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Peredaman Harmonisa Beban Rumah Tangga dengan Low Pass Filter LCL
No full textNearly 90% of the household electrical load today uses either electronic load or non-linear load. The use of non-linear load includes energy-saving lights, televisions, radio-tape recorders, computers, printers, chargers, air-conditioners, and other electro-domestic equipment. This non-linear load will cause harmonics. The objective of the research was to identify filter design by calculating Low Pass Filter LCL parameters and to filter harmonics which was caused by household equipment, according to IEC 61000-302 standard. The result of the measurement on household load in THDi was 32.2% with the power factor of 0.88. By using Matlab/simulink program, it was found that harmonics, soaked in Low Pass Filter LCL with Total harmonic Distortion, was decreased to 4.91% and the power factor was increased to 0.894; all individual harmonic values would meet the IEC 61000-3-2 standard.Sebagian besar pemakaian beban listrik rumah tangga di masyarakat saat ini hampir 90% memakai beban elektronika atau beban non linier. Pemakaian beban non linier diantaranya lampu hemat energi, televisi, radio-tape, komputer, printer, charger, pendingin ruangan dan peralatan electro domestics. Beban non linier tersebut merupakan beban yang menimbulkan harmonisa. Hasil pengukuran beban rumah tangga dengan THDI sebesar 32,2% dan faktor daya 0,88. Dengan memanfaatkan program Matlab/simulink dapat diperlihatkan bahwa harmonisa diredam oleh Low pass filter LCL sehingga Total Harmonic Distortion (THDI) diturunkan menjadi 4,91% dan factor daya naik menjadi 0,894, sehingga semua nilai harmonisa individu sudah sesuai standar IEC 61000-3-2.82 HalamanTesis Magiste
Analisis Penggunaan Dstatcom untuk Mengurangi Fluktuasi Tegangan yang Disebabkan oleh Tanur Busur Listrik Ac
No full textEAF (Electric Arc Furnace) is a non-linear load with rapid change of load causes
voltage fluctuations and flicker when connected to a weak electrical system.
Harmonics on the EAF is caused by the voltage-current characteristic is very
nonlinear from electric arc in each power cycle, whereas the voltage fluctuations
caused by electrical arc length change during smelting. Flicker is a voltage
fluctuation with changes in voltage amplitude of more than 0.5% in the frequency
range 3 ÷ 10 Hz, especially in the light of incandescent lamp cause discomfort to the
vision and provide a psychological effect on humans.
Phase shift between voltage and current caused by the furnace transformer
inductance and cable inductance resulted in an inductive reactive component which
becomes the load on the system causing the voltage source falls and fluctuates due to
rapid load changes. DSTATCOM, a VSC-based FACTS devices with capacitors on
the dc side are dynamically able to generate or absorb reactive power at the ac
system to improve voltage stability.
By using the European standard CENELEC EN 50160, the estimated flicker value
for the operation of the EAF no.1 in PT. Growth Sumatra Industry is Pst95%=3.9 ÷ 6.7
which has exceeded the flicker limit PstLimit=0.79 [ENRE 99/97]. DSTATCOM is
designed with a nominal power of +/- 12 MVAR to be installed on the steelwork
busbar EAF no.1 and modeled for the simulated use of Matlab / Simulink Power
System Blockset (PSB). With the criteria for evaluating %Flicker =
V / V x100 % base Δ , fluctuation of voltage amplitude at the PCC of +/-1.89% can be
reduced to +/-0.12%.EAF (Electric Arc Furnace) adalah beban non-linear dengan perubahan beban
yang cepat menyebabkan fluktuasi tegangan dan flicker bila terhubung pada sistem
kelistrikan yang lemah. Harmonisa pada EAF disebabkan oleh karakteristik teganganarus
yang sangat non-linear dari busur listrik pada setiap siklus daya, sedangkan
fluktuasi tegangan disebabkan oleh perubahan panjang busur listrik selama peleburan.
Flicker adalah fluktuasi tegangan dengan perubahan amplitudo tegangan lebih dari
0.5% pada rentang frekuensi 3 ÷ 10Hz, khususnya pada cahaya lampu pijar
menyebabkan ketidaknyamanan pada penglihatan dan memberikan efek psikologis
terhadap manusia.
