【作者】 严鋆；

【导师】 党存禄；

【作者基本信息】 兰州理工大学 ， 电力系统及其自动化， 2011， 硕士

【摘要】 电压跌落(voltage sag)已上升为最重要的电能质量问题,动态电压恢复器(DVR)被认为是目前解决电压跌落问题最有效的用户电力装置。为了提高电压跌落检测算法的实时性和准确性,以及DVR装置补偿电压跌落的经济性,本文对电压跌落检测方法和DVR电压补偿策略开展了研究,主要内容包括:传统的基于三相软件锁相环路的幅相检测系统,受三相电网负序分量和谐波分量的影响,动态响应速度低,无法准确提取三相基波正序分量的相位信息。本文基于双同步参考坐标系提出一种新的三相幅相检测方法,实现了dq变换的正序、负序解耦。该方法能将三相电网的基波正、负序分量分离,并分别检测出基波正序分量和基波负序分量的幅值及相位。仿真对比验证表明,该方法具有良好的动态响应性能,以及较高的测量精度。按能量提取方式的不同,DVR可以分为无储能装置类型和有储能装置类型。其中,无储能装置DVR亦称可连续运行动态电压恢复器(UDVR),有储能装置的DVR以直流电容器储能型DVR为代表。针对UDVR,本文综合跌落前电压补偿策略和同相电压补偿策略的优点提出一种改进的综合电压补偿策略,仿真验证表明该方法能够有效缓解由电压跌落引起的相位跳变,注入的补偿电压幅值也较小;对于直流电容器储能型DVR,本文考虑电压跌落的补偿时间问题,提出时间最优补偿策略,仿真结果证明DVR采用时间最优补偿策略能够获得比最小能量补偿策略更长的持续补偿时间。本文采用TMS320F2812型数字信号处理器(DSP)对三相DVR装置进行了软件控制设计,主要内容包括电压(电流)的AD采样、双dq变换正负序解耦算法流程、DVR补偿控制流程、空间矢量PWM的生成流程等内容。更多还原

【Abstract】 Voltage sag is the most important power issue, and dynamic voltage restorer (DVR) has been considered to be the most effective custom power device which alleviates voltage sags. In order to improve the real-time and accuracy of detection methods for voltage sag and ameliorate the economical efficiency of DVR, this paper mainly researches on the voltage sag detection method as well as the compensation strategy of DVR. The major contents of this paper are detailed as follows:The conventional magnitude-phase detection system based on three-phase software phase locked loop has a low speed of dynamic response affected by negative-sequence and harmonic components. Also it cannot exactly extract the foundational positive-sequence phase angle of a three-phase power system. This paper proposes a novel three-phase magnitude-phase detection method based on double synchronous reference frame. The proposed method can decouple the positive dq and negative dq sequences and detect the magnitudes/phases of foundational positive- and negative-sequence components of three-phase voltages. The simulation results verify that the proposed method has a high detecting precision and a good dynamic performance.According to different methods of energy extraction, DVRs could be classified as types: DVR with no energy storage (also named uninterrupted dynamic voltage restorer, UDVR) and DVR with energy storage. DC-link capacitor is the usual method of energy storage. This paper proposes an improved integrated compensation strategy for UDVR, and simulation results verify that the proposed strategy can alleviate phase jump compared voltage sags and the magnitude of injected voltage is low. On the other hand, this paper considers the compensation duration of DVR with DC-link capacitor and proposes the optimized time compensation strategy. The simulation results verify that DVRs which adopt the proposed strategy can obtain longer compensation duration than those which adopt minimize energy compensation strategy.This paper designs the software flowcharts of DVR based on TMS320F2812 DSP chip, which include AD sample, the decoupled double dq transform algorithm, compensation strategies and SVPWM algorithm.更多还原