开关电源功率因数校正控制算法的研究

发布时间：2018-03-21 22:12

本文选题：有源功率因数校正　切入点：控制算法　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：功率因数校正技术（PFC）是消除电力电子设备中的谐波污染，提高功率因数的有效方法。现阶段，对PFC技术的研究集中在电路拓扑、建模分析、控制策略等方面，其中控制策略的研究主要是针对特定的拓扑结构，通过使用不同的数学建模分析方法或者使用不同的控制原理对电路的性能进行优化，以达到提高电路PF值，降低成本的目的。本文首先分析了传统的基于平均电流模式的双环控制的PFC系统的原理，在建立主电路小信号模型及功率级传递函数的基础上，设计了系统的主电路及电压、电流控制器，建立了系统的仿真模型，仿真结果验证了系统的有效性。传统双环控制的PFC系统需要检测输入电压、输入电流和输出电压，不仅控制结构复杂，而且需要在每个开关周期执行电压采样、电流采样、电压误差信号计算、电流误差信号计算、电压环调节、电流环调节、计算占空比等操作，有很大的运算时间需求。为了解决这一缺点，在第三章的基础上设计了一种改进控制算法。这种算法的计算量大大少于传统算法的计算量，对运算时间的需求也大大减少。无论是传统双环控制的PFC还是改进算法的PFC都是基于对系统进行建模分析得到的。但由于PFC系统是非线性、时变的，很难建立其精确的数学模型。且当输入电压或负载变化很大时，常规的控制算法难以达到较高的控制要求。而模糊控制的对象不需要精确的数学模型，对参数变化及扰动不敏感。基于以上原因，将模糊自适应控制器与传统的PI控制器相结合，设计了基于模糊自适应PI控制的PFC系统。仿真证明，基于模糊自适应PI控制器的PFC系统不仅具有很好的功率因数校正效果，而且与传统的PI控制器相比，具有更好的抗扰性。
[Abstract]:Power Factor Correction (PFC) is an effective method to eliminate harmonic pollution and improve power factor in power electronic equipment. At present, the research on PFC technology focuses on circuit topology, modeling and analysis, control strategy, etc. The research of control strategy is mainly aimed at the specific topology, by using different mathematical modeling and analysis methods or using different control principles to optimize the performance of the circuit, in order to improve the PF value of the circuit and reduce the cost. In this paper, the principle of traditional dual-loop control PFC system based on average current mode is analyzed. Based on the small signal model of main circuit and power level transfer function, the main circuit and voltage and current controller of the system are designed. The simulation model of the system is established, and the simulation results verify the effectiveness of the system. The traditional double-loop control PFC system needs to detect input voltage, input current and output voltage. It not only has complex control structure, but also needs to perform voltage sampling, current sampling and voltage error signal calculation in each switching cycle. Current error signal calculation, voltage loop regulation, current loop regulation, duty cycle calculation and other operations have great computational time requirements. Based on the third chapter, an improved control algorithm is designed. Both the traditional double-loop control PFC and the improved PFC are based on modeling and analysis of the system. However, the PFC system is nonlinear and time-varying. It is very difficult to establish its exact mathematical model, and when the input voltage or load changes greatly, the conventional control algorithm is difficult to meet the higher control requirements, while the fuzzy control object does not need an accurate mathematical model. The PFC system based on fuzzy adaptive Pi control is designed by combining fuzzy adaptive controller with traditional Pi controller. The PFC system based on fuzzy adaptive Pi controller not only has good power factor correction effect, but also has better immunity than the traditional Pi controller.
【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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