Teknik dan Tenaga dan Listrik

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Dasar Teknik Tenaga Listrik

( 3 SKS )

Semester Genap 2009/2010 Prodi Teknik Elektro

Tujuan

Mengenal sistem tenaga listrik dari

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Syllabi

Mengenal generator / mesin serempak & memahami prinsip kerjanya

Mengenal beberapa penggerak mula

Mengenal saluran transmisi, saluran distribusi, trafo arus dan trafo tegangan

Mengenal transformator & dapat mengoperasikannya. Mengenal mesin tak serempak & dapat

mengoperasikannya

Mengenal mesin arus searah dan dapat mengoperasikannya

Mengenal berbagai macam beban listrik

Pola Perkuliahan

1 x 2 jam perkuliahan per pertemuan Laboratorium

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Sistem Penilaian

Ujian Akhir semester: 60% Ujian Tengah Semester: 40%

Grade : A = 80 – 100 B = 79 - 70 C = 69 - 55 D = 54.5 - 45 E = 44.5 - 0

Text Book

Stephen J. Chapman,”Electric Mchinery

Fundamental”, McGraw Hill 2001

Fitzgerald “ Electric machinery, 6th _ed “,Mc Graw hill 2003

Kilian, Modern Control Technology; Components and Systems, 2nd_edition_,

Delmar PUIL 2000

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Introduction

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Salah satu cara yang paling ekonomis,

mudah dan aman untuk mengirimkan energi adalah melalui bentuk energi listrik.

Pada pusat pembangkit, sumberdaya energi primer seperti bahan baker fosil (minyak, gas alam, dan batubara), hidro, panas bumi, dan nuklir diubah menjadi energi listrik.

Generator sinkron mengubah energi mekanis yang dihasilkan pada poros turbin menjadi energi listrik.

Melalui transformator penaik tegangan (step-up transformer), energi listrik ini kemudian dikirimkan melalui saluran transmisi bertegangan tinggi menuju pusat-pusat beban.

Peningkatan tegangan dimaksudkan untuk

mengurangi jumlah arus yang mengalir pada saluran transmisi yang dengan demikian berarti rugi-rugi panas (heat-loss) I2Rdapat dikurangi.

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Di pusat-pusat beban yang terhubung dengan saluran distribusi, energi listrik ini diubah menjadi bentuk-bentuk energi terpakai lainnya seperti energi mekanis (motor),

penerangan, pemanas, pendingin, dan sebagainya.

Satuan listrik

Arus listrik (I) => ampere

Tegangan listrik (V) = beda potensial => volt

Tahanan (R) = resistansi => ohm

Reaktansi (X) => ohm

Impedansi (Z)= R ± jX => ohm

Daya (S) = P ± jQ => volt ampere

Daya aktif (P) => watt

Daya reaktif (Q) => volt ampere reaktif

Energi (E) => watt-hour (watt-jam)

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Pembangkit listrik

Pusat Listrik Tenaga Uap (PLTU)

Pembangkit listrik

Pusat Listrik Tenaga Uap (PLTU)

A coal-fired power plant in Laughlin, Nevada U.S.A. Owners of this plant ceased operations

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Pembangkit listrik

Pusat Listrik Tenaga Air (PLTA)

Pembangkit listrik

Pusat Listrik Tenaga Air (PLTA)

Large dams such as Three Gorges Dam in China can provide large amounts of hydroelectricpower; it will have

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Pembangkit listrik

Pusat Listrik Tenaga Gas (PLTG)

Pembangkit listrik

Pusat Listrik Tenaga Gas (PLTG)

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Pembangkit Listrik

PLTGU

Pembangkit Listrik

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Pembangkit Listrik

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Pembangkit Listrik

Pembangkit Listrik Tenaga Nuklir ( PLTN )

Susquehanna Steam Electric Station, a nuclear power plant.

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Renewable energy

Solar

Renewable energy

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Renewable energy

Wind

Renewable Energy

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Renewable energy

Biomass

Renewable energy

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Transmisi

Summary

Listrik adalah cara yang paling efektif untuk mentransmisikan energi.

