PACKAGED TRANSFORMER SUBSTATIONS WITH THE INDUSTRIAL CAPACITY FROM 250 KVA TO 2500 KVA
Industrial packaged transformer substations are designed for reception, conversion and distribution of electric energy of 50 – 60 Hz three-phase alternating current with the 6-10/0,4 kV voltage. When installed in gas-compressor stations they are used for electrical power supply of users. They are also installed in indoor industrial substations in various industrial fields.
Industrial packaged transformer substations correspond to the ‘moderate’ climatic version of the 3 placement category according to GOST 15150-69.
Single-transformer industrial packaged transformer substations contain one input device installed in the high-voltage side, a power transformer, covers protecting the power transformer outputs and a distribution device installed in the low-voltage side.
Double-transformer industrial packaged transformer substations contain two input devices installed in the high-voltage side, two power transformers with protective covers and a distribution device installed in the low-voltage side. Besides they may be equipped with up to two inputs from a diesel electric station.
The KSO-399M-T cabinets are basically used as the voltage input devices.
According to the functional properties, the low voltage switchgears (RUNN cabinets) are divided into input cabinets (ShNV), linear cabinets (ShNL), section cabinets (ShNS) and relay cabinets (ShNR). The structure of the RUNN cabinets includes a busbar compartment, compartments containing automatic switches and compartments containing relay equipment. The connection terminals (inputs and outputs) may be of the busbar type or of the cable type:
- through cable channels located in the bottom of the cabinet with a connection inside the cabinet;
- in the upper part of the cabinet with a connection inside the cabinet.
Industrial packaged transformer substations are designed for bilateral maintenance. Current maintenance of the transformer substations is performed through the front side of the cabinet, while the busbar arrangement and cable connections may be accessed through the rear side.
The transformer substations contain the following protection systems:
- overload protection and time overcurrent protection;
- protection against single-phase short circuits;
- protection against phase-to-phase short circuits;
- protection against short circuits in transformer coils and outputs by means of high-voltage fuses;
- protection of control and alarm circuits by means of automatic switches.
The following alarm systems are installed in the transformer substations:
- automatic load transfer;
- the condition of input and section switches of the low voltage switchgears (RUNN);
- the condition of supply feeders of the low voltage switchgears (RUNN) (on request);
- emergency tripping of input and section switches of the low voltage switchgears (RUNN);
- overheating of power transformer coils;
- emergency tripping of the input switch.