基于小波變換的新型電力諧波檢測方法研究

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摘要：隨著電力電子器件在電網(wǎng)中的廣泛應(yīng)用，其產(chǎn)生的諧波電流大大加重了電力系統(tǒng)的諧波污染。因此，需對(duì)電網(wǎng)諧波的進(jìn)行有效地治理，改善供電質(zhì)量。諧波檢測是研究諧波治理的主要依據(jù)，進(jìn)行諧波檢測方法的研究具有非常重要的意義。
電力有源濾波器(APF)是治理諧波的有效手段。本文旨在為APF諧波治理裝置尋求更精確、快速的諧波檢測方法。
目前，在電力有源濾波器裝置中使用最多的是瞬時(shí)無功功率理論法，該方法具有能同時(shí)檢測有功分量和無功分量的優(yōu)點(diǎn)。論文在介紹了基于瞬時(shí)無功功率理論p-q、ip-iq諧波檢測法，以及基于瞬時(shí)無功功率理論d-q諧波檢測法；重點(diǎn)介紹了小波變換的理論，包括連續(xù)小波變換、離散小波變換、時(shí)頻特性和多分辨率分析。在上述理論基礎(chǔ)上，提出基于小波變換的d-q諧波檢測法，該方法利用小波變換將d-q法的LPF濾波環(huán)節(jié)替換，使其能夠更精確的檢測基波分量和各頻段諧波分量。
為了驗(yàn)證基于小波變換的d-q法檢測諧波的實(shí)際可行性和檢測效果，利用電力系統(tǒng)專用仿真軟件PSCAD/EMTDC，搭建了該方法的諧波檢測仿真模型，并進(jìn)行仿真分析。為了更有力地驗(yàn)證該方法精確度，分別采用ip-iq法和d-q法建立諧波檢測模型，并將仿真結(jié)果與基于小波變換的d-q法進(jìn)行比較。通過對(duì)比分析基波畸變率和檢測延遲時(shí)間，證明基于小波變換的d-q法的諧波檢測精度高于ip-iq法和d-q法，且能夠精確地檢測基波電流和各頻段諧波分量。

關(guān)鍵詞： ip-iq法 d-q法 小波變換 諧波檢測 Park變換 PSCAD/EMTDC
Research of A New Detection Method Based on Wavelet-transform for Harmonic of Power System
Abstract: The power electronic devices being widely used in the power system, which produces greatly harmonic current that increased power system harmonic pollution. Therefore, it is required to effectively govern the harmonic of power grid to improve the quality of power supply. The main basis for harmonic control study is harmonic detection, so it has important significance to study the method of harmonic detection.
Active power filter(APF) is an effective means to control harmonics. This paper seeks more accurate and rapid harmonic detection method for the APF harmonic control devices.
Currently, the most used is the instantaneous reactive power theory method in the device of active power filter. This method has the advantage of that it can simultaneously detect active component and reactive component. This paper focuses on p-q, ip-iq harmonic detection method of instantaneous reactive power theory, and d-q harmonic detection method of instantaneous reactive power theory; Focuses on the theory of wavelet transform, including the continuous wavelet transform, discrete wavelet transform, time-frequency characteristics and the multi-resolution analysis. The wavelet-transform-based d-q detection method is proposed based on the above theory, the wavelet transform will replace the LPF filter link of d-q method to enable detect the fundamental frequency component and harmonic components more accurate.
In order to verify the practical feasibility and effectiveness of wavelet-transform-based d-q detection method, it will build a simulation model of the harmonic detection method and simulation analysis in on the professional power system simulation software PSCAD/EMTDC. To verify the accuracy of the method more effectively, it will establish harmonic detection model of ip-iq and d-q method, the simulation results were compared with wavelet-transform-based d-q detection method. Experimental results prove that wavelet-transform-based d-q detection method is feasible, and can detect the fundamental and each band harmonic components more accurately by comparative analysis of the fundamental distortion and detection delay time.

Key words: ip-iq method d-q method wavelet transform harmonic detection park transformation PSCAD / EMTDC

目 錄
第一章 緒論 1
1.1 研究背景和意義 1
1.1.1 諧波的定義 1
1.1.2 諧波的來源 2
1.1.3 諧波對(duì)電力系統(tǒng)的危害 3
1.1.4 諧波畸變指標(biāo) 3
1.1.5 電網(wǎng)諧波電壓與諧波電流的限制 4
1.2 諧波檢測方法的研究現(xiàn)狀 5
1.3 本文的主要研究內(nèi)容 7
第二章 電力系統(tǒng)諧波檢測方法分析 8
2.1 模擬濾波器的諧波檢測方法 8
2.2 自適應(yīng)諧波檢測方法 8
2.3 基于傅里葉變換的諧波檢測方法 9
2.4 基于神經(jīng)網(wǎng)絡(luò)的諧波檢測方法 10
2.5 基于小波分析的諧波檢測方法 11
2.6 基于瞬時(shí)無功功率理論諧波檢測方法 12
2.6.1 p-q法原理 13
2.6.2 ip-iq法原理和建模 15
2.7 諧波檢測方法的發(fā)展方向 17
2.8 本章小結(jié) 17
第三章 基于小波變換的d-q諧波檢測方法 18
3.1 d-q諧波檢測法的原理和仿真模型 18
3.2 基于小波變換的d-q法 21
3.2.1 連續(xù)小波變換與逆變換 21
3.2.2 離散小波變換與逆變換 23
3.2.3 小波變換的時(shí)頻窗特性 24
3.2.4 多分辨率分析原理 25
3.2.5 基于小波變換的d-q法的原理 26
3.3 基于小波變換的d-q法仿真模型的設(shè)計(jì) 27
3.3.1 基于多分辨率分析的小波變換仿真模型 28
3.3.2 基于小波變換的d-q法的仿真模型 29
3.5 本章小結(jié) 31
第四章 并聯(lián)混合型電力有源濾波器設(shè)計(jì) 32
4.1 LC無源濾波器 32
4.2 電力有源濾波器 33
4.2.1 有源濾波器基本原理 34
4.2.2 基于電流跟蹤的單周控制電路 35
4.3 并聯(lián)混合型電力有源濾波器..