《基于PIC18F4431的逆变电源控制系统设计》.docVIP

基于PIC18F4431的逆变电源控制系统设计摘要 为获得设定频率与电压的优质正弦交流电, 本次设计了一种以PIC18F4431单片机为核心的逆变电源控制系统。该电源以220 V、50Hz交流电压为输入, 通过整流和逆变组合电路, 来实现逆变。硬件设计采用了自举式浮充驱动电路、基于真有效值转换芯片的检测电路、RCD 缓冲电路, 并给出了硬件设计原理图。软件设计采用单极性等面积脉宽调制( PWM ) 法调制、采样、中断的方式进行稳压调节, 并给出了软件流程图。 本文首先介绍了逆变电源的发展现状及趋势。文中分析了适合数字控制的基于DSP处理器TMS320F2812和智能功率模块(IPM)的逆变器硬件；介绍了SVPWM逆变技术的基本理论，详细推导出了五种具体的SVPWM实现模式，并通过比较说明不同实现模式的优缺点，得到本课题采用的一种优化模式，设计研究了基于SVPWM控制方式的软件；介绍了Q格式的基本理论，在程序中变量间的运算采用Q格式，提高了系统数据运算的速度和精度，实现了左定点处理器上进行高性能的浮点运算：详细讨论了片上模数转换模块的转换误差来源及影响，研究了减小转换误差的方法，采用了软件方法来对转换结果进行实时校正，提高了模数转换的准确度。 本课题是在参阅了国内外大量资料和逆变器必威体育精装版发展技术的基础上进行的高性能控制逆变器的一次有益的尝试和探索。整个控制系统经实验调试，证明本课题的软件设计研究是可行的。 关键词: PIC18F4431; 逆变电源;脉宽调制; 过流保护Abstract For produce a high quality sine wave, which frequency and voltage was set by user, an inverter control system based on PIC18F4431 micro contrller produced . The input o f the supply was 220 V、50 Hz AC,through rectifier and inverter circuit, to realize inverter. The hard are was designed by using a bootstrap drive circuit of floating channel a detection circu it based on RMS-DC chip, RCD buffer circuit, the schematicw as given. The software was designed by utilizing a unipolare-qualarea pulse width modulation( PWM ) modulation method, sampling and interrup tmode to regulate the voltage, the flow chart was presented. Combined with the latest development of modem technology of power electronic devices and digital signal processing, this paper studies the high-performance digital control system of inverter,with the TMS320F2812 as the dominant chip produced by Tl Company for general motor control and the intelligent power module(IPM) as the main power devices of the inverter In the first, the current situation and development trends of the inverters are presented in the paper. Following is the analyses of hardware of the inverter suiting for digital control based on digital signal processor TMS320F2812 and the intelligent power module(IPM);the basic theory of space vector pulse width modulation (SVPWM) is introduced, five specif