| Research and application on multi-level converters is one of the newest developments of modern power electronic, which is mainly used in the situation of high-performance voltage large capacity. Multi-level converters can reduce the output harmonic wave aberrance, small even none flitter is needed comparing with the two -level inverter. The whole efficiency is also high. Meanwhile the high-performance voltage large capacity output can be implemented by the low voltage apparatus. It is significant for the changing of high-performance voltage large capacity power and enhance the efficiency .It is one of the research hotspot of modern power electronic.The dissertation works on the application of multi-level converters in the permanent magnet synchronous machine. The development and actuality of multi-level converters, the research and actuality of three-level inverter is analyzed deeply. The law of diode-clamped three-level inverter voltage and current is also discussed exactly. This dissertation introduces and analyze work principle, calculation and simulation process of diode-clamped three-level inverter controlled by the space vector pulse width modulation technique(SVPWM).The reasons of the balance of neutral point potential are discussed .The method of SVPWM by examining the neutral point current is also proposed.Finally ,the main circuit and control circuit are designed by changing the voltage inverter to current invert .So the stator current multi-dimensional vector in machine can rotate circularly(steady state). The output current of inverter is controlled by calculating the turn on time and run-through interval of the invert switches basing on current vector space position. The control adopts vector control.
|
PDF Full Text Request