Untuk memperoleh energi listrik dapat

dibangkitkan dengan banyak cara, antara lain dengan cara konvensional ( fossil fuel ) atau

dengan menggunakan renewale energy

Tanpa energi listrik banyak peralatan yg tidak berfungsi, sehingga penting menjaga

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Lecture 1

Generator principles ( part 1 )

Material

Basic concept of electrical machines fundamentals: Rotational component measurements

Angular Velocity, Acceleration Torque, Work, Power

Newton’s Law of Rotation

Magnetic Field study

Production of a Magnetic Field Magnetic Circuits

Magnetic Behaviour of Ferromagnetic Materials How magnetic field can affect its surroundings:

Faraday’s Law – Induced Voltage from a Time-Changing Magnetic Field.

Production of Induced Force on a Wire.

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Introduction

Mesin-mesin listrik peralatan yang merubah energi mekanik menjadi energi listrik atau sebaliknya.

Energi Mekanik energi listrik : GENERATOR

Energi Listrik Energi Mekanik : MOTOR

Perubahan energi pada motor & generator melalui Medan Magnetis.

Basic concept of electrical machines

fundamentals

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Rotational Motion, Newton’s Law

and Power Relationship

Angular position, ( Posisi Sudut )

Adalah posisi sudut yang diukur dari suatu titik referensi.

Satuan nya adalah radians (rad) atau Derajat / degrees.

Konsep yang sama dengan posisi / jarak

Rotational Motion, Newton’s Law

and Power Relationship

Angular Velocity,

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Rotational Motion, Newton’s Law

and Power Relationship

Angular acceleration,

adalah perubahan kecepatan sudut terhadap waktu

Rotational Motion, Newton’s Law

and Power Relationship

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Rotational Motion, Newton’s Law

and Power Relationship

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Rotational Motion, Newton’s Law

and Power Relationship

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Rotational Motion, Newton’s Law

and Power Relationship

Case Study

Rotational Motion, Newton’s Law

and Power Relationship

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Rotational Motion, Newton’s Law

and Power Relationship

Case Study

Basic concept of electrical machines

fundamentals

Medan magnet adalah mekanisme mendasar mana energi diubah dari satu bentuk kebentuk

lain dalam motor, generator dan transformer.

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Basic concept of electrical machines

fundamentals

Production of a Magnetic Field

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Magnetic Field study • Magnetic Circuit

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

• Magnetic Circuit ( Contoh Soal )

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Basic concept of electrical machines

fundamentals

Magnetic Behaviour of Ferromagnetic Materials

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Basic concept of electrical machines

fundamentals

Energy Losses in a Ferromagnetic Core

Hysteresis Loss

Basic concept of electrical machines

fundamentals

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Basic concept of electrical

machines fundamentals

How magnetic field can affect its surroundings:

Faraday’s Law – Induced Voltage from a Time-Changing Magnetic Field.

‘If a flux passes through a turn of a coil of wire, voltage will be induced in the turn of the wire that is directly proportional to the rate of change in the flux with respect of time’

dt

d

e

_ind

=

−

φ

dt

d

N

e

_ind

=

−

φ

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Basic concept of electrical machines

fundamentals

How magnetic field can affect its surroundings:

Production of Induced Force on a Wire.

Basic concept of electrical

machines fundamentals

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Basic concept of electrical machines

fundamentals

Production of Induced Force on a Wire.

Basic concept of electrical

machines fundamentals

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Basic concept of electrical machines

fundamentals

The Linear DC Machine

Linear DC machine is the simplest form of DC machine which is easy to understand and it operates according to the same principles and exhibits the same behaviour as motors and generators.

Consider the following:

V_B

Switch

R

e_ind+ -B

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Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

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Basic concept of electrical machines

fundamentals

Contoh soal

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Basic concept of electrical machines

fundamentals

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Bilangan Kompleks K = a + jb

Metode Euler

ej _{= (cos + j sin )}

Bentuk Polar

K = a + jb = |K| < = (a2 _+b2₎1/2 _<tan-1_(b/a)

Sinyal Sinus/Cosinus

V(t) = V_m(Sin t) = V_m< 0

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Beban Resistif

I(t) = I_m. Sin ( t + ø) V(t) = R I(t)

