Research On Three-Phase High-Voltage PWM Inverter

In recent years, with the fast develop of semiconductor technology, the capacity of PWM inverter is become higher and higher. Under condition of the same capacity, the more input DC voltage is, the lower the input current will be. So in power supply system of watercraft, the high voltage PWM inverters will be wildly used。This dissertation base on practical project and has done the following work:This dissertation deduct the mathematic modules of three-phase PWM inverter under ABC three phase stator coordinate,αβtwo- phase stator coordinate and dq two-phase rotating coordinate , analyzing the characteristic under dq two-phase rotating coordinate. It also introduce the modulation method of Space Vector PWM, analysising the effects of coupling indq coordinate, simplifying the module of control system; Establish the accurate and averaging state modules of PWM inverter based on Matlab.In order to get the high quality output voltage, there have developed many waveforms–control methods. This dissertation researches the effects of PI parameters variation, giving the stable range of PI parameters. And also introduce the theory and characteristic of repetitive controller and give the design example. Because the high voltage and output power, there will be many problem in designing main circuits and control circuits, such as IGBT driving circuits,insulating high and low voltage,protection of impact current.,software magnetic bias correction. This dissertation researches these problems.According to the characteristic of PWM inverter, This dissertation designs the control circuit, introducing main control module and relative CMOS chips, giving the realizing of digital control method. At last, it calculates the parameters of the main circuits, establishing the experiment equipment and validating the theory result.