降壓變電所 的英文怎麼說
中文拼音 [jiàngyābiàndiànsuǒ]
降壓變電所
英文
receiving substation-
The emulational calculating theories of traction power supply system ' s operating charts combine with actual things of engineering design at present in chapter three, to set up traction web current distributing mathematical model, integral distributing mathematical model, locomotive distribution and obtaining current model at every moment, and on which making use of mathematical planning methods to set up mathematical models is based at every moment in every instance interval of the railroads. for instance, instantaneous current, instantaneous voltage descent and effective current, main changing capacity and so on, in addition, there are the minimum power shortage model, the optimal transformer substation location, the least engineering expenditure, the optimal mathematical model of traction power supply system. optimize design ' s algorithm of traction power supply system is introduced in detail in chapter four, where programming idea and realizing method of the computer software are given an explanation
本研究主要進行了以下工作:結合牽引供電系統運行圖的模擬原理和現行工程設計的實際情況,建立了牽引網電流分佈、積分分佈、任一時刻機車分佈和取流的數學模型;應用數學規劃方法建立了任一距離區間、任一時刻的瞬時電流、瞬時電壓降數學模型和有效電流、主變容量和主變壓降、最小功率損失、最佳變電所容量、最佳變電所位置、最少工程費用、最少運營維護費用和牽引供電系統方案最優等方面的數學模型;闡明了牽引供電系統優化設計的演算法和計算機軟體編程思想及實現方法;進行了工程實例計算;最後,對牽引供電系統優化設計技術應用進行了總結。All the transmission lines of west - east electricity transmitting project are inevitable to crossing the high altitude and icing areas. for the reducing of the air pressure and the absolute humidity, the electricity strength of insulators will drop obviously. therefore, it must be considered the effect on the insulators " flashover voltage caused by the change of altitude and ice when the insulation cooperation of transmission lines are being designed
「西電東送」工程的所有輸電線路都不可避免的要經過高海拔和覆冰地區,由於大氣壓力和絕對濕度的降低會使絕緣子的電氣強度顯著下降,因此在進行輸電線路的絕緣配合設計時必須考慮到海拔高度和覆冰的變化對絕緣子的閃絡電壓影響。A step - down transformer can reduced a voltage to whatever value is desired
降壓變壓器能把電壓降到所需的任何值。Practice of traction substation combined automation system of shanghai metro line no
淺議上海軌道交通9號線牽引降壓變電所綜合自動化系統的實現及其主要功能Secondly, their aims are made the investment of substations, feeders or running cost of electric power system minimum. but they do n ' t take into account of land utilization, street accessibility of right of way, etc., but demands of electric power system. generally, a straight line distance, namely, euclid distance, was used for calculating the distance between a load point and a substation, which is a straight forward but non - practical way for most planning techniques
其次受研究工具的限制,這些模型以工程投資、運行費用等最小為目標,僅能考慮導線載流量、電壓降等電力系統技術約束條件,簡化略去了用地限制、街道可達性等重要的自然約束條件,且求解這些模型的前奏是計算負荷點到變電所的歐幾里得距離(直線距離) ,簡便但不切合實際(這一點在城市電網規劃中尤其重要) ,因此較難給出技術上可行的最優解。In chapter 4, considering the features of high voltage transformer and the difficulties to make it, a reasonable design scheme with src was proposed, which efficiently reduced negative influence of distributing parameters of transformer on switching power supply and could completely utilize leakage inductance as resonant inductance
第四章中分析了高頻高壓變壓器的特點及難點,提出了合理的串聯諧振變換器的設計方案,能夠完全利用變壓器的漏感作為諧振電感,有效地降低了分佈參數給高壓大功率開關電源所帶來的不利影響。The result shows that, when the full - bridge power converter is joined with boost / buck dc chopper in parallel, it can serve a dc voltage of over 340v and a power of 800w, meanwhile, as output voltage of the fuel cells changes due to loadings, the sliding - mode controller can cause more rapid responses and robustness to the dc bus voltage source