= R I_mSin ( t + ø) V_m= R I_m

Tegangan sefasa dengan arus

Beban Induktif

I(t) = I_m. Sin ( t + ø) V_L(t) = L dI(t)/dt

= L Imd/dt {Sin( t + ø)} = L I_mCos( t + ø)

= L I_mSin( t + ø + 90o₎

V_L(t) = L I_mSin( t + ø + 90o₎

= V_mSin( t + ø + 90o_{) = V}

m<90o

V_m= L I_m

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Beban Kapasitif

V(t) = V_m. Sin ( t + ø) Ic(t) = C dV(t)/dt

= C V_md/dt {Sin( t + ø)}

= C VmCos( t + ø) = C VmSin( t + ø + 90o)

I_L(t) = C V_m Sin( t + ø + 90o₎

= I_mSin( t + ø + 90o_{) = I}

m<90o

I_m= C V_m

ARUS mendahului TEGANGAN

IMPEDANSI

Z = R + j X = R + j (X_L- X_C) Bentuk Polar

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Daya Rata-rata

p = v.i

Daya rata-rata = V_rms. I_rmsCos ø Tegangan efektif =

V_rms = V_m/(2)1/2

Arus Efektif =

I_rms = I_m/(2)1/2

Daya Kompleks

S = P + JQ = |S|<

S = Daya Semu = Volt.Ampere = VA P = Daya Nyata/Aktif = Watt

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Rangkaian tiga phase memiliki sumber tegangan tiga phase.

Beda phase antara phase yang satu dengan phase yang lain adalah 120 atau

Tegangan 3Ø di atas dapat dinyatakan dalam fungsi waktu sebagai berikut : Ea = Em sin wt

Eb = Em sin (wt - 2 /3) Ec = Em sin (wt - 4 /3)

fungsi-fungsi waktu diatas diubah ke bentuk imaginer: Ea = E

Eb = E(cos 2 /3 - j sin 2 /3) Ec = E(cos 4 /3 – j sin 4 /3 )

Hubungan antara tegangan Y dan tegangan

1. Eab = Ea – Eb

= E - E(cos 2 /3 - j sin 2 /3) = E(1 - (cos 2 /3 - j sin 2 /3) ) 1 - (cos 2 /3 - j sin 2 /3) =1 –( - ½ - j

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/6 (rad)

Arus 3Ø diatas dapat dinyatakan dalam bentuk fungsi waktu,sebagai berikut: Iab = Im sin wt

Ibc = Im sin (wt-2 /3) Ica = Im sin (wt-4 /3)

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Hubungan antara arus Y dan arus 1. Ia =Iab - Ibc

= I - I(cos 2 /3 - j sin 2 /3) = I (1 - (cos 2 /3 - j sin 2 /3) ) 1 - (cos 2 /3 - j sin 2 /3) =1 –( - ½ - j

½ ½ Jadi

Ia = 3 I = 3 Iab

maka dapat disimpulkan arus Y = 3 arus dan phasenya tertinggal sebesar /6 (rad)

sunber tegangan Y dan impedansi beban Y

Karena tegangan antara n dan n‘ adalah nol, kita dapatkan persamaan – persamaan :

Ea = Z Ia Eb = Z Ib Ec = Z Ic Atau

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Sumber tegangan dan impedansi beban

Pesamaan –persamaan dari gambar sebagai berikut : Eab = Z Iab

Ebc = Z Ibc Eca = Z Ica Atau

Iab = Eab / Z Ibc = Ebc / Z Ica = Eca / Z

Konversi impedansi antara hubungan dan Y

Z ‘ = Z . Z = 1 Z Z+Z+Z 3

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3-Phase Circuits

Balanced 3-phase

Balanced Complex Numbers

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Balanced Complex Numbers

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Balanced Complex Numbers

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Balanced Complex Numbers

It is evident from above that the sum of any three roots of the cube-root of any complex number is absolutely zero.

This is the essence of a balanced three phase system and indeed the most powerful tool in power transmission.

The results below are self-evident.

Balanced Complex Numbers

Consider a general complex number z

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Balances 3-phase Currents

Let us use the above discovery and KCL:

Suppose we have three currents such that

Balances 3-phase Currents

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Balances 3-phase Currents

Advantages of balanced 3-phase

supply

1.The elimination of a neutral wire is clearly the biggest saving.

