本文選題：微電網(wǎng) + 下垂控制　； 參考：《沈陽(yáng)農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：在全球更為重視以清潔能源為主體的分布式發(fā)電的今天,微電網(wǎng)是應(yīng)用于實(shí)際、將可再生能源發(fā)電大規(guī)模并網(wǎng)的有效方式,是將分布式電源和傳統(tǒng)電力系統(tǒng)相融合的橋梁。與傳統(tǒng)電網(wǎng)相比,微電網(wǎng)雖然可以提高供電的穩(wěn)定性、可靠性以及電能質(zhì)量,但是由于分布式發(fā)電所具有的間歇性和隨機(jī)性等帶來(lái)的潮流不穩(wěn)定的影響,暴露了其局限性。而功率的精確分配、維持電壓和頻率的穩(wěn)定等逆變器控制也逐漸成為了微電網(wǎng)領(lǐng)域中最為熱門(mén)的研究方向之一。傳統(tǒng)的集中控制方法無(wú)法解決現(xiàn)今多種模式運(yùn)行的微電網(wǎng)帶來(lái)的低可控、信息收集難引起的復(fù)雜系統(tǒng)控制,但基于多智能體的分布式控制法對(duì)于目前大量分布式并網(wǎng)引發(fā)的問(wèn)題解決有著明顯優(yōu)勢(shì)。本文通過(guò)多智能體控制理論應(yīng)用于微電網(wǎng)多逆變器的分布式控制當(dāng)中,獲得了使用與微電網(wǎng)孤島運(yùn)行時(shí)分布式發(fā)電的功率精確分配、微電網(wǎng)二級(jí)電壓與頻率的恢復(fù)控制等成果。具體內(nèi)容如下:針對(duì)傳統(tǒng)的下垂控制引起電壓、頻率偏移的問(wèn)題和考慮線路阻抗不匹配的實(shí)際情況,從微電網(wǎng)和分布式發(fā)電建模,二級(jí)控制器上存在的局限性分析出發(fā),提出了基于一致性算法的分布式二級(jí)電壓,頻率恢復(fù)控制策略。在二級(jí)頻率恢復(fù)控制中,提出了考慮有功功率精確分配的分布式二級(jí)頻率恢復(fù)控制器,在二級(jí)電壓恢復(fù)控制中,提出了考慮線路參數(shù)不平衡,利用動(dòng)態(tài)一致性控制的分布式平均電壓恢復(fù)控制策略。仿真驗(yàn)證了提出的分布式二級(jí)控制方法能夠保證電壓幅值和頻率恢復(fù)。針對(duì)傳統(tǒng)的下垂控制無(wú)功功率分配不精確的問(wèn)題和考慮線路阻抗不匹配的實(shí)際情況,從傳統(tǒng)電壓/無(wú)功下垂控制以及微電網(wǎng)傳輸線路阻抗特性等方面分析了負(fù)荷無(wú)功功率分配、微電網(wǎng)環(huán)流抑制的機(jī)理。通過(guò)虛擬阻抗調(diào)整,實(shí)現(xiàn)傳統(tǒng)的下垂控制方法導(dǎo)致有功功率和無(wú)功功率之間的解耦,建立了基于一致性算法的無(wú)功功率分配控制策略。該策略通過(guò)多智能體一致性算法發(fā)現(xiàn)無(wú)功功率分配誤差。使無(wú)功分配誤差自適應(yīng)調(diào)整虛擬阻抗,從而得到按照分布式發(fā)電容量反比例的等效線路阻抗。根據(jù)基于虛擬阻抗調(diào)整的無(wú)功功率按比例分配原理,實(shí)現(xiàn)多分布式發(fā)電之間的負(fù)荷無(wú)功功率精確分配。
[Abstract]:In today's world where more attention is paid to distributed generation with clean energy as the main body, microgrid is an effective way to connect renewable energy generation to the grid on a large scale, and it is a bridge between distributed power generation and traditional power system. Compared with the traditional power grid, microgrid can improve the stability, reliability and power quality of power supply, but its limitation is exposed because of the impact of power flow instability caused by the intermittent and randomness of distributed generation. The accurate distribution of power, the maintenance of voltage and frequency stability and other inverter control has gradually become one of the hottest research directions in the field of microgrid. The traditional centralized control method can not solve the complex system control caused by the low controllability and information collection caused by the multi-mode microgrid. But the distributed control method based on multi-agent has obvious advantages to solve the problems caused by distributed grid connection. In this paper, the theory of multi-agent control is applied to the distributed control of microgrid multi-inverter, and the results are obtained, such as accurate power distribution of distributed generation with isolated island operation of micro-grid, restoration control of two-stage voltage and frequency of micro-grid, and so on. The main contents are as follows: aiming at the problems of voltage and frequency offset caused by traditional droop control and considering the actual situation of line impedance mismatch, the paper analyzes the limitations of microgrid and distributed generation modeling, and the limitation of secondary controller. A distributed secondary voltage and frequency recovery control strategy based on consistency algorithm is proposed. In the two-stage frequency recovery control, a distributed second-stage frequency recovery controller considering the accurate allocation of active power is proposed. In the two-stage voltage recovery control, the unbalanced circuit parameters are considered. Distributed average voltage recovery control strategy based on dynamic consistency control. Simulation results show that the proposed distributed secondary control method can guarantee the voltage amplitude and frequency recovery. Aiming at the problem of inaccurate reactive power distribution in traditional droop control and considering the actual situation of line impedance mismatch, the load reactive power distribution is analyzed from the aspects of traditional voltage / reactive droop control and impedance characteristics of transmission line in microgrid. The mechanism of microgrid circulation suppression. The traditional droop control method leads to decoupling between active power and reactive power through virtual impedance adjustment. The reactive power allocation control strategy based on consistent algorithm is established. In this strategy, reactive power allocation error is detected by multi-agent consistency algorithm. The virtual impedance is adjusted adaptively by the reactive power distribution error, and the equivalent line impedance is obtained according to the inverse ratio of the distributed generation capacity. According to the principle of proportional distribution of reactive power based on virtual impedance adjustment, the accurate distribution of reactive power among multiple distributed generation is realized.
【學(xué)位授予單位】：沈陽(yáng)農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TM727;TM712
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本文編號(hào)：1968071