Container transformer stations

Substations were tested for compliance with the standards in force in accredited European laboratories.

Compliance with standards

• PN-EN 62271-202 - High-voltage switchgear and controlgear. High-voltage/low-voltage prefabricated substation; + related standards

* - apply to Rotoblok SF i TPM type MV switchgears.

NOTE!
1) Typical fuse links according to the standard IEC 282-1, DIN 43625 with thermal protector should be used.
2) In the calculation of rated current 20% overloading were not included.

The catalogue only presents example solutions for container substations.
Our many years of experience and a team of experienced engineers enable us to prepare a solution designed in accordance with individual needs of even the most demanding customers. This can be demonstrated by deliveries for the leading power distribution companies all over Europe, Asia and Africa, as well as to individual customers which represent most branches of industry. Our substations work with most of renewable energy sources, and are able to provide energy storage, improving power grid efficiency.

Design

The intended use of the main structure is the installation of MV and LV switchgears, remote control devices, signalling, measurement systems, transformers, power generators and other devices in accordance with the design.
Substation enclosures with internal service corridor are manufactured as complete, self-supporting reinforced concrete structures, forming a monolithic cast of side walls with a floor slab. The main structure of the substation with external servicing is constructed as a combination of side walls with a foundation basin.
Reinforcement of the main structure (side walls and floor) is constructed as a connected whole — a cage which guarantees equipotential bonding and shields from electromagnetic radiation generated by the devices installed inside. The reinforcement mesh is bonded with substation foundation and roof.
Enclosures are made of at least C30/37 concrete, which ensures high safety of operation and of members of the public, moreover guaranteeing many years of safe operation without the need to perform maintenance work. A hatch into the foundations, which also form a cable chamber, can be found in the floor of the corridor of the substation with an internal service corridor.

All metal elements installed on the outside of the substation are made from powder painted aluminium, with RAL palette colours. The list below contains the basic colour scheme for doors and ventilation louvres. Other materials and colour schemes are available on arrangement with the manufacturer. It should be however kept in mind that this will result in a longer order delivery time and an individual technical and price offer.

Colour
RAL 3003	RAL 7032	RAL 8004
RAL 8017	RAL 6001	RAL 8007
RAL 5010	RAL 7024	RAL 9010

NOTE!
The colours shown in the table may differ from reality.
When selecting colours always compare with the original colour chart.

Doors

Depending on intended use, the substation doors are single leaf (e.g. switchgear operation corridor) or double leaf (e.g. transformer chamber), and their size is adapted to the dimensions of the installed devices. They may be constructed either as solid doors or with ventilation louvres, and the double-shell construction prevents the condensation of water inside the substation. The basic protection rating is IP 23D or IP43 (on arrangement with the manufacturer it is possible to construct doors in another version).

All doors open outwards (opening angle up to 95^o — other angles on request), have a mechanism for locking in an open position and covered internal hinges with friction elements made of stainless steel. The doors have three-point locking bolts, locked with a lock adapted to the installation of cylinders with integrated protection against weather conditions. Additionally the doors can be independently equipped with a padlock attachment. For the substation with an internal service corridor, the door lock enables opening the doors from inside regardless of the position of the external handle, which prevents the locking of an employee inside the substation.

Ventilation louvres

The ventilation louvres (supply and exhaust) installed in transformer substations ensure a correct temperature is maintained inside transformer chambers and ensure ventilation of rooms where power engineering devices are installed.

Due to the ingenious, patented labyrinth design with high capacity, gravity ventilation is possible even for transformers with powers up to 1250 kVA while keeping the louvre dimensions to a minimum. This solution minimizes the operational costs of transformer substations due to elimination of the need to use intake or exhaust fans (the costs of electricity, servicing and spare parts, among others).

However, individual requirements concerning transformer substation ventilation should be taken into account, e.g. in case of installation of transformers or devices which generate significant amounts of heat, gravity ventilation must be supplemented with intake and exhaust fans. Their efficiency and location is selected by experienced engineers supported by IT tools.

In standard version ventilation louvres provide an IP 23D or IP 43 protection rating. Louvres with an IP 43 protection rating have internal protection against the ingress of insects.

In locations exposed to significant dust levels (e.g. industrial plants) it is possible to use ventilation louvres with filter cartridges. In this case it should be remembered, however, that an installation equipped with filter cartridges has to be fan-assisted in order to ensure appropriate exchange of air and requires regular cleaning or replacement of filter cartridges.

Cross-section of the IP 23D ventilation louvre

Forced ventilation, system with filters

IP 43 ventilation louvre

NOTE!
On arrangement with the manufacturer it is possible to use different systems of cable entries and seals.

