The Research Of PWM Switching Power Amplifier For Exciter

The exciter is one of the important instruments to study the dynamic performance characteristics of the material structure(the frequency,resonance frequency and amplitudes).A power amplifier is a driver of a given signal that is amplified by a power amplifier.As an important part of the excitation system,the performance index of the power amplifier indicates that the exciter system is good or bad.With the improvement of the control mode of the precision expansibility of the excitation device,the traditional linear amplifier and analog control have been unable to meet the demand,and digital control has become a trend.This paper firstly introduces the classification of power amplifier and compares the performance of each amplifier.The feasibility of the switch power amplifier applied to the exciter is analyzed.The one-cycle control is applied to the switching power amplifier and the control model based on one-cycle control is established.In this paper,the problem of dc bias in one-cycle control switch power amplifier is improved,and the compensation scheme is presented and verified by simulation test.On this basis,the realization of single cycle control digitization is studied and discussed,and a switching power amplifier based on micro-processing chip is designed according to the application demand of the exciter.With DSP28069 chip as the platform,the digital onecycle algorithm is the core,and the digital switch power amplifier with digital PI control is combined to improve the accuracy and drive capability of the control of the exciter.The system is divided into two parts: Software and hardware.Hardware includes power circuit design,hardware selection,hardware protection,isolation drive circuit design,detection and conditioning circuit design,etc.Software includes the digital PI algorithm program,Digital one-cycle algorithm program,A/D sampling procedure.The digital of one-cycle control became true.At the end of the paper,the modeling and simulation is designed by MATLAB,including the verification and harmonic analysis of the output performance of the power amplifier and the compensation scheme for dc offset problems.The simulation results show that the power amplifier is based on PWM control and is applicable to the vibration exciter.Figure[60]tablep[4]reference[64]...