Pergeseran fasa antara tegangan dan arus yang disebabkan oleh induktansi
transformator tanur dan induktansi kabel mengakibatkan munculnya komponen
reaktif induktif yang menjadi beban pada sistem sehingga menyebabkan tegangan
sumber jatuh dan berfluktuasi karena perubahan beban yang cepat. DSTATCOM
merupakan peranti FACTS berbasis VSC dengan kapasitor pada sisi dc secara
dinamis mampu untuk membangkitkan ataupun menyerap daya reaktif pada sistem ac
untuk meningkatkan kestabilan tegangan.
Dengan memakai standar Eropa CENELEC EN 50160, estimasi nilai flicker untuk
pengoperasian EAF no.1 di PT. Growth Sumatra Industry adalah Pst95%=3.9 s/d 6.7
yang telah melampaui batas emisi flicker PstLimit=0.79 [ENRE 99/97]. Kompensator
DSTATCOM dirancang dengan daya nominal +/-12MVAR untuk dipasangkan pada
steelwork busbar EAF no.1 dan dimodelkan untuk disimulasikan memanfaatkan
program Matlab/Simulink Power System Blockset (PSB). Dengan kriteria untuk
mengevaluasi %Flicker = V /V x100 % base Δ , fluktuasi amplitudo tegangan pada
PCC sebesar +/-1.89% dapat dikurangi menjadi +/-0.12%.120 HalamanTesis Magiste
Analisa Dampak Harmonisa terhadap Transformator Distribusi dan Kerugian Finansial
No full textThe increasing development of technology today, bringing the changing pattern of human life in performing daily activities, including in terms of completing tasks that they were not separated from the use of assistive devices. Tools used such as computers and other office equipment which is generally formed from the components of power electronics. A variety of application equipment almost entirely using power electronics components, such as equipment used in offices; industrial and residential. On the other hand, the energy crisis triggered increased use of Energy Saving Lamps (ESL). Though the computer; Bulb Low Energy and equipment that uses power electronics components is a type of non-linear loads, which became the cause of harmonics that can interfere with the distribution system including distribution transformer. To find out how big the influence of non-linear loads on the value of total harmonic distortion and financial losses caused by it required data. Through the method of direct measurement on the secondary transformer in the complex field Multatuli Business (BMM), obtained data showing that both the voltage and current harmonics due to load there. Once analyzed, found that the greater the impact loading on the transformer increased the total harmonic distortion (THDi), and energy losses. Energy losses that occur due to harmonics in one year is estimated at 52,925.91 kWh, which led to financial losses due to harmonics that are not readable by the kWh meter in one year is estimated to reach Rp 58,218,502.62 or about 15.127% of the value total bill per year.Meningkatnya perkembangan teknologi saat ini, membawa perubahan pola kehidupan manusia dalam melakukan aktivitas sehari-hari, termasuk dalam hal menyelesaikan tugas-tugasnya yang semuanya itu tidak terlepas dari penggunaan alat bantu. Alat bantu yang digunakan diantaranya seperti komputer serta peralatan kantor lainnya yang umumnya terbentuk dari komponen elektronika daya. Berbagai peralatan aplikasi hampir seluruhnya menggunakan komponen elektronika daya. Seperti peralatan-peralatan yang digunakan di perkantoran; industri maupun rumah tinggal. Di sisi lain, krisis energi menjadi pemicu meningkatnya penggunaan Lampu Hemat Energi (LHE). Padahal komputer; LHE dan peralatan-peralatan yang menggunakan komponen elektronika daya adalah merupakan jenis beban non-linier, yang menjadi penyebab terjadinya harmonisa yang dapat mengganggu sistem distribusi termasuk transformator distribusi. Untuk mengetahui seberapa besar pengaruh beban non linier terhadap nilai total distorsi harmonisa dan kerugian finansial yang disebabkannya diperlukan data. Melalui metode pengukuran langsung pada sekunder