates both the compensated SCM and SVM information, is constructed to enhance the adaptability of phase selection to the uncertain infeed level at the BESS side. Finally, the faulty type and specific faulty phase(s) are determined based on the sorted results of the GMR values for each phase. Comprehensive simulation results affirm the expected performance of the proposed FPS under various microgrid modes, as well as different BESS discharge/charge statuses.

A Wideband Energy-Efficient Multi-Mode CMOS Digital Transmitter

This article presents a wideband, energy-efficient digital transmitter (DTX) suitable for multi-mode/multi-band wireless communication applications. It features various operation modes comprising Cartesian (Modes-1/-2) and multi-phase (Modes-3/-4) configurations utilizing LO clocks with different duty cycle in the interleaving/non-interleaving configurations. The multi-phase operation compromises polar and Cartesian features by mapping the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I/Q$ </tex-math></inline-formula> signals into two non-orthogonal basis vectors with a 45° relative phase difference and a 3-bit phase selector scheme. The different operation modes are extensively analyzed and compared. Fabricated in a 40-nm CMOS process with an off-chip matching network, the proposed DTX occupies a core area of 0.72 mm2 and delivers 23.18-dBm RF peak power at 2.1 GHz from a 0.95-V supply voltage with drain/system efficiencies of 66.26%/52.59%, respectively. Utilizing a simple memory-less digital pre-distortion (DPD) for a 160-MHz four-channel 64-quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM) signal, the DTX delivers an average <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P _{\text {Out}}$ </tex-math></inline-formula> of 13.5/11.4/7.7/9.4 dBm, achieving an adjacent channel (power) ratio (ACL(P)R) of better than −42/−40/−40/−38 dBc and an average error vector magnitude (EVM) of −36/−34/−34/−32 dB, operating in Modes-1/-2/-3/-4, respectively. While transmitting a 200-MHz single-channel 256 (1024)-QAM OFDM signal at 2.4 GHz in Modes-1/-4, the average delivered output power is 14.11/9.29 (12.23/7.32) dBm with average drain and system efficiencies of 33.17%/26.3% (23.82%/22.83%) and 24.81%/22.85% (19.34%/18.81%), while the ACLR and EVM are better than −42/−41 (−43/−43) dBc and −34.6/−33.1 (−33.5/−33.9) dB, respectively.

Development of simulation model of smart phase selector device

In the quest for efficient and reliable power distribution systems, voltage asymmetry has emerged as a significant challenge. Voltage imbalances across different phases can lead to increased energy losses, compromised power quality, and reduced equipment lifespan. To address these issues, smart phase selector devices have gained attention as advanced electronic solutions for monitoring and managing voltage imbalances in low-voltage networks. This paper presents the development of a simulation model of a smart phase selector device using the Proteus software platform. Proteus offers a versatile environment for simulating electronic circuits and systems, making it an ideal choice for developing and evaluating the performance of the smart phase selector device. The primary objective of this research is to create a comprehensive simulation model that accurately represents the behavior and functionality of the smart phase selector device. Through a thorough literature review, the key principles and concepts underlying smart phase selector devices, voltage asymmetry, and related simulation techniques are explored. The developed simulation model incorporates the necessary circuit components, algorithms, and control mechanisms to faithfully simulate the operation of the smart phase selector device.

A Low-Jitter Ring-DCO-Based Fractional-N Digital PLL With a 1/8 DTC-Range-Reduction Technique Using a Quadruple-Timing-Margin Phase Selector

This work presents a fractional- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> ring-oscillator (RO)-based digital phase-locked loop (DPLL). To achieve ultralow jitter, the proposed RO-DPLL used a technique to reduce the dominant source of in-band noise, i.e., the thermal noise of the digital-to-time converters (DTCs). A key building block of this technique is the quadruple-timing-margin phase selector (QTM-PS) that dynamically selects the proper phase among the eight phases of the RO, effectively reducing the required dynamic range of the DTCs and, thus, suppressing the thermal noise significantly. Based on the reduced in-band noise, the dual-edge generator (DEG) doubles the bandwidth of the DPLL, further suppressing the jitter of the RO. The integrated background calibrator (IBC) that can perform multiple least mean squares (LMS)-based calibrations was used to guarantee the stable operation and performance of both the QTM-PS and the DEG. The proposed RO-DPLL was fabricated in 65-nm CMOS, and it used 0.139-mm2 silicon area and 15.67-mW power. At a fractional- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> frequency near 5.2 GHz, the rms jitter and the figure of merit (FoM) of the output signal were 188 fs and–243 dB, respectively.

