DOI: 10.14489/td.2017.01.pp.032-038

Shakhnin V. A., Chebryakova Yu. S.
THE ELECTRICAL-NOISE MONITORING THE CONCENTRATION OF DISSOLVED GASES IN OIL OF THE MAIN INSULATION OF POWER TRANSFORMERS
(pp. 32-38)

Abstract. The majority of the damages of power transformers is associated with a reduction of electric strength of oil-barrier insulation and its breakdown near the high voltage winding of the oil channel. Operational insulation properties are closely related to the presence of dissolved gases in oil, the concentration of which is greatly determined by partial discharges (PD). There are developed principles and criteria for assessing the insulation condition on the basis of the analysis of dissolved gases (ADG) to diagnose defects. However, traditional ADG techniques are time-consuming, require sampling the oil from the high voltage operating equipment. Therefore, they are inconvenient for continuous monitoring the insulation condition. The modern systems of oilmonitoring are expensive and require the installation of sensors on every transformer to be diagnosed, i.e. it does not provide remote monitoring. The paper presents the results of experimental studies of the statistical relationships of concentrations of dissolved gases in oil of the main insulation of power transformers with the parameters of partial discharges. The researcheswereconducted during theplanned survey of 58 transformers in electric substations of trunkelectric grids of Centre in the period from 2009 to 2015 years. The directional microwave antenna (type AShP-1) was used as sensor of electromagnetic radiation caused by partial discharges. The processing of signals was provided by the radio interferencemeasure P4-17. The scanning the object was provided by mechanism with parallel kinematics. Theadaptive algorithm wasapplied to control the movement of the antenna. This allowed to take into account the complexity of the topology, the high saturation of energy objects and large size of modern high-voltage equipment. Mathematical models were proposedfor remote electrical-noise monitoring of insulation. The estimation of the parameters of the models was done with a help of the main components method and multiple regression analysis. This approach allows to processthe experimental results in strong multicollinearity of the dataset and increase the stability of the model to random measurement errors. The possibility of electrical-noise monitoring the concentrations of four dissolved gases (СН4, С2Н6, С2Н4 and Н2) was experimentally established. These gases are the key or characteristic gasesfor the majority of developing defects of the electrical and thermal character.

Keywords: high-voltage equipment, electrical-noise remote monitoring, dissolved gases, partial discharges, mathematical models, mechatronic complex.

 

This article  is available in electronic format (PDF).

The cost of a single article is 350 rubles. (including VAT 18%). After you place an order within a few days, you will receive following documents to your specified e-mail: account on payment and receipt to pay in the bank.

After depositing your payment on our bank account we send you file of the article by e-mail.

To order articles please fill out the form below:

Purchase digital version of a single article Your name * Your e-mail * Your post address with index * Your phone number: * Comments to your order Type the characters you see in the picture below