Prefabricated compact substation.
Have you ever encountered this term?
If you’re in the industrial sector, perhaps you’ve heard it several times.
But what is it really and how does it work?
What are the different components of this?
Perhaps these are the questions which are popping to your mind right now.
Luckily, in this e-book about the definitive guide to the prefabricated compact substation, we will provide you with everything you need to know about this term.
A prefabricated compact substation is a substation at the end of the medium-voltage distribution network.
They are manufactured and assembled in the factory in advance including:
You see:
A complete compact substation specification is referred to as prefabricated substation.
It’s also known as “package unit substation” and “mini substation.”
It is within a housing or a group of enclosures that have passed type tests according to corresponding standards.
This prefabricated substation does not need the on-site installation program of electrical equipment.
Instead, they can be initiated after being transported directly to the place.
Thus, it makes it quick and convenient to deploy.
The prefabricated compact substation is also called as “packaged transformer substation“.
It is a type of distribution device that separates both the:
into the specific functional interval.
It assembles the high or low voltage electrical equipment in corresponding functional interval into complete substation function in the factory.
It is also installed on the outdoors and has a metal or concrete structure.
The function of the prefabricated compact substation is transfer high voltage to be low voltage, for example, The 11kV high voltage changed to be 380V working voltage through the transformer inside of the substation.
According to a specific wiring system, the factory prefabricated indoor and outdoor compact distribution equipment are progressively combined and installed in a:
The electric compact substation is movable, fully enclosed and heat-insulated substation.
Prefabricated compact substation in public
They are appropriate for urban network construction and transformation.
A packaged electrical substation is a new substation after the growth of civil substations.
The prefabricated substation is suitable for:
It transforms the original power distribution room and distribution station.
Then it becomes a new set of power distribution equipment.
A mini substation is a compact distribution device which combines:
in one or several mini substations according to an individual connection scheme.
It is appropriate for three-phase AC system with rated voltage 11/0.4KV.
These are utilized for line and distribution of electric energy.
According to the appearance and shell material, the transformer substation can be divided into:
Wooden strip type transformer substation features a robust anti-sun performance.
Wooden strip type compact substation
This type is not simple to heat condition, and it has the ability to lessen the running temperature of your internal equipment.
One good thing about this prefabricated substation is that it offers:
It has a good moisture-proof property and will not produce condensation due to cold and hot changes.
A stone type of package substation has excellent flame retardancy and excellent fire resistance.
Stone type prefabricated compact substation
The shape and color can be designated according to the surrounding environment.
Apart from its physical compact substation advantages, it can also beautify the environment.
This type of compact substation offers:
Iron type compact substation
It has excellent mechanical properties as well as impact resistance.
The overall structure of compact substation design can be divided into three parts:
Sulfur hexafluoride or vacuum circuit breaker, ring network switch, load switch and fuse can be designated for high voltage switch according to system requirements.
The metering device can also be installed on the high-pressure side.
The low-voltage side is usually equipped with the main switch and shunt feeder switch.
Meanwhile, some are equipped with only a feeder switch.
Feed directly to low-voltage terminal users.
Compensation capacitors and metering devices can also be installed.
Distribution transformers usually use oil immersed or dry type transformers.
The prefabricated substation is considered a low-voltage, transformer, and high-voltage switchgear distribution device.
It is a factory prefabricated outdoor and indoor compact distribution equipment.
That means, the low-voltage distribution, transformer voltage reduction, high-voltage power, and other functions are combined organically.
The body of the substation is composed of three (3) different parts:
Let’s discuss each of them.
The base is made of steel plate, angle steel, flat steel, channel steel and more.
They are bolted and welded together to build.
If you want to meet the requirements of ventilation, the following must be opened at corresponding lines.
On the other hand, the top cover channel steel and outer shell of the box are bent, welded and attached along with hinges, screws and other special accessories.
According to standard requirements, the material of the box shell should have:
into five anti-entry functions.
In the conventional packaged substation having a unified design, the insulation filler is geared in the shell.
The method isn’t longer utilized by the majority of designers though.
That’s because the insulation filler can stop intense sunlight radiation within the hot summer.
Apart from that, it can also obstruct the operation of the mini substation to generate a significant amount of heat dissipation.
There’s more you need to know aside from retaining the method of punching the blinds on the shell.
