基于UC3854的单相电流型PFC

论文摘要

论文主要研究了单相电流型PFC电路。由此,课题有以下两个主要目标：1)通过该PFC电路使得输入电压与输入电流同频同相,从而功率因数接近于1.2)输出电流为恒定值,从而输出端口可看作直流电流源。相对于传统的PFC电路,课题中主电路结构由Boost电路转换为Buck电路,从而使得输出电压可以低于输入电压。这使得在要求稳定的直流低压的场合,免去了降压环节。此外,在直流侧加入一个LC并联谐振滤波网络,在降低了直流侧电感的同时可获得稳定平滑的直流输出电流。控制电路部分不同于传统的电流型PFC电路间接控制输入电流的特点,采用基于UC3854的平均电流控制策略直接控制输入电流。通过该控制方案可使输入电流接近正弦并于输入电压同频同相。同时,与传统PFC电路所不同的是控制系统由两个电流环组成。传统的电压外环被电流外环所取代。输出电流通过电流传感器取样,从而送入外环信号输入端。结合上述主电路结构与控制策略,成功设计出一120W单相电流型PFC实验平台。通过该实验平台,输出电流稳定在1A,120v输出电压也低于220v(RMS)的输入电压。由此可见,该PFC电路克服了传统Boost PFC输出电压只能大于输入电压(峰值)的缺点。分析与实验结果都表明该单相电流型PFC电路可在输出端向负载提供稳定的直流电流的同时保证输入端电压与电流的同频同相,使功率因数接近于1.显而易见,该单相电流型PFC电路适用于电流型负载以及需要低的稳定的直流电压的场合,同样适用于电池的充电器以及UPS电源。

论文目录

• Abstract
• 摘要
• Introduction
• 1 Exordium
• 1.1 Harmonic Pollutions
• 1.1.1 Harmonic Source
• 1.1.2 Harm of Harmonic
• 1.2 Harmonic Managements
• 1.2.1 Harmonic standards
• 1.2.2 Harmonic Restraints
• 1.2.3 Reactive Power Compensation
• 1.2.4 Active Approaches
• 1.3 Power Factor Correction
• 1.3.1 The Role of PFC
• 1.3.2 An Introduction to Power Factor
• 1.3.3 PFC Specifications
• 1.4 The Significance and Scheme of Subject
• 2 Single Phase Current Source PFC
• 2.1 Comparisons of Single Phase Voltage Source PFC and Current Source PFC
• 2.1.1 An Induction to Single Phase Voltage Source PFC
• 2.1.2 Proposed Topology of Single Phase Current Source PFC
• 2.2 Analysis of Single Phase Current Source Buck Type PFC
• 2.2.1 Work Mode of the Power Stage Circuit
• 2.2.2 Special Requirements of the Circuit
• 2.2.3 Waveforms of the Proposed Converter
• 2.2.4 Modeling of Power Stage
• 3 Control Scheme
• 3.1 Comparisons of Current Control Scheme
• 3.1.1 Average Current Control
• 3.1.2 Peak Current Control
• 3.1.3 Hysteresis Current Control
• 3.2 Control Scheme for the Proposed Converter
• 3.2.1 Main Idea of Control Scheme
• 3.2.2 Application of UC3854
• 4 Analysis of the Entire System
• 4.1 Analysis of the Inner Loop
• 4.1.1 Modeling of the PWM Modulator
• 4.1.2 Inner Loop Compensator
• 4.1.3 Slope Match
• 4.1.4 Open Loop gain of the Inner Loop
• 4.2 Analysis of the Outer Loop
• 4.2.1 Control Object of the Outer Loop
• 4.2.2 Outer Loop Compensator
• 4.2.3 Open Loop Gain of the Outer Loop
• 4.3 Benefits of Squarer and Divider Circuits
• 4.4 Input Distortion of the Entire System
• 4.4.1 Input Distortion Sources
• 4.4.2 Determine of the Feedforward Network
• 4.4.3 Determine of the Outer Compensator
• 5 Entire System Designs
• 5.1 Power Stage Design
• 5.1.1 Input Capacitor Selection
• 5.1.2 Input Inductor Selection
• 5.1.3 Determine the Resonant Filter and the Output Inductor
• 5.1.4 Selection of Switch and Diode
• 5.1.5 Current Transducer Selection
• 5.1.6 Selection of Input Current Sense Resistor
• 5.2 Determinations of Control Circuits
• vac Selection'>5.2.1 R_vacSelection
• set and C_T Selection'>5.2.2 R_set and C_TSelection
• 5.2.3 Peak Current Limit Settings
• 5.2.4 Selection of Feedforward Network
• 5.2.5 selection of inner compensator
• 5.2.6 Selection of the Outer Compensator
• 6 Simulation and Experiment Results
• 6.1 Compensators Simulation
• 6.2 Entire System Simulations
• 6.2.1 Open Loop Simulation
• 6.2.2 Closed Loop Simulation
• 6.3 Experiment
• CONCLUSION
• REFERENCES
• Published Paper
• Acknowledgement