The Technology Of The On-line Monitoring For Transformer Insulation Fault Based On DGA In Neijiang Dazhouba Substation

The operation reliability of the power transformer, the key apparatus in electrical power system, influences the safe operation of electrical power system directly. In order to keep the electrical power system safe, inspection and diagnosis of transformer insulation must be reinforced. The components and contents of gases dissolved in transformer oil can be used to reflect internal insulation faults of operating transformer. On the base of investigation the status in quo of the on-line monitoring technology of gases dissolved in transformer oil at home and abroad, and analysis of the elements that can affect the generally experimental results of dissolved gases and the diagnoses technology, this paper presents the principle and solution of on-line monitoring system with eigenvalue of gases dissolved in oil. The researches are shown mainly as follows:1) The producing mechanism and dissolving process of gases dissolved in oil are analyzed deeply, and characteristics of insulation structure of power transformer, criterions of faults and the relationship between ordinary faults inside transformer and gases dissolved in transformer oil are studied too. Reliability of system and validity of diagnosis can be gained by analyzing the purposes of detecting gases dissolved in transformer oil on-line.2)The axiom,application principle and shortage of using three-ratio method to judge transformer faults are analyzed,and the paper presents the superiority of synthesize judge associate with multi-factor such as temperature.3) The principles of on-line monitoring technology of gases dissolved in transformer oil is analyzed, and the paper presents the on-line monitoring method which can detect six gases dissolved in oil, and is charactered with infiltrative film and multi-sensors.4) The paper concrete application analysis six gases monitoring system in Neijiang Dazhouba substation.: the system runs stably, and has the function of on-line monitoring and discovers the latent fault effectively and can become the warrant of condition service.