I. Introduction

In the high voltage circuit, normal operation, to cut off the short-circuit current of the load current is turned on and off with the failure, we need to have safe and reliable protection and accurate control stability. In the high-voltage circuits due to high operating voltage, current, arc generally difficult to extinguish. The arc is often produced in the switching equipment in the process of opening the arc high voltage power system has great energy, can form explosive gas in an instant, heat and noise issue. It can burn melt conductor damage the insulation, forming a short circuit, if force to extinguish the arc can also cause over-voltage. In this case we need to reduce or suppress arcing achieve arc extinguishing function, whereby the high voltage circuit breakers can be a good solution to this problem in the process of opening and closing.

II.Characteristics

High voltage circuit breaker (or high-voltage switch) it can not only cut off or closing high voltage circuit load current and load current, and when the system fails by the action of the relay protection devices, cutting off the overload current and short circuit current, which has considerable sound interrupter structure and sufficient drying capacity can be divided into: oil circuit breakers (oil circuit breaker, less oil circuit breaker), sulfur hexafluoride circuit breakers (SF6 circuit breakers), vacuum circuit breakers, air circuit breaker and so on.

III.Solutions

To ensure the high-voltage electrical in normal operations, maintenance, short-circuit and overvoltage safety, we consider a comprehensive program design and formulation in accordance with the following requirements:

1. Normal working conditions include voltage, current, frequency, mechanical load and other options.

2. Short-circuit conditions include short time withstand current, peak withstand current, closing and breaking current and other options.

3. Environment conditions include temperature, humidity and altitude.

4. Overvoltage withstand capability includes Insulation Levels.

5.The different characteristics of various types of high-voltage electrical include switch operating performance, with fuse protection characteristics, transformer load and accurate grade and other options.