大学MOOC Power Electronics(Harbin Institute of Technology)1461237167 最新慕课完整章节测试答案
AC-DC conversion (Rectifier)
Chapter 2 Test
1、单选题：
Which description is not ture for ordinary Thyristor?
选项：
A: Inside is a double transistor model of PNPN four layer semiconductor structure
B: When conducting, it should be saturation conduction, and there is only a small leakage current when blocking
C: Current is Injected into the gate when it is turned on and extracted from the gate when it is turned off
D: There are three link ends, anode pole, cathode pole and gate pole
答案: 【 Current is Injected into the gate when it is turned on and extracted from the gate when it is turned off】
2、单选题：
Which description is ture in normal operation characteristics of Thyristor?
选项：
A: Due to the load inductance, thyristor may flow through the reverse anode current
B: As long as the gate has a trigger current, the thyristor can be turned on
C: Once the thyristor is turned on, the gate loses its control function
D: In order to turn off the thyristor conducting, the anode current flowing through the thyristor should be reduced below the holding current
答案: 【 Once the thyristor is turned on, the gate loses its control function】
3、单选题：
The RMS value of the secondary side voltage of the transformer is U2. The single-phase bridge controlled rectifier supplies power for resistive load. The maximum forward voltage and reverse voltage that the thyristor can withstand are respectively ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
4、单选题：
When the single-phase bridge controlled rectifier supplies power for large inductive load, its conduction angle q is ( )
选项：
A: a
B: 90°
C: 180°-a
D: 180°
答案: 【 180°】
5、单选题：
As shown in the figure, the single-phase bridge controlled rectifier is loaded with a large inductance. The thyristor trigger phase range is ( )
选项：
A: a
B: 90°
C: 180°-a
D: 180°
答案: 【 90°】
6、单选题：
As shown in the figure, the inductance of single-phase bridge controlled rectifier circuit is large enough, U2=200V，a=60°, the average rectifier voltage is ( )
选项：
A: 127V
B: 90V
C: 180V
D: 200V
答案: 【 90V】
7、单选题：
In the commutation process of three-phase half wave controlled rectifier, the incorrect description of natural commutation point is ( )
选项：
A: If the thyristor is replaced by diode, the time of commutation
B: The earliest time when thyristor can trigger conduction
C: Intersection time of phase voltage
D: Intersection time of line voltage
答案: 【 Intersection time of phase voltage】
8、单选题：
When the load of three-phase half wave controlled rectifier is resistance, the maximum reverse voltage and maximum forward voltage of thyristor are respectively ( )
选项：
A: 
B: 
C: 
D: 