Generator Protection System Research Articles

Development of a Simulator for Steam Turbine Generator Protection System Based on a Distributed Control System

Development of a Simulator for Steam Turbine Generator Protection System Based on a Distributed Control System

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Generator protection system with reverse power relay on 1000 KVA 'Cummins' diesel generator at Cepu Human Resources Development Center

Each generator is designed to create a certain amount of electricity. However, there are situations when the generator cannot handle the current load. The solution is to employ two or more generators to produce as much power as the number of generators operating simultaneously or synchronizing (parallel generator). Several parameters must be configured throughout the synchronization process, including the phase sequence, voltage, frequency, and phase angle, which must be the same. An operation failure can occur if one of the prerequisites is not fulfilled, resulting in reverse power. The motoring condition is a condition that occurs when the primary mover of a parallel generator fails. A reverse power protection mechanism is required to prevent this motoring. When one of the generator's prime movers fails or the operation fails, the voltage and load will drop. The other generator then feeds another generator. The reverse power relay instructs the generator's main circuit breaker to open the circuit so that no additional equipment is harmed. This research aims to investigate and comprehend the reverse power relay protection system's use.

Stator earth fault detection & evaluation of delaminated stator bar ground wall-insulation of generator G-4 of HPP Chhukha – A case study

Protective devices are employed to monitor and isolate the faulty equipment whenever faults occur in the power system. In the generator protection system, a conventional stator earth fault protection, which is based on residual over voltage (aka neutral voltage displacement) principle, is observed to be inadequate. The paper thus, discusses on how helpful a modern approach of 100% stator earth fault protection scheme is, and proven effective in generator G- 4 of Chhukha Hydropower Plant (CHP). Also, to assess the health of stator windings, insulation resistance (IR) measurement is the foremost test that needs to be performed to qualify for go- ahead with other insulation tests. HV DC ramp and tan ẟ tests are not uncommon as the tests have been proven useful in evaluating the condition of the groundwall insulation of stator coils. Therefore, this paper also illustrates on investigation and analysis of the test results obtained for a bar, suspected to have groundwall insulation breakdown, due to a number of factors. The test results obtained are compared with that of the other test specimens.

Development of research and engineering solutions for the turbine generator and transformer digital protection and control system as exemplified by unit No. 8 of CHPP-21

Development of research and engineering solutions for the turbine generator and transformer digital protection and control system as exemplified by unit No. 8 of CHPP-21

Instantaneous Specific Protection Method Against Faulty Synchronizations of Synchronous Machines

The probability of faulty synchronization of a generator is very small, but not impossible. The main cause of a faulty synchronization is due to wiring errors caused during maintenance or commissioning when voltage transformer and synchronizing equipment are connected or reconnected wrongly. Faulty synchronizations of synchronous generators cause overcurrent and high electromagnetic torque values that can severely damage, not only the generators their selves, but also prime movers and step-up transformers. Moreover, they produce disturbances on the power system such as power oscillations and voltage sags that can end up collapsing the system if it is not cleared quickly. Despite that, conventional synchronous generator protection systems have not a specific function against faulty synchronizations. This paper presents and analyzes a new and specific protection method against faulty synchronizations. The method is based on an instantaneous low setting overcurrent protection that is only activated during synchronizations. Once the synchronization ends, the protection gets disabled in order to allow the increase of the generator power output. Consequently, it minimizes the damages and the disturbance in the power system through rapid detection and tripping. The method has been successfully validated by computer simulations for a thermal power plant 362 MVA turbo-generator, and by experimental tests on a 5 kVA laboratory generation unit.

Diagnosis and Protection of Alternators Against Mass Faults

Generator protection system is one of the complicated industrial systems incorporating many group elements; measurement transformer, relays, circuit breakers and wiring connectors. Generally, protection systems are described using four characteristics; dependability, Sensitivity, rapidity and selectivity. The stator earth fault is a relatively common type of fault. The generators normally have grounded high impedance, that is to say, a ground via a neutral point resistor. This resistance is normally dimensioned to give a ground fault current of the order of 5 to 15 A in the event of permanent earth fault in high voltage terminals of the alternator. Relatively low ground fault currents cause. The new protection technique, it is called an intermittent defect, this type of defect usually has the following characteristics, A very short earth current pulse of high intensity (up to several hundred amps), lasting less than 1 ms. It occurs / disappears automatically over half a period, possibly over several periods, depending on the state of the power grid and the characteristics of the fault. Over longer periods (from several seconds to several minutes), it can evolve into a permanent fault.

