average n. 1.平均,平均数。 2.一般水平,平均标准。 3.【商业】海损;海损费用;(给领航的)报酬。 arithmetical [geometrical] average【数学】相加[相乘]平均数,算术[几何]平均数。 general [particular] average 共同[单独]海损。 petty [accustomed] averages (支付给领航、港口等的)小额[例行]酬劳费。 above [below] the average 平常以上[以下]。 on an [the] average 平均;一般说来。 take [strike] an average 平均起来,折衷,扯平算。 up to the average 合一般标准。 adj. 1.平均的。 2.普通的,一般的。 3.【商业】按海损估价的。 The average age of the boys here is ten. 这些孩子的平均年龄是十岁。 students of average intelligence 智力水平一般的学生。 vt. 1.平均,均分。 2.平均是。 I average six hours work a day. 我每天平均工作六小时。 If you average 4 and 6, you get 5. 4和6均分得5。 vi. 1.平均。 2.(为得到更有利的平均价格而)买进(或)卖出(更多的股票、货物等)。 average down [up] 以低于平均价格买进[以高于平均价格卖出]。 average out 1. 最终达到平衡。 2. 达到平均数,平均为 (to) (The gain averaged out to 30 percent 利润平均为百分之三十)。
on average 按平均数计算; 平均,一般而言; 平均,一般说来; 平均;通常;普通; 平均起来,一般说来; 通常
on the average 按平均值; 平均,一般说来; 平均而言,通常; 平均起来,一般说来; 一般来说,平均来说
current adj. 1.通用的,流行的。 2.现在的,现时的,当时的。 3.流畅的;草写的。 the current price 市价。 current news 时事。 current expenditure 经常费。 current expenses 日常费用。 the current issue [number] (杂志的)本期。 the current week 本星期。 the current year 今年。 the 10th current [curt.] 本月十日。 current account 往来存款账;【法律】交互计算。 current English 现代通行英语,日常英语。 current handwriting 草书。 current money 通行货币。 current rate 现价,成交价。 current thoughts 现时代思潮。 pass [run, go]current 通用,流行。 n. 1.水流;气流;电流。 2.思潮,潮流;趋势,倾向。 3.进行,过程。 a cold current 寒流。 the Japan current 日本海流,黑潮。 the great current of events 天下大势。 a density 密着(海)流。 an alternating [a direct] current 【电学】交[直]流电。 current of air 气流。 current of time [the times] 时势,时代潮流 (go [swim] with [against] the current of the times 顺应[违反]时势)。
Based on the above discussion interleaving two - transistor forward topology is chose . in the second chapter , the operation of interleaving two - transistor forward topology is analyzed . chapter three presents the design procedure of a 3kva dc / dc converter and experimental results , hi the forth chapter , the small signal model of interleaving two - transistor forward under average current - mode control is developed 本文第一章讨论了具有隔离变压器的功率电路拓扑,根据讨论结果确定交错并联双管正激变换器作为选择方案;第二章交错并联双管正激变换器作了原理性分析:第三章完成了3kvadc dc电源模块的设计并给出试验结果;第四章建立了交错并联双管正激变换器平均电流控制方式的小信号模型,给出系统设计方法。
When using the method of periodically renewing electrolyte , the average current efficiency is 47 . 3 % ( ii ) the solubility of k2feo4 in the solution of naoh is higher than that of the same concentration of koh solution and both of them become low with the growth of the alkaline concentration . the solubility of k2feo4 in the mixed solution of koh and naoh was influenced by both of common ions effect and salting - out effect and the influence of common ions effect is more heavy . the rate of methanol ' s reacting with k2feo4 is proportional to the content of water in the solid k2feo4 . the stability of the potassium ferrate solution is far below the solid ( 2 ) k _ 2feo _ 4在naoh溶液中的溶解度高于同浓度koh溶液中的溶解度,且溶解度均随着碱溶液浓度的增大而降低; k _ 2feo _ 4在koh和naoh混合碱溶液中的溶解度,受到同离子效应和盐效应的共同影响,且同离子效应的影响更大;固态k _ 2feo _ 4被甲醇还原的速度与甲醇或固态k _ 2feo _ 4的含水量成正比; k _ 2feo _ 4溶液的稳定性远远低于固态k _ 2feo _ 4 ,少量水的存在,可促使k _ 2feo _ 4按溶解?分解?再溶解?再分解的过程分解。
The main job accomplished of this paper includes : according to the principle and the discussion of the single - phase active power correction , the pfc system , which adopts cuk power converter circuit and average current mode control scheme is indicated as the developing direction of pfc and regarded as the pfc system structure 全文围绕设计cuk型平均电流控制的功率因数校正电路展开,主要完成了以下工作:论文在分析有源功率因数校正器基本工作原理的基础上,通过比较几种不同拓扑的pfc变换器主电路和控制电路的优缺点,明确了本文所要研究的对象?平均电流型控制的cuk型pfc变换器。
With promulgation and obliging actualization of iec 1000 - 3 - 2 etc . international standards , power factor correction ( pfc ) technique become a hotspot of research in power electronics field . based on average current mode , the paper introduce the design and implementation of a fully digital controlled single - phase boost power factor corrector with fast response . the control - loop circuit is realized using digital control and the corrector can tend to unity power factor , lower current harmonics and high transfer efficiency 本文在平均电流模式控制的有源功率因数校正技术的基础上,设计了一种控制电路基于数字信号处理器( dsp ) 、主电路采用boost变换器拓扑结构的全数字单相功率因数校正器,用数字电路代替传统的模拟电路来实现对整个回路的控制,最终使得校正器具有输入功率因数接近于1 、低电流谐波以及高转换效率的特性。
Based on the analysis and comparison of the peak current - injection mode and average current mode control strategies , the method of designing average current control mode pi regulator is obtained . the digital simulation of the converter has been done with the help of matlab software . the good transient and stable character of the converter is attained while rated load 在分析与比较峰值电流模式与平均值电流模式控制策略的基础上,给出平均值电流模式pi调节器的设计方法,利用matlab软件对变换器进行了数字仿真,证实了变换器在额定功率范围内动、静态特性良好;过载情况下变换器具有自动限流、保护主功率器件的特性。
The operation principle of boost pfc converter was analyzed ; and the emulation model of boost pfc module under the average current control was set up . a novel method to sample synthetically the input current and output current was put forward in the text . this can realize the current sampling for the control of pfc and current sharing at the same time 分析了boostpfc变换器的工作原理,建立了基于平均电流控制的boostpfc模块的仿真模型;提出了一种新颖的输入输出电流综合采样方法,可同时实现pfc控制和均流控制的电流采样;建立了并联系统的仿真模型;研究设计了基于平均电流法的并联控制方案及实现电路。
Studies the work principle and key technology of the boost pfc circuit in theory , designs a small power digital boost pfc converter , this converter works in average current control means and based on tms320lf2407 dsp , adopts current and voltage double closed loop control and pi control arithmetic 从理论上分析和研究了数字控制boostpfc电路的工作原理和关键技术,设计了一款小功率基于tms320lf2407dsp的平均电流控制型的数字控制boostpfc变换器,该变换器应用了电压、电流双闭环控制和pi控制算法。