2. If we wanted to supply the same amount of power using single phases, we would have used 6 wires! But we have managed with just 3 of them.

3. The fact that line voltages are higher means

that the line currents are lower hence reduced losses.

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Line & Phase Values

In practice, when a 3-phase system is used, we do have both the currents & voltages as 3-phase. Their values may be given as phase or line values.

Let us consider a balanced 3-phase voltage system.

Just as we did in the case of currents, the voltage is given by:

Line & Phase Values

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Line & Phase Values

It is however usual to measure voltage

between one phase & another phase. So the value is that of one phase with respect to the other. Since it is measured between one phase & another it is referred as the ‘line voltage’.

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Phasors for Phase & Line Voltages

Phase & Line Voltages

The following conclusions are made:

1. The line voltages also constitute a balanced 3-phase system.

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Line & Phase Values

Please note that:

1. In a 3-phase system; the line values (voltage & current) are the ones specified. 2. It is very dangerous to touch any two line wire (because of much higher voltages). 3. All values are rms.

4. Red, Yellow, Blue represent .

v

₁

,

v

₂

,

v

₃

Line & Phase Values

While it is easy to identify phase & line voltages; caution is taken on phase & line currents.

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Star & Delta 3-ph representation

There are two distinct ways of representing 3-phase voltages/currents;

Star or Delta. [Star is sometimes called Wye]. Let us re-draw the phasors for 3-phase

voltages.

Star & Delta 3-ph representation

Phasors

1

v

2

v

3

v

1

v

2

v

3

v

Star

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Star & Delta 3-ph connections

Power connections

1

It is noted that:

A Star connection has a neutral point (n) and can be accessed when need arises. But the Delta connection does not have one.

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Star-Star connection

Supply-load connections

1

i

supply Load

n n

2

i

3

i

Star-Delta connection

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Line & Phase currents

In the star connection; the line current=phase current.

But in Delta connection; the line current DOES NOT equal to phase current e.g.

But we may use KCL to find the relationships between line and phase currents.

1

Power in 3-phase

We know that is 1-phase;

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3-phase Exercises

3-phase exercises

Exercise 3:

A 0.6MW, 416V, 3-phase, 50Hz load has a power factor of 0.5.

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Solution 1

The 3-phase voltages differ by angle only:

)

Solution 2

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Solution 3

The power factor improvement is done by connecting a capacitor between @ phase & the neutral point.

[Though it is possible to connect a capacitor between phases but then the capacitors are more expensive because of the higher (line) voltages].

Star-Star connection

1

i

Supply Load

n _n

2

i

C

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Solution 3

Since @ capacitor is connected across a phase & neutral; phase voltages must be used.

We are at liberty to use the phasor diagram studied earlier.

Solution 3

1

Ι

θ

φ

c

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Solution 3

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Solution 3

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Question 4

A 440V, 3-ph, Y-connected source has two loads connected as:

One load is balanced in @ phase with Z=10+j5.

The second load is balanced in @ phase with Z=15+j0.

(i) Find the average power to @ load. (ii) Find the total power delivered.

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Total load =(10+j5)+(15+j0)=25+j5=Z

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Soal 1

Diket A = 5 + j3 dan B = 8 300

Hitung;

1. A + B

2. A – B

3. A * B

4. A / B

Dalam bentuk vektor dan komplexs

Soal 2

2 buah watt meter dipasang pada supply dengan system 3 kawat 3 phase. Jika

tegangan beban 400 V dan arus 20 A, hitung

A. Pembacaan watt meter saat faktor daya = 1

B. Pembacaan watt meter saat faktor daya = 0.5

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Soal 3

Suatu sistem 3 phase 4 kawat mempunyai beban Za = 10L00 _{, Zb = 20L30}0_{dan Zc =}

10L-300 _{. Beban tersebut dihubungkan}

bintang dan disupply tegangan 400 V, 50 Hz. Hitung arus yang mengalir pada masing-masing fasa dan arus netralnya.

