T型三電平逆變器技術(shù)研究
發(fā)布時(shí)間：2018-11-03 18:52
【摘要】：隨著能源危機(jī)和環(huán)境污染問(wèn)題日益嚴(yán)重，，包括光伏發(fā)電在內(nèi)的新能源利用越來(lái)越受到人們重視。在可再生能源開(kāi)發(fā)中，交直流混合微電網(wǎng)技術(shù)是重要發(fā)展方向；其中，雙向AC/DC變換器作為交流母線和直流母線的傳輸媒介，其拓?fù)浜涂刂萍夹g(shù)亟待研究。在雙向AC/DC變換器拓?fù)涞倪x取上，T型三電平拓?fù)涓倪M(jìn)了傳統(tǒng)NPC三電平拓?fù)淦骷^(guò)多、損耗分布不均等缺點(diǎn)。因此，本文基于T型三電平拓?fù)湔归_(kāi)研究。 本文首先分析了單相T型三電平逆變器的工作原理和調(diào)制控制策略，搭建了損耗模型并研究了電路中各個(gè)器件的損耗分布，搭建了4kW的實(shí)驗(yàn)樣機(jī)平臺(tái)，給出了并網(wǎng)實(shí)驗(yàn)結(jié)果，包括并網(wǎng)穩(wěn)態(tài)和動(dòng)態(tài)波形、效率等。分析了三相T型三電平逆變器的工作原理，推導(dǎo)了其數(shù)學(xué)模型。通過(guò)去除產(chǎn)生大共模電壓的開(kāi)關(guān)矢量，得到一種低共模電壓的SVPWM調(diào)制算法。在該算法基礎(chǔ)上，采用了兩種不同的小扇區(qū)劃分方式，對(duì)比了逆變器運(yùn)行時(shí)的共模電壓和漏電流，得出了更有利于抑制漏電流的一種劃分方式。推導(dǎo)了兩臺(tái)并聯(lián)變換器的共模電壓等效模型，指出了共模電壓的脈動(dòng)幅值和頻率是影響漏電流大小的重要因素。采用載波移相180度的調(diào)制算法，可以抵消共模電壓頻譜中的開(kāi)關(guān)頻率次分量，使得漏電流得到有效抑制。同時(shí)，為了滿足不同的工況需要，研究了并聯(lián)逆變器系統(tǒng)的能量雙向流動(dòng)管理，分別采用逆變電壓環(huán)和整流電壓環(huán)判斷控制，保證了功率流的一致性，并加入直流側(cè)下垂控制實(shí)現(xiàn)了并聯(lián)逆變器的均流。 最后，搭建了兩臺(tái)T型三相三電平逆變器并聯(lián)實(shí)驗(yàn)樣機(jī)，設(shè)計(jì)了系統(tǒng)的功率電路、驅(qū)動(dòng)保護(hù)電路等，進(jìn)行了三相逆變器并網(wǎng)的動(dòng)態(tài)和穩(wěn)態(tài)實(shí)驗(yàn)。對(duì)比了在分別采用兩種不同小扇區(qū)劃分方式條件下，逆變器并網(wǎng)運(yùn)行時(shí)的共模電壓和漏電流。進(jìn)行了兩臺(tái)變換器并聯(lián)的穩(wěn)態(tài)實(shí)驗(yàn)，給出了整流運(yùn)行和逆變運(yùn)行狀態(tài)下的波形。實(shí)驗(yàn)結(jié)果驗(yàn)證了理論分析及仿真結(jié)果的正確性。
[Abstract]:With the increasing energy crisis and environmental pollution, people pay more and more attention to the use of new energy, including photovoltaic power generation. In the development of renewable energy, AC / DC hybrid microgrid technology is an important development direction, and the topology and control technology of bi-directional AC/DC converter, as the transmission medium of AC bus and DC bus, need to be studied urgently. In the selection of bi-directional AC/DC converter topology, T-type three-level topology improves the traditional NPC three-level topology with too many devices and uneven loss distribution. Therefore, this thesis is based on T-type three-level topology. In this paper, the working principle and modulation control strategy of single-phase T type three-level inverter are analyzed, the loss model is built and the loss distribution of each device in the circuit is studied, the experimental prototype platform of 4kW is built, and the experimental results of grid-connected experiment are given. Including grid-connected steady and dynamic waveforms, efficiency and so on. The working principle of three-phase T-type three-level inverter is analyzed and its mathematical model is deduced. A low common-mode voltage (SVPWM) modulation algorithm is proposed by removing switching vectors that generate large common-mode voltages. On the basis of this algorithm, two different small sector partitioning methods are adopted, and the common-mode voltage and leakage current are compared when the inverter is running, and a partition method is obtained which is more favorable to the suppression of leakage current. The equivalent common-mode voltage model of two parallel converters is derived. It is pointed out that the pulse amplitude and frequency of common-mode voltage are the important factors affecting the leakage current. The switching frequency subcomponent in the common-mode voltage spectrum can be cancelled by using the modulation algorithm of the carrier phase shift 180 degree, which can effectively suppress the leakage current. At the same time, in order to meet the needs of different operating conditions, the energy bidirectional flow management of parallel inverter system is studied. The inverter voltage loop and rectifier voltage loop judgement control are used to ensure the consistency of power flow. DC side droop control is added to realize the current sharing of parallel inverter. Finally, two parallel experimental prototypes of T type three-phase three-level inverter are built, and the power circuit and drive protection circuit of the system are designed, and the dynamic and steady state experiments of the three-phase inverter connected to the grid are carried out. The common-mode voltage and leakage current of the inverter in grid-connected operation are compared under the condition that two different small sectors are used. The steady state experiments of two parallel converters are carried out, and the waveforms of rectifier operation and inverter operation are given. The experimental results verify the correctness of the theoretical analysis and simulation results.