The majority of compact substation designers adopt the technique of extending the heat dissipation region.
It will also improve air convection to dissipate heat while lowering the manufacturing expenses.
The primary equipment in the substation design adopts the top domestic technology equipment like:
The intelligent design of the prefabricated substation like the production system adopts the microcomputer integrated device of the mini substation.
Every unit has an individual operation function.
They also transport protection function is accomplished.
The operation parameters could be set separately, and the temperature and humidity in the substation structure can be controlled.
In the HV substation design, if the designer creates the main wiring diagram, he can select the substation presented by the manufacturer to transform the models and specifications.
Lastly, due to the compact structure of the prefabricated compact substation, every substation creates an independent system.
That makes it changeable and flexible.
A European prefabricated compact substation high-voltage distribution device can be divided into:
from the way of the feeding line.
It can be distributed into:
It is a typical method in modern design.
SF6 series load switches with SF6 gas as an arc quenching medium have more cost than FN-10 series high voltage load switches.
You see:
This type of switch structure, with a fuse, no fuse, ground switch, etc.,
But it is generally equipped with the live display;
Furthermore, the operating mechanism is typically manual, but also electric operation.
With a fuse, when a short circuit fault occurs in the circuit:
There are also vacuum switches with vacuum as arc extinguishing medium.
They can be utilized alone or with fuses and can be used in series with the SF6 series load switches.
However, this will increase the cost, if the user does not have special requirements do not need to use such switches.
Apart from high-voltage distribution, the low-voltage pressure chamber of the European-type compact substation must be different in:
That’s according to various usage scenarios of mining and industrials enterprises or even residential quarters.
To make things simple:
The lighting supply and the power supply must be designed individually for those European-style prefabricated compact substations.
Typically, there are mostly utilized by mining and industrial sectors.
When using low-voltage metering, the Power Supply Bureau obliges individual metering of lighting power.
Why?
That’s because the unit cost of the lighting power is higher compared to power.
Further, the structural transmission substation design employed in the residential sectors, you don’t need to consider the issue of power consumption.
Amazing, isn’t it?
Did you know that prefabricated compact substation are geared with independent transformer room?
The transformer room includes:
Basically, when a medium voltage substation is running, a massive deal of heat is produced in the transformer chamber.
Thus, the ventilation and heat dissipation on the chamber must be considered on how to design a substation.
During high temperatures, more temperatures are increasing faster.
That denotes that only heat dissipation and natural ventilation cannot guarantee the safe and reliable operation of the mini substation.
The small capacity of the compact substation through temperature measurement protection and natural ventilation is designed as well.
Moreover, forced ventilation measures are also employed to fix it
Rmu in compact substation
Ring main unit for the outdoor compact substation was designed with the advantages of the uninterrupted power supply.
You see:
The question of what is rmu in a substation can be answered easily.
The function of RMU is to make sure that when the primary source of power supply shutdowns, another source could be feed as soon as possible.
Ring main units are insulated, which is one of the best and safest kinds of RMU in the market.
As an alternative, it can be presented as extendable rmu.
It can be referred to as an extendable compact ring main unit.
European, American and integrated transformer substation have their advantages and disadvantages.
European mini substations have:
Due to the direct external heat dissipation of the transformer cooling sheet, the cooling condition of the American-style prefabricated compact substation is relatively good.
However, its shape is worse than that of the European-style 11kv substation design.
The outdoor compact substation is less occupied.
The good thing here is that:
The advantages and disadvantages are the same as those of the American compact substation.
Also, the U. S. and universal compact substation can only be manufactured in China below 630 kVA capacity.
Meanwhile, the European substation can be up to 1250 kVA.
The capacity of the mini substation is in the range of 100 kVA up to 1250 kVA, maximum and not exceeding 16000 kVA.
A transformer substation adopts the state-of-the-art substation equipment layout idea.
Therefore, the look is impressive and the compact substation size was optimized to be 1/10 of the same capacity power substation.
Are you now wondering what the components of the prefabricated substation are?
Well, in this Chapter we will discuss with you EVERYTHING.
What is a feeder in prefabricated compact substation?
Did you know?
The feeder was formerly called as high-voltage switchgear.
It has receiving switchgear and feeder switchgear, high-voltage switchgear.
