电力电子技术试题及答案库

电力电子技术试题及答案库内容摘要：

单相半波可控整流电路，如（ 1）晶闸管内部短路， （ 2）晶闸管内部开路，在下面的坐标中画出其直流输出电压 Ud 和晶闸管两端电压 UT的波形。 指出下图中①～⑦各保护元件及 VD、 Ld 的名称和作用。 ① 星形接法的硒堆过电压保护； ② 三角形接法的阻容过电压保护； ③ 桥臂上的快速熔断器过电流保护； ④ 晶闸管的并联阻容过电压保护； ⑤ 桥臂上的晶闸管串电感抑制电流上升率保护； ⑥ 直流侧的压敏电阻过电压保护； ⑦ 直流回路上过电流快速开关保护； VD 是电感性负载的续流二极管； Ld是电动 机回路的平波电抗器； 为使晶闸管变流装置正常工作，触发电路必须满足什么要求。 A、触发电路必须有足够的输出功率； B、触发脉冲必须与主回路电源电压保持同步； C、触发脉冲要有一定的宽度，且脉冲前沿要陡； D、触发脉冲的移相范围应能满足主电路的要求； 下图为一单相交流调压电路，试分 析当开关 Q 置于位置 3 时，电路的工作情况并画出开关置于不同位置时，负载上得到的电压波形。 Q 置于位置 1：双向晶闸管得不到触发信号，不能导通，负载上无电压。 Q 置于位置 2：正半周，双向晶闸管 Ⅰ +触发方式 导通。 负半周，由于二极管 VD 反偏，双向晶闸管得不到触发信号，不能导通，负载上得到半波整流电压。 Q 置于位置 3：正半周，双向晶闸管 Ⅰ +触发方式 导通。 负半周，双向晶闸管Ⅲ 触发方式 导通，负载上得到近似单相交流电压。 1在下面两图中，一个工作在整流电动机状态，另一个工作在逆变发电机状态。 （ 1）、标出 Ud、 ED及 id的方向。 （ 2）、说明 E 与 Ud的大小关系。 （ 3）、当α与β的最小值均为 30度时，控制角α的移向范围为多少。 整流电动机状态：电流方向从上到下，电压方向上正下负，反电势 E 方向上正下负， Ud 大于 E，控制角的移相范围 0176。 ~90176。 逆变发电机状态：电流方向从上到下，电压 Ud 方向上负下正，发电机电势 E 方向上负下正， Ud 小于 E，控制角的移相范围 90176。 ~150176。 （英文版 ） easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of the code and rule , lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management , strengthen supervision and inspection, from the thorough investigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. strengthening supervision, discipline inspection and supervision of cadres to set an example for pliance with the code and rule is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection ans as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the awareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do ply with and . To firmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of concept, and consciously safeguard and implement party passes party, take the lead in practicing three strict real strict, so loyal, clean, play. To be good at learning, the Constitution and the code as morality, politics and brought to fruition。 to implement , do not want to, dare not, not with disciplinary ruler to supervision。 to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be plex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Bee more perfect. Life is the most important thing is not to win, but the struggle。 not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers。 not disillusioned after the heart, such as ashes, but experience the storm after the enlightenment。 not unrewarding perfunctorily, but calm attitude of life of unrestrained selfconfidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase the, life is a When no movie, pain is a beginning, the struggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is heaven, think impassability is hell. Since the living, to live better. Sometimes we because of too narrowminded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, pletely depends on how we look at and deal with it. Don39。 t always take everything back to things, and don39。 t get into a blind alley, don39。 t want to face, don39。 t be narrowminded. Poke to care, is a kind of openminded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people。 I am not afraid of the truth to tell the best friend, I39。 m afraid he turned to it as a joke to tell don39。 t 6, when we are in a positive frame of mind, you will find many good things。 and when we are in a negative state of mind, you will find many depressed things。 life happy and worry, all is you of life attitude, optimistic, good luck。 loss of sink, Eritrea pany. When you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7, people are tired, rest。 heart tired, calm. Grow up, mature, this society read. Tired and sad, squat down, to。