scholarly journals Construction of High Precision AC-DC Power Supply

2020 ◽  
Vol 8 (6) ◽  
pp. 2049-2051
Keyword(s):  
Power Supply ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Specific Load ◽  
Research Facility ◽  
Dc Power ◽  
Ac Power ◽  
Supply Equipment ◽  
Load Regulation ◽  
Efficiency Test

Several accessible power supply equipment with different difficulty levels and complexity mostly give a singular DC output that does not provide same use when an Output AC Power that is quite low to a great extent preferred. In this work, a stabilize, fixed and varying power supply device that has output voltage of 0.5 V to 18.15 V variable DC, and current range from 0 - 0.88 A with short circuit protection was constructed by using inexpensive materials, and fuse was used as circuit breaker . Likewise, we examined the regulation attributes of the power supply units that is just been constructed to a specific load regulation to decide its strength by contrasting it with a regular power supply device and ascertain the power supply's effectiveness through its efficiency. Test and examination were carried out utilizing the developed power supply unit to power loads of 10 to 50 Ω. The trend of the output results demonstrated that the power supply was in line with the standard PSU. The output supplied would be useful in research facility estimation to supply the power for direct incorporated circuits, delicate circuits, simple and advanced circuits, TTL and wide-ranging applications necessitating supply force.

scholarly journals Arc Discharge–Induced Ignition of Combustibles Placed on a Damaged AC Power Supply Cord

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 681
Author(s):  
Kiyoto Takenaka ◽  
Yusuke Ishikawa ◽  
Yukio Mizuno ◽  
Wenyi Lin
Keyword(s):  
Power Supply ◽  
Arc Discharge ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Research Papers ◽  
Ac Power ◽  
Induced Ignition ◽  
Fire Ignition ◽  
Intact Element

One of the major causes of unintentional electrical fires is short circuit of an electrically and/or mechanically damaged alternating power supply cord. Detecting of such an event and interrupting the power supply may be beyond the capability of a conventional electro-mechanical circuit breaker. A lot of research papers have been published related to arc fault of wiring and its detection method. Furthermore, arc fault circuit interrupters have been put into practical use. The objective of the present paper is to understand fault of damaged power supply cord under two selected situations observed in practical use or considered suitable to understand fire ignition. Using two kinds of samples similar to but different from samples prescribed in UL1699 standard, the ignition mechanism of combustibles is discussed based on the results of laboratory experiments. The findings herein underscore the important role of the arc in the ignition of combustibles that are placed on the damaged part of a power supply cord, which is normally followed by a short circuit of broken element conductors or breakage of intact element conductors. Moreover, a possible arc detection feature in the two situations is discussed based on a distorted voltage waveform.

scholarly journals Electrical Device Protection from Overvoltage in a DC Power Supply Network: Fast-acting Protection, Realized by an “Artificial” Short Circuit in the Input of the Protected Device

2020 ◽  
Vol 10 (1) ◽  
pp. 5314-5319
Author(s):  
S. K. Filipova-Petrakieva ◽  
Y. M. Shopov
Keyword(s):  
Power Supply ◽  
Supply Voltage ◽  
Classical Method ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Supply Network ◽  
Power Supply Voltage ◽  
Dc Power ◽  
Dc Power Supply ◽  
Fast Acting

In the present paper a protective device based on the so-called “artificial” short circuit in the input of the network, is proposed. To ensure the necessary time for switching on the protection, the increased power supply voltage is delayed to reach in the input of the protected device by additional inductance L, which is connected in series to the power supply. As a result of this forced short circuit, the DC-power supply is switched off by a standard protective circuit-breaker. The short circuit is realized by a fast-acting semi-conductor device (e.g. diac + thyristor, etc.). The controlling signal is formed as a voltage across a capacitor that is a part of RC-circuits connected in parallel to the DC-power supply network. An analytical expression for this voltage, using a classical method for transient analysis, is obtained. The main aim is to determine the exact time of switching on the protection. The research is confirmed with simulations by OrCAD PSpice under the exact values of the elements in the RC-circuits considered. Two rapid increase cases in the power supply voltage are considered: positive jump and linear increase. The suggested solution is applicable for overvoltage protection of different electrical devices. The electrical scheme, based on the electronic components, ensures a fast-acting breaking, which guarantees secure protection. Based on the analytical expressions, the synthesis of the circuit for control and protection is made and the respective values of its elements are calculated.

