Transcript Slide 1
RE1345 KONVERSI TENAGA LISTRIK II Vita Lystianingrum 1 RE1345 KONVERSI TENAGA LISTRIK II SILABUS RE1345 Konversi Tenaga Listrik II Electrical Power Conversion II Semester IV 2 SKS Tujuan: Memahami tentang dasar-dasar mesin listrik arus bolak-balik, khususnya: generator serempak, motor serempak, motor tak serempak. Prasyarat: Konversi Tenaga Listrik I 2 RE1345 KONVERSI TENAGA LISTRIK II 1: Klasifikasi mesin-mesin listrik dan konstruksi 2: Generator sinkron: proses terbangkitnya EMF dan macam-macam generator sinkron 3: Generator sinkron: berbeban, kerugian tegangan, diagram vektor untuk pf. lagging, pf. leading 4: Generator sinkron: menentukan voltage regulator dengan metode EMF dan karakteristik 5: Generator sinkron: kerja paralel 6: 7: Motor sinkron: metode start dan pengaruh perubahan arus eksitasi 8: Motor sinkron: torque dan contoh soal 9 & 10: UTS 3 References 1. Theraja, B. L., ‘Electrical Technology’, S. Chand & Company Ltd., 1978. 2. Karady, G., ‘Lecture Notes on Synchronous Generator’, www.eas.asu.edu/~karady/360_pp.html. 3. Zuhal 4 • Motivasi, Tujuan: – Menambah wawasan? • MAteri kuliah bisa didownload di: www.oc.its.ac.id • Komposisi Nilai – Tugas – UTS – UAS 20 % 40 % 40 % • Peraturan Kelas – Kelas dimulai jam 7.30 5 Review KTL 1: DC Machines • Generators convert mechanical energy to electric energy. • Motors convert electric energy to mechanical energy. • Faraday’s Law -> Dynamically & statically induced. • The construction of motors and generators are similar. 6 DC generator 7 DC generator 8 DC Motor Parts carbon brushes Field magnet rotor stator 9 AC Generators / Alternators • Same principles as DC generators -> armature winding & magnetic field. • Armature winding -> stator field winding -> rotor ** 10 Why stationary armature? • Without brush contact-> The output current can be led directly from fixed terminals on the stator (armature windings) to the load circuit. • Easier to insulate stationary armature winding for high AC voltages (may be as high as 30 kV or more) • Sliding contacts i.e. slip-rings are transferred to the lowvoltage, low-power DC field circuit-> easily insulated • **Armature windings can be more easily braced to prevent any deformation produced by the mechanical stresses 11 SYNCHRONOUS MACHINES Housing ,cooling ducts Stator Rotor Shaft Bearing Rotor winding Stator winding Connections 12 SYNCHRONOUS MACHINES Stator • Laminated iron core with slots • Steel Housing 13 SYNCHRONOUS MACHINES Iron core Stator details • Coils are placed in slots Coil Slots • Coil end windings are bent to form the armature winding. End winding 14 15 16 17 **2 kinds of rotor 18 SYNCHRONOUS MACHINES Round rotor Steel ring Shaft Wedges DC current terminals 19 SYNCHRONOUS MACHINES Rotor Details 20 SYNCHRONOUS MACHINES Round rotor Round rotor • The round rotor is used for large high speed (3600rpm) machines. • A forged iron core (not laminated,DC) is installed on the shaft. • Slots are milled in the iron and insulated copper bars are placed in the slots. • The slots are closed by wedges and re-enforced with steel rings. 21 SYNCHRONOUS MACHINES Round Rotor Machine • • • • The stator is a ring shaped laminated ironcore with slots. Three phase windings are placed in the slots. Round solid iron rotor with slots. A single winding is placed in the slots. Dc current is supplied through slip rings. Concept (two poles) A Stator with laminated iron-core Slots with winding B A C - C + + S N Rotor with dc winding C A - B B - + 22 Salient rotor • Usually for low- & medium-speed alternators 23 SYNCHRONOUS MACHINES • Concept (two poles) Salient Rotor Machine • The stator has a laminated iron-core with slots and three phase windings placed in the slots. • The rotor has salient poles excited by dc current. • DC current is supplied to the rotor through slip-rings and brushes. B- C+ N A+ AS C- B+ 24 25 SYNCHRONOUS MACHINES • Construction Construction • • • • • The picture shows the laminated iron core and the slots (empty and with winding). The winding consists of copper bars insulated with mica and epoxy resin. The conductors are secured by steel wedges. In large machines, the stator is liquid cooled. The iron core is supported by a steel housing. empty slots insulated winding 26 SYNCHRONOUS MACHINES Salient pole rotor construction • • • • The poles are bolted to the shaft. Each pole has a DC winding. The DC winding is connected to the slip-rings (not shown). A DC source supplies the winding with DC through brushes pressed into the slip ring. • A fan is installed on the shaft to assure air circulation and effective cooling. 27 SYNCHRONOUS MACHINES 28 SYNCHRONOUS MACHINES Construction • Low speed, large hydrogenerators may have more than one hundred poles. -> relationship between speed & poles • These generators are frequently mounted vertically. • The picture shows a large, horizontally arranged machine. 29 • Thank You, see you next week 30 • Different construction of synch. Gen & DC gen -> • Which one precedes? 31 32