question bank source: Production Safety Simulation Examination Yitong Official Account Mini Program
2022 Relay Protection Examination Questions are relay protection Job Certificate Questions New Version Textbook Outline Question Bank! The 2022 relay protection test questions and answers are based on the relay protection test textbook. The relay protection exam question bank passes the production safety simulation exam and passes the full question bank.
1. [Single choice question] Generally, the calculation of relay protection action value, ( ) and the verification of sensitivity are called tuning calculation of relay protection . (C)
A, power
B, phase
C, action time
2, [Single choice question] After the three-stage current protection is installed ( ) components, the three-stage direction current protection can be formed. (C)
A, low voltage
B, overcurrent
C, power direction
3, [Single choice question] neutral point ungrounded system has a single-phase grounding fault, and the fault line zero-sequence current ( ). (C)
A, equal to 0
B, equal to this line to ground capacitor current
C, equal to the sum of the capacitor currents of each non-fault line to ground
4, [Single choice question] The text symbol of intermediate relay is represented as (). (C)
A, KV
B, KA
C, KM
5, [Single choice question] After the low-voltage relay is operated, the return voltage of the low-voltage relay is called the low-voltage relay ( ) that returns the relay to the original state. (B)
A, maximum voltage
B, minimum voltage
C, any voltage
6, [Single choice question] Using the characteristics of interruption of waveform in the transformer excitation inrush current and continuous short circuit current , usually ( ) is used to form the transformer differential protection. (C)
A, second harmonic braking principle
B, differential relay with speed saturation converter
C, identification waveform interruption principle
D, waveform symmetry principle
7, [Single choice question] Overcurrent protection of current increase in action during faults, in order to make protection action, the sensitivity coefficient must (). (A)
A, greater than 1
B, less than 1
C, equal to 1
8, [Single choice question] Transformer failures are divided into two categories: external fuel tank failures and ( ). (A)
A, fault in the fuel tank
B, low-pressure casing failure
C, insulation failure
D, high-pressure casing failure
9, [Single choice question] The main component of transformer gas protection is gas relay , installed in (). (B)
A,
B in the transformer oil tank,
B in the connecting pipeline between the transformer oil tank and oil pillow in the
C,
D on the high-pressure casing,
10 on the low-pressure casing, [Single choice question] When the transformer leaks oil, the oil level will drop, and will be issued (). (A)
A, light gas signal
B, heavy gas signal
C, protective trip signal
D, overload signal
11, [Single choice question] In operation, ( ) and electric sparks or arcs are the direct causes of electrical fires. (A)
A, heat of current
B, voltage
C, ambient temperature
12, [Single choice question] When the backup power supply automatic input device is operated, the backup power supply is input by combining ( ) circuit breaker or backup transformer circuit breaker. (B)
A, working line
B, backup line
C, working transformer
D, working bus
13, [Single choice question] The operation time of the automatic input device of the backup power supply should be based on ( ) as the principle to reduce the self-starting time of the motor .(B)
A, load power outage time as short as possible
B, load power outage time as short as possible
C, self-initiated success rate as low as possible
D, device failure rate as low as possible
14, [Single choice question] When the backup power supply is automatically put into operation, when the voltage transformer is disconnected twice, the self-initiated device should (). (C)
A, delay action
B, acceleration action
C, non-action
D, reliable action
15, [Single choice question] For transformers with a capacity below 10,000kVA, when the overcurrent protection action time is greater than ( ), vertical differential protection should be installed. (D)
A, 2.5S
B, 1.5S
C, 1S
D, 0.5S
16, [Single choice question] For radial grids with power supply on one side, instantaneous current quick break protection should ( ) for lower line failures. (B)
A, correct action
B, no action
C, uncertain
17, [Single choice question] The requirement for limited-time current quick-break protection is that the protection scope must include ( ) in any case and has specified sensitivity. (A)
A, the full length of this line
B, the full length of this line and the lower line
C, part of this line
18, [Single choice question] The current and voltage relay are realized by ( ). (C)
A, micro current, voltage relay
