脉冲负载下低输入电流脉动直流电源的研究

发布时间：2018-04-26 16:59

本文选题：脉冲负载 + 输入电流脉动抑制　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：日前,航天器、雷达等功率具有脉冲特性的负载日益增多。当直流脉冲负载工作时,直流输入母线会产生较大的电流脉动,发生较大的辐射;此外,较大幅度的脉冲电流会引起蓄电池等储能装置较大的压降,减小使用寿命,同时也对母线的稳定度提出了更高的要求。本文针对脉冲负载工作时的功率特点,设计了两种适用于脉冲负载的直流电源系统,在输出稳压的同时实现直流母线输入电流低频脉动的抑制。针对脉冲负载下直流电源输入电流脉动较大的问题,本文选择电容器作为中间能量缓冲单元,设计了Boost变换器和Buck变换器级联的非隔离型混合储能直流电源系统结构。前级Boost变换器使用输入电流直接控制,通过脉冲负载工作时所需的平均功率计算电流参考给定值,针对电源系统平均功率发生漂移时闭环可能失效的问题,本文提出了采用数字电位计自动调节输入电流给定值的方法,较好的实现了直流母线低频电流脉动抑制。为了实现输入与输出的隔离,设计了双管正激变换器和Buck变换器级联的隔离型混合储能直流电源系统结构。在双管正激变换器中,本文提出了一种引入输入电流低频扰动的电压型控制方法,以反向电流增益传递函数和输出阻抗传递函数作为参考来设计闭环控制参数,从而使前级输出电容尽可能多的提供脉动功率,直流母线提供平均功率,实现直流电源母线输入电流低频脉动的抑制。在两种有源混合直流系统当中,后级Buck变换器均采用传统的电压闭环控制,在前级变换器输出电压变化时实现输出电压的稳定以及脉冲负载变化时较好的动态响应。在Saber软件中进行时域仿真,并搭建硬件电路。通过仿真和实验验证了本文设计的两种直流电源结构以及控制电路工作于低频脉冲负载工作模式的优越性,均能实现输入电流脉动小于电流平均值的?10%以及输出电压的较小波动。
[Abstract]:A few days ago, spacecraft, radar and other power with pulse characteristics of the load is increasing. When the DC pulse loads work, the DC input busbar will produce larger current pulsation and larger radiation. In addition, a larger pulse current will cause a larger voltage drop and reduce the service life of storage devices such as batteries. At the same time, the stability of the busbar is also required. According to the power characteristics of pulse load, two DC power supply systems suitable for pulse load are designed in this paper, which can suppress the low frequency pulsation of DC bus input current while output voltage is stabilized. In order to solve the problem of large pulsation of input current in DC power supply under pulse load, the capacitor is chosen as the intermediate energy buffer unit, and a non-isolated hybrid energy storage DC power supply system with cascaded Boost converters and Buck converters is designed in this paper. The former Boost converter uses input current to directly control, and the average power required by the pulse load is calculated by reference to the given value. In order to solve the problem of the closed-loop failure when the average power of the power supply system drifts, the input current is directly controlled. In this paper, a digital potentiometer is proposed to automatically adjust the input current, which can effectively suppress the low frequency current pulsation of DC bus. In order to realize the isolation of input and output, the isolated hybrid DC power supply system with cascaded two-transistor forward converter and Buck converter is designed. In this paper, a voltage mode control method with input current low frequency disturbance is proposed. The closed-loop control parameters are designed with the reference of reverse current gain transfer function and output impedance transfer function. Thus, the output capacitance of the front stage can provide as much pulsating power as possible, and the DC bus can provide the average power, so that the low frequency pulsation of the input current of DC power supply can be suppressed. In the two active hybrid DC systems, the conventional closed-loop voltage control is used in the rear stage Buck converter, which can stabilize the output voltage when the output voltage of the former converter changes and better dynamic response when the pulse load changes. The time domain simulation is carried out in Saber software, and the hardware circuit is built. The advantages of the two DC power supply structures designed in this paper and the control circuit working in the low frequency pulse load mode are verified by simulation and experiment. The input current pulsation is less than 10% of the average current and the output voltage fluctuates slightly.
【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】：2017
【分类号】：TM46

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