scholarly journals Shafting Torsional Vibration Analysis of 1000 MW Unit under Electrical Short-Circuit Fault

2021 ◽  
Vol 11 (19) ◽  
pp. 9205
Author(s):  
Honggang Pan ◽  
Yunshi Wu ◽  
Zhiyuan Pang ◽  
Yanming Fu ◽  
Tianyu Zhao
Keyword(s):  
Short Circuit ◽  
Power Grid ◽  
Two Phase ◽  
Shaft System ◽  
Three Phase ◽  
Speed Fluctuation ◽  
Grid Side ◽  
Generator Terminal ◽  
The Impact ◽  
Short Circuit Fault

Taking a 1000 MW turbine generator as the research object, the short-circuit fault in electrical disturbance is analyzed. Since it is very difficult to carry out fault analysis experiments and research on actual systems, simulation analysis is one of the more effective means of electrical fault diagnosis; the simulation’s results approach the actual behavior of the system and are ideal tools for power system analysis, and can provide an empirical basis for practical applications. The short-circuit fault model of the SIMULINK power system is built to analyze the two types of faults of generator terminals short-circuit and power grid short-circuit. The impact load spectrum, fault current and speed fluctuation between low-voltage rotors were extracted and analyzed. The conclusion is that the impact value of electromagnetic torque at the generator terminal is greater than that on the power grid side. The impact value of a two-phase short-circuit at the generator terminal is the largest, and that of a three-phase short-circuit on the power grid side is the smallest. The transient impulse current of a three-phase short-circuit at any fault point is greater than that of a two-phase short-circuit; the impulse current of the grid side short-circuit is much greater than that of the generator terminal short-circuit; the speed fluctuation and fluctuation difference caused by the three-phase short-circuit in the grid side are the largest. The alternating frequency of the transient electromagnetic force of the four kinds of faults avoids the natural frequency of the torsional vibration of the shaft system, and the torsional resonance of the shaft system in the time domain of the short-circuit fault will not appear. However, after the fault is removed, the residual small fluctuation torque in the system has a potential impact on the rotor system. This research shows an analysis of the structural integrity and safe operation of turbine generator units after a short-circuit fault, which can not only be applied to engineering practice, but also provide a theoretical basis for subsequent research.

Study on Dynamic Response of Torsional Vibration of Turbo-Generator Unit Caused by Short Circuit Fault

2012 ◽  
Vol 566 ◽  
pp. 248-252 ◽  
Author(s):  
Cheng Bing He ◽  
Dong Chao Chen ◽  
Yu Jiong Gu
Keyword(s):  
Torsional Vibration ◽  
Short Circuit ◽  
Dynamic Responses ◽  
Stable Operation ◽  
Two Phase ◽  
Time Frequency ◽  
Turbo Generator ◽  
Complex Morlet Wavelet ◽  
Generator Terminal ◽  
Short Circuit Fault

When short circuit faults happen near power plant or generator terminal, severe transient torque shock will act on the shaft system, which seriously affects the safe and stable operation of the unit. Using the increment transfer matrix method, the dynamic responses of torsional vibrations are calculated in this work. Combined with the complex Morlet wavelet and time-frequency contour map, the time-frequency domain characters of dynamic torque are analyzed. The analyzed results show that the torque value caused by three phase short circuit fault is largest. The order of torque value from high to low is two phase short circuit to ground, two phase interphase short circuit and single phase short circuit. The electric distance between short circuit point and generator is more short, and the torsional vibration is more serious.

scholarly journals Setting Kerja Waktu Relay Arus Lebih pada Penyulang Kikim di Gardu Induk Sungai Juaro

Electrician ◽  
2019 ◽  
Vol 13 (2) ◽  
pp. 57
Author(s):  
Sarinah Agi Dia Savitri ◽  
Feby Ardianto ◽  
Bengawan Alfaresi
Keyword(s):  
Electric Power ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Working Time ◽  
Power Station ◽  
Two Phase ◽  
Operation System ◽  
Excess Current ◽  
Three Phase ◽  
The Impact

