Single-phase Electric Power Research Articles

Pengaruh Harmonik Akibat Pengoperasian Motor Induksi Tiga Fasa Pada Sistem Tenaga Satu Fasa

The research conducted focuses on analyzing the harmonic effects resulting from the operation of a three-phase induction motor in a single-phase power system and examining changes in harmonic values due to load variations using two capacitors. This study is a continuation of previous research, which only addressed the influence of a single capacitor on a three-phase induction motor in a single-phase power system, without further exploration of the extent of harmonic impact on the motor. The induction motor operates based on the principle of magnetic induction. This investigation employs a single-phase induction motor with lower power capacity compared to a three-phase induction motor. Three-phase induction motors have a small starting torque, preventing them from starting under full load. The study involves increasing the starting torque of the three-phase induction motor and operating it in a single-phase electrical power system using capacitors to improve power factor during the starting process while analyzing its harmonic effects. The research findings indicate that as the load on the motor increases, both the motor speed and harmonic current values decrease. This is evident when there is no load, and the motor speed is 1475 rpm; adding a load does not exceed this speed. The motor speed decreases as the load increases, while the presence of harmonic current values is due to the linear load, such as incandescent light bulbs. The study is conducted by enhancing the starting torque of the three-phase induction motor, imposing a significant load. The motor demonstrates more optimal and stable performance with the new method compared to the old method. Additionally, the harmonic current values with the new method are lower than those with the old method.

ELECTROPLATING DRYING TIME MINIMIZATION THROUGH BOLT DRYER MACHINE

One of the steps after the electroplating/coating process on the product is the drying process. In Micro, Small and Medium Enterprises, the drying process on CIV KG 0741 bolts with a diameter of 10 mm and a length of 20 mm requires a drying time of 6 hours. Drying simply and naturally has limitations, requiring a large drying area depending on the weather, time and temperature, which cannot be controlled. A simple automatic dryer is needed using a single-phase electric power source and simple and ergonomic maintenance methods to obtain a quality product with a measurable drying duration. Design and analysis of drying on the dryer. The dryer with dimensions of 680 x 480 x 967.12 mm3 has a mass of 21.94 kg with a drum capacity of 20 kg. The motor propulsion used is 1 HP, 5.08 Nm of torque and capable of rotating at 1500 rpm with an effort of 39296.66 Joules. The dryer can dry as much as 20 kg of bolts in 5 minutes faster than solar energy, with a drying time of 15 minutes to 1 hour.

Hardware-in-the-Loop and Digital Control Techniques Applied to Single-Phase PFC Converters

Power electronic converters for power factor correction (PFC) play a key role in single-phase electrical power systems, ensuring that the line current waveform complies with the applicable standards and grid codes while regulating the DC voltage. Its verification implies significant complexity and cost, since it requires long simulations to verify its behavior, for around hundreds of milliseconds. The development and test of the controller include nominal, abnormal and fault conditions in which the equipment could be damaged. Hardware-in-the-loop (HIL) is a cost-effective technique that allows the power converter to be replaced by a real-time simulation model, avoiding building prototypes in the early stages for the development and validation of the controller. However, the performance-vs-cost trade-off associated with HIL techniques depends on the mathematical models used for replicating the power converter, the load and the electrical grid, as well as the hardware platform chosen to build it, e.g., microprocessor or FPGA, and the required number of channels and I/O types to test the system. This work reviews state-of-the-art HIL techniques and digital control techniques for single-phase PFC converters.

Model Rangkaian-T Pembangkit Listrik Tenaga Bayu untuk Analisis Aliran Daya Tiga-Fase

Akhir-akhir ini, penetrasi Pembangkit Listrik Tenaga Bayu (PLTB) pada sistem distribusi tenaga listrik mengalami peningkatan yang cukup signifikan. Penetrasi PLTB ini dapat memengaruhi kondisi keadaan mantap dan dinamik sistem tersebut. Lebih lanjut, sistem distribusi tenaga listrik biasanya tidak seimbang, sehingga harus dianalisis secara tiga-fase. Oleh karena itu, agar kondisi-kondisi sistem dapat dievaluasi dengan baik, pembentukan model tiga-fase dari komponen-komponen sistem (termasuk PLTB) merupakan hal yang sangat penting. Makalah ini mengusulkan metode sederhana dalam memodelkan dan mengintegrasikan PLTB kecepatan tetap untuk analisis keadaan mantap (atau analisis aliran daya) sistem distribusi tiga-fase. Metode yang diusulkan tersebut didasarkan pada model rangkaian-T yang sebelumnya telah berhasil diaplikasikan pada sistem fase-tunggal. Pada makalah ini, model rangkaian-T fase-tunggal tersebut dimodifikasi dan diperluas sehingga dapat memfasilitasi analisis aliran daya tiga-fase pada kondisi sistem tak-seimbang. Aplikasi usulan model pada dua sistem distribusi tiga-fase, yaitu sistem 33-simpul dan 25 simpul, juga diselidiki dan disajikan pada makalah ini. Hasil-hasil penyelidikan yang dilakukan pada sistem tersebut memperlihatkan bahwa metode yang diusulkan valid dan akurat.