The Design of Marine 24 V DC Uninterruptible Power Supply

2014 ◽  
Vol 536-537 ◽  
pp. 1537-1541
Author(s):  
Juan Xiao
Keyword(s):  
Power Supply ◽  
Short Circuit ◽  
Battery Management ◽  
Single Chip ◽  
Uninterruptible Power Supply ◽  
Management Scheme ◽  
Ac Power ◽  
Actual Use ◽  
Emergency Power ◽  
Uninterruptible Power

A marine DC uninterruptible power supply is designed. The UPS adopts PIC16C73 single-chip microcomputer to realize the battery management. Both AC power and battery power, the output voltage stability in 23 to 24 v.Via advanced battery management, two sections of charging, equalized charging and floating charging can automatic convert and the DCUPS has many functions of protection, such as over-voltage protection ,under voltage protection and short circuit protection.The actual use on the ship and other occasions showed that the DCUPS is convenient and practical,and is more simple, reliable and longer emergency power supply than the traditional AC-DC uninterruptible power supply management scheme.

The Necessity of Independent Configuration of the DC Power Supply System Used for Power Supply and Auxiliary Power Supply in Nuclear Power Plant

2018 ◽  
Author(s):  
Zhang Zhichao
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Power System ◽  
Power Supply ◽  
Nuclear Power ◽  
Power Supply System ◽  
Power Source ◽  
Dc Power ◽  
Auxiliary Power ◽  
Ac Power

At present, in the typical design of China’s nuclear power plant, main generation system is connected to the power grid by 500 kV system. 500 kV system as a priority power source, 220kV system as an auxiliary power source. Independent operation of 500kV and 220kV system, improved the reliability of power supply of nuclear power plant. However, the DC 220V power system used to control the 500kV and 220kV system in the switch station of partial nuclear power project is not independently configured, and the design form of one set of DC system is used in the transformer station. In recent years, there are many accidents that AC power enters into the DC power system, resulted in the loss of power source in the transformer station. The loss of external power source in the whole plant is very significant. In this paper, the influence of AC power entering into DC power system on relay protection device is analyzed, the measures to prevent the AC power into DC power system are discussed, the necessity of independent configuration of DC control power system for the 500kV priority power system and 220kV auxiliary power supply system is analyzed.

Improvement Strategy of Load Regulation of Boosting Power Supply Based on PID Algorithm

2015 ◽  
Vol 740 ◽  
pp. 261-264
Author(s):  
Sheng Zhang ◽  
Pei Zheng Li ◽  
Zhi Wei Chen
Keyword(s):  
Power Supply ◽  
Output Voltage ◽  
Voltage Divider ◽  
Input Voltage ◽  
The Other ◽  
Improvement Strategy ◽  
Pid Algorithm ◽  
Dc Power ◽  
Load Regulation ◽  
Dc Power Supply

As one of the most important parameters of Direct Current (DC) power supply, Load regulation determines the performance of whole system. In this paper, the internal structure as well as performance parameters of LM2577 boosting converter were deeply investigated and based on this investigation we proposed two new methods of improving its Load Regulation. One method (method 1) is to replace the resistor connected to the feedback pin of LM2577 with a programmable potentiometer and sample the variation of output voltage using an AD converter. The potentiometer is adjusted under the control of feedback algorithm to keep the output voltage stable, thus the load regulation enhanced. In the other method (method 2), the feedback pin of LM2577 is connected to an adder to stabilize the output voltage of DC power supply and increase the load regulation. A voltage divider made up of resistors divides the output voltage and provide the divided voltage to one input of the adder. The other adder input comes from DA converter controlled by microcontroller. To reduce the adjust time and increase the efficiency, PID algorithm is applied in the software part of the system. We use 12-bit AD (ADS1115), 12-bit DA (TLV 5638) and 10-bit programmable potentiometer (AD5293) to test the methods above under the condition of 5V input voltage and 600mA load current. When output is set to 7V, the load regulation is improved from 1.043%, the rate from application circuit in LM2577’s Datasheet, to 0.700% and 0.042% by applying the first and second method, respectively. When output voltage equals 12V, the improvement is from 0.658% to 0.008% and 0.008%. Meanwhile, the method 2 suppresses output voltage ripple to be less than 10mV.

scholarly journals Advantages of using a DC power system on board ship

2016 ◽  
Vol 52 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Rene Prenc ◽  
Aleksandar Cuculić ◽  
Ivan Baumgartner
Keyword(s):  
Energy Storage ◽  
Power System ◽  
Short Circuit ◽  
Storage System ◽  
Energy Storage System ◽  
Unity Power Factor ◽  
Dc Power ◽  
Ac Power ◽  
Lower Transmission ◽  
Ship Power System

This article is structured to present an overview of a DC ship power system. The main DC grid configurations will be presented and a difference to the AC system configuration will be highlighted. Compared to the AC power system used on board ships, DC has some obvious benefits which will be explored in this paper. These benefits include: improvement of prime mover efficiency and reduction of fuel costs, weight and space savings, unity power factor operation of generators, lower transmission losses, faster and simpler parallel connection of generators and simpler implementation of energy storage. Finally, some of the challenges introduced with the DC technology will also be explored. These include: high short-circuit currents, DC protection concept and expensive and possibly non-profitable energy storage system solutions.

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