實驗結果顯示,本論文之全橋式功率轉換器與升壓/降壓直流截波器並聯供電時,輸出電壓可達340v以上,輸出功率約為800w ,同時,當燃料電池之輸出電壓因負載而改變時,本論文所提出之滑動模式控制器能使直流鏈電壓具有較快速的響應及強健性。Gca silicon commutate battery charger are the ideal portable tools for charging, they are composed with the conditions of voltage dropping through rectifier transformer, then the bridge rectifying of rectification circuit. the output full - wave pulstin current charge the storage battery. the voltage changing composed with multiband switch. the outputcurrent can be adjusted. this kind of product used any moment onctarging anyplace
Gca系列整流充電機是由整流變壓器的降壓,再經過流電路的橋式整流,輸出全波脈動直流對電瓶進行充電,電壓調速同多頭波段開關組,輸出流可以調節,該產品用任何需要補充充電的場所。Aimed at conquering the local - searching shortcoming in ga, after establishing fuzzy regulation scale of normal voltage, a socalled on - site regulation expert anowledge based on the plantrstation concept in power systemis implemented to eliminate voltage / reactive power overlimit, to amer decrease investinentand to minimiting active power loss. 2
在給出合格電壓的模糊調整裕度的基礎上,提出採用基於廠、站概念的就地調整的專家規則進行輔助變異決策,以增強遺傳演算法的局部收斂性;所採用的專家規則主要包括越限校正、進一步減少無功設備投資和降低網損三個方面。Abstract : on the basis of the theory of controlled phase - changes of piezoceramics, high - temperature polarizing technology makes initial working temperature a little higher than curie temperature of a sample, but the polarization voltage needed is greatly lower than the one needed in normal polarization ( only 1 / 10 - 1 / 5 ). the improved polarizing technology can make polarization more complete
文摘:壓電陶瓷的高溫極化是利用受控的場致有序化的順電鐵電相變原理,使起始極化溫度略高於樣品的居里溫度,但所需的極化電壓大大低於常規極化,僅為1 / 10 - 1 / 5 ;選擇較高的降溫升壓速率,可使極化趨于更加完全,具有常規極化工藝無可比擬的優越性。Moreover, chloride channel blockers, dids and sits, also significantly prevented sts - induced neuronal cell death. with whole - cell patch - clamp recordings, we found chloride channel currents increased significantly with time when holding potential at 60mv and 80mv after 5min and 10 min of sts exposure. these results indicate that potassium channel, especially bk channels, and chloride channel contribute to sts - induced neuronal apoptosis and apoptotic volume decrease, which is probably one of the mechanisms underlying mediation of neuronal apoptosis by potassium channel
用斜坡電壓模式記錄的結果顯示, 10min內正常細胞在鉗制電壓下電流未發生明顯變化,氯通道阻斷劑dids可以抑制所記錄到的電流,加藥10mln就使電流峰值降低到原來的36 % ,向浴槽液中加凋亡誘導劑stssmin后, + 8伽mv鉗制電壓下電流即增大,為加藥前的131 . 3 % ,加藥后10min電流進一步增大,是加藥前的巧5 . 9 % ,而且電流隨時間延長具有繼續增大的趨勢。Soft starters decline only the electric voltage and do not decline the frequency, and make the starting torque turn small, therefore the soft starters be applicable only to the induction motors which drive the low starting torque machine such as blower fan and pump. this paper designed a soft starter adopting the discrete frequency method to start induction motors. it declines not only the electric voltage, but also makes the frequency lower at the same time, so starting torque turns more
由於軟起動器只降壓不降頻,電機的起動轉矩較小,所以傳統軟起動器只適用於風機、水泵類低起動轉矩的負載。本文設計並研製了一種採用分級變頻方法的新型軟起動控制器,在降壓的同時實現有級變頻,從而提高了異步電動機的起動轉矩。This paper studies on used the ac servo system based on ti dsp ( lf2407a ) and the foc and digital signal processing thorem, achieves following results : algorithm. we employ svpwm ( space voltage pwm ) algorithm, improve the efficiency of the electric source, and decrease the harmonious elements. we build the mathematic model of the system and simulate it on matlab platform, dsigne segmented pid regulator to adapt variable speed and widen the speed range. measurement. the velocity and electric current measuring, we adopt multi - sampling - rate and digital filter principles. as more improvements we make, the whole system gets a good results. pc control. the complete controlling system can be controlled remotely. so we develop the pc controlling program.