Now it’s called receiving switchgear for the incoming switchgear and called feeder switchgear for the outgoing switchgear.
It is a type of outlet situation of the high voltage switchgear.
That means that the high voltage outlet is direct to the transformer.
In the last Chapter, you already know that the compact substations have three compartments:
To fully understand the substation components, read further the list of substation equipment list we prepared for you.
Prefabricated compact substation compartments
The significant components of the high voltage distribution parts include:
Let’s take a look at each of them.
The live display device is composed of:
The two parts are connected by the installation to form a voltage display device.
It is used to reflect the power supply or no electricity of the high voltage circuit in the display device.
The indoor electromagnetic lock is an electronic control mechanism interlocking device.
This component can prevent misoperation of high voltage switchgear.
It is also used in front and back switchgear doors of indoor high voltage switchgear.
It serves to prevent misoperation.
Apart from that, it is an indispensable locking device for power generation and power supply departments.
The function of the high voltage switch is to:
High voltage fuse is also known as high voltage current limiting fuse for transformer protection.
Because the high voltage load switch can only cut off the load current, when encountering short circuit and overload, the current becomes larger, and the load switch is loaded.
You see:
It is impossible to cut off the current at this time, and the large current will be cut off by the fuse.
The grounding device works to ensure personal safety during overhaul.
The indoor high voltage grounding switch is the main component of the 12kV indoor AC metal armored prefabricated compact substation and other high voltage compact substation.
The function of lighting arrester is to limit overvoltage to protect electrical equipment of AC power system from atmospheric overvoltage and operating overvoltage damage.
As a reminder for you, low voltage distribution works to:
Following are the components of the low voltage compact substation:
The lighting arresters function to limit overvoltage to protect electrical equipment of an AC power system from atmospheric overvoltage and operating overvoltage damage.
This is utilized to compensate the inductive current in the power grid.
It’s also utilized to:
These substation components can be used for:
Did you know?
Contactor with inrush suppression device can effectively reduce the impact of inrush current on the capacitor.
It can also restrain the overvoltage during the interruption.
The large current is changed into the small current in proportion.
That is used for current, electric energy measurement and relay protection.
The isolating switch is inaccessible from the incoming switchgear in the front.
The same is true, but the selection of rated current is different
With transformer distribution, the prefabricated substation can be installed along with different kinds of the oil filled transformer.
What’s more:
It can also be installed along with cast resin dry type transformer.
Its distribution substation components include:
After knowing the different substation transformer parts and distribution substation components, what’s next?
In this Chapter, you will learn what the purpose of a substation is and how a substation works.
A compact substation is suitable for:
This prefabricated compact substation has the advantages of:
The environment has been coordinated and has been vigorously developed.
The prefabricated compact substation is a compact distribution device that combines
in one or several boxes according to a particular connection scheme.
It is appropriate for a three-phase AC system with rated voltage 11/0.4KV.
These mini substations are utilized for line and distribution of electric energy.
Mainly they are composed of:
They are installed in a moisture-proof, rust-proof, dust-proof, rat-proof, fire-proof, burglar-proof, heat-proof, fully blocked, movable steel box fully blocked operation.
The packaged substation shell is made of steel plate or alloy plate.
They are geared with double top cover and good heat insulation.
What’s more:
The shell and skeleton are all sheltered by antisepsis.
They have long time outdoor premises (complete sets of equipment) too.
On the other hand, the shape and color can be synchronized with the environment at one time.
It is simple to install.
A cable room is organized under the foundation of a European type compact substation.
A manhole is also prepared in the low-voltage room to enter the cable room for work.
From the perspective of volume, the compact transformer is fortified with:
Meanwhile, the American type transformer is smaller because of the single body installation (electric meter box).
The load side switch and the current limiting fuse are utilized to keep the high voltage side of the transformer.
When a phase-1 fuse is formed, the load switch 3 is switched on at the same time with the fuse pin collision to prevent the phase-out operation.
The load switch is demanded to cut the transfer current.
The low voltage side is preserved by load switch plus current limiting fuse.
The high voltage side of American type compact substation is upheld by a fuse.
While the load switch is only utilized for switching and cutting off the high voltage load current.
When the high-voltage side grants a phase fuse, the voltage on the low-voltage side will drop.