B, integrated circuit current, voltage relay
C, software algorithm
19, [Single choice question] The AC safety voltage stipulated in my country is (). (C)
A, 220V, 42V, 36V, 12V
B, 380V, 42V, 36V, 12V
C, 42V, 36V, 12V, 6V
20, [Single choice question] In the circuit breaker control loop , the operating power supply voltage is ( ) is called strong power control. (B)
A, 48V and below
B, 110V or 220V
C, 380V
D, 10kV
21, [Single choice question] After the time relay is started, the contact is activated after the set time delay is delayed. (A)
A, closed
B, disconnect
C, arbitrary position
22, [Single choice question] The limited-time current quick-break protection of this line has an overlap area with the instantaneous current quick-break protection range of this line. When a fault occurs in the overlap area, it is (). (B)
A, the limited-time current quick-break protection action of this line trips
B, the instantaneous current quick-break protection action of this line trips
C, the all-action trips
23, [Single choice question] The zero-sequence current II section protection of this line action current is (). (B)
A, combined with zero-sequence current I-segment protection of the lower line,
B, combined with zero-sequence current I-segment protection of this line,
C, combined with zero-sequence current II-segment protection of the lower line,
24, [Single choice question] The differential protection of a transformer uses a differential relay with a speed saturated converter. When the no-load is closed, due to the large transformer capacity, the excitation inrush current is equivalent to the fault current, so the protection is ( ). (B)
A, reliable trip
B, lock
C, send trip signal
D, delay trip
25, [Single choice question] A line of a certain substation uses three-stage current protection, the setting value of the limited-time current speed break is 10A, and when a phase-to-phase fault occurs at the end of the line, the maximum short-circuit current (three-phase short-circuit in the maximum operation mode) is 30A, and the minimum short-circuit current (two-phase short-circuit in the minimum operation mode) is 15A, and the sensitivity coefficient of the limited-time current speed break protection is ().(A)
A, 1.5
B, 2
C, 3
D, 4
26, [Single choice question] According to statistical analysis of electric shock accidents, electric shock accidents change significantly with the season, and the ( ) season is more prone to occur and concentrated every year. (B)
A, one; two
B, two; three
C, three; four
27, [Single choice question] The intermediate link in the power system that contacts ( ) and users is called the power network. (C)
A, power transmission line
B, transformer
C, power plant
28, [Single choice question] When the motor capacity is ( ), the longitudinal differential protection adopts two-phase wiring. (C)
A,
B, 2MW or above
C, 5MW or less
29, [Single choice question] The grounding fault current of the motor is, the neutral point non-grounding system is more important than the neutral point through resistance grounding system ( ). (B)
A, large
B, small
C, equal
30, [Single choice question] The longitudinal differential protection wiring of the motor adopts ratio braking characteristics, which should ensure that the unbalanced current of the external three-phase short-circuit motor is avoided during normal operation, when the external three-phase short-circuit motor supplies short-circuit current outward, and ( ) differential circuit is not allowed to be avoided. (C)
A,
B when the internal two-phase short circuit is
B when the internal three-phase short circuit is
C when the motor is fully voltage started
31. [Single choice question] The motor is equipped with overvoltage protection, and when the voltage between the three phases is higher than the set value, protect (). (A)
A, tripping
B after delay, sending out abnormal signal
C, not acting
32, [Single choice question] When the motor uses fuse -high voltage contactor to control, the current quick break protection should be coordinated with ( ). (A)
A, fuse
B, high voltage contactor
C, overload protection
33, [Single choice question] Electric sparks and arcs are important causes of electrical fires, because the temperature of electric sparks is high and can reach ( ), and flammable materials are easily ignited. (B)
A, 1000℃-2000℃
B, 3000℃-6000℃
C, 500℃-800℃
34, [Single choice question] The voltage relay in relay protection device is connected to the secondary test of ( ). (B)
A, current transformer
B, voltage transformer
C, circuit breaker
35, [Single choice question] In the relay protection device, the voltage relay is connected to the ( ) of the voltage transformer. (B)
A, primary side
B, secondary measurement
C, primary and secondary side
36, [Single choice question] The function of the automatic low-frequency load reduction device is ( ) and to ensure the power consumption of important loads. (B)
