The current research results of partial discharge in GIS equipment show that due to the relatively high dielectric strength of SF6 gas, the duration of the partial discharge pulse in the high-pressure SF6 gas in GIS equipment is very short, about a few nanoseconds, and the wave head has a very short duration. The rise time is only about 1ns. This kind of steep pulse with extremely short duration, including signals up to GHz, will generate electromagnetic waves flowing on the GIS equipment casing. High-frequency discharge pulse current flows through the grounding wire, and the casing is connected to the ground. Presents a high frequency voltage and generates electromagnetic waves in the surrounding space. Partial discharge will also cause a sudden increase in the pressure of the channel gas, generate longitudinal waves or ultrasonic waves in the gas of the GIS equipment, and various sound waves, such as longitudinal waves, transverse waves and surface waves, appear on the metal shell. Partial discharges in GIS equipment can also cause SF6 gas to decompose or emit light. These physical and chemical effect changes accompanied by partial discharge are the basis for online detection of GIS equipment. The detection methods of partial discharge in GIS equipment can be roughly divided into two categories: electricity detection method and non-electricity detection method. method, SF6 gas decomposition product detection method.
GDPD-300UF UHF Partial Discharge Detector
HV Hipot GDPD-300UF UHF partial discharge detector (UHF partial discharge instrument) can be widely used in partial discharge detection of power systems, including high-voltage switchgear, ring main unit, voltage/current transformer, transformer (including dry Insulation state detection of equipment such as transformers), GIS, overhead lines, cables, etc., the discharge degree of electrical equipment is measured by the following indicators.
Product Features of UHF Partial Discharge Detector
Configure different sensors to achieve partial discharge detection of almost all electrical equipment;
The user-friendly man-machine interface facilitates the data management of different equipment, including the traceability of historical data trends, horizontal and vertical data analysis, and realizes 360° comprehensive diagnosis of the equipment under test;
Built-in ultrasonic sensor and transient ground voltage (hereinafter referred to as TEV) sensor, which can be connected to special sensors such as transformers, GIS, overhead lines, and cables;
The non-invasive detection method is adopted, no power failure is required during the test, and no additional high-voltage source is required, which is more convenient to use than the traditional pulsed partial discharge detector;
The test bandwidth range is 30kHz~2.0GHz, which is suitable for the detection principle of various frequency bands.
Post time: Feb-22-2022