DESIGNATION
Pole-mounted substation is designed for electric power reception of three-phase alternating current, frequency of 50 Hz with the highest operational voltage up to 12 kV (rated operational voltage of 6 or 10 kV), transformation of electric power to a voltage of 0,4 kV in the system with deadly earthed neutral of transformer on the LV side and for electrical power distribution among end users.
All equipment of substation is located directly on the supporting block of air high-voltage power transmission line in the voltage class of 10(6) kV. In terms of design, all equipment of transformer substation mounted on metal structures, which are fixed to the power transmission line pillars of СВ 105, СВ 110 and similar.
DESCRIPTION
Complete transformer substation of pole-mounted type consist of HV distributing gear, power transformer, LV distributing gear, metal structures of separate units fastening (power transformer, HV distributing gear, electricity box and LV distributing gear, LV current distributor) and earthing elements.
HV distributing gear consist of three single pole combined units of safety disconnector and three surge arrester installed on each phase.
Safety disconnector are designed for protection of power transformer and distributing system against short circuit and limiting overload currents, for connection and disconnection of complete transformer substation of pole-mounted type to HV grids without load if there is capacitive and inductive currents in it with providing a visual clearance of a chain. Automatic tilting of cartridge fuse is carried out at operation of a fuse. Operation of disconnection, connection, removal and installation of the cartridge with fuse is carried out from the earth by an operating pole.
Surge arrester are designed for protection of power transformer against a lighting surge overvoltage. the installed surge arrester is chosen proceeding from voltage class of complete transformer substation of pole-mounted type – 10 kV (the highest operating voltage of 12 kV) or 6 kV (the highest operating voltage of 7,2 kV)
Power transformer should be designed according to the GOST 52719-2007, the rated voltage on the LV side of 380 V with deadly earthed neutral with the vector group of Y/Y-0 or Y/Zн -11.
LV distributing gear are designed in two options arrangements: in electric box design or based on mast disconnecting switch. At electric box design of LV distributing gear shield body of input and energy accounting is mounted on the each output line on the supporting block in which is installed:
Shield body is provided with operational panel closing the electric meter and units. Operational panel has a window for meter readings and the slot for access to the protection unit, also the possibility of sealing the operational panel in the closed position exists.
Mast disconnecting switch is designed for protection against overload and short-off circuit by means of fuse element as well as for connection and disconnection of an alternating current of a network by means of the operating pole. The connection is carried out by the self-supporting insulated conductors. When using LV distributing gear on the base of the mast disconnecting switch for the energy accounting it is recommended to install on the output lines designed by the self-supporting insulated conductors, active-energy meter with wireless remote sensors. It is recommended to install the surge arresters mounted on the self-supporting insulated conductors for protection against lightning switching surge voltage on the output lines designed by the self-supporting insulated conductors.
MAIN PARAMETERS
OPERATING CONDITIONS
Pole-mounted substation is designed for electric power reception of three-phase alternating current, frequency of 50 Hz with the highest operational voltage up to 12 kV (rated operational voltage of 6 or 10 kV), transformation of electric power to a voltage of 0,4 kV in the system with deadly earthed neutral of transformer on the LV side and for electrical power distribution among end users.
All equipment of substation is located directly on the supporting block of air high-voltage power transmission line in the voltage class of 10(6) kV. In terms of design, all equipment of transformer substation mounted on metal structures, which are fixed to the power transmission line pillars of СВ 105, СВ 110 and similar.
DESCRIPTION
Complete transformer substation of pole-mounted type consist of HV distributing gear, power transformer, LV distributing gear, metal structures of separate units fastening (power transformer, HV distributing gear, electricity box and LV distributing gear, LV current distributor) and earthing elements.
HV distributing gear consist of three single pole combined units of safety disconnector and three surge arrester installed on each phase.
Safety disconnector are designed for protection of power transformer and distributing system against short circuit and limiting overload currents, for connection and disconnection of complete transformer substation of pole-mounted type to HV grids without load if there is capacitive and inductive currents in it with providing a visual clearance of a chain. Automatic tilting of cartridge fuse is carried out at operation of a fuse. Operation of disconnection, connection, removal and installation of the cartridge with fuse is carried out from the earth by an operating pole.
Surge arrester are designed for protection of power transformer against a lighting surge overvoltage. the installed surge arrester is chosen proceeding from voltage class of complete transformer substation of pole-mounted type – 10 kV (the highest operating voltage of 12 kV) or 6 kV (the highest operating voltage of 7,2 kV)
Power transformer should be designed according to the GOST 52719-2007, the rated voltage on the LV side of 380 V with deadly earthed neutral with the vector group of Y/Y-0 or Y/Zн -11.
LV distributing gear are designed in two options arrangements: in electric box design or based on mast disconnecting switch. At electric box design of LV distributing gear shield body of input and energy accounting is mounted on the each output line on the supporting block in which is installed:
- three-pole load disconnecting switch is designed for connection, conducting and interrupting of rated current in the normal operation conditions, current connection in emergency service, and as well as for fulfilment of functions of the disconnector;
- three-pole automatic disconnecting switch is designed for protection of electric network against current and short circuit overload;
- three-pole surge arrester is designed for protection against lightning switching surge voltage;
- light indicator of voltage in each phase;
- three-phase active-energy meter of direct connection is designed for active-energy accounting on the each output line (It is supplied as an option by agreement with the customer).
Shield body is provided with operational panel closing the electric meter and units. Operational panel has a window for meter readings and the slot for access to the protection unit, also the possibility of sealing the operational panel in the closed position exists.
Mast disconnecting switch is designed for protection against overload and short-off circuit by means of fuse element as well as for connection and disconnection of an alternating current of a network by means of the operating pole. The connection is carried out by the self-supporting insulated conductors. When using LV distributing gear on the base of the mast disconnecting switch for the energy accounting it is recommended to install on the output lines designed by the self-supporting insulated conductors, active-energy meter with wireless remote sensors. It is recommended to install the surge arresters mounted on the self-supporting insulated conductors for protection against lightning switching surge voltage on the output lines designed by the self-supporting insulated conductors.
MAIN PARAMETERS
| Description | Value |
|---|---|
| Capacity of power transformer, kVA | 40,63 |
| Rated voltage on the HV side, kV | 6, 10 |
| Maximum operating voltage on the HV side, kV | 12 |
| Rated voltage on the LV side, kV | 0.4 |
| Short-time thermal current within 1 sec. on the HV side, kА | 6.3 |
| Short time electrodynamic current on the HV side, kА | 16 |
| Insulation level as per GOST 1516.1-76: with oil-filled transformer | Normal insulation |
| Design of HV neutral | Insulated neutral |
| Design of LV neutral | Deadly earthed neutral |
| No load and short-circuit losses of transformer | As per specification for used transformer |
OPERATING CONDITIONS
- Ambient air temperature – climatic category У as per GOST 15150 and GOST 15543.1.
- Placement category - 1 as per GOST 15150 and GOST 15543.1.
- Wind speed up to 15 m/sec. (wind pressure up to 146Pа) at glaze ice thickness up to 20 mm, Wind speed up to 36 15 m/sec. (wind pressure up to 800Pa) without glaze ice.
- Pollution level of environmental – atmosphere of I and II type as per GOST 15150.
- Absolute altitude of unit up to 1000 m. It is available to apply the complete transformer substation of pole-mounted type for work at absolute altitude more 1000 m in compliance with requirements of GOST 15150-69, GOST 1516.1-76, GOST 8024-84, GOST 12434-83.
- As external mechanical stability the complete transformer substation of pole-mounted type is according to mechanical design group М1 as per GOST 17516.1.