A, ensure normal operation of ordinary loads
B, ensure safe and stable operation of power system
C, ensure selective relay protection action
37, [Single choice question] The regulations stipulate: When the grounding capacitor current in the generator direct distribution network is greater than 5A, the neutral point grounding method adopts (). (A)
A, grounded by arc suppression coil grounded by
B, direct grounded by
C, grounded by resistor
38, [Single choice question] drop fuse is installed with ( ), allowing the load current of a certain size to be cut off. (B)
A, fuse
B, arc suppression grid
C, nut
D, spring
39, [Single choice question] When the bulldozer is driving on a concave and convex road, the body is violently vibrating due to uneven roads, which is easy to ( ). (A)
A, damaged parts
B, overturn
C, injured
D, crash
40, [Single choice question] The protection range of time-limited current speed break protection is the full length of the line, and sensitivity verification should be selected ( ) for verification.(B)
A, the most favorable situation for protection
B, the most unfavorable situation for protection
C, any situation
41, [Single choice question] zero-sequence voltage usually uses three single-phase voltage mutual, safe production simulation test, sensor or ( ) to obtain. (C)
A, three single-phase current transformers
B, one single-phase current transformer
C, three-phase five-column voltage transformer
42, [Single choice question] Comparison of the protection operation time limit of zero-sequence current III segment protection operation time limit of reaction phase-to-phase fault overcurrent protection operation time limit (). (B)
A, zero-sequence current III segment protection operation time limit is greater than overcurrent protection operation time limit
B, zero-sequence current III segment protection operation time limit is less than overcurrent protection operation time limit
C, zero-sequence current III segment protection operation time limit is equal to overcurrent protection operation time limit
43, [Single choice question] Common abnormal operating states in the operation of high-voltage motor are: starting time is too long, ( ) or three-phase imbalance, blockage, overcurrent caused by overload, and supply voltage is too low or too high. (C)
A, inter-turn short circuit of one-phase winding
B, inter-phase short circuit fault of stator winding
C, one-phase fuse fuse
44, [Single choice question] High-voltage motors are usually equipped with longitudinal differential protection or current quick break protection, ( ), protection of excessive starting time, overheating protection, blocking protection, overcurrent protection, single-phase grounding protection, low voltage protection, etc. (C)
A, gas protection
B, distance protection
C, negative sequence current protection
45, [Judgement Question] In the three-stage current protection, the time limit overcurrent protection constitutes the backup protection of the line. (√)
46. [Multiple choice question] A phase grounding fault occurs in the system without the neutral point grounding, UAB, UAC decreases, and UBC remains unchanged. (×)
47. [Judgement Question] In secondary system , a system that is composed of a signal sending mechanism, a receiving display element and its loop wiring to achieve accurate and timely display of the working status of the primary system and equipment is called a signal system. (√)
48. [Multiple choice question] In the secondary system, the system that consists of a DC power supply and a power supply network to supply the working power of the secondary system is called the operating power system. (√)
49. [Multiple choice question] In transformer protection, current quick-break protection and zero-sequence current are backup protection of the transformer. (×)
50. [Multiple choice question] The fundamental reason for the excitation surge current of the transformer is that the magnetic flux in the transformer core cannot be suddenly changed. (√)
51. [Judgement Question] The transformer excitation current exists on the power supply side and the load side. (×)
52. [Multiple choice question] In the wiring of transformer , the backup transformer generally uses the clear backup method. 'Safe Production Simulation Exam One-time Pass' (√)
53. [Multiple choice question] In transformer differential protection, TA line disconnection monitoring is used to send a signal when the current transformer is disconnected twice. (√)
54. [Multiple choice question] Transformer differential protection can ensure selectivity in principle, and the operation time is set to 0.5S. (×)
55. [Multiple choice question] The differential components of transformer differential protection usually use ratio braking characteristics, and external short-circuit current is introduced as the braking amount. (√)