Soal 4

Sistem 400 Volt ( fasa ke fasa ), 3 fasa, 50 Hz mensupply beban yang seimbang dengan besar beban 8 + j6 ohm. Hitung daya

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Soal 5

3 impedansi yang mempunyai nilai yang sama, tahanan 8 ohm dan reaktansi 6 ohm, dihubungkan pada suulay 200 V, 3 phase.

Hitung daya yang dibutuhkan jika Dihubung bintang

Dihubung delta/ segitiga

Soal 6

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Lecture 2

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Lecture 3

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Penelitian potensi panas bumi di Indonesia sudah di mulai sejak tahun 1926 di Kamojang Jawa Barat oleh Belanda dan diteruskan oleh bangsa Indonesia setelah

kemerdekaan.

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Lecture 4

Energy conversion ( Renewable Energy )

Renewable Energy

Apakah Renewable Energy ?

Renewable energy adalah Sumber Energy

yang tidak habis dipakai / digunakan.

Mengapa Demikian ?

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Jenis – Jenis Renewable Energy

Hydroelectric Power (PLTA) Geothermal Energy (PLTPB) Wind Power

Tidal wave Power Solar Cell Power

Hydroelectric Power (PLTA)

Pembangkit Listrik

menggunakan tenaga air Umumnya dibuat bendungan untuk mendapatkan energi kinetik yang besar untuk menggerakkan turbin

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Komponen utama PLTA

Reservoir Penstock Turbin Generator Step up trafo menuju Transmisi Listrik

Proses kerja PLTA

Air ditampung di reservoir (bendungan) Air bertekanan tersebut mengalir melalui penstock (pipa air) menuju turbin

Turbin berputar dan memutar generator Medan fluksi yang dibangkitkan

mengeluarkan Listrik.

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Perhitungan Energi pada PLTA

POWER (kW) =

Head (meter) x Flow (m3/detik) x Grafitasi(9,81) x Efisiensi (0,6)

Dimana Head = Net Head

= (Gross Head – Losses)

Geothermal Energy (PLTPB)

Pembangkit Listrik

menggunakan Panas Bumi Tekanan uap panas yang digunakan untuk

menghasilkan Energi Listrik Mulai digunakan pada tahun 1904 di Larderello,

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Komponen utama PLTPB

Production Well Steam Pressure tank Turbin dan Generator Injection Well

Resources geothermal

hydrothermal fluids hot dry rock

geopressured brines magma, and

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Proses Kerja PLTPB

Air panas bertekanan di pompa dari Production Well

Lalu uap bertekanan dengan Air Panas dipisah

Air panas ditampung agar menghasilkan Uap Uap panas bertekanan disalurkan ke Turbin. Turbin menggerakkan Generator.

Wind Power (PLTB)

Angin adalah salah satu bentuk energi yang tersedia di alam, Pembangkit Listrik Tenaga Bayu mengkonversikan energi angin menjadi energi listrik dengan menggunakan turbin angin atau kincir angin. Cara kerjanya cukup

sederhana, energi angin yang memutar turbin angin, diteruskan untuk memutar rotor pada generator dibagian belakang turbin angin, sehingga akan menghasilkan energi listrik. Energi Listrik ini biasanya akan disimpan

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Ocean Wave

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Proses Kerja

Arus laut yang memiliki daya besar menggerakkan kincir

Kincir tersebut biasa di join dengan Gear box untuk mendapatkan kecepatan tinggi

Putaran yang cepat menggerakkan Generator

Dan generator menghasilkan Listrik

Solar Cell

Pembangkit dengan menggunakan Energi cahaya matahari Bahan yang digunakan adalah

Photovoltaic Cell

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Cara Kerja

Ketika silikon tersinari oleh matahari proses pelepasan elektron dalam silikon tersebut terjadi sehingga terbangkitlah energi listrik DC

Kemudian disalurkan melalui penghantar untuk digunakan oleh peralatan listrik DC

Baterai diperlukan untuk menyimpan listrik DC sebelum kemudian digunakan atau dikonversi menjadi listrik AC.

Inverter digunakan untuk

mengubah listrik DC manjadi AC, dalam beberapa kasus bahkan penggunaan

Daftar pustaka

http://www.inforse.org

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Lecture 5

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Lecture 6

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The End

Lecture 7

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Material

Single phase AC motor

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