• Slope of approx ~ 2-3^o,
• Height above the substation structure level - 130 mm,
• Resistance to mechanical loads - 2500 N/m².

Hip (cottage) roofs
Slope: 20-25^o, height: 700-800 mm

Gable roofs
Slope: 20-25^o, height: 700-800 mm

Shed roofs
Slope: 5-12^o, height: 400-800 mm

Hip (cottage) roofs
Slope: 30-40^o, height: 1200 mm

Gable roofs
Slope: 30-40^o, height: 1200 mm

Zakopane style roofs
Slope: 45-50^o, height: 1850 - 2500 mm

Example manufacturer: http://gamrat.pl/oferta/systemy-rynnowe

NOTE!
The views present standard heights of enclosures. It is possible to construct the main structure of the substation up to a height of 3500 mm, however such solutions should be consulted every time with the manufacturer.

ZPUE S.A. has its own fleet, as one of few companies manufacturing prefabricated container substations. Provision of transport services is intended to lower the costs of transporting ZPUE S.A. equipment and to improve the quality of customer service. We offer a transport set with a gross vehicle weight rating of 70 tonnes, which can carry even up to 50 tonnes of cargo. Our road tractors are the latest generation models which meet Euro 6 exhaust emissions (standard for allowed exhaust emissions for new vehicles sold in the European Union).

Example of transformer substation transport

All works related to substation placement should be performed in accordance with a technical design drawn up on the basis of current standards and industry regulations and local guidelines, taking into account geotechnical conditions. The guidelines specified below should be treated as examples, which should be verified every time using data at the given substation location. The first stage of substation placement is excavation of a trench. External earthing of the substation in the form of an earthing ring (or other, in accordance with local earthing requirements) should be placed in the prepared trench.

Under the foundation a sand and gravel bed with a final thickness (after compaction) of at least 20 cm should be constructed. The thickness of the sand and gravel bed should be adapted to the local water and soil conditions and the local freezing zone. The surface of the sand and gravel bed should be level in the substation placement plane, and the quality of bed preparation in the excavation confirmed in the acceptance report. The foundation basin of the substation should be placed in the prepared location. Place a single layer of sealing tape on the upper part of the foundation basin. When placing the sealing tape, make sure that it does not overlap and does not stretch. This could cause damage or deformation.

Place the main structure of the substation over the foundation prepared in this manner, and then place the roof over it. The next stage is covering the foundation, performed by stages, with 20 cm layers of compacted filtering soil. Special care should be taken when covering the excavation at the site of contact with foundation wall, not to break the applied water insulation of vertical surfaces. Pay special care in the location where cables enter the cable entries, since mechanical compaction may cause damage to entries or cables.

It is important that the walls of the foundation basin protrude by no less than 10 cm above the final ground level. Placement in complex and complicated water and soil conditions, in mining areas and post-mining areas is recommended after a separate, individual design is prepared by a certified design body, with required geological and engineering documentation, under supervision performed by duly authorised personnel.

Example placement of a substation with an internal service corridor

NOTE!
The placement diagram above, due to the method of raising the main structure, is dedicated to substations with dimensions not exceeding: length: 5460; width: 3060; height: 2350.

The placement of an MRw-bS type substation is performed in the same manner as for an MRw-b type substation, with the difference that after the sand and gravel bed is made, a reinforced concrete stabilisation slab is poured, which prevents slab faulting and non-uniform settling of individual substations. Recommended minimum thickness of reinforced concrete slab 20 cm, C16/20 class concrete, minimum reinforcement with meshes at the top and bottom using ribbed bars Ø10/Ø12 mm top/bottom, spaced no more than 25 cm apart, made of AIIIN steel (e.g. RB 500W, 20G2VY-b — weldable steel), top and bottom reinforcement shifted in relation to each other by half of mesh size.

The actual and target thickness of the stabilising slab and the used reinforcement should be verified with structural calculations, taking into account load-bearing capacity at the placement site, taking into account the weight of the complete substation with equipment.

Example placement of a substation with external servicing

NOTE!
Placement of a substation with dimensions exceeding: length: 5460; width: 3060; height: 2350 should be performed in the same manner as on the figure above (elements used to raise the substation should be screwed into threaded sleeves prepared in the lower part of side walls or in the floor, depending on the construction version).

A substation placement site for an Mzb type substation with external servicing should be prepared in the same manner as for an MRw-b type substation.

The difference will stem only from the substation's design. In case of MRw-b type substations, the foundation and the main structure form two independent elements, whereas in case of an Mzb type substation with external servicing these elements form a single unit (foundation is combined with the main structure), which should be placed in the prepared excavation. Then a transformer is inserted from above (before the roof is attached), and in the last stage the roof is placed on the substation's main structure.