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Simulation of Active Filtering Applied to A Computer Centre
No full textIn this paper, the implementation of a shunt active power filter with a small series reactor for a three-phase system is presented. The system consists of computer loads, which are harmonic voltage sources, with significant unbalanced components. The filter consists of a three-phase current-controlled voltage source inverter (CC-VSI) with a filter inductance at the AC output and a DC-bus capacitor. The CC-VSI is operated to directly control the AC grid current to be sinusoidal and in phase with the grid voltage. The simulation results indicate that the filter along with the series reactor is able to handle the harmonic voltage sources, as well as the unbalance, so that the grid currents are sinusoidal, in phase with the grid voltages and symmetrical.
Abstract in Bahasa Indonesia :
Dalam makalah ini dijelaskan tentang penggunaan filter aktif type paralel dengan menggunakan reaktor kecil yang dipasang secara seri untuk sistem tiga phasa. Jaringan sistem ini menggunakan komputer sebagai beban yang merupakan sumber harmonisa tegangan; sekaligus menimbulkan ketidakseimbangan sistem. Filter daya aktif merupakan current-controlled voltage source inverter (CC-VSI) tiga phasa dengan sebuah filter induktansi pada keluaran AC dan sebuah kapasitor DC-bus. CC-VSI dioperasikan untuk mengendalikan secara langsung arus jala-jala AC menjadi sinusoidal dan sephasa dengan tegangan jala-jala. Hasil simulasi menunjukkan bahwa filter dengan reaktor seri mampu untuk mengatasi sumber harmonisa tegangan dan juga ketidakseimbangan beban sehingga gelombang arus menjadi sinusoidal, sephasa dengan tegangan jala-jala dan simetris
Katakunci: filter daya aktif, distorsi harmonik
Analisa Gangguan Satu Fasa ke Tanah yang Mengakibatkan Sympathetic Trip pada Penyulang yang tidak Terganggu di PLN APJ Surabaya Selatan
No full textTwenty kilovolts power distribution network system at East Java use high resistance (500 ?) grounding system that makes maximum single phase to ground fault current 25 Amperes. To detect this fault current, a Directional Ground Relay (DGR) is used. If a single phase to ground fault occurrs on Semolo feeder, then Gebanglor feeder and Srikana feeder which are supplied by the same bus with Semolo feeder (Nissin bus) will also trip (sympathetic trip). Sympathetic trip is caused by the total leakage current of arresters, transformers and low voltage panels on Gebanglor feeder dan Srikana feeder which is more than 2 Amperes (tap current setting of DGR is 2 Amperes). After maintenance, the total leakage current of the arresters on Gebanglor feeder is 0.046 Amperes and Srikana feeder is 0.026 Amperes.
Abstract in Bahasa Indonesia :
Sistem distribusi tenaga listrik 20 kV di Jawa Timur menggunakan sistem pentanahan dengan tahanan tinggi 500 Ohm sehingga arus gangguan satu fasa ke tanah maksimum adalah sebesar 25 Ampere. Untuk mendeteksi arus gangguan ini digunakan DGR (Directional Ground Relay). Apabila pada penyulang Semolo terjadi gangguan satu fasa ke tanah, maka penyulang Gebanglor dan Srikana yang dicatu dari bus yang sama dengan penyulang Semolo (bus Nissin) juga ikut trip (sympathetic trip). Penyebab terjadinya sympathetic trip adalah arus total kebocoran dari arrester, body trafo dan body panel TR GTT pada penyulang Gebanglor dan Srikana yang melebihi tap setting arus DGR sebesar 2 Ampere. Setelah dilakukan perbaikan, arus total kebocoran arrester pada penyulang Gebanglor menjadi sebesar 0.046 Ampere dan penyulang Srikana sebesar 0.026 Ampere.
