Pada masa kini, pembangunan yang cepat dalam peranti kuasa dan mikro pengawal telah mengakibatkan pacuan pemboleh ubah kelajuan bagi induksi motor arus ulangalik menjadi semakin pupolar. Terdapat banyak strategi untuk mengawal kelajuan mesin arus ulang-alik, tetapi kebanyakan pacuan arus ulang-alik terkawal menggunakan konsep kawalan skalar. Dalam projek ini, pembinaan, litar setara dan prinsip operasi motor induksi dikaji dan sistem pacuan kawalan skalar dibina dalam Matlab Simulink untuk mengawal kelajuan motor induksi. Dua jenis kawalan skalar yang dibentangkan iaitu kawalan skalar secara terbuka dan kawalan skalar secara tertutup. Implementasi proses projek melibatkan penentuan spesifikasi reka bentuk sistem, pemodelan matematik bagi pacuan dan pembinaan sistem pacuan dalam Simulink. Tindakan transien pacuan kawalan scalar menunjukkan kelajuan motor bertindak balas kepada pengubahan kelajuan rujukan dan tork beban. Kajian simulasi menunjukan kawalan skalar secara tertutup dengan pengawalaturan gelincir oleh alat kawalan PI memberi gelinciran kelajuan yang lebih baik daripada kawalan skalar secara terbuka dalam kedua-dua keadaan beban penuh dan tiada beban. Kawalan skalar secara terbuka yang tradisional memberi kestabilan yang buruk semasa beroperasi dalam keadaan frekuensi yang rendah. Jadi, satu penambahbaikan untuk kawalan scalar secara terbuka dengan penambahan voltan, kompensasi rintangan pemegun dan kompensasi frekuensi gelinciran telah dibuat dalam kawalan scalar secara terbuka. Kajian Simulasi mengesahkan implementasi skim penambahbaikan memberi kestabilan yang lebih baik.
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Nowadays, with technological advances and rapid development in solid state power devices and micro controllers, variable speed drives for AC induction motor are becoming more and more popular. There are many control strategies to control the speed of an AC machines, however the major part of all controlled ac drives belongs to the scalar controlled method. In this project, the construction, equivalent circuit and the principle operation of the induction motor is studied and scalar controlled drive systems are built up in Matlab Simulink to control the speed of the induction motor. There are two types of scalar control systems which are open loop scalar control and close loop scalar control. This project involves the design specifications, mathematical modeling of the drive and the Simulink implementation of the drive systems. The transient response of the scalar control drive is presented which shows the speed of motor in response to the changes of the speed reference and the load torque. The simulation results show that the close loop scalar control with the slip regulation by using the PI controller gives better speed regulation under both the no load and full load conditions if compared with open loop scalar control. The traditional open loop control has the disadvantage of poor steady precision when working in low frequency range. Hence, an improved open loop scalar control with the boost voltage, stator voltage compensation and slip frequency compensation were implemented in the open loop scalar control. The simulation results validate the implementation of improved scheme which has better control ability at low speed range.
Scalar control of induction motor using matlab simulink_Loke Joo Yong_E3_2011_NI