Power transformers
Generator transformers
Autotransformers
Power plant auxiliary and standby transformers
Transformers for substations of backbone and distribution networks and industrial enterprises
Transformers for DC transmission lines and high-capacity converter substations of tie-lines
Special transformers:
Generator transformers.jpg)
Generator transformers manufactured by JSC “ZTR” are purposed for power transmission, generated at electric power plant to high voltage backbone network. Three-phase transformers rated for capacity up to 160-200 MVA and single-phase transformers to the extent of 1250 ĚÂŔ can be produced with split generator windings for simultaneous connection to two generators. Transformers can be equipped with built-in on-load or off-circuit tap changers. JSC “ZTR” manufactures the generator transformers rated for capacity up to 1250 MVA and voltage up to 750 kV.
Autotransformers.jpg)
Autotransformers are purposed for interconnection of two high-voltage networks rated for different voltages (110, 220, 330, 400, 500, 750 kV), including that for regulation of power flows in the networks and maintenance of required voltage levels under the load by means of built-in tap changers. Normally transformers manufactured by JSC “ZTR” are equipped with delta-connected stabilizing tertiary winding to be used for power supply of local consumers. In some cases the tertiary winding is connected to the generator to ensure simultaneous power transmission of two voltages in the network, e.g. 110 č 220 kV.
Power plant auxiliary and standby transformers
Two types of auxiliary transformers are produced by JSC “ZTR”: generator transformers to be connected to the power plant generators, and standby transformers to be fed from high-voltage network. Standby transformers ensure supply of the power plant within construction period as well as during operation – in case of emergency shutoff of the generators. Both types of transformers are normally manufactured with split windings and on-load tap changers. Winding splitting ensures short-circuit current decrease and maintaining of sufficient voltage level in one of the windings in case of short-circuiting of other winding.
Transformers for substations of backbone and distribution networks and industrial enterprises..jpg)
Transformers for substations of backbone and distribution networks as well as industrial enterprises are generally purposed for voltage decrease from 10-330 kV (more seldom 500 kV) to the level of local distribution networks 6-35 kV, including the networks of industrial enterprises. Double- and three-winding transformers of this type as well as the transformers with split winding are produced at JSC “ZTR”. Almost all such transformers are equipped with built-in on-load tap changers.
Transformers for DC transmission lines and high-capacity converter substations of tie-lines
Transformers for DC transmission lines and high-capacity converter substations of tie-lines manufactured by JSC “ZTR” are purposed for operation together with high-power HV converters (e.g. ± 400 or ± 750 kV), to be used for rectification of AC or for inverse operation – DC inversion. The specific feature of these transformers is operation at impact of DC high voltages as well as at nonsinusoidal currents. Such type transformers are equipped with on-load regulation at power winding side. Valveside winding can be split, at this, one part may be star-connected and other – delta-connected.
Special transformers
Transformers for metallurgical companies
Transformers for metallurgical companies manufactured by JSC “ZTR” are purposed for voltage decrease in the backbone network 110 – 220 kV to the level of metallurgical company network (normally 35 kV) that fed the transformers to be operated directly for furnace load. The special feature of such transformers is their ability to operate in the conditions of frequent ON – OFF and load impacts.
Transformers for railway substations
Transformers for railway substations manufactured by JSC “ZTR” are purposed for application at the substations for voltage decrease in the backbone network 110-500 kV to voltage level of overhead contact system (normally 27 or 27.5 kV). The company produced single- or three-phase, two- or three-winding transformers of this type. In the latter case one of the secondary windings are employed for power supply of overhead contact system and the other operates for local public network 6-35 kV.
Phase-shifting (phase-inverting) transformers.jpg)
Phase-shifting (phase-inverting) transformers manufactured by JSC “ZTR” are purposed for application in the network system as a power source with phase shift for certain regulated angle as related to the main voltage, that ensures desired distribution of power flow in the network, for example to decrease electrical energy losses or for other purposes. Such equipment may perform the specified function singly or being included into an assembly consisting of other transformers or autotransformers. Such type transformers can be extremely various as referred to electric circuits, parameters as well as embodiment. The above products are designed and supplied by the special requests exclusively.
Line regulating transformers
Line regulating transformers manufactured by JSC “ZTR” are purposed for voltage regulation in the networks 6-35 kV in such cases when required voltage level in this network could not be ensured by only existing built-in regulating transformers.
Earthing transformers
Earthing transformers manufactured by JSC “ZTR” are purposed for creation of artificial earthing point in the networks with ungrounded neutral (35 kV and lower). Usually the zigzag-connected winding is employed for this purpose with off circuit voltage regulation. The transformers of such type are often equipped with star-connected winding for substation auxiliary power supply (generally for 0,4 kV).
Furnace transformers
Furnace transformers manufactured by JSC “ZTR” are generally purposed for the plants- manufacturers of ferroalloys and graphite. The transformers of such type is not included in the company main products, but sometimes can be supplied by the special requests.
Transformers rated for two nominal voltages
Transformers rated for two nominal voltages manufactured by JSC “ZTR” can be applied in such cases when it is scheduled by the network development plan to transfer it in future to another voltage class. For this purpose, based on the special requests, the factory produces transformers with re-connection of the windings to another rated voltage. Re-connection is generally carried out on the de-energized transformer by means of re-arrangement of bolted jumpers via special hatches with partial oil draining.
