Green Solution for Insulation System of a Medium Frequency High Voltage Transformer for an Offshore Wind Farm

Abstract

High Voltage Direct Current (HVDC) transmission represents the most efficient way for transporting produced electrical energy from remotely located offshore wind farms to the shore. Such systems are implemented today using very expensive and large power transformers and converter stations placed on dedicated platforms. The present study aims at elaborating a compact solution for an energy collections system. The solution allows for a minimum of total transformer weight in the wind turbine nacelle reducing or even eliminating the need for a sea-based platform(s). The heart of the project is a Medium Frequency Transformer (MFT) that has a high DC voltage insulation towards ground. The transformer is employed in a DC/DC converter that delivers the energy into a serial array without additional conversion units. The insulation design methodology of an environmentally friendly HV insulation system for an MFT, based on pressboard and biodegradable oil, is introduced. The measurement method and results of the measurements of electrical conductivities of the transformer oil and Oil Impregnated Pressboard (OIP) are reported. The measurements show that the biodegradable ester oil/OIP conductivities are generally higher than the mineral oil/OIP conductivities. Numerical simulations reveal that the performance of the insulation system is slightly better when ester oil is used. Additionally, a lower temperature dependency for ester oil/OIP conductivities is observed, with the result that the transformer filled with ester oil is less sensitive to temperature variations.

Application of back propagation neural network in complex diagnostics and forecasting loss of life of cellulose paper insulation in oil-immersed transformers

“… In situations when the BPNN algorithm experiences a shortage of data, data augmentation is employed to improve the size and diversity of the data. Data augmentation involves making numerous transformations and adjustments to existing data, by creating modified copies of a dataset using existing data 125 , 126 . Lastly, data visualization is employed to further study and comprehend the data.…”

Thermal Analysis and Structure Optimization of a Dry-type Transformer with Ceramic Insulated Windings for Offshore Platform

“…In addition, the high temperature, high humidity and high heat environment of the ocean requires power transformers to operate reliably at high temperatures [6]. Insulation damage and overheating fault are the main factors leading to equipment damage [7] [8]. Therefore, it is of great significance to improve the operating temperature, enhance the insulation performance in salt fog environment and reduce the weight of the equipment for the application and promotion of dry-type transformers on offshore platforms.…”

Intelligent Blanking of Silicon Steel Coil in a Transformer Core Oriented to Green Manufacturing

“…Xiang [10] presented a circuit evolution of the high step-ratio transformer-coupled RMMC into its low step-ratio transformer-less RMMC counterpart. Kharezy [11] designed a compact solution for an energy collections system that allowed for a minimum of total transformer weight. It is obvious that all these studies on transformers made great contributions to structure, principle, and design methods to improve their performance.…”