Fujian electric power company recruitment written test questions and their answers as long as it is the power company recruitment test questions, thank you.

1. Fill in the blank: (65438+ 0 for each blank, ***20)

1. A three-phase asynchronous motor, with each phase impedance of 32+j24ω and line voltage of 380V. If Y-shaped wiring is adopted, the phase current IP=, line current IL= and power P=.

2. Installing the equalizing ring on the post insulator can improve the flashover voltage, because.

3. The power generation capacity of the power plant should meet the load power of users.

4. The methods to improve the frequency can be divided into two categories: and.

5. According to the distribution situation, equipment and wires can be selected.

6. Automatic switching-in devices for standby power supply and standby equipment can be divided into: and.

7. There are two grounding methods for neutral point of power system, and.

8. The inductive reactive power of synchronous generator when it is over-excited.

9. Increasing the working voltage of the system can stabilize the system statically.

10. Protection scale with microcomputer as the core component.

1 1. The most common faults in power system are.

12. The sum of three-phase currents when there is zero sequence current in the system.

13. The grounding resistance of the generator is not only related to the nature of the land, but also related to.

14. The power direction relay adopts 90 wiring, which has the advantage that when two-phase short circuit occurs in the forward direction, it does not.

Second, the choice: (2 points for each question, ***30 points)

1. The following is not a DC operating power supply ().

380V B.220V C.110V D.48V

2. Under which of the following circumstances is the synchronous generator more stable? ().

A. Short circuit ratio is small B. Overexcitation C. Underexcitation D. Synchronous reactance is large

3. The power factor refers to the cosine of the included angle ().

A. phase voltage and phase current.

4. In order to ensure that the system frequency changes within the specified range, () should be maintained.

A. active power balance B. constant voltage C. reactive power balance

5. The impedance relay to join the memory circuit and introduce the third phase voltage is ().

A. full impedance relay B. directional impedance relay C. offset impedance relay D. power directional relay

6. If you want to ensure that any group of buses will not interrupt the power supply of each socket when a short circuit occurs, you should choose ().

A. double-bus connection B. double-bus sectional busbar C. bridge connection D. two-thirds connection

7. The transformation ratio of the three-phase transformer is 3, and the rated voltage is added to the low-voltage side, and P0 = 3000 W； is measured; If the rated voltage is added to the high voltage, the power is ().

a . 9000 w b . 3000 w c . 1500 w d . 1000 w

8. High frequency directional protection is to compare two ends () to decide whether to act.

A. power direction B. current direction C. voltage magnitude D. current magnitude

9. Direct-looking ranging uses () for signal transmission.

A. short-wave channel B. medium-wave channel C. microwave channel D. optical fiber channel

10. The content of power system management is equipment management, which should ensure the reliability of equipment and power supply and ().

A. completeness B. repair rate C. utilization rate D.

1 1.

A. Power sales B.C.D Power consumption monitoring

12. The quasi-synchronous parallel voltage deviation cannot exceed the rated voltage ().

a . 3 ~ 5% b . 5 ~ 10% c . 10 ~ 15% d . 15 ~ 20%

13. The following () cannot be used to measure AC high voltage.

A. voltage-dividing capacitor B. electrostatic voltmeter C. high-resistance microammeter D. voltage-dividing resistor

14.

Asian Development Bank.

15.

Asian Development Bank.

3. Short answer: (6 points for each question, ***30 points)

1. What is three-stage current protection? How do paragraphs meet the selectivity requirements?

2. What are the measures to improve the static stability of the system?

3. What are the one-to-one control and one-to-one N-line selection control methods for circuit breakers? What occasion are they suitable for?

4. What are the closing conditions of the no-load line? When is the operating overvoltage the highest?

5. What special problems need to be considered when using reclosing in two-terminal power supply network?

Four. Drawing and analysis: (65438+ 00 points for each question, ***20 points)

1. Draw the main wiring diagram of single bus with bypass bus, two power supplies and four outgoing lines, and explain the operation steps of secondary bus charging.

2. What effect will the creeping of the power direction relay have on the protection device? How to eliminate creeping of inductive power directional relay?

The answer is study,