【作者】 陈文娅；

【导师】 张加胜；

【作者基本信息】 中国石油大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 传统的变频/工频运行切换控制只能实现交流电动机在切换前后运行频率和转向(相序)的一致,而由于切换前后交流电源的相位不同,往往会导致电机的电流和转矩发生较大的瞬时冲击性波动,对变频器、电网、电机及其负载都会带来严重冲击,同时会产生刺耳的噪声污染、缩短设备寿命,甚至会导致设备损坏。本课题以单片机数字化测控技术为核心,研究开发一种交流电机变频/工频运行切换锁相同步控制系统。主要研究内容包括:(1)强、弱电信号的频率与相位检测;(2)应用C8051F系列单片机实现包含变频器的锁相环(PLL)控制;(3)通过软件编程和系统调试完成变频/工频平滑切换的锁相同步控制系统。本论文设计实现了一种将变频器作为锁相环路中的一个环节—压控振荡器的系统组成方案;提出了一种鉴频/鉴相组合分时切换和以PI调节器取代低通滤波器的PLL新型控制方法;针对变频器输出PWM电压基波相位检测的困难,提出了一种新型PWM波相位检测电路和参数设计方法。本系统经单片机配合外围硬件实现智能化软件分析判断,通过PLL闭环自动调节变频器输出频率,与电网达到同频同相后,产生控制切换指令信号,使接触器发生切换,实现变频/工频平滑切换的锁相同步控制。通过计算机仿真和实验研究结果,证明了本系统方案及检测与控制方法的正确性与可行性。更多还原

【Abstract】 Traditional variable frequency/work frequency switching control systems only make frequency and turning (phase sequence) of AC motor identical switching around, as difference of AC power supply phases switching around, often can result in instantaneous impact of fluctuations of motor current and torque, this can bring serious impact to transducer, electrified netting, motor and load, produces harsh noise pollution, shorten equipment life at the same time, even leads to damage equipments.This paper studies a sort of the phase-locked synchronization control system of AC motor variable frequency/work frequency switching based on SOC (C8051F015). This study includes the major: (1) the frequency and phase detection of strong, weak electricity signals; (2) realizing the phase-pocked loop (PLL) which includes transducer control by C8051F series SOC; (3) completing the smooth switching control system by programming and system debugging. The paper designs one composition program which makes transducer as a tache of PLL; puts forward a new control method about the comparing of frequency/phase combination system by the switching way of time-sharing and make PI regulator replace the low-pass filter; Aimed at the problem that is the fundamental wave phase check of transducer output, we bring forward a new phase detection circuit and design parameters method of PWM wave.This system realizes intelligent software analysis judgment by SOC and periphery hardware, uses PLL close loop to make output frequency of transducer fulfill self-regulation, after output frequency and phase of transducer is the same as electrified netting, produces control instruction signals to make contactors switch, completes phase-locked synchronization control of variable frequency/work frequency smooth switching. By computer simulation and analyzing a great many of experimental results, the validity and feasibility of this systematic scheme and control circuit is verified.更多还原