Synchronous Generator Out of Step Detection Using Real Time Load Angle Data

Although the power system usually always appears stable and reliable to consumers, a lot of work and research goes into keeping the power system both stable and reliable under constantly changing conditions and in these increasingly demanding times. One of the key issues in the power system is maintaining stability after large disturbances in order to prevent the loss of synchronicity of the generators in the system. Today’s generator protection systems mostly use measurements of impedance change to detect generator out of step. This article discusses the possibility of detecting the loss of synchronicity by using real time load angle measurements. The authors propose a real time load angle measurement algorithm and present the results of the algorithm’s testing performed on a real hydrogenerator. The results show that the developed algorithm gives highly accurate real time load angle measurements with the maximum possible resolution and that the load angle can be used for detecting the synchronous generator out of step.

Analysis of Dynamic Arc Parameters for Vacuum Circuit Breaker Under Short-Circuit Current Breaking

The vacuum circuit breaker (VCB) is an important vacuum switch widely used in generator protection systems and medium-voltage distribution power systems. For observing the vacuum arc behavior variation and analyzing the dielectric recovery characteristics and interrupting capability of VCBs, an experimental platform for a 40.5-kV/31.5-kA/2500-A VCB was established. Under the condition of typical short-circuit current breaking, the short-circuit current breaking test was carried out and the vacuum arc image was collected to obtain the curve of voltage versus current during the breaking process and the arc resistance distribution. By analyzing the variation trend of dynamic arc resistance, a physical and mathematical description of dynamic arc resistance was obtained by the curve fitting method. By comparing and analyzing the experimental data of arc resistance, it is shown that the physical and mathematical description can appropriately describe the spatiotemporal variation of arc resistance in the arcing interval.

Power Generator Automation, Monitoring and Protection System

Power Generator Automation, Monitoring and Protection System

RELE PROTEKSI GANGGUAN GENERATOR 65 MW PADA PLTU PT. PLN (PERSERO) TANJUNG ENIM

Protection system is essential for generating power. This protection is designed to protect and minimize the damage that occurs when the disorder. Plant protection system should work according to condition quickly react in the event of disruption, selective, sensitive / insensitive to interference, reliable / reliability, stability and economical. If the conditions are not met, it will affect the performance of the plant. Generator protection system also aims to protect the generators electric service reliability and continuity. With the achievement of system reliability and efficiency are met.  Keywords : Generato Protection, Relay Protection

발전기 보호용 계자상실 계전기의 적용 분석

Abstract – Recently, the LOE(loss of excitation) incidents are occurred in domestic synchronous generator frequently, the synchronous generator protection system has been much attention for the LOE protection of the incidents that threats synchronous generators and power systems. This paper was showed the characteristics and practices of distance relay that widely used LOE protection relaying in generator. Firstly, the operating characteristics and the impedance locus for LOE of the generator protection were introduced. Even if the conventional simulation program is used for modeling, but it is difficult to implement a LOE modeling and simulation of synchronous generator. So, the LOE relay operation data collected from thermal power plant and nuclear power plant in real fields were analyzed. By reviewing the applications of GE Mho relays, the reliability of LOE for synchronous generator protection in domestic were improved.Key Words : Distance relay, Generator protection, Impedance locus, Loss of excitation, Mho relay, Stability†교신저자 : 강릉원주대학교 전기공학과 교수․공박E-mail : cwpark1@gwnu.ac.kr*한국기술교육대학교 전기전자통신공학부 교수․공박 접수일자 : 2014년 11월 12일수정일자 : 2014년 11월 17일최종완료 : 2014년 11월 19일

발전기보호반을 위한 IED의 설계에 관한 연구

A large generator is an important role in transferring an electric power to power system. The IEDs of large generator often use microprocessor technology to obtain a digital relay system with a wide range of measuring, protection, control, monitoring, and communication functions. However, all generator protection and control systems in Korea imported from abroad and are being operated. In order to reduce the large expense and improve the reliable operation, development of generator protection and control system by domestic technology is required. This paper deals with the design of the IED of generator protection panel for development of generator protection and control system. The major emphasis of the paper will be on the description of hardware and signal processing test results and measurement accuracy of the prototype IED. By developing of generator IED based on DSP and microprocessor, replacement of the generator protection panel imports are expected to be effective.

