Simulation Research of Frequency Converter
Based on MATLAB/Simulink
Abstract
The technology of frequency conversion and velocity adjustment has already become an effective method of both saving energy and improving product quality.The low-voltage frequency converter technology is already mature,but the high-voltage converter has not got a universal topology structure at present.Among the numerous solutions,cell series multi-level high-voltage frequency converter technology,depending on its obvious advantages in input and output harmonic,efficiency,input power factors etc,has occupied a share in market,especially,it has good market prospect in fan and pump industries.
This report mainly introduces the simulation research of cell series multi-level 6KV HVF(high voltage frequency).The concrete content consists of the following aspects:
⒈The development and trend of HVF technology,the requirements both in domestic and abroad market for HVF are reviewed.The advantages and disadvantages of different HVF types are analyzed in detail,and therefore,the scheme design is proposed based on this analysis.The basic principle of cell series multi-1evel PWM converter is described here.The description thoroughly illustrates the internal traits of cell series multi-level HVF.
⒉Based on MATLAB/Simulink,the modeling and simulation research of 6KV complete the modeling of the pulse signal,cell circuit,one-phase,three-phase and the frequency converter system.By simulation research,it is proved that the cell series multi-level HVF has got great superiority on eliminating harmonics.Shown by the simulation current waveform,without special filtrating circuit,the sine of its current waveform is already very high. The line voltage of the frequency changer owns 21 steps,and its sine value is better than phase-voltage,also the harmonic content of the frequency converter line voltage is very low,which the largest value is 10 harmonic waves,its amplitude value counts 1.19606% of a fundamental wave.
Key words:cell series, multi-level, high voltage , MATLAB/Simulink