34 / 2024-03-29 09:10:02

Study on the Rapid Protection Device of High-voltage Switchgear

High Voltage Switchgear,Fast Protection,Fast Data Window Algorithm

Nowadays, with a large number of new energy sources with intermittent and fluctuating characteristics, the stability and reliability of the power grid are facing greater challenges. At the same time, the user-side requirements for the reliability of the power supply of the distribution network are also increasing. Higher. The subject of this paper is how to meet the requirements of the spring operating mechanism of the high-voltage switchgear for the protection action time when a fault occurs at the end of the distribution network, and to achieve the goal of quickly removing the fault.

Firstly, this paper studies the fast protection software algorithm. The data window of the protection algorithm not only reflects the phasor characteristics, but also affects the protection action time. This paper uses the fast data window algorithm after differential filtering to extract the power frequency fundamental phasor from the collected fault current, and calculate the fault current component As a criterion of protection action. In order to judge the voltage and current changes after the fault, check the reliability of the algorithm and the calculation speed, a MATLAB/Simulink simulation test was carried out. The result showed that the shortest data window of the algorithm response is 5ms, which can meet the requirements of fast protection. The calculation process of the algorithm is written into the program code and embedded in the device, which cooperates with the sudden change start element, the direction element, and the low-voltage blocking element to realize the fast protection function.

Secondly, this paper designs the hardware module of the device. The action time of the conventional relay circuit is 3-5ms, while the IGBT controls the action time within 100 microseconds. Under the premise of satisfying reliability, economy and environmental adaptability, it is designed with the characteristics of high switching frequency and short action time of IGBT The IGBT action circuit meets the requirements of protecting fast action. Among the main hardware modules, the AC and binary input modules are used to collect voltage, current signals, and other operating status signals, and convert them into weak current signals for protection and control; the main processing and open-out modules are used to collect And processing voltage and current transformer data, to meet the requirements of protecting high-speed sampling.

Tests have verified that when an interphase short-circuit fault occurs at the end of the distribution network, the device can achieve protection action within 8ms, and can quickly cut off the fault within 30ms in cooperation with the circuit breaker of the bounce mechanism. It is suitable for high voltage switchgear such as switch cabinet, ring main cabinet, pole switch, etc. It has certain economic and social value.