Influence of Negative Sequence Injection Strategies on Faulted Phase Selector Performance

Renewable power is expected to increase drastically in the coming years due to the energy transition. A large part of the newly installed generators will be connected to the power system through inverters and electronic converters, whose behaviour differs from the generators connected synchronously to the network. One of the main differences is the current contribution during symmetrical and asymmetrical faults which can affect protection systems. New grid codes establish requirements for fast current injection, but the converter’s maximum current limitations during faults make it difficult to establish control strategies for such current contribution. This paper studies the performance of faulted phase selector algorithm of a commercial relay under the current contribution from renewables before unbalanced faults. Two positive and negative sequence current injection strategies in compliance with new Spanish grid code requirements are proposed and tested under fault conditions in HiL (Hardware in the Loop). Test results show that the selected injection strategy affects the fault phase identification algorithm. Furthermore, the negative sequence injection requirements established in the new grid code improve the relay performance when line-to-line faults are applied, but they are not enough to identify all fault types.

Study on a new fault phase selector in interconnection line with wind turbine based on doubly-fed induction generator’s wind farm

The fault current characteristics of wind turbine based on doubly fed induction generator (DFIGWT) is complicated. The conventional superimposed phase selectors cannot meet the requirements of phase selection in the interconnection line based on DFIGWT’s wind farm. In this paper, according to the low voltage ride-through strategy of DFIGWTs, the shortcomings of traditional superimposed phase selector are analyzed. Then, a new fault phase selector is proposed based on the amplitude ratio between superimposed phase voltage and superimposed phase-to-phase voltage. According to the proportional relationship between the superimposed phase voltage and superimposed phase-to-phase voltage in the interconnection line with DFIGWT-based wind farm, the fault phase selection coefficients are proposed. Based on the proposed fault phase selection coefficients, the fault phases under different fault conditions can be identified. Finally, the effectiveness and reliability of the proposed fault phase selector are validated by simulation. Test results show that the proposed method is not affected by the LVRT control strategies and can meet the phase selection requirements of new energy sources under different LVRT strategies conditions.

A novel high-speed transient-based phase selector for AC transmission line connected to LCC-HVDC inverter station

Affected by commutation failure and fast control of line-commutated-converter (LCC) high-voltage direct-current (HVDC) inverter station, conventional phase selectors exist adaptability problems. In this paper, a novel faulted phase selector for AC lines connected to LCC-HVDC inverter station, based on the ratio of transient current energy, is proposed. Firstly, the inadaptability of conventional phase selection methods is briefly analyzed in this paper. Besides, the current relationship of the initial stage of the fault is immune to the commutation failure disturbance, and the current information of this stage is constructed as a transient energy ratio which is used to select the fault phase. On this basis, considering the weak amplitude characteristics of high-frequency signals, synchronous squeezed S-transform (SST) is introduced to process signals in this paper. PSCAD/EMTDC simulation results verify that the proposed phase selector can effectively avoid the DC-side commutation failure and control influence, achieve fast and reliable phase selection, and is weakly affected by the fault resistance, fault distance, initial fault angle, and noise interference.

A 56 GS/s 8 Bit Time-Interleaved ADC in 28 nm CMOS

This paper presents a real-time output 56 GS/s 8 bit time-interleaved analog-to-digital converter (ADC), where the full-speed converted data are output by 16-lane transmitters. A 64-way 8 bit asynchronous SAR array using monotonous and split switching strategy with 1 bit redundancy is utilized to achieve a high linearity and high-power efficiency. A low-power ring voltage-controlled oscillator-based injection-locked phase-locked loop combining with a phase interpolator-based time-skew adjuster is developed to generate the 8 equally spaced sampling phases. Digital gain correction, digital-detection-analog-correction offset calibration, and coarse–fine two-step time-skew calibration are combined to optimize the ADC’s performances. An edge detector and phase selector associated with a common near-end data-transmission position and far-end data-collection instant are designed to avoid reset competition and implement deterministic latency. Fabricated in a 28 nm CMOS process, the prototype ADC achieves an outstanding SNDR of 36.38 dB at 56 GS/s with a 19.9 GHz input, where 7.25 dB and 9.33 dB are optimized by offset-gain calibration and time-skew calibration, respectively. The ADC core occupies an area of 1.2 mm2 and consumes 432 mW power consumption.