Kata kunci: penyulang, gangguan satu fasa ke tanah, sympathetic trip, dan directional ground relay
Simulation of Active Filtering Applied to A Computer Centre
No full textIn this paper, the implementation of a shunt active power filter with a small series reactor for a three-phase system is presented. The system consists of computer loads, which are harmonic voltage sources, with significant unbalanced components. The filter consists of a three-phase current-controlled voltage source inverter (CC-VSI) with a filter inductance at the AC output and a DC-bus capacitor. The CC-VSI is operated to directly control the AC grid current to be sinusoidal and in phase with the grid voltage. The simulation results indicate that the filter along with the series reactor is able to handle the harmonic voltage sources, as well as the unbalance, so that the grid currents are sinusoidal, in phase with the grid voltages and symmetrical.
Abstract in Bahasa Indonesia :
Dalam makalah ini dijelaskan tentang penggunaan filter aktif type paralel dengan menggunakan reaktor kecil yang dipasang secara seri untuk sistem tiga phasa. Jaringan sistem ini menggunakan komputer sebagai beban yang merupakan sumber harmonisa tegangan; sekaligus menimbulkan ketidakseimbangan sistem. Filter daya aktif merupakan current-controlled voltage source inverter (CC-VSI) tiga phasa dengan sebuah filter induktansi pada keluaran AC dan sebuah kapasitor DC-bus. CC-VSI dioperasikan untuk mengendalikan secara langsung arus jala-jala AC menjadi sinusoidal dan sephasa dengan tegangan jala-jala. Hasil simulasi menunjukkan bahwa filter dengan reaktor seri mampu untuk mengatasi sumber harmonisa tegangan dan juga ketidakseimbangan beban sehingga gelombang arus menjadi sinusoidal, sephasa dengan tegangan jala-jala dan simetris
Katakunci: filter daya aktif, distorsi harmonik
Analisa Gangguan Satu Fasa ke Tanah yang Mengakibatkan Sympathetic Trip pada Penyulang yang tidak Terganggu di PLN APJ Surabaya Selatan
No full textTwenty kilovolts power distribution network system at East Java use high resistance (500 ?) grounding system that makes maximum single phase to ground fault current 25 Amperes. To detect this fault current, a Directional Ground Relay (DGR) is used. If a single phase to ground fault occurrs on Semolo feeder, then Gebanglor feeder and Srikana feeder which are supplied by the same bus with Semolo feeder (Nissin bus) will also trip (sympathetic trip). Sympathetic trip is caused by the total leakage current of arresters, transformers and low voltage panels on Gebanglor feeder dan Srikana feeder which is more than 2 Amperes (tap current setting of DGR is 2 Amperes). After maintenance, the total leakage current of the arresters on Gebanglor feeder is 0.046 Amperes and Srikana feeder is 0.026 Amperes.
Abstract in Bahasa Indonesia :
Sistem distribusi tenaga listrik 20 kV di Jawa Timur menggunakan sistem pentanahan dengan tahanan tinggi 500 Ohm sehingga arus gangguan satu fasa ke tanah maksimum adalah sebesar 25 Ampere. Untuk mendeteksi arus gangguan ini digunakan DGR (Directional Ground Relay). Apabila pada penyulang Semolo terjadi gangguan satu fasa ke tanah, maka penyulang Gebanglor dan Srikana yang dicatu dari bus yang sama dengan penyulang Semolo (bus Nissin) juga ikut trip (sympathetic trip). Penyebab terjadinya sympathetic trip adalah arus total kebocoran dari arrester, body trafo dan body panel TR GTT pada penyulang Gebanglor dan Srikana yang melebihi tap setting arus DGR sebesar 2 Ampere. Setelah dilakukan perbaikan, arus total kebocoran arrester pada penyulang Gebanglor menjadi sebesar 0.046 Ampere dan penyulang Srikana sebesar 0.026 Ampere.
