三相三線制有源電力濾波器關(guān)鍵技術(shù)的研究
發(fā)布時間：2018-12-31 17:26
【摘要】：現(xiàn)今,有源電力濾波器已經(jīng)成為一種主流的電能質(zhì)量調(diào)節(jié)裝置,其中并聯(lián)型有源電力濾波器是各類有源電力濾波器中發(fā)展最為成熟的一種,也是實用化最多的一種有源電力濾波器。本文的研究對象是應(yīng)用于三相三線電網(wǎng)系統(tǒng)的并聯(lián)型有源電力濾波器,著重分析和比較了現(xiàn)今主流的實用化技術(shù)。本文對幾種不同結(jié)構(gòu)的LCL開關(guān)紋波濾波器進(jìn)行了比較分析,并給出了一種基于迭代算法的并聯(lián)陷波器LCL濾波器設(shè)計方法。在確定系統(tǒng)主電路拓?fù)浜拖嚓P(guān)參數(shù)前提下,對比分析了并聯(lián)陷波器LCL濾波器、選擇阻尼LCL濾波器和LRCL濾波器的濾波器特性。利用LCL濾波器的諧振頻率公式和特定頻率下高頻紋波支路的電路等效,設(shè)計了一種可以精確確定濾波器諧振頻率的迭代算法,避免了直接對高階濾波器系統(tǒng)的分析,并由此給出了并聯(lián)陷波器LCL濾波器的設(shè)計方法,該方法算法簡單,設(shè)計誤差小。針對電流跟蹤控制采用PI控制時濾波器的諧波補償精度低的缺點,本文設(shè)計了一種由PI環(huán)節(jié)并聯(lián)準(zhǔn)諧振環(huán)節(jié)構(gòu)成的三相三線制有源電力濾波器電流跟蹤控制策略。在建立系統(tǒng)數(shù)學(xué)模型的基礎(chǔ)上,設(shè)計了一種適用于特定次諧波補償?shù)碾娏骺刂撇呗?在傳統(tǒng)PI控制的基礎(chǔ)上,增加若干個準(zhǔn)諧振環(huán)節(jié)對諧波指令電流與補償電流的誤差的特定頻率成分進(jìn)行積分,提高電流控制的跟蹤精度。為了防止母線穩(wěn)壓外環(huán)的影響,電壓外環(huán)的輸出不通過準(zhǔn)諧振環(huán)節(jié)。這種控制策略能夠高精度的跟蹤特定頻率的諧波,而且有較好的母線穩(wěn)壓性能。本文對變流器直流母線不均壓的內(nèi)在原因進(jìn)行了分析。針對均壓控制策略為冗余小矢量法時正負(fù)母線電壓偏差大的缺點,從矢量選擇和作用時間計算兩方面對其進(jìn)行改進(jìn),設(shè)計了一種改進(jìn)的冗余小矢量均壓控制策略。該控制策略能夠有效的減少正負(fù)母線電壓差的波動范圍,改善了均壓控制的動態(tài)性能,仿真和實驗驗證了改進(jìn)的正確性。研究并比較了FFT諧波檢測法和ip-iq諧波檢測法。當(dāng)電網(wǎng)頻率波動時,頻譜泄露和柵欄效應(yīng)會嚴(yán)重影響FFT諧波檢測的精度,對比了采用不同加窗算法時FFT諧波檢測的精度,布萊克曼-哈爾斯窗擁有良好的旁瓣特性,能夠很好的抑制頻譜泄露。對ip-iq諧波檢測的低通濾波器和鎖相環(huán)進(jìn)行了分析和設(shè)計,鎖相環(huán)和低通濾波器的精度分別影響了ip-iq諧波檢測的相位和幅值精度。在電網(wǎng)頻率波動時,ip-iq法的幅值檢測精度略微高于FFT法,FFT法相位檢測精度略微高于ip-iq法。
[Abstract]:Nowadays, active power filter (APF) has become a mainstream power quality regulator, among which shunt APF is one of the most mature active power filters. It is also the most practical active power filter. The research object of this paper is shunt active power filter which is applied to three-phase three-wire power system. In this paper, several LCL switching ripple filters with different structures are compared and analyzed, and a design method of parallel notch filter LCL filter based on iterative algorithm is presented. On the premise of determining the topology and related parameters of the main circuit of the system, the filter characteristics of the parallel notch filter LCL filter and the damping LCL filter and LRCL filter are compared and analyzed. Using the resonant frequency formula of LCL filter and the circuit equivalence of high frequency ripple branch at specific frequency, an iterative algorithm is designed to accurately determine the resonant frequency of filter, which avoids the direct analysis of high order filter system. The design method of parallel notch filter LCL filter is presented. The algorithm is simple and the design error is small. Aiming at the disadvantage of low harmonic compensation accuracy of the filter when current tracking control adopts PI control, this paper designs a three-phase three-wire active power filter current tracking control strategy, which is composed of PI parallel quasi-resonant link and three-phase three-wire active power filter. Based on the mathematical model of the system, a current control strategy suitable for special subharmonic compensation is designed. Based on the traditional PI control, A number of quasi-resonant links are added to integrate the specific frequency components of the error between the harmonic command current and the compensation current to improve the tracking accuracy of the current control. In order to prevent the influence of the bus voltage stabilized outer loop, the output of the voltage outer loop does not pass through the quasi-resonant link. This control strategy can track harmonics at specific frequencies with high accuracy and has good bus voltage stabilization performance. In this paper, the internal causes of the uneven voltage of DC busbar in converter are analyzed. Aiming at the disadvantage of large voltage deviation between positive and negative busbar when the voltage sharing control strategy is redundant small vector method, this paper improves it from two aspects: vector selection and operation time calculation, and designs an improved redundant small vector voltage sharing control strategy. This control strategy can effectively reduce the fluctuation range of positive and negative bus voltage difference and improve the dynamic performance of the voltage sharing control. The simulation and experimental results show that the improved method is correct. FFT harmonic detection method and ip-iq harmonic detection method are studied and compared. When the frequency of power network fluctuates, spectrum leakage and fence effect will seriously affect the accuracy of FFT harmonic detection. Compared with different windowed algorithms, the accuracy of FFT harmonic detection is compared. The Blackman-Hals window has good sidelobe characteristics. It can restrain spectrum leakage very well. The low pass filter and phase locked loop for ip-iq harmonic detection are analyzed and designed. The precision of phase locked loop and low pass filter affect the phase and amplitude accuracy of ip-iq harmonic detection, respectively. The amplitude detection accuracy of ip-iq method is slightly higher than that of FFT method, and that of FFT method is slightly higher than that of ip-iq method.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TM761