DESIGN ANALYSIS OF AN AUTOMATIC PHASE SELECTOR

Power instability in Nigeria caused by overbearing demand of power by consumers and lack of proper maintenance of the power system devices among others has brought about the need for alternative power sources such as generators, solar, typical inverters and other alternative supplies which requires one form of switching or the other to achieve phase selection during power failure. This paper gives a design analysis of an automatic phase selector linking available power supplies, that is; switching between a three-phase public utility supply, as a result of total power outage in the public supply to an alternative secondary supply (in this case a Generator and an Inverter system) and back when power is restored. The design adopts the use of a microcontroller-based system interconnected with other hardware components for proper isolation, switching and visualization of switching conditions. The system design is divided into two major part: the hardware which consists of the power supply, sensing circuit, controller or control logic circuit, display and the power electronics switching unit and the software instruction code on the microcontroller unit. The design analysis was first carried out accompanied with computer simulation on a software tool (Proteus 8 Professional, version 8.4) to carry out performance evaluation of the sub-circuits, thereafter, a practical implementation of the design was carried out and tested with the utility power supply using five (5) switches, three of which represents the three-phase primary supply and the other two represents the secondary supply.

ПРИЗНАКИ ПОВРЕЖДЕННОЙ ФАЗЫ ПРИ ОДНОФАЗНЫХ ЗАМЫКАНИЯХ НА ЗЕМЛЮ

Relevance Devices for determining the location of fault on power lines assume a known type of short circuit and faulty phases. However, their algorithms, as a rule, can not distinguish the faulty phase. Therefore, the determination of faulty phases during short circuits on power lines is performed by separate devices – faulty phase selectors. The transient resistance at the point of closure has a strong influence on the work of selectors. The influence of transient resistance is especially strong at single phase-to-ground faults. Therefore, the study of the effect of transient resistance on the work of selectors at single phase-to-ground faults is an urgent task. Aim of research The aim of the article is to investigate and develop features of a faulty phase at single phase-to-ground faults via transient resistance in networks with an isolated neutral. Research method To study the features of a faulty phase, the article uses vector diagrams and graphs of changes in phase voltages when the transient resistance changes at fault location. When closing through a transient resistance, it is assumed that the vertices of the linear voltage triangle on the vector diagram and the neutral potential move around the circles with increasing transient resistance, and the ground potential remains unchanged. To study the change in the magnitude of phase voltages during short circuits through the transient resistance, a new variable was introduced — the angle by which the neutral voltage vector, taken with the reverse sign, lags behind the voltage vector of the faulty phase in the pre-emergency mode. The introduction of such a variable simplifies the equations for stresses and makes the analysis of the effect of transient resistance more general and visual. Results It is shown that, depending on the magnitude of the transient resistance, the lowest of the phase voltages in single phase-to-ground faults can be either the voltage of the faulty phase or the voltage of the unfaulted phase lagging in relation to the faulty one. At the same time, the lowest value of the phase voltage can be a sign of a faulty phase only in the range of transient resistances from zero to the boundary value. The features of a faulty phase during short circuits through the transient resistance are formulated. It is shown that the features of a faulty phase using angular relations between stresses are valid for any value of the transient resistance. While the features based on the determination of the phase with the lowest phase voltage act only in a limited range of transient resistance values. Keywords: single phase-to-ground fault, network with isolated neutral, faulty phase, transient resistance

Fault classification and phase selector algorithm for half-wavelength transmission lines

This study presents a new phase selector algorithm and fault type classification for very long transmission lines, known as the half-wavelength lines (HWL). For this work, the Clarke components variation rate method applied to current magnitudes was used. The method was implemented in a real-time digital simulation hardware-in-the-loop (HIL) test environment. We applied different fault types at each 5% line length, obtaining Clarke component current phasors. The proposed algorithm is stable for the native behavior of the half-wavelength line, including the resonance zones and their mitigation procedures. In addition, the algorithm is immune to the fault insertion angle, fault resistance, and line loading level. Finally, the algorithm could be applied in commercial microprocessor-based relays or could be used as a post-fault analysis tool.