採用磁場定向脈寬調制演算法,提高了電源利用率,降低了逆變電壓的諧波,改善了電機的運行特性,降低了對電網的污染;在matlab平臺上建立了交流永磁同步伺服電機和電壓空間矢量脈寬調制控制系統的數學模型,在模擬的基礎上,對傳統pid調節器進行了改進,提出轉速調節器和電流調節器採用分段pid結構,根據給定轉速所處的區間,自動選擇相應pid調節器的參數,拓寬了調速范圍,提高了控制精度。Compare to the operation under the dcm mode, the power switches of the inverter under the ccm mode has lower peak current and rms current, so the efficiency can be improved. as the synchronous rectification strategy can reduce the conduction losses of the rectifier, and also due to the zvs realization of all synchronous rectifiers, the
採用非互補導通控制,在ccm模式下由於功率管電流峰值和有效值的減小,逆變器變換效率較dcm模式下有所提高;另外, ccm模式下,反激逆變器採用同步整流控制,減小了整流二極體的導通壓降,並且電路中同步整流管可實現零電壓開通。Evaporative cooling can keep a low and uniform wall temperature. it can reduce the volume, the weight of the electrical equipments. meanwhile, it is safe and reliable even in short - time emergency overloads, so this cooling method really shows great promise on the application of large electrical equipment
採用此種冷卻方式的大型變壓器等電氣設備換熱效率高、能耗少;發熱表面溫度均勻;結構緊湊、製造所需材料減少、製造成本下降;壽命延長;重量減輕、體積減小;安全可靠。What the subject researching is that power energy should be measured with base wave ammeter to power systematic nonlinear user ; and that it is high veracious by base wave ac parameters measurement method to those not bad contaminative. it is well known that all kinds of ac parameters including of base wave and harmonics, but the content of harmonics in power systems increase largely with the mass disturbance to power using high - power electric equipment. which makes wave shape of voltage and current aberrence, so the measurement veracity and reliability decreased largely. at the same time brings out serious infuency to safe run of power system and electric equipment. the power which any non - linear loads consumes can be divided into two sides, one is base power absorbed in power and the other is minus harmonics power
本課題所研究的問題是針對電力系統非線性負載用戶採用基波電度表來計量電能;而對諧波污染不嚴重的線性用戶採用基波交流參數測量的方法仍然具有較高的準確性。眾所周知,各種交流參量都包含基波和各次諧波,然而隨著電力電子技術的迅速發展,大功率的用電設備對電網的干擾也是越來越嚴重,導致電力系統諧波含量迅速增長,使電壓和電流的波形產生嚴重畸變,測量的準確性和可靠性都大大降低,同時也對電力系統和用電設備的安全運行帶來嚴重的影響。任何一種非線性負載所消耗的功率都可以分為兩部分,一部分為從電網中吸取的基波功率,另一部分則是負的諧波功率。If the speaker needs more current ( its overall impedance drops ) then a lower amplifier output impedance will allow that current to be drawn out of the amplifier without causing much of a change in the applied voltage - and that means less distortion
如果揚聲器需要更大電流(揚聲器的整體阻抗降低) ,那麼一個低輸出阻抗的放大器可以容許在輸出相應電流的同時,所施加的電壓變化更小,這也意味著失真更小。If the speaker needs more current ( its overall impedance drops ) then a lower amplifier output impedance will allow that current to be drawn out of the amplifier without causing much of a change in the applied voltage - and that means [ i ] less [ / i ] distortion
如果揚聲器需要更大電流(揚聲器的整體阻抗降低) ,那麼一個低輸出阻抗的放大器可以容許在輸出相應電流的同時,所施加的電壓變化更小,這也意味著失真更小。分享友人