Distributed generation integrating a photovoltaic-based system with a single- to three-phase UPQC applied to rural or remote areas supplied by single-phase electrical power

This paper presents a distributed generation (DG) system integrating a photovoltaic (PV) system with a 1-Phase to 3-Phase unified power quality conditioner (UPQC-1PH-3PH). The system named DG-UPQC-1PH-3PH injects into the grid the energy produced from a PV array, contributing to feed loads connected to a local three-phase four-wire electrical system, to attend consumers of rural and/or remote areas supplied by single-phase utility. Besides the injection of active power into the grid, the DG-UPQC-1PH-3PH improves power quality indicators, such as voltage sags/swells, grid voltage harmonics, and power factor. Multi-resonant state-feedback controllers are employed to ensure sinusoidal grid current and load voltages, while an effective PV array voltage control is achieved by using a multi-loop proportional-integral controller. Since the DG-UPQC-1PH-3PH inverters handle the power produced by the PV system plus those demanded by the load, the converters sizing must be carefully performed. Thus, curves that allow the sizing of the power converters based on the power flow through the converters are presented. The static performance is experimentally tested considering several operation conditions involving the utility grid voltage, load and energy produced by the PV array, while its dynamic behavior is evaluated when the PV array is subjected to abrupt solar irradiation changes.

Low-cost platform for the evaluation of single phase electromagnetic phenomena of power quality according to the IEEE 1159 standard

This paper presents the development of a data acquisition system and the evaluation of the electromagnetic phenomena associated with power quality according to the IEEE Standard 1159-1992 and applied to the particular case of single-phase electrical power systems. The evaluation software is implemented in the Labview® professional software using a NI 6009 USB board of the National Instrument® as acquisition device. The hardware implementation of the sensors was shown. Also the development of the algorithm and the design of a graphical user interface for viewing of the voltage and current waveforms, spectra, frequency and the power quality disturbances such as sags, swells, undervoltage, overvoltage, so on. Likewise, at the end a concise analysis of costs is presented to show that the developed system has a lower price to current solutions that are available in the market. Finally a study case was shown.

An improved excitation control technique of three-phase induction machine operating as dual winding generator for micro-wind domestic application

Single-phase generation schemes are widely utilized for harnessing wind power in remote and grid secluded applications. This paper presents a novel control methodology for a three-phase induction machine working as a single-phase dual winding induction generator. Three-phase induction machines providing single-phase output with proper control strategy can be beneficial in grid secluded micro-wind energy conversion systems compared to single-phase induction generators. Three-phase induction machines operating in single-phase mode are mostly excited asymmetrically to provide single-phase power leading to unbalanced current flow in the stator windings causing heating and insulation breakdown. The asymmetrical excitation also initiates torque pulsations which results in additional stress and vibration at the machine shaft and bearings degrading the machine performance. The proposed control is chiefly aimed to minimize this unbalance. The variable excitation required for the proposed generator is provided through a single-phase inverter with photovoltaic panels. The suitability for such a generator along with its control is tested with appropriate simulations and experimental results. The induction generator with the proposed control strategy is expected to be useful in remote and grid isolated households as a standalone source of single-phase electrical power.

A fast, simple and accurate time-varying frequency estimation method for single-phase electric power systems

This paper presents a simple and accurate method to estimate time-varying frequency for single-phase electric power systems, based on three equally spaced samples. A sinusoidal voltage signal model, without dc offset, with time-varying frequency was assumed. Analytical formulas are derived. The method shows good estimation accuracy over a real world wide range of frequency changes. Simulations have been performed.

Neural Network-Based Approach for Identification of the Harmonic Content of a Nonlinear Load in a Single-Phase System

In this paper an alternative method based on artificial neural networks is presented to determine harmonic components in the load current of a single-phase electric power system with nonlinear loads, whose parameters can vary so much in reason of the loads characteristic behaviors as because of the human intervention. The first six components in the load current are determined using the information contained in the time-varying waveforms. The effectiveness of this method is verified by using it in a single-phase active power filter with selective compensation of the current drained by an AC controller. The proposed method is compared with the fast Fourier transform.

