Analisis Pengaruh Surja Hubung Terhadap Tegangan Lebih Transien Dengan Menggunakan Electromagnetic Transients Program

The rejection load causes the phenomena of transients over voltage, and this could cause damaged to the electrical power system. In order to know how much the voltage arose by the load rejection in SUTT 150kV, an appropriate way to predict possible voltage is needed. The research studies the problem of transients over voltage that occur as a result of rejection load in SUTT 150kV Payakumbuh – Koto Panjang. Simulation is carried out using EMTP (Electromagnetic Transient Progam) software. The result of simulation shows, transient over voltage at the time of the rejection load still exist with in a safe condition. Transients over voltage in every measurement point become larger which shows the function of distance towards load

A new windings design for improving single-phase induction motor performance

Single-phase induction (asynchronous) motors are widely used at home. These motors have two windings and usually operate at a lower performance than 3-phase asynchronous motors which have three windings. For this reason, this study aims to design a new winding of a single-phase asynchronous motor by increasing the number of phases in the motor windings in order to increase the performance of the motor. This research was focused on 36 slot capacitor-start capacitor-run asynchronous motor. The design used 4 non-identical windings in the motor, where three windings acted as auxiliary windings and one winding acted as main winding. The rated current of the designed motor winding was 2.74 A for the main winding and 3.15 A for the auxiliary winding. The performance of the designed motor compared to the traditional single-phase asynchronous motor with the same structure of stator, rotor, and rated current. A traditional single-phase asynchronous motor had data: 1 HP, 220 V, 8.3 A, 1440 RPM, 50 Hz, and 4 poles. The results of this study indicated that the designed motor operated with power factors almost close to unity and had higher output power, torque, and efficiency than the traditional single-phase asynchronous motors

Disturbance Modeling on Transmission Lines Using Wavelet Transform Method: A Review

This paper introduces a number of methods for identifying disturbances on transmission lines and provides algorithms for classifying various disturbance types. working with the discrete wavelets transform (DWT) and various embedded systems techniques using a simulator to carry out digital simulations of system trials using the controlled technique, the nature of disturbance in distinct sub-systems is determined. The analysis of transmission lines using the wavelet transform is the main topic of this study, along with techniques for transmission line protection. These factors include channel capacity, channel length, simulation software, mother wavelet type, parameters, sampling frequency, and type of disturbance analysis

Proposal of analysis method to reduce back-flashover rate taking account of tower footing resistance

The number of lightning stroke on the tower of the 150 kV Koto Panjang-Payakumbuh transmission line located the rocky area has been observed. The high value of tower footing resistance indicates the occurrence of the back-flashover in the transmission line at intensity of 74%. The back-flashover occurrence is dominantly triggered by the tower footing resistance value. Also, the rate of back-flashover has an effect on the value of the tower footing resistance by considering the number of electrode installations. A design is proposed for the grounding system of the tower footings in order to reduce the rate of back-flashover. The results presenting in numerical simulation indicates that it works properly after adding 4 electrodes. That is to say, installing 4 electrodes in each tower has successfully decreased the tower footing resistance value, back-flashovers rate 80% and 90-95% of present value respectively. The insulator voltage can be reduced to less than half of the present voltages as much as 30-50%. In more detail, in tower 77, the value of the tower footing resistance drops to 2.84 Ω, the flashover rate drops to 0.57/100 km/year and the insulator voltage drops to 0.99 MV when a disturbance occurs

インドネシア西スマトラの150kV 送電線雷トリップアウトに関する研究

博士(工学)doctoral創造科学技術大学院静岡大学甲第976号ET

Analisis Variasi Ketebalan Coating Senyawa Glasir terhadap Daya Tahan Dielektrik Isolator Keramik Saluran Transmisi 150kV

ABSTRAK Penelitian ini bertujuan untuk mengetahui seberapa besar nilai coating isolator yang dapat ditembus listrik berdasarkan Basic Insulator Level (BIL). Metode yang digunakan dalam perhitungan tegangan tembus listrik ialah metode Anderson dalam hal ini Critical Fashover (CFO). Untuk mengetahui penurunan daya tahan dielektrik isolator dapat dilihat dari seberapa besar tegangan flashover yang dihasilkan. Hasil dari perhitungan disimulasikan dengan MATLAB logika fuzzy. Pada penelitian ini ketika isolator disetting pada coating 0,3 mm dengan waktu kejadian flash 2 μs maka tegangan flashover yang dihasilkan sebesar 1,3 MV. Hasil simulasi ini menunjukan bahwa pada coating 0,3 mm tegangan flashover yang dihasilkan melebihi dari BIL isolator yang sudah ditetapkan yakni sebesar 1,27 MV. Isolator dalam kondisi seperti ini dapat ditembus listrik atau daya tahan dielektriknya menurun. Secara bersamaan ketika kemampuan coating berkurang, maka dapat diklasifikasikan isolator dalam keadaan kotor. Kata kunci: isolator, coating, dielektrik, BIL, dan fashover   ABSTRACT This research aims to determine the value of the insulator that can be penetrated by electricity based on the Basic Insulator Level (BIL). The method used in the calculation of breakdown voltage is the Anderson method, in this case, Critical Flashover (CFO). To know a decrease in the dielectric resistance of the insulator can be seen from whatever the voltage resulting from a large flashover. The results of the calculations simulated with fuzzy logic Matlab. In this research, when the insulator set on a coating of 0.3 mm with a flash event time of 2 μs, then flashover voltage resulted in 1.3 MV. The simulation results show that at the coating 0.3 mm the result of flashover voltage exceeds the BIL insulator that has been set at 1.27 MV. Insulator in this condition can be penetrated by electricity or the dielectric resistance decreases. Simultaneously when the coating ability is reduced, then can be classified as a dirty insulator. Keyword: insulator, coating, dielectric, BIL, and flashove

Tower-Footing Resistance and Lightning Trip-outs of 150 kV Transmission Lines in West Sumatra in Indonesia

The trip-out rates calculated by taking account of the reduction in the tower-footing resistance due to the ionizing effect agree well with the observed ones. This indicates the importance of the impulse resistance in the analysis of the lightning performance of the line. The trip-out rate at the lower arm is high for the cases of the average grounding resistance of 33.3 ohms, and the rates at the upper arm are high for the cases of the average grounding resistance of 5.6 ohms. Such à trend can be simulated by the IEEE method using the impulse resistance. The trend for the trip-out ratio to become high with the increase in the span length is significant after improvement of the tower-footing resistance. However, the trend is weak before improvement of the tower-footing resistance. This is because in the case of the high tower-footing resistance the flashover occurs before the arrival of the wave reflected from the adjacent towers due to the high potential rise of the tower. Therefore, the degree of the influence of the span length on the trip-out ratio is dependent on the tower-footing resistance. The local lightning activity significantly affects the trip-out rate