移相全桥DC-DC变换器及其数字控制的研究

发布时间：2018-04-26 12:36

本文选题：移相全桥DC-DC变换器 + 零电压开关　；参考：《华中科技大学》2015年硕士论文

【摘要】：随着电力电子技术和控制理论的飞速发展,电力电子产品得到了更为广泛的应用。而应用于斩波电路的移相全桥DC-DC变换器,相比于一般的硬开关电路,能够实现功率开关管零电压开关(ZVS),控制容易,在功率变换的众多场合倍受欢迎。移相全桥DC-DC变换器能够实现ZVS功能和大功率能量转换,本文基于移相全桥DC-DC变换器的基本拓扑结构,介绍了其详细的工作过程和滞后桥臂实现ZVS的条件,结合实际应用要求设计出谐振器件的参数。采用了小信号建模方法和PWM等效法建模的方法对移相全桥DC-DC变换器进行数学建模,采用模型的Bode图设计出合适的PI控制器参数,并通过Matlab/Simulink仿真验证移相全桥DC-DC变换器的数学模型和PI参数的正确性。本文介绍了移相全桥DC-DC变换器变压器出现偏磁的原因,并通过检测变压器原边电流并进行闭环补偿达到消除高频变压器偏磁的目的。本系统控制板硬件电路的控制芯片为TI公司的DSP(TMS320F28335)和ALTERA公司的FPGA(EP4CE30F23I7),驱动板硬件电路的控制芯片为ALTERA公司的FPGA(EP3C5E144I7)。控制板FPGA通过电压电流传感器对模拟量采样滤波,采集输出直流电压和变压器原边电流;控制板DSP对输出电压闭环控制,用于稳定输出电压;驱动板FPGA对高频变压器原边电流闭环控制,用于消除高频变压器的偏磁,电压环和电流环均采用数字PI控制器,实验波形证明电压环能够稳定输出电压,电流环能实现偏磁补偿,因此验证了本系统设计的正确性。
[Abstract]:With the rapid development of power electronics technology and control theory, power electronics products have been more widely used. The phase-shifted full-bridge DC-DC converter which is applied to chopper circuit can realize ZVS converter with zero voltage switch compared with the common hard switching circuit. It is easy to control and is popular in many power conversion situations. Phase-shifted full-bridge DC-DC converter can realize ZVS function and high-power energy conversion. Based on the basic topology of phase-shifted full-bridge DC-DC converter, this paper introduces its detailed working process and the condition of realizing ZVS by lagging arm. The parameters of the resonant device are designed according to the practical application requirements. The small signal modeling method and the PWM equivalent method are used to model the phase-shifted full-bridge DC-DC converter. The appropriate Pi controller parameters are designed by using the Bode diagram of the model. The mathematical model and Pi parameters of phase-shifted full-bridge DC-DC converter are verified by Matlab/Simulink simulation. This paper introduces the cause of bias magnetic field in phase-shifted full-bridge DC-DC converter transformer. The purpose of eliminating bias magnetic field of high-frequency transformer is to detect the primary current of transformer and compensate it with closed loop. The control chip of the hardware circuit of the system control board is TI's DSP TMS320F28335) and ALTERA's FPGA EP4CE30F23I7, and the control chip of the drive board's hardware circuit is ALTERA's FPGA EP3C5E144I7. The control board FPGA collects the output DC voltage and transformer primary current through voltage and current sensor, and the control board DSP controls the output voltage closed-loop to stabilize the output voltage. The driving board FPGA controls the primary current of high frequency transformer in closed loop, which is used to eliminate bias of high frequency transformer. Digital Pi controller is used in voltage loop and current loop. The experimental waveform shows that the voltage loop can stabilize the output voltage. The current loop can realize magnetic bias compensation, so the correctness of the system design is 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】：TM46

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