三相PWM整流器启动优化控制及其实验系统研究

发布时间：2018-10-08 07:49

【摘要】：三相PWM整流器具有直流侧输出电压稳定、能量双向流动、输入功率因数高、交流侧输入电流谐波含量小等优点。随着电力电子技术的发展，三相PWM整流器广泛地应用于直流传动系统、电力系统、储能系统等工业领域。本文通过分析三相PWM整流器的拓扑结构，得出了其稳定运行在整流状态、逆变状态、无功补偿状态时，交流侧输入电流、电网电压、端电压与交流侧输入有功功率和无功功率的关系。介绍了空间矢量调制技术的原理，及其实现方法。建立了三相PWM整流器在三种常用坐标系下的数学模型；为了消除两相旋转dq坐标系下dq轴的互相耦合项ωL,加入了前馈解耦控制算法。通过分析电流内环和电压外环的控制框图，得出PI调节器的比例系数和积分系数的计算方法。搭建了基于matlab仿真平台的三相PWM整流器的仿真模型，仿真结果证明了控制算法的正确性。本文为了解决三相PWM整流器启动时产生冲击电流的问题，分析了启动冲击电流产生的原因，提出了分段启动控制策略以及实现分段启动控制策略的具体步骤：电流内环的分段启动控制、电压外环的分段启动控制，给出了参数的计算方法。搭建了基于matlab仿真平台的三相PWM整流器启动时的仿真模型，仿真结果证明分段启动控制策略能够有效地抑制其启动时产生的冲击电流。本文设计了三相PWM整流器的实验平台，，给出主电路的交流侧滤波电感、直流侧母线电容的计算方法。设计了以DSP为核心的控制板，控制板包括采样电路、保护电路、电源电路、PWM控制电路等。三相PWM整流器的DSP程序主要包括：主程序、EPWM1计数器下溢中断程序、外部中断1程序、外部中断2程序、ECAP1捕获中断程序，同时给出每个程序的流程图。通过分析每个程序的流程图，对其响应过程进行说明。实验结果证明分段启动控制能够有效地抑制三相PWM整流器的启动冲击电流，同时还能解决启动时直流侧输出电压的超调问题。
[Abstract]:Three-phase PWM rectifier has the advantages of stable DC side output voltage, two-way energy flow, high input power factor and low harmonic content of AC side input current. With the development of power electronic technology, three-phase PWM rectifier is widely used in DC drive system, power system, energy storage system and other industrial fields. By analyzing the topology of three-phase PWM rectifier, it is obtained that the AC side input current and power network voltage can operate stably in the state of rectifier, inverter and reactive power compensation. The relationship between terminal voltage and AC input active power and reactive power. The principle and implementation of space vector modulation are introduced. The mathematical model of three-phase PWM rectifier in three common coordinate systems is established, and a feedforward decoupling control algorithm is added in order to eliminate the mutual coupling term 蠅 L of the dq axis in the two-phase rotating dq coordinate system. By analyzing the control block diagram of current inner loop and voltage outer loop, the calculation method of the proportion coefficient and integral coefficient of PI regulator is obtained. The simulation model of three-phase PWM rectifier based on matlab simulation platform is built, and the simulation results prove the correctness of the control algorithm. In order to solve the problem of impulse current generated by three-phase PWM rectifier during startup, this paper analyzes the causes of starting impulse current. The piecewise startup control strategy and the concrete steps to realize the piecewise start control strategy are put forward: the subsection start control of the current inner loop and the subsection start control of the voltage outer loop. The calculation method of the parameters is given. The simulation model of three-phase PWM rectifier based on matlab simulation platform is built. The simulation results show that the piecewise startup control strategy can effectively suppress the impulse current generated by the three-phase PWM rectifier. In this paper, the experimental platform of three-phase PWM rectifier is designed, and the calculation method of AC side filter inductor and DC side busbar capacitance of main circuit is given. A control board based on DSP is designed. The control board includes sampling circuit, protection circuit, power circuit and PWM control circuit. The DSP program of three-phase PWM rectifier mainly includes: main program EPWM1 counter overflow interrupt program, external interrupt 1 program, external interrupt 2 program ECAP1 capture interrupt program. At the same time, the flow chart of each program is given. By analyzing the flow chart of each program, the response process is explained. The experimental results show that the piecewise startup control can effectively suppress the starting impulse current of the three-phase PWM rectifier and solve the overshoot problem of the DC side output voltage during startup.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM461

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