Space Vector Model for Nine Switch Inverter
CHAPTER 1
INTRODUCTION
1.1 GENERAL Nowadays, there is a demand of power supply. As an electrical engineer, it is necessary to design system with low cost, reduced losses and higher efficiency. This paper proposes nine-switch converter with single controller, rather than using 12 switches for operation of drives separately. In electrical vehicle drives mostly AC motors are used. It is because of its well known advantages like simplicity, reliability, lack of mechanical commutator and brushes, ability to work under unfriendly conditions (dust, humidity, etc.) and low cost. The most popular AC machines are induction motors - IM and permanent magnet synchronous motors - PMSM. These motors can be supplied from power electronics converters (like VSI inverters). Therefore, are used in various applications like hybrid electric vehicles HEV, public transport, machine tools drives, etc. Some of these applications have to work above nominal speed. This is essential in EV and public transport drives. High-speed operation can be achieved either by increasing supply voltage (not always possible) or by field weakening. In the IM field-weakening operation can be easily performed.
The above requirements are not fulfilled in scalar control, where only angular speed (frequency) and magnitudes of flux, current and voltage vectors are adjusted. Instantaneous positions of these vectors are not controlled. Therefore, space vector control methods have been strongly developed. In this case, not only angular speed (frequency) and magnitudes of flux, current and voltage vectors, but also instantaneous position of these vectors is controlled. This ensures excellent dynamic and stable steady state operation of space vector control methods.
1.2 OBJECTIVE
The aim of this project is to develop the space vector modulation (SVM) of nine-switch inverter
INTRODUCTION
1.1 GENERAL Nowadays, there is a demand of power supply. As an electrical engineer, it is necessary to design system with low cost, reduced losses and higher efficiency. This paper proposes nine-switch converter with single controller, rather than using 12 switches for operation of drives separately. In electrical vehicle drives mostly AC motors are used. It is because of its well known advantages like simplicity, reliability, lack of mechanical commutator and brushes, ability to work under unfriendly conditions (dust, humidity, etc.) and low cost. The most popular AC machines are induction motors - IM and permanent magnet synchronous motors - PMSM. These motors can be supplied from power electronics converters (like VSI inverters). Therefore, are used in various applications like hybrid electric vehicles HEV, public transport, machine tools drives, etc. Some of these applications have to work above nominal speed. This is essential in EV and public transport drives. High-speed operation can be achieved either by increasing supply voltage (not always possible) or by field weakening. In the IM field-weakening operation can be easily performed.
The above requirements are not fulfilled in scalar control, where only angular speed (frequency) and magnitudes of flux, current and voltage vectors are adjusted. Instantaneous positions of these vectors are not controlled. Therefore, space vector control methods have been strongly developed. In this case, not only angular speed (frequency) and magnitudes of flux, current and voltage vectors, but also instantaneous position of these vectors is controlled. This ensures excellent dynamic and stable steady state operation of space vector control methods.
1.2 OBJECTIVE
The aim of this project is to develop the space vector modulation (SVM) of nine-switch inverter