How to operate high voltage online in Dalian University of Technology?

Reference answer 16 online operation of high voltage technology in spring1;

First, multiple choice questions

1、D 2、B 3、A 4、A 5、D

1. The following method can improve the strength of gas medium is ().

A. improving the shape of the electrode

B. Adopt high air pressure

C, adopting a strongly electronegative gas

D. All the above measures can be taken.

2. The number of collision ionization times after positive ions travel along the electric field direction is called ().

A.α coefficient

B.β coefficient

C.γ coefficient

D.μ coefficient

3. Corona discharge is a kind of ().

A. Self-sustaining discharge

B. non-self-sustaining discharge

C. Arc discharge

D. discharge in uniform field

4. The following statement is true ().

A. Under the action of electric field, the insulation gap composed of dielectric loses its insulation performance and forms a conductive channel, which is called breakdown.

Breakdown voltage refers to the highest critical voltage of insulation breakdown.

C the maximum average electric field strength in insulation during breakdown is called breakdown field strength.

D. All the above statements are correct.

5. When Pd>& gt26.66 kPa? Cm, the following statement is true ().

A. The discharge at atmospheric pressure is a spark channel.

B, the discharge time is shorter than the travel time for positive ions to reach the cathode in the channel.

The cathode material has little effect on the discharge voltage.

D. All the above statements are correct.

6. The most important form of charged particles in gas is ().

A. Impact ionization

B. photoionization

C. thermal ionization

D. surface ionization

7. The following statement about Thompson's theory is incorrect ().

A Thomson theory holds that self-sustaining discharge is a necessary condition for gas gap breakdown.

B. Thomson theory holds that electron space collision ionization is the main factor of ionization.

C. Thompson theory is applicable to high pressure and long gap.

D Thompson's theory is applicable to low pressure and short gap.

8. The following method can't improve the strength of the gas medium is ().

A. improving the shape of the electrode

B. Using space charge to improve electric field distribution

C. Adopt low air pressure

D, adopting high vacuum

9. When Pd>& gt200mmHg? Cm, the following statement is true ().

A. Discharge at atmospheric pressure is glow discharge.

B, the discharge time is longer than the travel time for positive ions to reach the cathode in the channel.

The cathode material has little effect on the discharge voltage.

D. All the above statements are correct.

10. Under the action of electric field, the insulation gap composed of dielectric loses its insulation performance, and the process of forming conductive channel is called ().

A. Failure

B. Exemption

C. flashover

D. corona