Disconnecting switch contact state detection device and method based on electric field sensor

Abstract

The invention discloses a disconnecting switch contact state detection device based on an electric field sensor. The disconnecting switch contact state detection device comprises a DSP (digital signal processor) unit, a DSP resetting module, a DSP crystal oscillation module, a liquid crystal display module, a starting button, a shielding plate opening button, a prewarning module and a photocoupling isolating module are connected on the DSP unit respectively, the photocoupling isolating module is connected with an A / D conversion module and a signal conditioning module respectively, a self-adaptive amplifying module, an electric field signal extracting module and an electric field sensor are connected on the A / D conversion module sequentially, and a temperature and humidity sensor is connected on the signal conditioning module. The invention further discloses a detection method based on the detection device. Complete electric isolation is realized, and requirements on insulating performance in the field of power system detection are guaranteed effectively. Contact state of a disconnecting switch can be acquired and prewarned, and parameters like voltage and environment can be displayed.

Description

technical field [0001] The invention belongs to the technical field of off-line detection of power transmission and transformation equipment, and relates to a contact state detection device of an isolating switch based on an electric field sensor, and also relates to a detection method based on the detection device. Background technique [0002] Power transmission lines and substations are used to transmit the power energy of power plants to users. With the continuous advancement of technology, users have increasingly high requirements for power quality. Power quality includes voltage, frequency and waveform. These effects are relatively phase-deficient in the system The impact is not obvious. Non-full-phase operation will have a great impact on the system. Due to the unbalanced three-phase current, it may cause a large current to pass through individual windings of generators and transformers, resulting in overheating. According to statistics, asynchronous motors used in va...

AI Technical Summary

Problems solved by technology

Its working principle and structure are relatively simple, but due to the large amount of use and high reliability requirements, it has a greater impact on the design, construction and safe operation of substations.

[0004] There may be three states between the moving and static contacts of the isolating switch. One is that there is an obvious separation gap between the two contacts, indicating that the isolating switch is completely disconnected at this time; the other is that the two contacts are completely closed, indicating that this When the two sides of the isolating switch are completely connected; the third is that the two contacts seem to be closed but are actually disconnected. At this time, the impression given to the staff is that the isolating switch is closed, but in fact it is disconnected. Could not complete the power supply

The third situation is the most harmful because it is difficult for the staff to know. It is one of the most important reasons for the lack of phase. It is mainly due to the burnt contact of the isolating switch or the loosening of the screw, resulting in poor contact or no contact. As a result, a certain phase is not powered on

However, at the substation site, these poor or inaccessible conditions cannot be seen, so the voltage situation on the outlet side of the isolating switch cannot be known at the substation site. Therefore, it is necessary for site operators and inspectors to Detect the contact state of the isolating switch

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