逆变器输出波形复合控制技术

发布时间：2018-06-22 16:53

本文选题：主电路设计 + 开环频率测试　；参考：《华中科技大学》2015年硕士论文

【摘要】：随着风电、光伏发电以及潮汐能发电等分布式发电的飞速发展,并网逆变器得到了非常广泛的研究和应用。独立式逆变电源在军事、医疗、银行、通讯等领域应用同样广泛,如何通过一些简单实用的控制方法来提高其输出电能质量仍显得意义重大,本文以一台大功率的逆变电源为研究对象,从输出电压波形的控制和负载扰动抑制方面展开研究。本文首先对逆变器的主电路和滤波器进行了设计,接着以状态空间平均法建立了逆变器在静止坐标系与同步dq坐标系下的数学模型,并推导出了逆变器的传递函数和方框图模型。建立好其数学模型后,本文通过频率特性测试得到了等效阻尼、谐振频率等电路参数,建立了与实际样机一致的控制对象。在研究逆变器的控制技术时,以频率特性测试建立好的控制对象为基础,首先对重复控制的工作原理、特性判定准则、设计方法做了介绍。接着对基于PI控制与重复控制的串联结构和并联结构两种复合控制器进行了公式推导,再通过伯德图对比及分析,得出了两种复合控制器的特点。接着推导了复合控制器的设计方法以及复合控制系统的动稳态特性判定标准。根据理论分析,本文在Simulink中搭建了仿真模型,同时也搭建了实验样机,通过仿真和实验对复合控制方法进行了验证,论证了复合控制器的实效性,也证明了本文关于复合控制方法的理论分析是正确的。最后针对逆变器电源实际运行中可能面临的短路以及负载切换等冲击,为了保障设备及人生安全,同时提高设备持续供电能力,本文设计了对应的软硬件限流保护措施,通过实验验证了保护措施的有效性。文章最后针对逆变器带载时存在的稳态误差和负载切换时较大的电压波动,本文引入了输出电流前馈控制,推导出了前馈函数及前馈控制框图。由于全前馈函数复杂,旋转坐标系下存在较强耦合,所以通过简化前馈的方式进行补偿。最后通过仿真验证了该简化前馈控制方法有效性和实用性,同时也验证了之前理论分析的正确性。
[Abstract]:With the rapid development of wind, photovoltaic and tidal power generation, grid-connected inverters have been widely studied and applied. Independent inverter power sources are also widely used in military, medical, banking, communications and other fields. How to improve the output power quality through some simple and practical control methods is still of great significance. In this paper, a high-power inverter is studied from the aspects of output voltage waveform control and load disturbance suppression. In this paper, the main circuit and filter of the inverter are designed firstly, and then the mathematical model of the inverter in the stationary coordinate system and the synchronous dq coordinate system is established by using the state space averaging method. The transfer function and block diagram model of the inverter are derived. After the mathematical model is established, the equivalent damping, resonant frequency and other circuit parameters are obtained through the frequency characteristic test, and the control object is established in accordance with the actual prototype. In the study of inverter control technology, based on the established control object of frequency characteristic test, the working principle, characteristic criterion and design method of repetitive control are introduced. Then, the formulas of two kinds of composite controllers based on Pi control and repetitive control are deduced, and the characteristics of the two kinds of composite controllers are obtained through the comparison and analysis of the Byrd diagram. Then, the design method of the composite controller and the criterion of the dynamic and steady characteristics of the composite control system are deduced. According to the theoretical analysis, the simulation model is built in Simulink, and the experimental prototype is also built. The method of compound control is verified by simulation and experiment, and the effectiveness of the composite controller is proved. It is also proved that the theoretical analysis of the compound control method in this paper is correct. Finally, aiming at the impact of short circuit and load switching in the actual operation of inverter power supply, in order to ensure the safety of equipment and life, and to improve the ability of continuous power supply of the equipment, the corresponding current limiting protection measures of hardware and software are designed in this paper. The effectiveness of the protective measures is verified by experiments. Finally, aiming at the steady state error of inverter with load and the large voltage fluctuation during load switching, this paper introduces the output current feedforward control, and deduces the feedforward function and feedforward control block diagram. Because of the complexity of the full feedforward function and the strong coupling in the rotating coordinate system, the compensation is carried out by simplifying the feedforward method. Finally, the effectiveness and practicability of the simplified feedforward control method are verified by simulation, and the correctness of the previous theoretical analysis is also verified.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM464

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