基于超级电容储能技术的动态电压恢复器的设计与研究

发布时间：2019-06-18 18:06

【摘要】：电网电压瞬时跌落是电力系统中危害最大、出现概率最高的动态电能质量问题,必须采取措施进行治理。动态电压恢复器(Dynamic Voltage Restorer, DVR)被认为是目前解决电压瞬时跌落最有效的途径,该装置串联在供电系统与负载之间,可以对电网电压进行动态补偿。超级电容器作为新型储能器件,其具有高能量密度,快速充放电,寿命长,无污染等特点。因此采用超级电容储能的新型动态电压恢复器抑制电压瞬时跌落的前景十分光明。本文针对电网电压瞬时跌落,设计了一款基于超级电容储能的主旁路式小型动态电压恢复器；提出了一种快速检测电压瞬时跌落新方法；并且围绕超级电容充放电技术进行了相关深入研究,提出了变流恒压快速充电方法,以及多段式恒压放电方法,本文具体研究内容主要包括：(1)针对动态电能质量问题中电压瞬时跌落时电压特征量改变问题进行了详细研究,并且分析了动态电压恢复器的主要工作原理及超级电容器充放电原理及等效模型。(2)采用主旁两路供电新思路设计了一种基于超级电容储能的新型动态电压恢复器,并完成了该装置的硬件设计及软件设计。硬件设计包括新型超级电容均压充放电电路,半桥式DC-DC变换器电路、全桥逆变电路、采样调理电路、主控单元电路等等；软件设计包括主程序编写,AD、定时器中断程序编写,保护程序编写等等；并进行了制板、焊接,成功制作出一台样机,其最大电压恢复时间可达3s。(3)提出了一种新型检测电压瞬时跌落方法——基于单相电压αβ-dq变换连续求导的检测算法,并对该方法进行了理论分析、仿真验证,该算法实时性好,可以快速准确判断出电网发生跌落；同时本文结合数字采样技术对算法中“过冲响应”所带来噪声提出了累加优化处理方法,该处理方法工程实用性强,上机试验效果明显。(4)针对超级电容充放电特性及常用的充放电方式,本文结合双向DC-DC变换器提出了超级电容能量流动控制策略,并采用小信号建模方法制定出精确的双闭环控制策方法,通过自动控制理论中校正原理详细计算出控制器的PI参数；该方法实现了超级电容器Buck模式下先恒流再恒压的快速充电,Boost模式下稳压放电；并在此基础上提出超级电容器变流恒压充电方法,以及多段稳压放电方法,进行了Simulink仿真验证；通过这种控制策略后动态电压恢复器中超级电容器充、放电效果得到大幅改善。
[Abstract]:The instantaneous voltage drop of power grid is the dynamic power quality problem with the greatest harm and the highest probability in the power system, so measures must be taken to deal with it. Dynamic voltage restorer (Dynamic Voltage Restorer, DVR) is considered to be the most effective way to solve the instantaneous voltage drop at present. The device is connected in series between the power supply system and the load, and can dynamically compensate the voltage of the power grid. As a new type of energy storage device, supercapacitor has the characteristics of high energy density, fast charge and discharge, long life, no pollution and so on. Therefore, a new type of dynamic voltage restorer with supercapacitor energy storage has a bright prospect of suppressing instantaneous voltage drop. In this paper, a small main bypass dynamic voltage restorer based on supercapacitor energy storage is designed for instantaneous voltage drop of power grid, and a new method for fast detection of instantaneous voltage drop is proposed. The related research on supercapacitor charge and discharge technology is carried out, and the variable current constant voltage fast charging method and multi-stage constant voltage discharge method are put forward. The main research contents of this paper are as follows: (1) the voltage characteristic change problem of voltage instantaneous drop in dynamic power quality problem is studied in detail. The main working principle of dynamic voltage restorer, the charge and discharge principle and equivalent model of supercapacitor are analyzed. (2) A new dynamic voltage restorer based on supercapacitor energy storage is designed by using the new idea of main and side power supply, and the hardware design and software design of the device are completed. The hardware design includes a new type of supercapacitor equalizing voltage charge and discharge circuit, half bridge DC-DC converter circuit, full bridge inverter circuit, sampling conditioning circuit, main control unit circuit and so on. The software design includes main program writing, AD, timer interrupt programming, protection program writing and so on. A prototype has been successfully fabricated and welded, and its maximum voltage recovery time can reach 3. (3) A new detection method of instantaneous voltage drop based on single-phase voltage 伪尾-dq transform is proposed, and the theoretical analysis of the method is carried out. the simulation results show that the algorithm has good real-time performance and can quickly and accurately judge the fall of power grid. At the same time, combined with digital sampling technology, this paper proposes a cumulative optimization processing method for noise caused by "overshoot response" in the algorithm, which is practical in engineering and obvious in computer test. (4) according to the charge-discharge characteristics of supercapacitors and the commonly used charging and discharging methods, this paper proposes a supercapacitor energy flow control strategy combined with bidirectional DC-DC converter. The accurate double closed-loop control strategy method is worked out by using the small signal modeling method, and the PI parameters of the controller are calculated in detail through the correction principle in the automatic control theory. This method realizes the fast charging of supercapacitor with constant current and then constant voltage in Buck mode and steady voltage discharge in Boost mode. On this basis, the method of variable current constant voltage charging of supercapacitor and the method of multi-stage steady voltage discharge are put forward and verified by Simulink simulation. Through this control strategy, the discharge effect of supercapacitor in dynamic voltage restorer is greatly improved.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM714.2

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