Generator step-up transformers (GSU)
Generator step-up transformers (GSU)
Generator step-up transformers (GSU) are the critical link between the power station and the transmission network, often operated day and night at full load. They must be built to withstand extreme thermal loading without ageing prematurely. ABB have successfully passed the world’s first and highest voltage short circuit test, on a 315 mega volt ampere (MVA), 765 kilovolt (kV) generator step up transformer (GSU).
GSU take the voltage from the generator voltage level up to the suitable transmission voltage level.
These transformers are located in a power station and are built as single-phase or three-phase units.
There are two (2) basic technologies for designing and manufacturing: core and shell. With shell-formed transformers, the primary and secondary are on one leg and surrounded by the core. With a core-formed transformer, cylindrical legs windings cover the core legs.
HVDC Converter Transformers
HVDC converter transformers
HVDC (high-voltage direct current) is a highly efficient alternative for transmitting large amounts of electricity over long distances and for special purpose applications. As a key enabler in the future energy system based on renewables, HVDC is truly shaping the grid of the future.
ABB pioneered HVDC transmission technology in the 1950s and continuously develops the HVDC technology to meet the demands of economic and sustainable transmission and integration of different electricity generation types.
The ultra-high voltage (UHV) technology is an advancement of HVDC, transmitting large amount of power with minimum losses and integrating renewables often located at a great distance from centers of the demand. ABB successfully developed and tested 1,100 kV converter transformer technology breaking the record for the highest DC voltage levels ever.
Large Distribution Transformers
Large distribution transformers
Large distribution transformers are used for receiving energy from higher voltage levels and to transform and distribute this energy to lower voltage substations or directly to large industrial consumers.
Transformers in this range are three-phase and can be manufactured with off-circuit tap changer or on-load tap changer. Transformers provided with on-load tap changer usually have a separate tap winding.
The core is constructed of grain-oriented steel laminations. The windings are made of either copper or aluminum conductor and wound in a foil or multi-layer configuration. The tank construction can be a corrugated fin wall type or of a rigid construction type with radiators typically used for larger transformer. Fans can also be mounted on the radiators to provide additional cooling capacity.
Medium Distribution Transformers
Medium distribution transformers
Medium distribution transformers are used to step down three-phase high voltage to low voltage for energy distribution, mainly in the countryside or low-density populated areas.
The transformers are three-phase, oil-immersed hermetically sealed, adaptable for pole-mounting or assembly in substations.
On request, the transformer can be equipped with an oil conservator and the transformer tanks surface can be hot dip zinc coating.
Shell Specialty Transformers
Polytransformers, multispare and high voltage mobile transformers
ABB offers a full range of transformers to address any generation or transmission contingency a customer might have. These include multi-functional units such as the polytransformer, universal generator and mobile transformers.
Single Phase Distribution Transformer
Single-phase distribution transformers
Range up to 315 kVA
ABB liquid-filled, single-phase distribution transformers are specifically designed for networks where it is not practical to have a three-phase supply.
They are typically used for servicing residential overhead distribution loads.
They are also suitable for light commercial loads, industrial lighting and diversified power applications.
Small Distribution Transformers
Small distribution transformers
Small distribution transformers are typically oil-immersed and suitable for pole-, pad- or ground-mounting. They represent an economical option for certain networks, particularly those with low population densities.
Depending upon requirements, transformers may be connected between two phases of a three-phase system (two high voltage bushings) or from one phase to ground (single high voltage bushing).
The units are suitable for residential overhead distribution loads, as well as light commercial or industrial loads and diversified power applications.
System Intertie Transformers
System intertie transformers
Substation transformers transfer the incoming high voltage to the next lower voltage level. As an example, incoming high voltage of 400 kV would be transferred down to 220 kV.
In general substation transformers are equipped with on-load-tap changers (OLTC). Incoming transmission lines are connected to the transformers through bushings and cables through cable boxes and cable sealing ends. These transformers are built in core form with auto connected windings, ie common main winding and a separate low voltage winding.
TXpert Digital Distribution Transformers
TXpert digital distribution transformers
ABB has launched the world’s first digital distribution transformer to meet the needs of today’s evolving grid. The TXpert is a digital solution that measures and stores essential data and provides analytics that indicate asset performance, providing actionable intelligence.
The sensors and industrial components for TXpert are integrated with the distribution transformer during manufacturing. Its unique and fully-incorporated sensing and computing functionality ensures data accuracy that is time-synchronized to facilitate both inference and predictive analytics.
The TXpert is built upon an expandable digital platform for installing future analytics and remaining relevant over time. It is also flexible to support a wide range of customer communication mediums, protocols and software tools. The TXpert has a built-in Wi-Fi and a wired Ethernet connection for simple access to your encrypted data without interrupting transformer operation.