Relay Protection Setting Calculation and Analysis of Auxiliary Power System for Hydropower Plants

2014 ◽  
Vol 574 ◽  
pp. 324-328
Author(s):  
Nian Fang ◽  
Xian Shan Li ◽  
Hao Xu ◽  
Yu Long Du
Keyword(s):  
Power System ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Hydropower Plant ◽  
System Protection ◽  
Auxiliary Power ◽  
Hydropower Plants ◽  
Actual Operation ◽  
Setting Calculation

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.

Power Plant Station Protection System against Voltage Fluctuation

2015 ◽  
Vol 793 ◽  
pp. 65-69 ◽  
Author(s):  
Abadal Salam T. Hussain ◽  
Waleed A. Oraibi ◽  
Fadhel A. Jumaa ◽  
F. Malek ◽  
Syed F. Ahmed ◽  
...  
Keyword(s):  
Power Plant ◽  
Power System ◽  
Short Circuit ◽  
Electrical Power ◽  
Circuit Breaker ◽  
Digital Signal ◽  
Short Circuit Current ◽  
Electrical Power System ◽  
System Protection ◽  
Protective Relay

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.

First Superconducting Fault Current Limiter in Russian Power Grid

2021 ◽  
Vol 4 (4) ◽  
pp. 4-16
Author(s):  
Michael E. MOZAH ◽  
◽  
Sergey V. SAMOYLENKOV ◽  
Andrey P. VAVILOV ◽  
Evgeny P. PROKHOROV ◽  
...  
Keyword(s):  
Power System ◽  
High Voltage ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Superconducting Fault Current Limiter ◽  
Current Limiter ◽  
Technical Solutions

Superconducting fault current limiter (SFCL) is an innovative method for reducing the level of short-circuit currents in high-voltage electrical networks. This reduces the number of points of separation of the electrical network in conditions of short-circuit current limitation and thereby increases the network capacity and reliability of power supply to consumers. At the same time, the development of such devices poses new challenges for power engineers related to the integration of this equipment into the existing power system. The article discusses the process of implementation and pilot operation of the SFCT 220 kV pilot project (produced by CJSC “SuperOx”) at the 220/20 kV “Mnevniki” high-voltage substation in Moscow. The project required an extensive set of scientific studies and tests to confirm the characteristics of new devices and the possibility of their use in Russian power systems, the use of digital modeling technologies to test the operability of relay protection devices, as well as the development of new methodological documents for calculating the short-circuit current and relay protection parameters. As a result of the work, SFCT was switched on at the 220/20 kV “Mnevniki” substation at the end of 2019. The subsequent operation of the SFCT in 2019-2020 fully confirmed the declared characteristics of the device and the correctness of the selected technical solutions. The article is devoted to the features of the process of integrating a new device into the existing power system, the main technical solutions, the results of testing and operation of the device, as well as possible prospects for the development of SFCT technology.

Generating Various Inverse Time over Current Numerical Relays Using Microcontroller for Power System Protection

2013 ◽  
Vol 415 ◽  
pp. 149-154
Author(s):  
Vinay Barhate
Keyword(s):  
Power System ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Current Sensor ◽  
Load Current ◽  
Analog To Digital ◽  
Protection Relay ◽  
System Protection ◽  
Laboratory Setup

Power System fault is defined as undesirable condition that occurs in the power system. These undesirable conditions such as short circuit, current leakage, ground short, over current and over voltage. This paper is an attempt to design and fabricate inverse time over current protection relay using basic Microcontroller. The 8051 Microcontroller will cause the circuit breaker to trip when the current from load current reaches the setting value in the micro controller and generates a time delay for tripping as per the type of Characteristics for which it is designed, may it be IDMT or normal inverse, very inverse or extremely inverse over current Relay. First the load current need to measure in order to monitor it using current sensor and when such condition arise, it will isolate in the shortest time possible without harming the any other electrical devices. The current sensor processes the signal using current to voltage converter, precision rectifier, Analog to Digital convertor, peripheral interfacing devices with Microcontroller chip takes the suitable action of generating trip signal at appropriate time for expected pick up value of current. It is tested with laboratory setup and found working satisfactory.

Research on Short-Circuit Current of Wind Power System and its Impact on Relay Protection

2014 ◽  
Vol 1070-1072 ◽  
pp. 258-263
Author(s):  
Hua Bo Shi ◽  
Zhi Chen ◽  
Gan Li ◽  
Bo Zhou
Keyword(s):  
Power System ◽  
Wind Power ◽  
Short Circuit ◽  
Relay Protection ◽  
Short Circuit Current ◽  
Green Energy ◽  
Stable Operation ◽  
Technical Problems ◽  
Wind Power System ◽  
The Impact

Wind energy is clean and renewable energy with rich resources. As one of the most promising green energy, wind power has become an important part of the electricity supply. But there are still many technical problems to be solved related to wind power generation and integration, because it may have significant impact on safe and stable operation of the power grid. Therefore, the doubly-fed wind generator and direct-driven permanent-magnet wind power generator are studied. Their models are built in PSCAD/EMTDC for electromagnetic transient simulation, in order to study the characteristics of their short circuit fault current, as well as the impact on the relay protection of the wind power system. The research outcomes provide a reference and basis to wind power failure characteristics research.

Protection Coordination of 33/11 kV Power Distribution Substation in Iraq

2021 ◽  
Vol 39 (5A) ◽  
pp. 723-737
Author(s):  
Yamur M. Obied ◽  
Thamir M. Abdul Wahhab
Keyword(s):  
Time Delay ◽  
Power System ◽  
Power Distribution ◽  
Software Package ◽  
Short Circuit ◽  
Distribution Network ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Earth Fault ◽  
Current Characteristics

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.

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