The Research And Design Of Cell Series Mid-Voltage & High-Power Inverter

With the development of electrical drive technology recently, Mid-voltage & High power inverter has already become one of research focus in AC drives. It not only could enhance the turnout and quality of products, but also could economize large numbers of power energy and reduce production cost if Mid-voltage motor could change their velocity smoothly using Mid-voltage inverter. It has huge market potential and widely application in the future .Based on the actual common use main loop topology of the middle voltage frequency converter system, this elaborated and analyzed 6kV/400kW cell series middle voltage inverter system.In the first place, The thesis analyzed the mechanism of cell series carrier wave phase shift style PWM modulation technology in theory, then analysed and designed in simulation used of Simulink based on MATLAB6.5. Afterwards, made one kind of high performance V/f s control schemes to the middle voltage inverter system. By means of Compensating the descent of stator voltage using vector control, compensating the discrepancy of rotate speed and place restrictions on the maximum current of motor, Achieving to a excellent V/f control scheme with good characteristic of low frequency performance and against-fault functions.At the same time , in this paper , same good idea of Siemens corporation , such as time slot, joint were used in middle voltage converter . Which improved the variability , Freeness and convenient quality of the system . Meanwhile we have Designed some modularization software with systematic configuration capacity , and one instance out of many , some such as control word and status word , sequential control, V/f curve, restart while Instantaneous power failure, communication function and the technology conditioner. Besides, a automatic maintaining output voltage algorithm was proposed based on power compensation of networkvoltage.