伪连续导电模式开关变换器建模分析与控制技术研究

发布时间：2018-09-05 11:20

【摘要】：电感电流伪连续导电模式(Pseudo-Continuous Conduction Mode,PCCM)是开关变换器的一种特殊工作模式,它兼顾了电感电流连续导电模式(Continuous Conduction Mode,CCM)和电感电流断续导电模式(Discontinuous Conduction Mode,DCM)开关变换器的优点,适用于宽负载或宽功率范围,且具有解耦控制和抗交叉影响能力强的特点。因此对PCCM开关变换器进行研究具有重要意义。为了提高PCCM开关变换器的轻载效率,本论文提出了一种适用于PCCM开关变换器的定关断时间控制技术。在详细分析定关断时间控制PCCM Buck变换器工作原理的基础上,通过仿真对比分析了传统恒定参考电流(Constant Reference Current,CRC)控制和定关断时间控制PCCM Buck变换器的稳态性能、瞬态性能和宽负载范围内的效率。开关电源的V~2(Voltage-Voltage,V~2)控制技术具有快速的负载瞬态响应速度。结合V~2控制技术,本论文提出一种适用于PCCM开关变换器的V~2定续流时间控制技术。在详细分析V~2-CRC控制和V~2定续流时间控制PCCM Buck变换器工作原理的基础上,分别建立了 V~2-CRC控制和V~2定续流时间控制PCCM Buck变换器的小信号模型,得到了两种控制方式下PCCMBuck变换器的"控制-输出"、"输入-输出"、"输出阻抗"传递函数。通过仿真对比分析了两种控制下PCCMBuck变换器的频域性能,并通过时域仿真验证了频域分析的正确性。建立了传统CRC控制PCCM Buck变换器的离散迭代映射模型,基于离散迭代映射模型,当负载电阻、电感等效串联电阻、输入电压、续流参考值、电感和输出电容等电路参数发生变化时,分析了 PCCM Buck变换器的动力学行为。建立相应的时域模型,得到对应参数下变换器的输出电压和电感电流的时域波形,验证了离散建模的正确性。所得结论对于研究和控制PCCM Buck变换器具有重要意义。最后,搭建了不同控制方式下PCCM Buck变换器的实验平台,通过实验研究验证了理论分析和仿真分析的正确性。
[Abstract]:Inductance current pseudo-continuous conduction mode (Pseudo-Continuous Conduction Mode,PCCM) is a special mode of switching converter. It takes into account the advantages of inductance current continuous conduction mode (Continuous Conduction Mode,CCM) and inductance current intermittent conductive mode (Discontinuous Conduction Mode,DCM) switching converter. It is suitable for wide load or wide power range, and has strong ability of decoupling control and anti-cross effect. Therefore, it is of great significance to study the PCCM switching converter. In order to improve the light-load efficiency of PCCM switching converters, this paper presents a switching time control technique suitable for PCCM switching converters. Based on the detailed analysis of the working principle of the fixed turn-off time control (PCCM Buck) converter, the steady-state performance of the traditional constant reference current (Constant Reference Current,CRC) control and the turn-off time control (PCCM Buck) converter is analyzed by simulation. Transient performance and efficiency over a wide load range. Vt 2 (Voltage-Voltage,V~2) control technology of switching power supply has fast transient response speed of load. Combined with V2 control technology, this paper presents a V2 constant current time control technique for PCCM converter. Based on the detailed analysis of the principle of V~2-CRC control and PCCM Buck converter, the small signal models of PCCM Buck converter controlled by V~2-CRC control and VX 2 control are established, respectively. The "control-output", "input-output" and "output impedance" transfer functions of PCCMBuck converters under two control modes are obtained. The frequency domain performance of PCCMBuck converter under two kinds of control is analyzed by simulation, and the correctness of frequency domain analysis is verified by time domain simulation. The discrete iterative mapping model of traditional CRC controlled PCCM Buck converter is established. Based on the discrete iterative mapping model, when the load resistance, inductance equivalent series resistance, input voltage, continuous current reference value are obtained, The dynamic behavior of PCCM Buck converter is analyzed when the circuit parameters such as inductance and output capacitance change. The corresponding time-domain model is established and the output voltage and inductance current waveforms of the converter are obtained under the corresponding parameters, which verifies the correctness of the discrete modeling. The conclusions are of great significance for the study and control of PCCM Buck converters. Finally, the experimental platform of PCCM Buck converter with different control modes is built, and the correctness of theoretical analysis and simulation analysis is verified by experimental research.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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