，
本文編號：2396886
[Abstract]:Nowadays, active power filter (APF) has become a mainstream power quality regulator, among which shunt APF is one of the most mature active power filters. It is also the most practical active power filter. The research object of this paper is shunt active power filter which is applied to three-phase three-wire power system. In this paper, several LCL switching ripple filters with different structures are compared and analyzed, and a design method of parallel notch filter LCL filter based on iterative algorithm is presented. On the premise of determining the topology and related parameters of the main circuit of the system, the filter characteristics of the parallel notch filter LCL filter and the damping LCL filter and LRCL filter are compared and analyzed. Using the resonant frequency formula of LCL filter and the circuit equivalence of high frequency ripple branch at specific frequency, an iterative algorithm is designed to accurately determine the resonant frequency of filter, which avoids the direct analysis of high order filter system. The design method of parallel notch filter LCL filter is presented. The algorithm is simple and the design error is small. Aiming at the disadvantage of low harmonic compensation accuracy of the filter when current tracking control adopts PI control, this paper designs a three-phase three-wire active power filter current tracking control strategy, which is composed of PI parallel quasi-resonant link and three-phase three-wire active power filter. Based on the mathematical model of the system, a current control strategy suitable for special subharmonic compensation is designed. Based on the traditional PI control, A number of quasi-resonant links are added to integrate the specific frequency components of the error between the harmonic command current and the compensation current to improve the tracking accuracy of the current control. In order to prevent the influence of the bus voltage stabilized outer loop, the output of the voltage outer loop does not pass through the quasi-resonant link. This control strategy can track harmonics at specific frequencies with high accuracy and has good bus voltage stabilization performance. In this paper, the internal causes of the uneven voltage of DC busbar in converter are analyzed. Aiming at the disadvantage of large voltage deviation between positive and negative busbar when the voltage sharing control strategy is redundant small vector method, this paper improves it from two aspects: vector selection and operation time calculation, and designs an improved redundant small vector voltage sharing control strategy. This control strategy can effectively reduce the fluctuation range of positive and negative bus voltage difference and improve the dynamic performance of the voltage sharing control. The simulation and experimental results show that the improved method is correct. FFT harmonic detection method and ip-iq harmonic detection method are studied and compared. When the frequency of power network fluctuates, spectrum leakage and fence effect will seriously affect the accuracy of FFT harmonic detection. Compared with different windowed algorithms, the accuracy of FFT harmonic detection is compared. The Blackman-Hals window has good sidelobe characteristics. It can restrain spectrum leakage very well. The low pass filter and phase locked loop for ip-iq harmonic detection are analyzed and designed. The precision of phase locked loop and low pass filter affect the phase and amplitude accuracy of ip-iq harmonic detection, respectively. The amplitude detection accuracy of ip-iq method is slightly higher than that of FFT method, and that of FFT method is slightly higher than that of ip-iq method.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TM761
，
本文編號：2396886
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