ATPDraw5.7p4 모델링 데이터를 이용한 전압억제 과전류계전기 동작특성에 관한 연구

The market of domestic Power Plant Generator Protection and Control System (GPCS) is narrow and required the high reliability, and technology. So, it is still operated as turn-key. In recent years, digital relays has evolved into IED can perform the control and monitoring functions without central monitoring based on IEC61850 international standards communications, and attention for advancement of smart grid and ECMS has been increased in South Korea. The increasing attention on multi-function IED, DGPS(digital generator protection system), for internal fault protection of large generator results in starting a national project in South Korea, the IED prototype development for next-generation power units. The voltage restrained overcurrent relay have been used as back-up overcurrent protection for generators. In this paper, voltage restrained overcurrent relay is one of the back-up protective factors in generator protection IED was presented. For evaluation performance of the voltage restrained overcurrent relay, the data of ATPDraw5.7p4 modeling was used. BR

대형 발전기 주보호를 위한 디지털 비율차동 계전기법

An AC generator is an important component in producing an electric power and so it requires highly reliable protection relays to minimize the possibility of demage occurring under fault conditions. It is a need for research of digital generator protection system(DGPS) for the next-generation ECMS and an efficient operation of protection control system in power station. However, most of protection and control system used in power plants have been still imported as turn-key and operated in domestic. This may cause the lack of the correct understanding on the protection systems and methods, and thus have difficulties in optimal operation. In this paper, presented ratio differential relaying(RDR) is main protective element in generator protection IED. The fault detection technique, operation zone and setting value of the RDR were studied and, compared with two of the fault detection algorithm. For evaluation performance of the RDR, the data obtained from ATPDraw5.7p4 modeling was used. The proposed methods are shown to be able to rapidly identify internal fault and did not operate a miss-operation for all the external fault.<BR>

Over-excitation Relaying for Digital Generator Protection using the 765 kV Power System Modeling Data in Korea

A large AC generator is an important component of the power system. Researches on the AC generator relaying for the next-generation ECMS and an efficient operation of protection control system are necessary. These require developments on detailed generator modeling and internal fault analysis, and prototyping for multifunctional IED device dedicated to next-generation production. In this paper, over-excitation relaying algorithm is one of the main protection elements which have an important role in DGPS(Digital Generator Protection System), was proposed. This paper first briefly introduces a principles of over-excitation and DFT-based gain compensation algorithm was adopted for the frequency measurement. Subsequently, protection scheme of over-excitation was presented. The 765[kV] modeling data of South Korea using EMTP-RV was used for simulations. The simulation result of over-excitation relaying are also provided.

Upgrading and enhancing the generator protection system by making use of current digital systems

Upgrading of power plant systems and equipment is becoming a major theme for many utilities. Due to operational cost pressures, competitiveness, life extension, and the desire for better productivity, condition assessment programs are being implemented. One aspect of this is the enhancement/upgrade of existing generator protection schemes with digital systems. Traditionally this protection has been provided by a complement of discrete component relays. These relays have included both electromechanical and static types. Considering a digital enhancement/upgrade offers the owner of installed generation equipment several unique advantages. These include more complete machine protection, diagnostics capabilities for greater productivity and maintenance optimization, life extension with minimal implementation, and the operational advantages of sequence of events, present values and communications capabilities.

Design of a combined digital global differential and volt/hertz relay for step-up transformers

The author presents the specifications and design principles of a digital relay covering the global differential and volt/hertz functions for a generator step-up transformer unit. It is the second and last relay developed in the project for an integrated digital generator protection system at Hydro-Quebec. The design of this system is based on a number of premises: use of low-cost standard bus cards together with digital signal processors to achieve sufficient computing power, grouping of many protection functions in the same independent crate, and implementation of functional redundancy by distribution of the same function between at least two independent crates. It is estimated that the ultimate systems will cost less than existing generator protection systems and offer substantial benefits.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>