Determination of Timing Parameters of Dust Clouds Explosion in Dependence on the Size of the Vessel Volume

EN 14034 standard defines the requirements for igniter, to determine the properties of dust clouds. The standard specifies the conditions for occurrence of explosions of dust clouds. According to the standard, equipment with a volume of 1m3 and 20L can be used to determine the explosion parameters of dispersed dusts. The equipment has the time parameters of dispersing and the ignition system defined in the Standard. Experimental determination of time parameters is required for a different chamber volume. The article therefore deals with the determination of parameters for dispersing system in the 291 litre chamber. Determination of igniter delay was performed on the base of setting the time relay. Activation of pressurised air flow was determined by calculation, and it was subsequently experimentally verified in laboratory conditions. A video camera recording was selected for measuring the rate of nitrocellulose ignition from the resistance wire. The result of this study is determination of the igniter timing in dependence of the explosion chamber volume. The time delay of the nitrocellulose igniter is 320 ms.

Analisis Koordinasi Over Current Relay Dan Ground Fault Relay Terhadap Keandalan Sistem

This research had done base on case study in the feeder of substation 20 kV Jababeka. Existing data showed that condition is well with not too long differential, over all setting on the Overcurrent Relay (OCR) – Ground Fault Relay (GFR) in the field is well. From calculated result can be seem that current of short circuit disturb is influenced by distance between disturbance points. Using over current relay has important purpose in the protection of electricity system. The qualification need setting minimum time of over current relay in the feeder not less than 0.3 second. This consider to the relay will not in trip condition in rush current from distribution transformator that has been connected in the distribution system when the feeder starts operated. Starting time for relay in the feeder is faster than work time in the incoming side with average time about 0.4 second for one phase disturbance side. But for three phase and two phase disturbance side, work time relay has interval time about 0.4 second and than increase with average increament about 0.1 second when transmission line is longer (from distance aspects about 0%, 25%, 50%, 75% and 100%).

STUDI PENGARUH PEMASANGAN NGR 40 OHM PADA UPRATING TRANSFORMATOR 2 GI GIANYAR TERHADAP GANGGUAN HUBUNG SINGKAT 1 PHASA TANAH

Along with the development of ever-increasing burden on the GI Gianyar then the transformer unit 2 with a capacity of 30 MVA will be uprating with a capacity of 60 MVA transformer. To maintain the continuity and reliability of the flow of electrical power to the consumer , NGR (Neutral Grounding Resistance) and relay SBEF is used as the safety equipment of the short circuit 1 phase to ground was not in to the neutral point of the transformer. Uprating of transformers that have been done changes on 1 phase fault current to ground when using a direct earthing systems with a value to become 1838.21 A. While the value of the short-circuit current 1 phase to ground after pairing NGR 40 Ohm value is fixed at 288.675 A, so that the current setting and time relay SBEF fixed at 90 A and 7.067 seconds. The analysis result from the effect of installation NGR and rele SBEF on the transformer 60 MVA against short circuit 1 phase to ground has the ability good protection for the value of the fault current is able to be reduced from 1838,21 A into 288.675 A after pairing NGR 40 Ohm and time is needed SBEF to handle distractions 7.067 seconds. Intisari- Seiring dengan perkembangan beban yang terus meningkat di GI Gianyar maka transformator unit 2 berkapasitas 30 MVA akan di lakukan uprating (penggantian) dengan transformator berkapasitas 60 MVA. Untuk menjaga kontinyuitas dan keandalan aliran daya listrik sampai ke konsumen (beban), NGR (Neutral Grounding Resistance) dan rele SBEF dipergunakan sebagai peralatan pengaman dari gangguan hubung singkat phasa tanah agar arus gangguan 1 phasa ke tanah tidak sampai mengalir ke titik netral transformator. Dari uprating transformator yang sudah di lakukan terjadi perubahan pada arus gangguan 1 phasa ke tanah jika menggunakan sistem pentanahan langsung (solid grounding) menjadi 1838,21 A. Sedangkan nilai dari arus hubung singkat 1 phasa ke tanah setelah dipasangkan NGR 40 Ohm nilainya tetap sebesar 288,675 A, sehingga setting arus dan waktu rele SBEF tetap sebesar 90 A dan 7,067 detik. Hasil analisis pengaruh pemasangan NGR dan rele SBEF pada transformator 60 MVA terhadap gangguan hubung singkat 1 phasa ke tanah menghasilkan kemampuan proteksi yang lebih baik karena nilai arus gangguan yang mampu di kurangi dari 1838,21 A menjadi 288,675 A setelah dipasangkan NGR 40 Ohm dan waktu yang di butuhkan SBEF untuk menangani gangguan 7,067 detik.

STUDI ANALISA KOORDINASI RELAI GFR INCOMING BUSBAR 20 KV DAN GFR SALURAN UNTUK MENGAMANKAN GANGGUAN SATU PHASA KETANAH DI TRANSFORMATOR 3 GARDU INDUK KAPAL

Disruption of the distribution system is generally caused by a short circuit that causes overcurrent, one single phase short circuit to ground. Single phase to ground disturbances that occurred at the feeder should be secured by a ground fault relays in feeders. However, due to an error of coordination, interference with the feeder perceived also to the incoming side of the transformer so that ground fault relays on the incoming 20 kV ordered PMT 20 kV at the transformer side open. Working time ground fault relays in feeders Peguyangan is for 0.25 seconds. While working time ground fault relays in the incoming 20 kV is for 0.5 seconds. This indicates that differences in work time relay by 0.25 seconds is considered selective. The event of disruption of the ground phase, GFR relay coordination in securing the area of ??interference must be gradual. Where the value of working time ground fault relays in the base should be longer than the time ground fault relays working on a feeder. It aims to work ground fault relays working order, so that errors can be avoided in the security and do not lead to the spread of disturbed areas.

Design and Experimental Research of Automatic Control System of Material Transport Car Based on Siemens S7-300 PLC

Aiming to the problem of the traditional relay control system, such as high failure rate, low precision control, complex installation, slow system response, etc ,which caused by the extensive uses of intermediate relay, time relay, counter and other devices in the system, this paper provides a design of an automatic control system which integrates automatic positioning, automatic feeding, automatic cleaning equipment based on siemens S7-300 PLC instead of the traditional relay control system and carry out simulation analysis by PLCSIM software, compared with the material transport car model motion excellent to verify the rationality of the control system design.

Fuzzy Logic Overcurrent Relay Using Sugeno Technique

The overcurrent relay is the simplest and most economical type of protective relay, the relay is designed to operate when more than a predetermined amount of current flows into a particular portion of the power system. Time delay between relay's main zone and it's backup will keep the selectivity of the system, The inverse definite minimum time relay will calculate the time delay inversely proportional to the fault current level. This technique has some weaknesses where the time delay provided for a given case maybe too high and if the fault is not isolated immediately then damage could be caused to other connected equipment in the power system. This paper presents the fuzzy logic relay using Sugeno technique to determine the time delay, and using of symmetrical components application in detecting fault type, also it presents a comparison between times calculated by other techniques.