A quick fault location and isolation method for distribution network based on adaptive reclosing

Feeder automation is important to improve the reliability of power supply for distribution network. Existing voltage-time feeder automation scheme exists the problems of long fault processing time and the upstream switches of the fault point need to tolerate fault current twice and the upstream sections need to experience two short time power outage. In this paper, a quick fault location and isolation method for distribution network based on adaptive reclosing is proposed. Three key technologies of the strategy are introduced, including a phase segregated switch of the distribution network based on the permanent magnet operating structure, the phase selector based on transient current characteristics, and the temporary fault and permanent fault identification method based on the power frequency voltage characteristics. The proposed strategy can avoid the second impact on upstream switches and power-off of the upstream section in case of the permanent fault and can effectively shorten the fault processing time.

A novel voltage phase selector for inverter-interfaced system based on two-stage control strategy

Due to the special fault features of the inverter-interfaced system, traditional phase selectors exist adaptability problems. In this paper, a novel voltage phase selector based on a two-stage control strategy is proposed, which is not influenced by the special features of the converter. First, the fault features of the converter during fault ride through (FRT) operation are analyzed. Second, using the high controlled-ability of the converter, the control strategy is divided into two stages by adding disturbances to the power references of the control system at the second control stage. On this basis, a novel superimposed sequence network is defined as the subtraction of the compound sequence networks under the first and the second control stage. Then, the phase-angle differences of sequence voltages in the novel superimposed sequence network are analyzed, which are not influenced by the fault features of the converter and can be used to establish phase selection criteria. The simulation results show that the proposed phase selection scheme is immune to the fault features of the converter system, fault resistance, fault location and the operation modes of the remote end system.

Application of a robust faulted phase selector to high-resistance and weak-infeed fault conditions on a 1000-kV UHV transmission line

This work proposes the use of a novel faulted phase-selection phasor-based algorithm to solve the high-resistance and weak-infeed fault condition selection problem in existent long compensated transmission lines. The algorithm was originally developed for future half-wavelength lines (3000 km for 50 Hz system or 2500 km for 60 Hz), and was slightly modified and tested in a real 645 km 1000 kV Ultra High Voltage transmission system. The algorithm was implemented in a programmable protective relay and tested using a real-time simulator. A series of tests under extreme conditions (such as high impedance fault and very week infeed system together) were conducted to evaluate the performance and robustness of the proposed algorithm.

Design and Fabrication of Robotic Arm for the assembly of Phase Selector Switch

This paper explores the robot arm where the ability of human to do a project is restrained however now not with the aid of his mental electricity however through his bodily energy. A humanoid mechanical technology is another difficult field. To co-work with people, humanoid robots not just need to include human like structure and structure, yet more significantly, they should arrange human like conduct with respect to the movement, correspondence and intelligence. In environmental factors where human exchange can't be conceivable to do a specific errand, the robots can do. Robots are used for lean industrial processes and have diversified their contributions to meeting lines inside the production international. The main focus of this project is to design and develop the mechanism for robotic arm for lifting. It is a type of mechanical arm, usually programmable, with similar functions to a human arm. The arm might be a unit system or might be an aspect of a more unpredictable mechanical cycle. The end effectors or mechanical hand can be intended to play out any ideal undertaking, for example, welding, holding, turning etc., depending on the application. The mechanical arm is planned and designed with four degrees of freedom and modified to achieve precisely basic light material lifting undertaking to aid the creation line in any industry. 3D printing strategy is utilized in this undertaking to create the parts of the automated arm. Hence, it gave more exact measurements and gigantic time and cost expensive in creation. The automated arm is furnished with 4 servo engines to interface the parts and bring arm development. A sequential construction mechanical system can improve its efficiency through developing the assembling pace and its consistency. They additionally spare individuals from dreary and tedious mechanical production system employments. Many industries are yet to implement such automation in their meeting traces, as they do no longer have the technical recognize how of the changeover, or the concern of failure of investment. It is proposed to layout and increase a low price assembly robotic which could overcome the above drawbacks. We have also included Design Thinking process before starting to do this experiment. The stages of Design Thinking such as Empathize, Define, Ideate, Prototype & test, Evolve are performed in the complete fabrication of the robotic arm. Many industries are yet to implement such automation in their assembly lines, as they do not have the technical knowhow of the changeover, or the fear of failure of investment. To proceed in this direction, a case study was conducted at a phase selector switch making company. Presently the company does manual assembly of the switches, which is a hindrance to the growth of the company. This process required a pilot study to explore the possibility as well as the implementations issues of robots in the assembly. The present system uses a belt conveyor system which has no feedback signals and the speed of the conveyor is not synchronized with the rate of assembly. It is generally not advised to transfer small size components in a conveyor since picking, orienting and inserting the components will be cumbersome. When the size of the component is considerably small, manual assembly is not recommended as per the guidelines of DFMA (Design for manufacture and assembly). Manual error is more prone to assembly of the part in a wrong orientation, especially for those components that are symmetrical.The parts to be assembled are both axi-symmetric as well as prismatic in shape. Constraints in loading and unloading of casing were also reported. In this work, the design and development of a low cost assembly robot is done which can overcome the above drawbacks.