transformator di kompleks Bisnis Multatuli Medan (BMM), diperoleh data yang menunjukkan bahwa baik tegangan maupun arus akibat beban terdapat harmonisa. Setelah dianalisa, diperoleh bahwa semakin besar pembebanan pada transformator memberi dampak meningkatnya distorsi harmonisa total (THDi), dan rugi-rugi energi. Rugi-rugi energi yang terjadi akibat harmonisa dalam satu tahun diperkirakan mencapai 52.925,91 kWh, yang menyebabkan terjadinya rugi-rugi finansial akibat harmonisa yang tidak terbaca oleh kWh meter dalam satu tahun diperkirakan mencapai Rp 58.218.502,62 atau berkisar 15,127% dari nilai tagihan total per tahun.79 HalamanTesis Magiste
Analisis Penempatan Optimal Bank Kapasitor pada Sistem Distribusi Radial dengan Metode Genetik Algorithm \Aplikasi : PT. PLN (Persero) Cabang Medan
No full textWith time development, the need for electricity is increasingly high. The amount of
reactive power (Q) will result in a non-optimal power distribution, because a big
apparent power (S) will be needed to serve the increasing active power (P). To
optimize the consumption of electric power in radial distribution systems, the optimal
bank capacitor can be placed as reactive power compensation. In radial distribution
system, the reactive power compensation needed should be split into several buses
that the distribution of compensated rective power becomes more optimal, thus, the
optimal value of respective bank capacitor that will be placed in the system needs to
be determined. To set the rating and the optimal position of bank capacitor in the
radial distribution system, an analysis of power flow using an E.T.A.P 4.0 software
should be done first, where the out-put of power flow is the in-put to the process of
Genetic Algorithm. The Genetic Algorithm is used to find the optimal value of each
bank capacitor which will be placed in the buses which are randomly selected. The
optimal value of each bank capacitor found through the Genetic Algorithm is 1600
kVAR which is placed on: C1 = A = bus 1272; C2 = B = bus 1397; C3 = C = bus
1478 and C4
≥
= D = bus 1486 with the capacity of respective bank capacitor = 400
kVAR and the system voltage has reaced 95 % of nominal voltage.Seiring dengan perkembangan zaman, maka kebutuhaan terhadap energi listrik
semakin meningkat. Besarnya kebutuhan daya reaktif (Q) akan menyebabkan
penyaluran daya yang tidak optimal, karena akan dibutuhkan daya semu (S) yang
besar untuk melayani daya aktif (P) yang juga bertambah. Untuk mengoptimalkan
pemakaian daya listrik pada sistem distribusi radial dapat dilakukan dengan
penempatan optimal bank kapasitor sebagai kompensasi daya reaktif. Dalam sistem
distribusi radial kompensasi daya reaktif yang dibutuhkan, sebaiknya dibagi ke
beberapa bus agar penyebaran daya reaktif yang dikompensasikan lebih optimal
dengan demikian perlu ditentukan nilai optimal masing-masing bank kapasitor yang
akan ditempatkan pada sistem. Untuk menentukan rating dan letak optimal bank
kapasitor pada sistem distribusi radial terlebih dahulu dilakukan analisa aliran daya
dengan bantuan software E.T.A.P 4.0 dimana hasil out-put aliran daya merupakan
input pada proses Genetik Algorithm. Untuk menentukan rating dan letak optimal
bank kapasitor. Genetik Algorithm digunakan untuk mencari nilai optimal masing masing bank kapasitor yang akan ditempatkan pada bus yang dipilih secara acak..
Nilai optimal masing-masing bank kapasitor yang didapat dengan menggunakan
Genetik Algorithm adalah sebesar1600 kVAR yang diletakkan pada: C1 = A = bus
1272 ; C2 = B = bus 1397 ; C3 = C = Bus 1478 dan C4
≥
= D = Bus 1486 dengan
masing-masing kapasitas bank kapasitor = 400 kVAR dan tegangan sistem telah
mencapai 95 % dari tegangan nominal.244 HalamanTesis Magiste
Analisis Dampak Harmonisa terhadap Kinerja Rele Proteksi Arus Lebih Statis
No full textIn recent years, there has been an increase of using electronical devices.