56. [Judgement Question] Transformer failures are divided into two categories: internal tank failures and external tank failures. (√)
57. [Multiple choice question] Transformer gas protection includes light gas protection and heavy gas protection. (√)
58. [Judgement Question] Backup Protection is generally shorter than the main protection action delay. (×)
59. [Multiple choice question] All connection lines between devices in the secondary circuit need to be marked, and the markings are combined with numbers and text to indicate the nature and purpose of the circuit.(√)
60. [Multiple choice question] When rescuing the person who was electrocuted from the power supply, no insulation measures were taken, and the rescue personnel shall not directly contact the person who was electrocuted or the person who was electrocuted from the skin or wet clothes. (√)
61. [Multiple choice question] When the backup power supply is automatically put into operation, when the backup power supply is put into operation, the relay protection should accelerate the operation when the backup power supply is put into operation when the fault is put into operation. (√)
62. [Judgement Question] When the backup power supply is automatically put into operation, when the backup power supply is not voltage-free, backup self-loading device should act quickly. (×)
63. [Judgement Question] In the differential protection of the transformer in the differential relay during external failure, the current flowing into the differential relay is an unbalanced current. (√)
64. [Judgement Question] There is an error in the actual current transformer during the current conversion process. The ratio of primary current to secondary current is not equal to its change ratio, which is called the change ratio error. (√)
65. [Judgement Question] For under-volume relay protection devices that react to lower fault parameters and operate, the sensitivity is calculated as the operation parameters of the protection device divided by the maximum calculated value of the fault parameters when a metal short circuit occurs at the end of the protection range. (√)
66. [Multiple choice question] For oil-immersed transformer with a capacity of 800kVA or above and in-shop oil-immersed transformers with a capacity of 400kVA or above, gas protection should be installed. (√)
67. [Multiple choice question] Electrical equipment and devices that may cause electric sparks, arcs and high temperature hazards during operation should not be placed in flammable and dangerous places. (√)
68. [Multiple choice question] The secondary device in the substation is combined and optimized for design, and uses advanced computer technology, modern electronic technology, communication technology and signal processing technology to integrate the integrated automation system called substation automation . (√)
69. [Multiple choice question] A hidden danger rectification notice should be issued for the accident hazards found during the inspection, and the person, time and measures should be set to be rectified. After the major accident hazards are rectified, the relevant departments shall organize a review. (√)
70. [Multiple choice question] Commonly used voltage transformer wiring methods include star wiring, V-V wiring, two-phase current difference wiring, etc. (√)
71. [Judgement Question] When the time limit current speed break protection of this line and the time limit current speed break protection of the lower line are coordinated, it has the characteristics of reduced operation current, improved sensitivity, increased protection range and short operation time. (×)
72. [Multiple choice question] When the current through current relay is greater than the operating current, the relay acts and the moving contact is disconnected. (×)
73. [Multiple choice question] The method of microcomputer protection to analyze, calculate and judge the sampled data of the analog-to-digital conversion system, and realize various relay protection functions is called data acquisition. (×)
74. [Multiple choice question] The various functions and principles of microcomputer protection are mainly reflected in the software. (√)
75. [Multiple choice question] When cutting off the power and fire, cut off the low-voltage wires in the same way, the three should be cut off. (×)
76. [Multiple choice question] In circuit breaker control, it can be divided into strong power control and weak power control according to the different operating power supply. (√)
77. [Multiple choice question] In the circuit breaker control circuit, the operating power supply voltage is 'safe production simulation test '110V or 220V is called strong electric control. (√)