Kata kunci: penyulang, gangguan satu fasa ke tanah, sympathetic trip, dan directional ground relay
Pengaruh Ketidakseimbangan Beban Terhadap Arus Netral dan Losses pada Trafo Distribusi
No full textThe unbalanced load in electric power distribution system always happen and it is caused by single phase loads on low voltage system. The effect of the unbalanced load is appear as a neutral current. These neutral current cause losses, those are losses caused by neutral current in neutral conductor on distribution transformers and losses caused by neutral current flows to ground. In conclusion, when high unbalanced load happened (28,67%), then the neutral current that appear is also high (118,6 A), ultimately the losses that caused by the neutral current flows to ground will be high too (8,62%).
Abstract in Bahasa Indonesia :
Ketidakseimbangan beban pada suatu sistem distribusi tenaga listrik selalu terjadi dan penyebab ketidakseimbangan tersebut adalah pada beban-beban satu fasa pada pelanggan jaringan tegangan rendah. Akibat ketidakseimbangan beban tersebut muncullah arus di netral trafo. Arus yang mengalir di netral trafo ini menyebabkan terjadinya losses (rugi-rugi), yaitu losses akibat adanya arus netral pada penghantar netral trafo dan losses akibat arus netral yang mengalir ke tanah. Setelah dianalisa, diperoleh bahwa bila terjadi ketidakseimbangan beban yang besar (28,67%), maka arus netral yang muncul juga besar (118,6A), dan losses akibat arus netral yang mengalir ke tanah semakin besar pula (8.62%).
Kata kunci: ketidakseimbangan beban, arus netral, losses
Pengaruh Ketidakseimbangan Beban Terhadap Arus Netral dan Losses pada Trafo Distribusi
No full textThe unbalanced load in electric power distribution system always happen and it is caused by single phase loads on low voltage system. The effect of the unbalanced load is appear as a neutral current. These neutral current cause losses, those are losses caused by neutral current in neutral conductor on distribution transformers and losses caused by neutral current flows to ground. In conclusion, when high unbalanced load happened (28,67%), then the neutral current that appear is also high (118,6 A), ultimately the losses that caused by the neutral current flows to ground will be high too (8,62%).
Abstract in Bahasa Indonesia :
Ketidakseimbangan beban pada suatu sistem distribusi tenaga listrik selalu terjadi dan penyebab ketidakseimbangan tersebut adalah pada beban-beban satu fasa pada pelanggan jaringan tegangan rendah. Akibat ketidakseimbangan beban tersebut muncullah arus di netral trafo. Arus yang mengalir di netral trafo ini menyebabkan terjadinya losses (rugi-rugi), yaitu losses akibat adanya arus netral pada penghantar netral trafo dan losses akibat arus netral yang mengalir ke tanah. Setelah dianalisa, diperoleh bahwa bila terjadi ketidakseimbangan beban yang besar (28,67%), maka arus netral yang muncul juga besar (118,6A), dan losses akibat arus netral yang mengalir ke tanah semakin besar pula (8.62%).
Kata kunci: ketidakseimbangan beban, arus netral, losses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Investigation on Voltage Quality Problems on the Process of Cement Industry Production in Indonesia: A Case Study of Cement Kupang Factory - Indonesia
No full textThe decline in the quality of electric power becomes a serious problem in the industrial sector and affects a significant cost loss. One of the dominant power quality problems is the voltage dip. The use of electric motors in an industry becomes one of the main causes. This paper discusses the investigation on voltage dip problems at a cement factory at Kupang,, Indonesia. The cement factory uses an induction motor as the prime mover and is proven to trigger a voltage dip because of its high starting current. Based on the observed data of the disturbance, a single line diagram was created. The single line diagram was analyzed using an equivalent circuit. It was found out that as the induction motor was started, it created a very significant voltage drop as of 20.43 % to 62.26 %. The voltage dip correlated to the capacity of the induction motor used. The larger the capacity of the induction motor, the larger the voltage dip occured
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