Electric power or non-linear charge not only as a load but also as a control device
resulting the form of voltage and currents to become non siniusoidal in the power
system because the electronical power tools produce harmonisa.This research is
focused on static relay. The objective of the research is to analyze the impact of
harmonic on the accuracy of static relay operation in fulfilling the relay current-time
settings not only in the characteristic of inverse or definite but also instantaneous.
Static type over current protection relay is widely used to protect power transformers
and conductor of the over current disturbances and placed at the base of 20 kV
medium voltage distribution network. Static type relay is set up based on
fundamental current. This research benefits in finding out some interferences of
relay operation due to harmonic disturbances. Furthermore, it coordinates protection
between relay of time-current characteristics of both the reliability of the protected
equipment and other protective equipment in order to conduct appropriate
functioning.
The results shows that when the THDi increases, harmonic distorts the
current (It) and the fundamental current decreases eventhough it is not linear. It
flows inside the coils so that the relay trip goes faster than time setting for inverse
time-current characteristics (Standard Inverse, Very Inverse and Extremely Inverse).
For the characteristics of Definite and Instantaneous time setting, these harmonics do
not affect the relay trip time even though harmonic distorts the currents (It) flow in
the coil of relay trip, relay trip time fulfills the time setting. Therefore, it is
recommended that all non-linear load components of the power system should be
equipped with harmonic filter thus it can reduce harmonic up to THDi 5% and all
relays should be reset to cope with non-linear load conditions and protection
coordination of other available protection system.Tahun-tahun belakangan ini, terjadi peningkatan penggunaan peralatan
elektronika daya atau beban non linier baik sebagai beban maupun sebagai alat
kontrol yang mengakibatkan bentuk tegangan dan arus menjadi non siniusoidal di
dalam sistem tenaga karena peralatan tersebut memproduksi harmonisa. Arus yang
mengalir dalam kumparan trip rele adalah jumlah vektor arus fundamental dan arus
harmonisa disebut arus terdistorsi harmonisa atau arus total(It). Rele ada dua jenis
yaitu rele elektromekanis dan rele statis. Pada penelitian ini, rele yang diteliti jenis
statis. Adapun tujuan penelitian ini adalah untuk menganalisis dampak harmonisa
terhadap keakuratan operasi rele statis dalam memenuhi setelan arus-waktu rele baik
dalam karakteristik Inverse, Definite maupun dalam karakteristik Instantaneous. Rele
proteksi arus lebih jenis statis banyak digunakan untuk memproteksi transformator
daya dan penghantar dari gangguan arus lebih dan ditempatkan di pangkal jaringan
distribusi tegangan menengah 20 kV. Rele jenis statis di setting berdasarkan arus
fundamental. Penelitian ini bermanfaat untuk mengetahui adanya gangguan operasi
rele akibat harmonisa dan selanjutnya untuk melakukan koordinasi proteksi antara
karakeristik arus-waktu rele baik terhadap ketahanan alat yang diproteksi mampu
dengan alat proteksi lainnya agar dapat melaksanakan fungsi proteksinya dengan
tepat.
Adapun hasil penelitian ini adalah THDi naik maka arus terdistorsi harmonisa
(It) bertambah dan arus fundamental menurun sekalipun tidak linier. It ini mengalir
didalam kumparan trip rele sehingga rele trip lebih cepat dari pada waktu trip setting
untuk karakteristik arus-waktu inverse (Standard Inverse, Very Inverse dan
Extremely Inverse). Untuk karakteristik arus-waktu Definite dan Instantaneous,
harmonisa ini tidak mempengaruhi waktu trip rele yaitu sekalipun arus terdistorsi
harmonisa (It) mengalir dalam kumparan trip rele, waktu trip rele memenuhi waktu
setting. Karena itu disarankan supaya semua komponen beban non linier sistem
tenaga dilengkapi filter harmonisa sehingga harmonisa dikurangi menjadi THDi ≤ 5%
dan dilakukan penyetelan ulang semua rele untuk menyesuaikan dengan kondisi
beban non linier dan koordinasi proteksi dengan sistem proteksi yang ada.196 HalamanTesis Magiste
Analisis Dampak Harmonisa terhadap Kinerja Rele Proteksi Arus Lebih Statis
No full textIn recent years, there has been an increase of using electronical devices.
