It is an effective measure for power enterprises to improve the voltage level of system by raising and lowering tap position main transformer. For parallel operation transformer, whole process adjusting must strictly meet conditions operation. Aiming at a case backup protection action transformer caused improper implementation regulation measures, this paper analyzes uneven load distribution in...

Economically transformers constitute one of the largest investments in a Power system. For this reason, transformer condition assessment and management is a high priority task. If a transformer fails, it would have a significant negative impact on revenue and service reliability. Monitoring the state of health of power transformers has traditionally been carried out using laboratory Dissolved G...

Ferroresonance is a highly destructive power quality phenomenon caused by complex oscillations generated by nonlinear magnetizing inductances in ferromagnetic materials and capacitive elements in power systems. In an effort to better understand ferroresonance and predict bifurcations and responses, an improved nonlinear transformer model for dynamic and steady-state operating conditions is deve...

Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this m...

The power transformer is a major apparatus in a power system; it is of great importance to detect incipient failures in power transformers as early as possible in order to minimize system outage. In this paper, the modified grey model was applied to predict the oil-dissolved gas trend of power transformers. Then, the future fault of power transformer can directly be identified by the trend anal...

Early detection of power transformer fault is important because it can reduce the maintenance cost of the transformer and it can ensure continuous electricity supply in power systems. Dissolved Gas Analysis (DGA) technique is commonly used to identify oil-filled power transformer fault type but utilisation of artificial intelligence method with optimisation methods has shown convincing results....

Reliable and continued performance of power Transformer is the key to profitable generation and transmission of electric power. Failure of a large power transformer not only results in the loss of very expensive equipment, but it can cause significant guarantied damage as well. Replacement of that transformer can take up to a year if the failure is not disastrous and can result in tremendous re...

High frequency models of large power transformers are required for analysis of transient interaction phenomena between transformers and the power system. Fast transient overvoltages may lead to transformer dielectric failures. Deeper understanding of the mechanisms may help to take actions against possible damages. This paper describes the simulation principle of transient interaction in matter...

This paper develops a novel dynamic correction method for the reliability assessment of large oil-immersed power transformers. First, with the transformer oil-paper insulation system (TOPIS) as the target of evaluation and the winding hot spot temperature (HST) as the core point, an HST-based static ageing failure model is built according to the Weibull distribution and Arrhenius reaction law, ...

A transformer is the most valuable and expensive property for power utility, thus ensuring its reliable operation is a major task for both operators and researchers. Online impulse frequency response analysis has proven to be a promising technique for detecting transformer internal winding mechanical deformation faults when a power transformer is in service. However, as so far, there is still n...