基于变频器负载的三相单管Boost整流控制系统

发布时间：2018-12-26 12:18

【摘要】：随着电力电子技术的发展，变频器在工业自动化的领域中也得到了广泛的应用。但传统的变频器存在输入电流畸变较严重的问题，从而导致了对电网的污染，严重干扰了其它的用电设备。因此，本文主要对变频器负载的三相单管Boost整流控制系统进行了深入研究。针对三相单管Boost电路输入电流5次谐波污染的问题，，提出了一种基于输入电流基波幅值闭环的谐波注入方法。在保证直流母线电压闭环的前提下，将输入电流基波幅值调节器的输出作为系统单管占空比的注入依据，以实现对电网电流的控制，提高了系统输入功率因数。为进一步改善系统输入功率因数，提出了一种基于电压误差补偿的谐波注入方法。采用PR控制器提取出数字整流后电网电压信号中6次谐波分量，对直流母线电压误差进行补偿，以降低母线电压波动、减小输入电流中5次谐波含量。另外，根据输入电流THD对注入信号的幅值进行优化选择，使系统在不同功率段下均具有较好的谐波抑制效果。为了满足系统中降低直流母线电压、减小直流母线电容的控制需求，提出了一种基于功率注入的单管Boost型变频调速系统控制方法。通过对系统功率进行闭环控制，并将功率闭环的输出注入到整流侧单管占空比中，以达到减小直流母线电压纹波、维持系统稳定的效果。仿真结果表明，在减小直流母线电容的前提下，并配合本文所提的控制方法，系统输入功率因数得到了有效的提高。针对逆变器共模电压问题进行了深入的研究，分析了传统共模电压抑制方式所存在的缺陷，提出了一种改进的共模电压抑制策略，利用一组固定的非零矢量来合成零矢量，不仅有效的对共模电压进行了抑制，而且还解决了传统共模电压抑制算法引起的电流畸变问题。搭建了基于DSP的三相单管Boost变频调速系统实验平台，对系统主拓扑参数进行了选择，并对控制系统软硬件设计进行了简要介绍。最后，针对该实验平台做了初步的实验验证。
[Abstract]:With the development of power electronics technology, inverter has been widely used in the field of industrial automation. However, the traditional frequency converter has the problem of serious distortion of input current, which leads to the pollution of power grid and seriously interferes with other electric equipments. Therefore, this paper mainly studies the three-phase single-transistor Boost rectifier control system with inverter load. In order to solve the problem of fifth harmonic pollution of input current in three-phase single-transistor Boost circuit, a harmonic injection method based on fundamental amplitude closed-loop of input current is proposed. On the premise of the DC bus voltage closed loop, the output of the input current fundamental wave amplitude regulator is regarded as the injection basis of the duty cycle of the system, so as to realize the control of the power network current and improve the input power factor of the system. In order to further improve the input power factor of the system, a harmonic injection method based on voltage error compensation is proposed. The sixth harmonic component of the digital rectified voltage signal is extracted by using PR controller, and the DC bus voltage error is compensated to reduce the voltage fluctuation and the fifth harmonic content in the input current. In addition, the amplitude of the injection signal is optimized according to the input current THD, which makes the system have better harmonic suppression effect at different power levels. In order to reduce the DC bus voltage and reduce the DC bus capacitance in the system, a control method based on power injection for single-tube Boost variable-frequency speed regulating system is proposed. In order to reduce the voltage ripple of DC bus and maintain the stability of the system, the output of the power loop is injected into the duty cycle of the rectifier through the closed-loop control of the system power. The simulation results show that the input power factor of the system is improved effectively under the premise of reducing the DC busbar capacitance and cooperating with the control method proposed in this paper. In this paper, the common-mode voltage problem of inverter is deeply studied, the defects of the traditional common mode voltage suppression method are analyzed, and an improved common-mode voltage suppression strategy is proposed, which uses a set of fixed non-zero vectors to synthesize zero vectors. Not only the common mode voltage is effectively suppressed, but also the current distortion caused by the traditional common mode voltage suppression algorithm is solved. The experiment platform of three-phase single-tube Boost variable frequency speed regulation system based on DSP is built, the main topology parameters of the system are selected, and the design of software and hardware of the control system is briefly introduced. Finally, a preliminary experiment is carried out on the platform.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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