scholarly journals Considerations on Current and Voltage Unbalance of Nonlinear Loads in Residential and Educational Sectors

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 102
Author(s):  
Gabriel Nicolae Popa ◽  
Angela Iagăr ◽  
Corina Maria Diniș

Most often, electrical consumers in the residential and educational sectors are different from industrial electrical consumers. Whereas the vast majority of industrial electrical consumers are low-voltage, three-phase (with three or four wires), electrical consumers in the residential and educational sectors are low-voltage, single-phase. However, in practice, electrical consumers in the residential and educational sectors are in large numbers. Usually, current and voltage unbalances are lower in the industrial sector compared to the residential and educational sectors, where there are a large number of low-voltage, single-phase consumers that are connected/disconnected in an uncontrollable way and that need to be wired and balanced on each phase of power transformers from power substations. The purpose of this paper is to present the results of electrical balance and improve the power factor in the power substation from residential and educational sectors. The paper investigates the current and voltage unbalance of nonlinear con sumers in the residential and educational sectors. For this purpose, we performed measurements in the laboratory and the power substation to investigate the unbalance in the three-phase system. Laboratory measurements were made in the unbalanced operation of the single-phase electrical consumers connected at three-phase system. The measurements from power substation were carried out after the electrical consumers were uniformly spread among the three phases from the low-voltage power network, on two different days: a workday and a weekend day. The current and apparent power unbalance were reduced and the power factor was improved using the capacitive single-phase electric consumers (e.g., personal computers, which are in large numbers in such sectors) evenly across the phases.

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1542
Author(s):  
Hyun-Jun Lee ◽  
Dae-Shik Lee ◽  
Young-Doo Yoon

This paper proposes a new unified power flow controller (UPFC) topology. A single phase of them system with the proposed topology consists of an N:2 transformer with a center tap at the low-voltage side and a power converter module comprising full- and half-bridge converters. A three-phase system can be implemented with three devices. While the conventional UPFC topology uses two three-phase transformers, which are called series and parallel transformers, the proposed topology utilizes three single-phase transformers to implement a three-phase UPFC system. By using an autotransformer structure, the power rating of the transformers and the voltage rating of switches in the power converter module can be significantly decreased. As a result, it is possible to reduce the installation spaces and costs compared with the conventional UPFC topology. In addition, by adopting a full- and half-bridge converter structure, the proposed topology can be easily implemented with conventional power devices and control techniques. The techniques used to control the proposed topology are described in this paper. The results obtained from simulations and experiments verify the effectiveness of the proposed UPFC topology.


2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Vengadeshwaran Velu ◽  
Norman Mariun ◽  
Mohd Amran Mohd Radzi ◽  
Nashiren Farzilah Mailah

Three-phase system has numerous advantages over the single-phase system in terms of instantaneous power, stability, and cost. Three-phase systems are not available in every location particularly in remote rural areas, hill stations, low voltage distribution homes, and so forth. Having a system that is capable of converting directly the readily available single-phase system to three phases will have greater usability in various applications. The routine techniques adopted in the direct ac-ac single-phase-to-three-phase converters do not yield the best desired outputs because of their complexity in the segregation process and bidirectional nature of the input signal. Other initiatives use ac-dc-ac converters which are huge and costly due to dc link energy storage devices. Further, none of these systems provide a convincing result in producing the standard three-phase output voltages that are 120° away from each other. This paper proposes an effective direct ac-ac single-phase-to-three-phase conversion technique based on space vector pulse width modulation based matrix converter system that produces a convincing three-phase output signals from a single-phase source with balanced modulation index characteristics. The details of the scientific programming adopted on the proposed technique were presented.


2015 ◽  
Vol 135 (3) ◽  
pp. 168-180 ◽  
Author(s):  
Ryota Mizutani ◽  
Hirotaka Koizumi ◽  
Kentaro Hirose ◽  
Kazunari Ishibashi

2018 ◽  
Vol 215 ◽  
pp. 01023 ◽  
Author(s):  
Zuriman Anthony ◽  
Erhaneli Erhaneli ◽  
Zulkarnaini Zulkarnaini

A 1-phase induction motor usually has a complicated windings design which compares to polyphase induction motor. In addition, a large capacitor start is required to operate the motor. It is an expensive way to operate the motor if it compare to polyphase induction motor. So, a new innovation method is required to make the motor more simple and cheaper. This research is purposed to study a new winding design for a single-phase capacitor motor. Winding design of the motor was conducted to a simple winding design like a 4-phase induction motor that has four identical windings. The comparator motor that use in this study was a Three-phase induction motor with data 1400 RPM, 1.5 HP, 50Hz, 380/220V, Y/Δ, 2.74/4.7A, 4 poles, that had the same current rating which the proposed method. The result showed that the motor design on this proposed method could be operated at 88.18 % power rating with power factor close to unity.


Author(s):  
Achmad Solih ◽  
Jamaaluddin Jamaaluddin

Panel system power distribution at Lippo Plaza Mall Sidoarjo consists of several parts, namely from Cubicle 20 KV, 20 KV step-down transformer for 380 V, then the supply to LVMDP (Low Voltage Main Distribution Panel) The new panel to the user. Before delivery to users to note that the power factor is corrected using a capacitor bank. Less good a power factor is turned into inductive load on the capacitor bank so that temperatures high  because of high load resulting capacitor bank erupt. To overcome in this study proposes a safety panel automation power distribution control system using a microcontroller. Control system microcontrollers for safety panel power distribution consists of: Microcontroller (Arduino Nano), Light sensor (LDR), temperature sensor (LM35DZ), LCD 16x2 I2C, Actuators (fan, buzzer, relay switch breaker network three phase), switch ( relay 5 VDC), ADC as Input data. The working principle of this microcontroller LM35DZ if the sensor detects a high temperature fan will flash, if the LDR sensor detects sparks then the buzzer will sound as a warning sign of the dangers and disconnected the electricity network. From the design of a safety tool for power distribution panels due to high temperatures or sparks as well as the expected rate of fire outbreaks can be prevented.


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