A 0.9 pJ/b, Reference Clock Free, Delay-Based, All-Digital Coherent BPSK Demodulator

This letter proposes a novel reference clock free, delaybased coherent binary phase-shift keying (BPSK) demodulator suitable for biomedical devices which receive power and data through the same wireless link. The proposed BPSK demodulator mixes the BPSK input signal and its copy delayed by a half of the carrier period to generate a data Hipping signal whose rising edges indicate when the phases of the BPSK signal Hip. The data are then recovered by sampling the BPSK input signal using the derived data Hipping signal. A phase selector recovers the coherent clock with a 50% duty cycle by selecting either the delayed BPSK input or its complement according to the recovered data. The open-loop operation of the proposed BPSK demodulator enables it to achieve a data rate as high as the carrier frequency. The all-digital implementation makes the demodulator compact, low power, and able to operate at 0.5 V. A test chip running with a 13.56-MHz carrier has been designed and fabricated. Measurement results show that at 0.9 V and a data rate of 13.56 Mb/s, the proposed demodulator only consumes 12.2 μW, corresponding to an FoM of 0.90 pJ/b. This FoM is at least 61 times better than those of the state-of-the-art designs.

Transient energy‐based combined fault detector and faulted phase selector for distribution networks with distributed generators

Transient energy‐based combined fault detector and faulted phase selector for distribution networks with distributed generators

Програмне забезпечення розрахунку і вибору уставок параметрів спрацьовування модуля фазового селектора з сектором навантаження

Програмне забезпечення розрахунку і вибору уставок параметрів спрацьовування модуля фазового селектора з сектором навантаження

Wireless Network Smart Grids for Continuous Power Supply and Monitoring

Advent of electric power revolutionized the life of a civilized human. From the early dated discoveries of Nikola Tesla, Alessandro Volta to the latest applications of electricity has made it indispensable for our daily life. The wide-ranging applications of power have made ease of living. From greenland to brownland we are dealt with the utilization of the electricity. Power generation, transmission, distribution, and efficient utilization promote the progress of a nation. Power crisis which has been abating. India suffers large deficits which need to be overcome at the earliest. We see a lot of power outages and most of the time we never know the reason behind it. Even in the 21st century, the digital age, we should not be facing this problem. One of the reasons behind the shortfall of a proper power supply is the inefficient power monitoring ensued by breakdowns, repairs and maintenance work of power plants, transformers, and transmission lines. This project is designed as the one-time solution to monitor the outages in real time without the requirement of a meatware. A power monitoring system automatically analyzes and retrieves the power quality events. The monitoring system comprises of smart grids and a centralized workstation. Smart grids contribute towards sending data of power supply status to the workstation continuously. Based on the status drawn by the grids the workstations analyze the data and intimate the electricity boards about the power outages. Thus elimination of manual summoning the designated authorities by automatic monitoring acts as the core of the proposed project. The automatic switching to an alternative resource is done by the automatic phase selector. The smart grids also promote to increase efficiency and energy conservation. The gravity of the paper is power monitoring and shift to a secondary power resource in the absence of the primary. Power monitoring acts as a preventive measure to recover the huge deficits suffered by the power crisis.