Based On The Research Of Cascaded High Voltage Convertor

Facing the new situation of strained resources and environmental capacity's increasingly tightens, accelerate energy saving and emission reduction technology research is important. At present, the high voltage inverter have been widely application in the energy industry of our country, such as metallurgy, oil and power plant and so on, it has an important role in reducing energy consumption in our country. But our country's high pressure frequency inverter technology still not mature, some important power device is still in dependence foreign imports, face up the huge market demand of nation, development multilevel inverter energy-saving and popularized, it has the important meaning in improving efficiency and energy saving.This paper based on the project of blowers inverter, study the adopted cascade type high voltage inverter. Introduce cascade high-voltage converter several topological structure, due to the unit serial multilevel high-voltage converter used in this project ,analyze in detail its working principle; aimed at the problem of converter harmonic interference, research separately from the project practice, circuit structure and modulation method; research the method of how to determine switching angle, conversion angle and voltage vector play a key role in three PWM arithmetic of high-voltage converter, compare the merit and demerit of three arithmetic; according to the fan pumps with load control V/F, can't accurately control motor speed problem, use the fuzzy PI dual mode control method, when the system fluctuation big ,use the fuzzy control, when the system fluctuation small, use the PI control, the switch between them by a program to decide; last devise the main circuit, control circuit and protection system of unit serial multilevel high-voltage converter, analyze the power blower consumption's change before and after frequency conversion, reflect converter's energy conservation result.