Analysis and calculation for LV auxiliary power system short-circuit current of the fossil fuel power plant

2015 ◽  
Vol 4 (4) ◽  
pp. 15
Author(s):  
Yunfeng Zhang ◽  
Hourong Pan

<p>Currently, in power plants, the application of the extinction coil in high voltage auxiliary power system neutral point is less experienced. A research done on nuclear power plant and conventional fossil fuel power plant proved that using an auxiliary power system’s different characteristics was leading to different demands of the grounding modes. Thus, this research was done by selecting the grounding mode of high voltage auxiliary power system neutral point on the main nuclear power plants and the partial fossil fuel power plants together with the calculation of practical engineering, and optimal design schemes. The high voltage auxiliary power system neutral point grounding modes have been induced in the large-scale into the nuclear power plant and the conventional fossil fuel power plant. Methods in determining the neutral point grounding modes are used by analyzing the principles commonly used grounding modes and requirements of related codes. First, choose the suitable grounding mode according to the calculation result of capacitive current. Then, choose more conducive grounding mode to the operation of power plant according to the operation of technology equipment. The power is required from the configuration, connection of auxiliary power and the cut from the accident of auxiliary power. As some power plants which are under-construction will be putting into operation one after another, the whole set of perfect security arrangements and operating experiences will also be accumulated inevitably. As a conclusion, high voltage auxiliary power system neutral point grounding modes directly affect the running of the auxiliary power system and even affect the security of the nuclear safety and the operation of the power plant. I hope this article can play a role for reference on the selection of the auxiliary power system grounding modes.</p>


2015 ◽  
Vol 4 (4) ◽  
pp. 15
Author(s):  
Yunfeng Zhang ◽  
Hourong Pan

<p>Currently, in power plants, the application of the extinction coil in high voltage auxiliary power system neutral point is less experienced. A research done on nuclear power plant and conventional fossil fuel power plant proved that using an auxiliary power system’s different characteristics was leading to different demands of the grounding modes. Thus, this research was done by selecting the grounding mode of high voltage auxiliary power system neutral point on the main nuclear power plants and the partial fossil fuel power plants together with the calculation of practical engineering, and optimal design schemes. The high voltage auxiliary power system neutral point grounding modes have been induced in the large-scale into the nuclear power plant and the conventional fossil fuel power plant. Methods in determining the neutral point grounding modes are used by analyzing the principles commonly used grounding modes and requirements of related codes. First, choose the suitable grounding mode according to the calculation result of capacitive current. Then, choose more conducive grounding mode to the operation of power plant according to the operation of technology equipment. The power is required from the configuration, connection of auxiliary power and the cut from the accident of auxiliary power. As some power plants which are under-construction will be putting into operation one after another, the whole set of perfect security arrangements and operating experiences will also be accumulated inevitably. As a conclusion, high voltage auxiliary power system neutral point grounding modes directly affect the running of the auxiliary power system and even affect the security of the nuclear safety and the operation of the power plant. I hope this article can play a role for reference on the selection of the auxiliary power system grounding modes.</p>


2015 ◽  
Vol 793 ◽  
pp. 65-69 ◽  
Author(s):  
Abadal Salam T. Hussain ◽  
Waleed A. Oraibi ◽  
Fadhel A. Jumaa ◽  
F. Malek ◽  
Syed F. Ahmed ◽  
...  

Electrical Power System protection is required to protectboth the user and the system equipment itself fromany fault, hence electrical power system is not allowed to operate without any protection devices installed. Power System fault is defined as the undesirable condition that occurs in the power system. Some of these undesirable conditions are short circuit, current leakage, ground faultand over-under voltage. With the increasing loads, voltages and short-circuit duty in power plant, over voltage protection has become more important today. Here, the component that had been used is PIC 16F877a microcontroller to control the whole system and especially on the circuit breakers as well as the LCT display unit is used to display the voltage level and type of generator that used to serve the load. Sensors are used to measure both thevoltage and the load. The controlled digital signal from PIC microcontroller is converted by using the digital analog converter to control the whole circuit. Thus a device called protective relay is created to meet this requirement. The protective relay is mostlyoften coupled with circuit breaker in a way that it can isolate the abnormal condition in the system.


2014 ◽  
Vol 574 ◽  
pp. 324-328
Author(s):  
Nian Fang ◽  
Xian Shan Li ◽  
Hao Xu ◽  
Yu Long Du

The configuration and setting calculation of auxiliary power protection are directly related to the regular and safe operation of the equipments, thereby affecting the security and stability of the power plant. The system features are analyzed in depth according to the operational requirements of auxiliary power system protection in Xiangjiaba hydropower plant ,the system model is built on the basis of the actual project, and a variety of short-circuit current calculations are carried out. At last, the setting of the auxiliary power system relay protection is completed. This thesis also proposes solutions to the emerging problems in the process of protection setting. The results of the setting have been applied to the actual operation and no misoperation or maloperation caused by improper constant setting value has occurred so far in Xiangjiaba hydropower plant.


2011 ◽  
Vol 10 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Catalin Nisulescu ◽  
Delia Calinoiu ◽  
Adrian Timofte ◽  
Andreea Boscornea ◽  
Camelia Talianu

2021 ◽  
Vol 39 (5A) ◽  
pp. 723-737
Author(s):  
Yamur M. Obied ◽  
Thamir M. Abdul Wahhab

The coordination between protective devices is the process of determining the most appropriate timing of power interruption during abnormal conditions in the power system. The aim of this work is to coordinate the protection of the 33/11 kV power distribution substation in Iraq using the CYME 7.1 software package. In this paper overcurrent and earth fault relays are simulated in two cases, with time delay setting and instantaneous setting, to obtain the Time Current Characteristics (TCC) curves for each Circuit Breaker (CB) relay of Al-Karama substation (2×31.5 MVA, 33/11 kV) in Babil distribution network. The short circuit current at each CB is calculated and accordingly, the protection coordination for Al-Karama substation has been simulated. The TCC curves have been obtained in two cases for overcurrent and earth fault relays; in a case with time delay setting and in the case with the instantaneous setting. The setting takes into consideration the short circuit current at the furthest point of the longest outgoing feeder and the shortest outgoing feeder.


Sign in / Sign up

Export Citation Format

Share Document