78. [Multiple choice question] In the circuit breaker control circuit, the operating power supply voltage is 48V and below is called weak current control. (√)
79. [Judgement Question] The auxiliary contact of the circuit breaker is connected to the protection trip circuit. After the protection operation, the trip circuit can be disconnected, which can prevent the contacts of the intermediate relay from disconnecting the trip circuit and protecting the contacts. (√)
80. [Judgement Question] The use of current transformers in the power system can isolate the secondary equipment from the primary high voltage to ensure the safety of staff. (√)
81. [Multiple choice question] The power system is a whole composed of power plants, substations, power transmission lines, distribution lines, and power users.(√)
82. [Multiple choice question] The high-set value of the motor current quick-off protection is adjusted according to the maximum load current that avoids the motor. (×)
83. [Multiple choice question] Various non-grounded asymmetric faults of the motor include short circuit between turns of the motor, phase disconnection, reverse phase sequence connection, and large unbalance of the supply voltage. (√)
84. [Multiple choice question] When the overload protection of the motor is simplified, the overload protection with the reverse time limit characteristic can be used. (×)
85. [Multiple choice question] The motor longitudinal differential protection wiring is connected to the current transformer on the machine side and the other side to the current transformer on the neutral point side. (√)
86. [Judgement Question] Motor negative sequence current protection, locking negative sequence current protection when I21.2I1 (I2 negative sequence current, I1 positive sequence current). (√)
87. [Judgement Question] After the motor is tripped by overheating protection during operation, the accumulated heat is reduced to the fixed value of the overheating accumulation locking motor restart, the motor prohibits the restart circuit from operating, and the motor cannot start again. (×)
88. [Multiple choice question] When the motor is tripped by overheating protection during operation, the motor is disabled. "Safe production, simulation test, one-point pass, stop restarting circuit, and the motor can start again. (×)
89. [Judgement Question] Instantaneous current quick-break protection reaction line failure, the current decreases and there is no action delay. (×)
90. [Multiple choice question] The voltage relay in the relay protection device is connected to the secondary measurement of the current transformer. (×)
91. [Multiple choice question] The secondary measurement of the current relay in the relay protection device is connected to the current transformer. (√)
92. [Judgement Question] The principle that the control switch control switch does not correspond to the circuit breaker position, which means that the control switch is at the position after the switch is opened, and the circuit breaker is actually at the disconnection position. (×)
93. [Judgement Question] The principle that the control switch position of the automatic reclosing switch does not correspond to the circuit breaker position means that the control switch is at the position after closing, and the circuit breaker is actually in the disconnected position. (√)
94. [Judgement Question] When the automatic reclosing gate is locked by the operating system's air pressure is too low, if the air pressure is too low after the circuit breaker is operating, the automatic reclosing gate will automatically close. (×)
95. [Judgement Question] When the automatic reclosing gate is locked by the operating system with too low hydraulic pressure, if the hydraulic pressure is too low after the circuit breaker is operating, the automatic reclosing gate will not be operated. (√)
96. [Judgement Question] The operation process of the incoming line is described as a working line breaking down and tripping. When the monitoring backup line has no current and the working line has voltage, the working line is put into the working line. (×)
97. [Multiple choice question] Usually, the relay protection requires that the error of the current transformer must not exceed 10%. (√)
98. [Multiple choice question] Transformer differential protection composed of waveform interruption principle is locked when the interruption angle is greater than the set value. (√)
99. [Judgement Question] Stage-type zero-sequence current protection has the characteristics of high sensitivity, small delay and little protection range affected by the system operation mode. (√)
100. [Multiple choice question] The operating mechanism of isolating switch usually has three forms: pneumatic operation, electric operation and electro-hydraulic operation. (√)
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