【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)】：TM464
[Abstract]:With the increasing energy crisis and environmental pollution, people pay more and more attention to the use of new energy, including photovoltaic power generation. In the development of renewable energy, AC / DC hybrid microgrid technology is an important development direction, and the topology and control technology of bi-directional AC/DC converter, as the transmission medium of AC bus and DC bus, need to be studied urgently. In the selection of bi-directional AC/DC converter topology, T-type three-level topology improves the traditional NPC three-level topology with too many devices and uneven loss distribution. Therefore, this thesis is based on T-type three-level topology. In this paper, the working principle and modulation control strategy of single-phase T type three-level inverter are analyzed, the loss model is built and the loss distribution of each device in the circuit is studied, the experimental prototype platform of 4kW is built, and the experimental results of grid-connected experiment are given. Including grid-connected steady and dynamic waveforms, efficiency and so on. The working principle of three-phase T-type three-level inverter is analyzed and its mathematical model is deduced. A low common-mode voltage (SVPWM) modulation algorithm is proposed by removing switching vectors that generate large common-mode voltages. On the basis of this algorithm, two different small sector partitioning methods are adopted, and the common-mode voltage and leakage current are compared when the inverter is running, and a partition method is obtained which is more favorable to the suppression of leakage current. The equivalent common-mode voltage model of two parallel converters is derived. It is pointed out that the pulse amplitude and frequency of common-mode voltage are the important factors affecting the leakage current. The switching frequency subcomponent in the common-mode voltage spectrum can be cancelled by using the modulation algorithm of the carrier phase shift 180 degree, which can effectively suppress the leakage current. At the same time, in order to meet the needs of different operating conditions, the energy bidirectional flow management of parallel inverter system is studied. The inverter voltage loop and rectifier voltage loop judgement control are used to ensure the consistency of power flow. DC side droop control is added to realize the current sharing of parallel inverter. Finally, two parallel experimental prototypes of T type three-phase three-level inverter are built, and the power circuit and drive protection circuit of the system are designed, and the dynamic and steady state experiments of the three-phase inverter connected to the grid are carried out. The common-mode voltage and leakage current of the inverter in grid-connected operation are compared under the condition that two different small sectors are used. The steady state experiments of two parallel converters are carried out, and the waveforms of rectifier operation and inverter operation are given. The experimental results verify the correctness of the theoretical analysis and simulation results.
【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)】：TM464
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 周京華,蘇彥民,沈傳文,張琳;基于多電平逆變器通用組合拓?fù)浣Y(jié)構(gòu)的調(diào)制策略研究[J];電工技術(shù)學(xué)報(bào);2005年08期
2 馬琳;孫凱;Remus Teodorescu;金新民;;高效率中點(diǎn)鉗位型光伏逆變器拓?fù)浔容^[J];電工技術(shù)學(xué)報(bào);2011年02期
3 吳衛(wèi)民;何遠(yuǎn)彬;耿攀;錢照明;汪i襠
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