基于广义迭代DFT的快速分次谐波提取研究
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摘要
分次谐波提取是电能质量领域的关键技术之一,广泛应用于谐波分析、补偿和治理等。总体而言,谐波提取方法可分为时域和频域两大类,时域方法大多难以同时兼顾稳定提取精度和动态响应性能;频域方法以离散傅里叶变换(DFT)及其延伸算法为代表,其中迭代DFT具有算法简洁、稳态精度高等优点。然而,传统迭代DFT算法受限于单一僵硬的结构,动态响应慢,至少需要一个基波周期,难以适应谐波变化频繁的应用场合。针对此问题,重构传统迭代DFT算法,以更灵活形式适应输入信号的谐波频谱,提出广义迭代DFT,更具一般性和快速性。搭建了实验平台,其结果表明,针对常见的三相整流性负载产生的谐波,所提算法可以在1/3基波周期内达到稳态,验证了所提算法的可行性和优势。
Selective harmonic extraction is one of the core techniques in the area of power quality, which is widely applied for harmonic assessment, compensation and so on.Generally, harmonic extractions techniques can be divided into time-domain and frequency-domain methods.The time-domain methods can hardly balance the steady-state accuracy and dynamic responses.The frequency-domain methods, referring to the discrete Fourier transform(DFT) based techniques, features prominent advantages like simplicity, enhanced selectivity and steady-steady accuracy.Yet, they also suffer from disadvantages of slow dynamics and rigid structures.To alleviate these problems, proposes to reconstruct the traditional iterative DFT in order to adapt for the specific harmonic patterns of the input signal.The proposed technique is actually the extended and generalized iterative DFT with the features of flexible structure and fast dynamics. Prototype is built to verify the effectiveness of the proposed method.Experiments show that fast responses of 1/3 fundamental cycle are achieved for typical applications of the three-phase diode rectifier.
Selective harmonic extraction is one of the core techniques in the area of power quality, which is widely applied for harmonic assessment, compensation and so on.Generally, harmonic extractions techniques can be divided into time-domain and frequency-domain methods.The time-domain methods can hardly balance the steady-state accuracy and dynamic responses.The frequency-domain methods, referring to the discrete Fourier transform(DFT) based techniques, features prominent advantages like simplicity, enhanced selectivity and steady-steady accuracy.Yet, they also suffer from disadvantages of slow dynamics and rigid structures.To alleviate these problems, proposes to reconstruct the traditional iterative DFT in order to adapt for the specific harmonic patterns of the input signal.The proposed technique is actually the extended and generalized iterative DFT with the features of flexible structure and fast dynamics. Prototype is built to verify the effectiveness of the proposed method.Experiments show that fast responses of 1/3 fundamental cycle are achieved for typical applications of the three-phase diode rectifier.
引文
[1]徐超,朱强,张红卫.基于SAPF和逆变器统一控制光伏并网策略研究[J].电力电子技术,2015,49(11):24-28.
[2] L Asiminoaei,F Blaabjerg,S Hansen.Detection is Key-harmonic Detection Methods for Active Power Filter Applications[J].IEEE Ind. Appl. Mag.,2007,13(4):22-33.
[3] X Yuan, W Merk, H Stemmler, et al. Stationary-frame Generalized Integrators for Current Control of Active Power Filters With Zero Steady-state Error for Current Harmonics of Concern Under Unbalanced and Distorted Operating Conditions[J].IEEE Trans. on Ind. Appl.,2002,38(2):523-532.
[2] L Asiminoaei,F Blaabjerg,S Hansen.Detection is Key-harmonic Detection Methods for Active Power Filter Applications[J].IEEE Ind. Appl. Mag.,2007,13(4):22-33.
[3] X Yuan, W Merk, H Stemmler, et al. Stationary-frame Generalized Integrators for Current Control of Active Power Filters With Zero Steady-state Error for Current Harmonics of Concern Under Unbalanced and Distorted Operating Conditions[J].IEEE Trans. on Ind. Appl.,2002,38(2):523-532.