本文選題：鎖相環(huán) + 無鎖相環(huán)�。� 參考：《南京航空航天大學(xué)》2014年碩士論文

【摘要】：隨著能源危機(jī)和環(huán)境污染的加重,風(fēng)能、太陽能等新能源的開發(fā)和利用成為時(shí)代的焦點(diǎn),三相雙向變流器作為分布式發(fā)電系統(tǒng)中與電網(wǎng)相接的設(shè)備起著至關(guān)重要的作用。鎖相環(huán)技術(shù)常用于控制系統(tǒng)中檢測電網(wǎng)電壓的相位和頻率,但由于電網(wǎng)電壓存在不平衡和畸變的問題,鎖相角的計(jì)算會(huì)產(chǎn)生一定的誤差。因此,研究三相變流器的無鎖相環(huán)控制策略成為電力電子領(lǐng)域的一大熱點(diǎn)。本文首先介紹了鎖相環(huán)技術(shù)和無鎖相環(huán)技術(shù)的研究現(xiàn)狀及發(fā)展趨勢,同時(shí)分析了不同電網(wǎng)電壓情況下的常規(guī)鎖相環(huán)的鎖相誤差。本文設(shè)計(jì)并完成了一臺(tái)18kVA全數(shù)字控制的三相雙升壓/雙降壓變流器,針對(duì)常規(guī)鎖相環(huán)容易受電網(wǎng)電壓影響的這一問題,提出兩類變流器的無鎖相環(huán)控制策略:直接功率控制和直接電流控制,并建立數(shù)學(xué)模型驗(yàn)證其可行性。仿真與實(shí)驗(yàn)證明,與鎖相環(huán)控制策略相比,無鎖相環(huán)控制策略能夠快速精確地從不平衡以及含有畸變的電網(wǎng)電壓中分離出基波正序分量,提高系統(tǒng)在電網(wǎng)電壓不理想條件下的運(yùn)行能力。之后本文從鎖相效果、適用范圍、算法復(fù)雜性以及動(dòng)態(tài)響應(yīng)速度等角度對(duì)提出的無鎖相環(huán)控制策略進(jìn)行對(duì)比。為了解決電網(wǎng)角頻率出現(xiàn)偏差時(shí)對(duì)基于二階廣義積分器的無鎖相環(huán)控制策略的影響,提出了一種基于二階廣義積分器的鎖頻環(huán)控制策略,建立了其在頻域上的數(shù)學(xué)模型,并分析了其動(dòng)態(tài)響應(yīng)性能。仿真和實(shí)驗(yàn)表明,該鎖頻環(huán)只需采用負(fù)增益系數(shù)的積分器即可實(shí)現(xiàn)頻率鎖定,適用于變流器的不平衡控制、諧波抑制以及頻率突變的場合。最后,采用常規(guī)鎖相環(huán)控制和鎖頻環(huán)控制策略在實(shí)際電網(wǎng)情況下進(jìn)行變流器雙向運(yùn)行實(shí)驗(yàn)對(duì)比,證明了本文提出的新型鎖頻環(huán)的優(yōu)越性。
[Abstract]:With the aggravation of energy crisis and environmental pollution, the development and utilization of new energy, such as wind energy and solar energy, has become the focus of the times. Three-phase bidirectional converter plays an important role as the equipment connected with the power grid in the distributed generation system. Phase-locked loop (PLL) technology is often used to detect the phase and frequency of power grid voltage in control system. However, due to the imbalance and distortion of power grid voltage, the calculation of phase-locked angle will cause some errors. Therefore, the study of phase-free loop control strategy of three-phase converter has become a hot spot in power electronics field. In this paper, the research status and development trend of PLL technology and PLL technology are introduced, and the phase locked error of conventional PLL under different grid voltage is analyzed. In this paper, a three-phase double boost / double step-down converter with 18kVA full digital control is designed and completed, aiming at the problem that the conventional PLL is vulnerable to the influence of power grid voltage. This paper presents two kinds of phase-locked loop control strategies for converters: direct power control and direct current control, and establishes mathematical models to verify their feasibility. The simulation and experiments show that compared with the PLL control strategy, the PLL control strategy can quickly and accurately separate the fundamental positive sequence component from the unbalanced and distorted grid voltage. Improve the system operation ability under the condition of the imperfect voltage of the power network. Then this paper compares the proposed control strategy from the aspects of phase locking effect, application range, algorithm complexity and dynamic response speed. In order to solve the influence of angle frequency deviation on the phase locked loop control strategy based on second order generalized integrator, a frequency locked loop control strategy based on second order generalized integrator is proposed, and its mathematical model in frequency domain is established. The dynamic response performance is analyzed. Simulation and experiments show that the frequency locking can be realized only by using an integrator with negative gain coefficient, which is suitable for unbalanced control of converter, harmonic suppression and frequency abrupt change. Finally, the conventional phase-locked loop control and frequency-locked loop control strategy are used to compare the bidirectional operation of the converter in the actual power network, which proves the superiority of the novel frequency locked loop proposed in this paper.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM46
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本文編號(hào)：1868881