Electric power or non-linear charge not only as a load but also as a control device
resulting the form of voltage and currents to become non siniusoidal in the power
system because the electronical power tools produce harmonisa.This research is
focused on static relay. The objective of the research is to analyze the impact of
harmonic on the accuracy of static relay operation in fulfilling the relay current-time
settings not only in the characteristic of inverse or definite but also instantaneous.
Static type over current protection relay is widely used to protect power transformers
and conductor of the over current disturbances and placed at the base of 20 kV
medium voltage distribution network. Static type relay is set up based on
fundamental current. This research benefits in finding out some interferences of
relay operation due to harmonic disturbances. Furthermore, it coordinates protection
between relay of time-current characteristics of both the reliability of the protected
equipment and other protective equipment in order to conduct appropriate
functioning.
The results shows that when the THDi increases, harmonic distorts the
current (It) and the fundamental current decreases eventhough it is not linear. It
flows inside the coils so that the relay trip goes faster than time setting for inverse
time-current characteristics (Standard Inverse, Very Inverse and Extremely Inverse).
For the characteristics of Definite and Instantaneous time setting, these harmonics do
not affect the relay trip time even though harmonic distorts the currents (It) flow in
the coil of relay trip, relay trip time fulfills the time setting. Therefore, it is
recommended that all non-linear load components of the power system should be
equipped with harmonic filter thus it can reduce harmonic up to THDi 5% and all
relays should be reset to cope with non-linear load conditions and protection
coordination of other available protection system.Tahun-tahun belakangan ini, terjadi peningkatan penggunaan peralatan
elektronika daya atau beban non linier baik sebagai beban maupun sebagai alat
kontrol yang mengakibatkan bentuk tegangan dan arus menjadi non siniusoidal di
dalam sistem tenaga karena peralatan tersebut memproduksi harmonisa. Arus yang
mengalir dalam kumparan trip rele adalah jumlah vektor arus fundamental dan arus
harmonisa disebut arus terdistorsi harmonisa atau arus total(It). Rele ada dua jenis
yaitu rele elektromekanis dan rele statis. Pada penelitian ini, rele yang diteliti jenis
statis. Adapun tujuan penelitian ini adalah untuk menganalisis dampak harmonisa
terhadap keakuratan operasi rele statis dalam memenuhi setelan arus-waktu rele baik
dalam karakteristik Inverse, Definite maupun dalam karakteristik Instantaneous. Rele
proteksi arus lebih jenis statis banyak digunakan untuk memproteksi transformator
daya dan penghantar dari gangguan arus lebih dan ditempatkan di pangkal jaringan
distribusi tegangan menengah 20 kV. Rele jenis statis di setting berdasarkan arus
fundamental. Penelitian ini bermanfaat untuk mengetahui adanya gangguan operasi
rele akibat harmonisa dan selanjutnya untuk melakukan koordinasi proteksi antara
karakeristik arus-waktu rele baik terhadap ketahanan alat yang diproteksi mampu
dengan alat proteksi lainnya agar dapat melaksanakan fungsi proteksinya dengan
tepat.
Adapun hasil penelitian ini adalah THDi naik maka arus terdistorsi harmonisa
(It) bertambah dan arus fundamental menurun sekalipun tidak linier. It ini mengalir
didalam kumparan trip rele sehingga rele trip lebih cepat dari pada waktu trip setting
untuk karakteristik arus-waktu inverse (Standard Inverse, Very Inverse dan
Extremely Inverse). Untuk karakteristik arus-waktu Definite dan Instantaneous,
harmonisa ini tidak mempengaruhi waktu trip rele yaitu sekalipun arus terdistorsi
harmonisa (It) mengalir dalam kumparan trip rele, waktu trip rele memenuhi waktu
setting. Karena itu disarankan supaya semua komponen beban non linier sistem
tenaga dilengkapi filter harmonisa sehingga harmonisa dikurangi menjadi THDi ≤ 5%
dan dilakukan penyetelan ulang semua rele untuk menyesuaikan dengan kondisi
beban non linier dan koordinasi proteksi dengan sistem proteksi yang ada.196 HalamanTesis Magiste
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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