The Research On Inverter Control Technique Based On Intelligent Control Algorithm

Compared with the normal two-level inverters, multilevel inverters have the advantage of less harmonic, small switch loss, high voltage and so on. So multilevel technology has been becoming a hotspot both at home and abroad presently, it has been widely applied to medium and high voltage, large capacity frequency conversion and speed-adjusting system and high voltage DC transmission system.Taking the diode clamped three-level inverter as example, the thesis introduces its working principle and the common control policies in detail, also the modulator approaches of SVPWM and the algorithm is analyzed emphatically, especially the quantum chemistry calculation's acting time of synthetic reference vectors, and the sector zones. The causes of neutral-point potential fluctuation are analyzed, and the comparison. Give fixed and non-fixed frequency hysteretic loop current method. Both two methods produce the PWM control signal based on current ratio change. The control result of non-fixed frequency dual hysteretic method is more accurate.The key and innovation of this paper is that method of fuzzy control is pulled into it, the error current and its ratio are adjusted based on fuzzy rule. The size and orientation of the three phases are controlled through adjustment of the ring width. The simulation is carried out, and its performance index is improved, which shows the feasibility of the method.Based on the theoretical analysis above, I made the circuit of diode clamped three-level inverter with TMS320F2812 as its control core. The driving wave of SVPWM is obtained from the circuit with the algorithm program. Because of unreliability, the output voltage is not good, the versifications are needed to be done with new switching elements of IGBT.