Analysis And Design On High Frequency Inverter System

In the high-speed, high-precision NC machine tool system, the spindle speed is 300000 rpm or above, so a high frequency inverter system is necessary. At present, in this thesis, we will study some key problems about the high frequency inverter technology.Through analyzing the principle of the high frequency inverter technology, the pulse width modulation (PWM) and pulse amplitude modulation (PAM) are proposed. This thesis analyzes in detail the principle of PWM and PAM, this thesis also analyzes and compares the characteristics of the two modulation schemes by using MATLAB.First, we design a high frequency inverter system using MOSFET based on PWM. The switching frequency of the MOSFET can reach up to hundreds of KHz, and the output of the system can reach as high as 5000 Hz, which can meet the requirements of the low power drive system. The characteristic analysis of the system is demonstrated by using MATLAB. Then, another high frequency inverter technology based on PAM/PWM combination control is put forward. This strategy can reduce the harmonic pollution of the power grid, and has a wide speed range. At last, the experiment results prove that the control system can be used from 1 to 5 kHz, and has stronger Load-bearing ability, anti-interfence ability and better speed adjusting performance.In this thesis, we analyze and design the PWM high frequency inverter system based on the TMS320F2812 DSP which is produced by the TI Company. The system is mainly composed of three phases AC power source, rectifying circuit, filter circuit, PAM, PWM frequency inverter, driving circuit, control circuit and protecting circuit. The current, voltage and speed to control the power switch IGBT on or off, so the inverter circuit can produce three-phase sinusoidal AC signal with adjusted frequency. It can fit the output requirement of the high frequency inverter system.