Intisari — Gangguan-gangguan yang sering terjadi pada operasi sistem tenaga listrik dapat mengakibatkan terganggunya penyaluran tenaga listrik ke konsumen, sehingga menimbulkan arus hubung singkat yang cukup besar, untuk menghindari akibat gangguan tersebut diperlukan perlindungan jaringan dengan memasang suatu relay proteksi. Tujuan dari penelitian ini adalah melakukan simulasi menggunakan software ETAP dan perhitungan arus hubung singkat serta setting waktu kerja relay arus lebih. Metode yang digunakan untuk menganalisis gangguan hubung singkat yaitu 1) identifikasi data, 2) simulasi, 3) perhitungan, 4) hasil dan analisis serta 5) kesimpulan. Hasil penelitian, simulasi software ETAP arus gangguan hubung singkat maksimum pada jarak 25% dengan arus gangguan tiga fasa sebesar 2877.341 A, dua fasa sebesar 2672.708 A, dan satu fasa sebesar 2491.835 A. Gangguan minimum pada jarak 100% dengan arus gangguan tiga fasa sebesar 502.032 A, dua fasa sebesar 434.671 A, dan satu fasa sebesar 347.035 A. Sedangkan untuk hasil simulasi waktu kerja relay arus lebih sisi incoming sebesar 1 detik dan sisi outgoing sebesar 0.55 detik, hasil perhitungan waktu kerja relay arus lebih sisi incoming sebesar 0.99 detik dan sisi outgoing sebesar 0.54 detik.Kata kunci — Gangguan Hubung Singkat, relay arus lebih, ETAP Power Station 12.6.0.  Abstract — Interferences that often happen in an operation system of electric power can cause in disruption of distribution the electric power to consumers, so it causes quite large shor-circuit current. To avoid the impact of that inrerferences,setting relay portection to protect the network is needed. The purpose of the reserch is doing a simulation using ETAPsoftware, calculating the short-circuit current, and setting the working time of excess-current relay. The method that used to analyze the interferences of short-circuit current are : 1) data identifying, 2) Simulation, 3) calculation, 4) result and analysis and, 5) conclution. The results of the research show that the maximum interferences of short -circuit current at 25% of distance with three phase Interferences is 2877,341 A, two -phase is 2672,708 A, and one-phase is 2491,835 A. The minimum Interferences at 100% distance with three phase Interferences is 502,032 A, two -phase is 434,671 A, and one-phase is 347,035 A. And the result of the simulation time of excess-current relay on incoming side is 1 second and on feeder side is 0.55 second, the results of the calculation working time of excess-current relay on the incoming side are 0.99 second and on the feeder, a side is 0.54 secondKeywords— short circuit, over current relay, ETAP power station 12.6.0

scholarly journals Analisis Pengaruh Kompensasi Impedansi Urutan Nol (Kzn) terhadap Kehandalan Sistem Proteksi Rele Jarak (Distance Relay) pada Penghantar Harapan Indah di Gardu Induk Plumpang

2021 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Deni Almanda ◽  
Juniyanto Juniyanto
Keyword(s):  
Single Phase ◽  
Short Circuit ◽  
Relay Protection ◽  
Protection System ◽  
Distance Relay ◽  
Two Phase ◽  
Test Tool ◽  
Three Phase ◽  
Zero Sequence ◽  
Short Circuit Fault

