Question

describe the impulse current test performed lightening arresters.how do you conclude that the arrester has passed the test?​

Answer 1

Answer:

Application, 2017

6.2.1.2 The principle of insulation coordination

The basic principle of UPFC insulation coordination is to select the appropriate design parameters of the arresters based on the overvoltage level which may appear on the equipment, and then to determine the insulation level of the electrical equipment considering operational safety, technical feasibility, and cost efficiency to minimize manufacturing cost, maintenance cost, and accident cost.

As the main overvoltage protection devices of the UPFC, arresters can significantly inhibit switching and lightning overvoltage. Arresters in the UPFC can be divided into two kinds, AC arresters and DC arresters. The former is used to protect the series and parallel transformers and ancillary equipment, and the latter is used to protect the converter valves.

DC arresters’ operating conditions differ as follows from those of AC arresters:

1.

2.

3.

DC arresters have a higher insulation requirement.

The general process of UPFC insulation coordination is as follows:

1.

2.

3.

Initially determine the coordination current and residual voltage of arresters and levels of insulation equipment;

4.

5.

Properly reduce the coordination current and the residual voltage if the maximum surge current is small or arresters need to be in parallel. Adjust the rated voltage or even the arrester configuration plan if necessary, and finally determine the protection configuration and the insulation level of the equipment.

Explanation:

OK SIR