전기철도 급전시스템의 순시전압강하 보상을 위한 단상 배전 STATCOM의 적용

AC 전기철도 시스템은 동적 단상부하가 빠르게 변화하고, 전철 급전변전소에서 3상 전력을 단상 전력으로 변환한다. 이것은 일반 배전 시스템과 비교해서 AC 전기철도 시스템의 전기적인 현상들이 다르다는 것을 나타낸다. AC전기철도 열차부하의 전기적인 특성은 동적부하의 운영과 운행 스케쥴, 트랙의 구배 등에 따라 연속적인 변화를 받고 있다. 이와 같은 열차부하의 운영에 따른 급전거리가 길어 전압강하, 전압 불평형 및 고조파 왜곡현상 등의 전력품질 저하요인이 발생하게 된다. 이러한 문제점은 상위계통인 송전시스템의 안정도에 악영향을 줄뿐만 아니라, 전기철도 급전시스템의 전력품질 저하, 전기철도차량의 통신장비, 운행 및 수송량 제한에도 영향을 미치게 된다. 따라서 본 논문에서는 전기철도시스템의 과도상태 평가를 위해 PSCAD/EMTDC를 이용한 평가모델을 제시하고, 전압 강하에 주안점을 두어, 전기철도 급전시스템의 말단 분기점(Sectioning Post)에 정지형 무효전력 보상장치인 단상 배전 STATCOM(Single-phase Static Synchronous Compensator)을 설치하여 그 작용에 따른 전압강하 보상을 평가하였다.

Rotary ultrasonic motor driven by a disk-shaped ultrasonic actuator

A rotary ultrasonic motor, including a disk-shaped ultrasonic actuator and a rotor, is developed, and the characteristics of the motor, including speeds, torques, output powers, and efficiencies, against various preload forces, voltages, and frequencies are investigated. The actuator is developed on a thin piezoelectric buzzer with three fixed screws and driven by a single-phase electrical power source. Here, the buzzer is composed of a nickel-alloy disk and a piezoceramic disk, and the screws are individually arranged at 90/spl deg/, 120/spl deg/, and 150/spl deg/ arc locations on the nickel-alloy disk. An optimal driving point of the actuator for driving the rotor in both clockwise (CW) and counterclockwise (CCW) directions is located at a point on the 90/spl deg/ arc edge region, and the CW and CCW directions are controlled by the frequency of the electrical power source. In doing so, the principle, construction, and driving mechanism of the actuator are first expressed. Then, the principle is verified according to vibration mode analysis with ANSYS simulation. The ANSYS simulation concerns the numerical model, structure, and mesh analysis as well. Moreover, a driving and measuring system, including an ac power supply system and a system that measures speed and twist forces, is constructed to evaluate the performance of the actuator and motor.

Analysis of Catenary Voltage of an AT-Fed AC HSR System

This paper represents an exact modeling for autotransformer (AT)-fed ac high-speed railroad (HSR) using constant current mode. AC HSR has rapidly changing single-phase load, and at a feeding substation, three-phase electric power is transformed to the paired directional single-phase electric power. As the train moves along a section of line between two adjacent ATs, analysis of the catenary voltage in AT-fed ac HSR system is a quite complicated work. Therefore, in order to solve this complicated system, this paper proposes a novel and efficient method with generalized equations for the catenary voltage of AT-fed ac HSR. The voltage profile through the entire railroad system can be solved regardless of the number and position of trains, feeding distance from substation, and normal or extension mode. In the case studies, the results of the proposed equation for the catenary voltage profile are compared with those of the simulation using PSCAD/EMTDC.

Development of Single Phase Feeding Power Conditioner for Shinkansen Depots.

The feeding transformer for AC electric railways converts three-phase electric power into a pair of single-phase electric power supplies for driving electric cars. To prevent the fluctuation of three-phase voltage, however, a single phase feeding suits car depots. Authors have developed a single-phase feeding power conditioner (SFC) for unbalanced voltage compensation. This paper describes the principle and test results of using SFC. SFC is made of a scalene Scott-connected feeding transformer and a pair of self-commutated inverters, which connect the secondary side of a transformer and are coupled with the DC side capacitor. Each inverter operates independently in order to control reactive power. On the other hand, SFC controls active power from larger to small load phase circuits via the DC capacitor to keep the active power balanced.

Energy Production and Performance of a Wind-Driven Induction Generator

ABSTRACT A modern wind turbine, an Enertech Model 44/25*, was installed on May 26, 1982, at the USDA Conservation and Production Research Laboratory, Bushland, TX. The wind machine, acquired for a determination of agricultural applications, had a 25-kW induction generator which provided 240 V, 60 Hz, single-phase electric power. The horizontal-axis wind turbine had a 13.4-m diameter, three-bladed, fixed-pitch rotor and was mounted on a 24.4-m tower. The blades were laminated epoxy-wood attached to a steel hub. The wind turbine operated 64% of the time, and was available for operation over 95% of the time. The unit had a net energy production of over 100,000 kW-h for a 20-month period in an average windspeed of 5.9 m/s at a height of 10 m. Power curves were established for the wind turbine at two different pitch settings and with two different sets of blade-tip brakes..