Pada saat terjadi gangguan hubung singkat di saluran transmisi Gardu Induk Plumpang, rele jarak berfungsi sebagai proteksi utama. Penelitian ini bertujuan untuk mengetahui pengaruh kompensasi impedansi urutan nol (kzn) terhadap kehandalan sistem proteksi rele jarak (distance relay) pada penghantar harapan indah di Gardu Induk Plumpang. Setting rele jarak yang didapatkan dari PT PLN (Persero) UPT Pulogadung disimulasikan menggunakan alat uji Omicron. Hasil simulasi gangguan hubung singkat satu fasa, gangguan hubung singkat dua fasa, dan gangguan hubung singkat tiga fasa menggunakan setting lama Z1 = 2.58 Ω, Z2 = 3.87 Ω, dan Z3 = 7.30 Ω, kZn = 0.93 Ω < -0.4° rele jarak tidak bekerja selektif, maka dilakukan resetting. Hasil resetting rele jarak yaitu Z1 = 2.58 Ω, Z2 = 3.87 Ω, dan Z3 = 7.30 Ω, kZn = 0.68 Ω < -0.6°. Setelah dilakukan resetting dan disimulasikan gangguan hubung singkat satu fasa, gangguan hubung singkat dua fasa, dan gangguan hubung singkat tiga fasa, rele jarak bekerja secara handal. Kesimpulannya kZn dapat mempengaruhi kehandalan sistem proteksi rele jarak pada penghantar harapan indah di Gardu Induk Plumpang.In the event of a short circuit in the transmission line of the Plumpang Substation, the distance relay serves as the main protection. This study aims to determine the effect of zero sequence impedance compensation (kzn) on the reliability of the distance relay protection system at the Harapan Indah conductor at the Plumpang Substation. The distance relay setting obtained from PT PLN (Persero) UPT Pulogadung was simulated using the Omicron test tool. Simulation results of single phase short circuit, two phase short circuit, and three phase short circuit using the old setting Z1 = 2.58 Ω, Z2 = 3.87 Ω, and Z3 = 7.30 Ω, kZn = 0.93 < -0.4° relay distance does not works selectively, then resetting is done. The results of resetting the distance relay are Z1 = 2.58 Ω, Z2 = 3.87 Ω, and Z3 = 7.30 Ω, kZn = 0.68 < -0.6°. After resetting and simulating single-phase short circuit, two phase short circuit, and three phase short circuit fault, the distance relay works reliably. In conclusion, kZn can affect the reliability of the distance relay protection system on the beautiful hope conductor at the Plumpang Substation.

scholarly journals Nonlinear Variable Resistor-Based FCL for Fault Ride-Through Performance Enhancement of DFIG-Based Wind Turbines

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mehdi Firouzi ◽  
Mohammadreza Shafiee ◽  
Mojtaba Nasiri
Keyword(s):  
Wind Turbines ◽  
Performance Enhancement ◽  
Short Circuit ◽  
Variable Resistor ◽  
Fault Ride Through ◽  
Three Phase ◽  
Bridge Type ◽  
Doubly Fed ◽  
Grid Side ◽  
Short Circuit Fault

Fault ride-through (FRT) requirement is a matter of great concern for doubly fed induction generator (DFIG-) based wind turbines (WTs). This study presents a nonlinear variable resistor- (NVR-) based bridge-type fault current limiter (BFCL) to augment the FRT performance of DFIG-based WTs. First, the BFCL operation and nonlinear control design consideration of the proposed NVR-based BFCL are presented. Then, the NVR-BFCL performance is validated through simulation in PSCAD/EMTDC software. In addition, the NVR-based BFCL performance is compared with the fixed resistor- (FR-) based BFCL for a three-phase symmetrical short circuit fault at the grid side. Simulation results reveal that the NVR-based BFCL provides a smooth and effective FRT scheme and outperforms the FR-based BFCL.

scholarly journals Complex Electronic Protection for Low-voltage Three-phase Induction Motors

2020 ◽  
Vol 11 ◽  
pp. 11-17
Author(s):  
Gabriel Nicolae Popa ◽  
Corina Maria Diniș
Keyword(s):  
Induction Motors ◽  
Low Voltage ◽  
Short Circuit ◽  
Electronic Devices ◽  
General Purpose ◽  
Two Phase ◽  
Dc Voltage ◽  
Electric Drives ◽  
Normal Limits ◽  
Three Phase

Low-voltage three-phase induction motors are most often used in industrial electric drives. Electric motors must be protected by electric and/or electronic devices against: short-circuit, overloads, asymmetrical currents, two-phase voltage operation, under-voltage, and over-temperature. To design the electronic protection currents, voltages and temperature must be measured to determine whether they fall within normal limits. The electronic protection was design into low capacity PLC. The paper presents the designs and analysis of complex electronic protection for general purpose low-voltage three-phase induction motors. The electronic protection has Hall transducers and conversion electronic devices for AC currents to DC voltages, AC voltages to DC voltage, temperature to DC voltage, a low capacity PLC, switches, motor’s power contactors, and signalling lamps has been developed. Experiments with complex electronic protection, for different faults are presented. The proposed protection has the advantages of incorporating all usual protections future for the low-voltage three-phase induction motors.

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