本文選題：低壓直流系統(tǒng) + 直流安全電壓��； 參考：《重慶大學(xué)》2014年碩士論文

【摘要】：節(jié)能環(huán)保的低壓直流（low voltage direct current, LVDC）供電方式在民用建筑等常規(guī)領(lǐng)域具有很大的應(yīng)用潛力，其安全保護(hù)問題的成功解決將成為LVDC系統(tǒng)向常規(guī)領(lǐng)域推廣的關(guān)鍵所在。低壓供電系統(tǒng)的安全主要體現(xiàn)為有合適的接地措施，并在故障時(shí)能保證電氣設(shè)備及人身的安全。論文從LVDC系統(tǒng)接地型式、短路保護(hù)兩方面展開研究，為LVDC系統(tǒng)的進(jìn)一步推廣提供一定的理論依據(jù)。 低壓系統(tǒng)接地型式的選擇主要由系統(tǒng)電擊防護(hù)性能與供電連續(xù)性決定，尤以電擊防護(hù)性能為重點(diǎn)。安全電壓限值是研究低壓系統(tǒng)電擊防護(hù)性能的基礎(chǔ)，且直流電通過人體時(shí)的電擊效應(yīng)與交流電有著本質(zhì)的差異。論文首先結(jié)合國際標(biāo)準(zhǔn)IEC60479-1，對(duì)比了直流電與交流電電擊效應(yīng)，給出了直流電的安全閾值曲線，分析了不同方向直流電通過人體時(shí)的安全電壓限值。同時(shí)，，論文還對(duì)目前所能獲得的直流電可能含有高頻紋波的現(xiàn)象，討論了直流紋波對(duì)人體電擊效應(yīng)的頻率加權(quán)效應(yīng)及影響。 基于對(duì)直流安全電壓的分析，論文探討了理想直流源、單相橋式整流器兩種直流供電電源系統(tǒng)各接地型式的電擊防護(hù)性能。重點(diǎn)詳細(xì)分析了基于直流微網(wǎng)、電壓平衡器的直流雙極供電系統(tǒng)的接地故障參數(shù)，利用Matlab/Simulink軟件構(gòu)建了DC±190V系統(tǒng)進(jìn)行驗(yàn)證。在此基礎(chǔ)上，討論了各接地型式的供電連續(xù)性、電擊防護(hù)性能與保護(hù)設(shè)備要求，與傳統(tǒng)交流220V供電系統(tǒng)的對(duì)比表明，低壓直流供電系統(tǒng)在電氣安全方面有較明顯的優(yōu)勢；直流TT系統(tǒng)在配備RCD的情況下，其供電連續(xù)性和電氣安全性能可以得到很好兼顧，相較直流IT和直流TN系統(tǒng)而言，更適合作為該類含有電壓平衡器的直流雙極供電系統(tǒng)的接地型式，并給出了保證其電氣安全的接地電阻取值范圍及保護(hù)裝置技術(shù)要求。 針對(duì)LVDC系統(tǒng)的短路故障及保護(hù)配合問題，論文討論了PWM控制的三相橋式整流器的短路故障，分別基于外特性曲線和開關(guān)函數(shù)模型，給出了兩種簡化短路模型。然后重點(diǎn)利用直流變換電源，搭建小型的直流供電網(wǎng)絡(luò)，對(duì)線路短路、負(fù)載短路的故障參數(shù)分別進(jìn)行測量，得到了LVDC系統(tǒng)短路電流的變化情況，并分析了各短路故障對(duì)直流供電電源的影響，測試了直流斷路器與直流電源、直流負(fù)載自身保護(hù)的相互配合情況。
[Abstract]:Low-voltage DC low voltage direct current, LVDC) power supply mode with energy saving and environmental protection has great application potential in conventional fields such as civil buildings. The successful solution of its safety protection problem will become the key to popularize the LVDC system to the conventional field. The safety of low voltage power supply system is mainly reflected by proper grounding measures, and the safety of electrical equipment and personal can be guaranteed in the event of failure. In this paper, the grounding type and short circuit protection of LVDC system are studied, which provides a theoretical basis for the further popularization of LVDC system. The selection of grounding type of low voltage system is mainly determined by the system electric protection performance and the continuity of power supply, especially the electric shock protection performance. The safe voltage limit is the basis of studying the electric shock protection performance of low voltage system, and the electric shock effect of DC passing through the human body is essentially different from that of AC. Combining with the international standard IEC60479-1, this paper compares the electric shock effect between DC and AC, gives the safety threshold curve of DC, and analyzes the safe voltage limit when DC passes through human body in different directions. At the same time, the frequency weighting effect of DC ripple on human body is discussed. Based on the analysis of DC safe voltage, the paper discusses the protective performance of each grounding type of DC power supply system with ideal DC source and single-phase bridge rectifier. The grounding fault parameters of DC bipolar power supply system based on DC microgrid and voltage balancer are analyzed in detail, and the DC 鹵190V system is constructed by Matlab/Simulink software. On this basis, the continuity of power supply, the protective performance of electric shock and the requirements of protective equipment are discussed. The comparison with the traditional AC 220V power supply system shows that the low-voltage DC power supply system has obvious advantages in electric safety. When DC TT system is equipped with RCD, its power supply continuity and electrical safety performance can be well taken into account, compared with DC IT and DC TN systems, It is more suitable to be the grounding type of DC bipolar power supply system with voltage balancer, and the range of grounding resistance and the technical requirements of protective device are given to ensure its electrical safety. Aiming at the problem of short circuit fault and protection coordination of LVDC system, this paper discusses the short circuit fault of three phase bridge rectifier controlled by PWM. Based on the external characteristic curve and switch function model, two simplified short circuit models are given. Then the DC power supply is used to build a small DC power supply network. The fault parameters of short circuit and load short circuit are measured, and the variation of short circuit current in LVDC system is obtained. The influence of each short-circuit fault on DC power supply is analyzed, and the mutual cooperation between DC circuit breaker and DC power supply, DC load self-protection is tested.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TM862

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 吳衛(wèi)民;何遠(yuǎn)彬;耿攀;錢照明;汪i襠

本文編號(hào)：1862720