三相三线制有源电力滤波器控制策略研究

发布时间：2019-05-09 10:59

【摘要】：随着电网智能化和现代化的不断发展,越来越多具有低功率因素、非线性、不平衡特性的用电设备接入电网,使得电网中暂态冲击、高次谐波、三相不平衡等问题日益严重。因此,对电能质量的治理势在必行。有源电力滤波器(Active power filter,APF)作为一种新型改善电能质量的装置,具有动态响应速度快,补偿精度高、不易发生谐振等优点,引起人们的广泛关注。本文对APF谐波电流检测方法,电流环控制策略,直流侧电压控制策略等影响APF性能的关键技术进行较为深入的研究。快速准确的检测谐波电流是有源电力滤波器滤波性能的前提,本文在分析传统FBD谐波电流检测法的基础上,指出FBD法和ip-iq法的内在联系,将两种方法相互结合。针对传统FBD检测法的不足,提出一种改进型FBD检测方法。该方法利用广义积分器提取基波电压的正序分量,采用移动均值滤波法替代传统的低通滤波器,避免低通滤波器造成的滞后误差,通过仿真验证本文所提方法的有效性。有源电力滤波器电流环控制要求是补偿电流能够快速准确地跟踪指令电流信号,本文针对pk?1次谐波,提出一种基于通用内模的改进型重复控制,它可以根据负载的状态有选择地抑制谐波,调节重复控制的补偿范围。针对PI控制很难实现无差跟踪的缺点,采用并联的重复PI复合控制策略实现指令电流的无差追踪;针对无差拍控制依赖系统精确建模的缺陷,采用串联的重复无差拍复合控制策略消除周期性稳态误差,分别对两种控制策略进行仿真分析,仿真验证了复合控制策略的可行性。针对电网电压波动造成APF补偿效果变差的情况,采用一种电压跟随器使直流侧电压随着电网电压的波动而变化,提高APF的补偿效果。本文对三相三线制有源电力滤波器电流环控制策略进行实验研究,分别对文中所提的两种复合控制策略进行验证,通过实验验证了基于通用内模的复合控制策略的有效性。
[Abstract]:With the continuous development of intelligence and modernization of power grid, more and more electrical equipment with low power factors, nonlinear and unbalanced characteristics are connected to the power grid, which makes the transient impact, high order harmonics, three-phase imbalance and other problems more and more serious. Therefore, the treatment of power quality is imperative. As a new device to improve power quality, active power filter (Active power filter,APF) has many advantages, such as fast dynamic response, high compensation precision, not easy to occur resonance and so on. In this paper, APF harmonic current detection method, current loop control strategy, DC side voltage control strategy and other key technologies affecting the performance of APF are studied in depth. Fast and accurate detection of harmonic current is the premise of active power filter filtering performance. Based on the analysis of traditional FBD harmonic current detection method, this paper points out the internal relationship between FBD method and ip-iq method, and combines the two methods with each other. In view of the shortcomings of traditional FBD detection, an improved FBD detection method is proposed. In this method, the positive sequence component of fundamental voltage is extracted by generalized Integrator, and the moving mean filtering method is used to replace the traditional low-pass filter to avoid the lag error caused by low-pass filter. The effectiveness of the proposed method is verified by simulation. The current loop control of active power filter (APF) requires that the compensation current can track the command current signal quickly and accurately. In this paper, an improved repetitive control based on general internal model is proposed for pk?1 subharmonics. It can selectively suppress harmonics according to the state of the load and adjust the compensation range of repetitive control. In view of the disadvantage that PI control is difficult to realize zero-difference tracking, the parallel repetitive PI compound control strategy is used to track the command current without difference. Aiming at the defect of accurate modeling of deadbeat control dependent system, the repeated deadbeat compound control strategy in series is used to eliminate the periodic steady-state error. The two control strategies are simulated and analyzed respectively, and the feasibility of the compound control strategy is verified by simulation. In order to reduce the compensation effect of APF caused by voltage fluctuation, a voltage follower is used to make the DC side voltage change with the fluctuation of power network voltage, so as to improve the compensation effect of APF. In this paper, the current loop control strategy of three-phase three-wire active power filter is studied experimentally. the two composite control strategies proposed in this paper are verified by experiments, and the effectiveness of the composite control strategy based on general internal model is verified by experiments.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761

【参考文献】