Answers to common technical questions about high voltage switch dynamic characteristics tester

A: During field tests, there is often a high induced voltage between the break of the high-voltage switch (especially above 220KV) and the ground. This voltage is large in value and small in energy, but it is enough to threaten the safety of the instrument itself. Inside the instrument, a discharge circuit is connected between the break signal input terminal and the ground. The ground wire is connected first, and the discharge circuit is actually connected first. At this time, when the break signal line is connected, even if the break induces a high voltage, it can be discharged to the ground through the discharge circuit, thereby ensuring the safety of the instrument's break channel.

(2) How to determine whether the port of the high-voltage switch dynamic characteristics tester is normal?

A: Select [Test] - [Closing Test], and the real-time status of the 12 fractures will be displayed at the bottom of the LCD screen of the high-voltage switch dynamic characteristics tester . The screen display is as follows:

In this interface, you can check whether the break channel of the high-voltage switch dynamic characteristics tester is intact. If the break input is suspended, it should display "open", and if it is short-circuited to the ground, it should display "closed". So short-circuit each break to the ground and observe the changes in the status display to determine whether the instrument's break time channel is normal.

(3) What is the opening/closing speed? What is the difference between the opening/closing speed of a switch defined by time segment and distance segment?

Answer: The so-called opening (closing) speed refers to the average speed of a period of time (or a distance) just after the high-voltage switch is opened (just before opening). If time is used as the definition standard, the IEC standard and China's national standard are generally defined as the average speed of 10ms before and after closing. In view of the different definitions of some countries or some switch manufacturers, our company's instruments can be redefined through a computer and a matching speed definition to add a degree. It can be defined as a time period or a distance segment, which can flexibly and conveniently provide speed testing for high-voltage switches. Taking the vacuum switch as an example, the opening distance of a 10KV switch is generally S=11mm, and its closing (opening) speed is defined as the average speed of 6mm just before closing (just after opening). Some manufacturers also define it as the following:
a) The closing speed takes the average of the entire process, and the opening speed takes the average speed of 6mm just after opening;
b) The closing speed takes the average of the entire process, and the opening speed takes the average of the entire process;

With the speed definition program addition function, it is also convenient to perform speed tests according to specific vacuum switches. In addition, when performing speed tests on vacuum switches, the average speed of the entire opening process is very low due to the effect of the buffer mechanism during the opening process. Generally, the average speed before the buffer mechanism takes effect during the opening process of the vacuum switch is defined as the average speed of the entire process, that is, the average speed of the entire process is taken for closing, and the average speed of 6mm just after opening is taken for opening, which is closer to the actual value. Since the opening distance of a 35KV vacuum switch is generally S=22mm, all the values ​​6 in the above speed definitions for 10KV vacuum switches can be changed to 10 or 11.