The plastic case automatic air switch under-voltage maintenance or overcurrent maintenance will operate.
Thus, the low-voltage operation will not occur.
Some components on prefabricated substation should be inspected and maintained regularly.
It includes:
The defects should be found and repaired in time.
The preventive insulation test should be carried out regularly.
The packaged substation will be postponed for more than three months, and all preventive tests should be carried out before commissioning.
The transformer must be cut off if you want to replace the high-voltage fuse without interrupting ability,
The mechanical interlock should be removed correctly during operation.
Also, the insulated operating rod should be used.
All incoming and outgoing cable holes in packaged substation should be blocked.
Doing this will prevent small animals from entering and cause accidents.
The floor of a prefabricated compact substation should be selected at a higher level.
That’s an alternative to not choosing a lower level.
Doing this will avoid rainwater pouring into the substation affecting the operation of the equipment.
When the concrete platform is poured, there should be a gap between the:
That will facilitate the laying of the cable inlet and outlet.
When excavating the foundation, if it encounters the ground accumulated by garbage or rotten soil, it is necessary to dig up the solid soil.
Then fill the better soil and compact it, and then fill the composite soil or road slag to ensure the stability of the foundation.
Compact substation testing
Before docking and unloading the vessel in which the equipment is located,
must inspect the equipment one by one.
They must promptly raise the problems.
Collecting the pictures and data and make relevant written records should also be observed.
Even signing and confirming when recording is necessary, too.
Before hoisting equipment, it is necessary to carry out a safety inspection on
It’s also crucial to check the operation of hoisting equipment.
All of which is normal before hoisting can be carried out.
Equipment hoisting should be strictly carried out according to the standard of construction technology for large equipment hoisting engineering.
Compact substation Hoisting for installation
Are you now done transporting your compact substation by sea or land to the construction site?
If so, the service technician of the manufacturer, the personnel of the logistics center and the material department shall check whether the change is damaged or destroyed in the course of land transportation.
When complications are found, they should be promptly put forward and photographic data collected and relevant written records made.
When recording, the personnel of all parties should sign and confirm.
Then the equipment should be recorded without damage.
The crane driver should recognize the stopping position of the crane and the loader.
The position will be based according to the changing installation position of the substation and the site conditions.
Doing this will ensure that the
are within the scope of the crane construction operation.
Nonetheless, what if the installation position of the compact substation is far from the road?
What if the crane can’t meet the installation requirements of the substation on the road?
If that’s the case, the unique construction scheme of the compact substation in the six districts and eight districts ought to be referred to.
After the transformer substation is installed in the correct position, the high and low voltage cables should be excavated.
The mega-ohm meter must be employed to determine whether the insulation grade of the cables is qualified or not.
Further, the cables with unqualified insulation grade should be strictly forbidden to carry out follow-up construction.
Compact substation installation
After the insulation test is qualified, the personnel can arrange high and low voltage cables.
These cables will be laid in the transformer.
You see:
The high and low voltage cable head is made by the electric technician.
Before the cable head is made, it should be checked whether the cable circuit is consistent with:
After the cable head is complete, the substation should change the base port to seal up.
That’s the time where the cable sign will be installed.
After the compact substation is installed, you can install the grounding device.
Bear in mind that the type and quantity of grounding electrode and grounding trunk line should meet the requirements of design drawings.
The following areas should meet the specifications and design requirements:
Whenever installing huge equipment like a prefabricated substation, it’s important to be as safe as possible.
Following are the safety rules you need to consider when installing the compact substation:
The driver of the crane should not obey others’ command.
However, the emergency stop signal should be implemented immediately.
A compact substation is known as a:
As discussed in the previous Chapters, it is composed of high and low voltage equipment, and transformer incorporated inside the factory.
The complete name of this type of transformer is prefabricated compact substation.
It’s a type of power equipment that can be hoisted and transported by combining power with low and high voltage distribution in one or various switchgears.
The compact substation is widely utilized in the construction of the railway, urban power grid, and railway.
That’s thanks to its neat look, compact structure, simple movement and installation and more.
Did you know that the packaged substation’s relay protection system can safeguard transformer components?
Compact substation fault
Yes, you read that right.
Every time the power system happens or presents an abnormal working state, it can cut off the fault-free equipment automatically, selectively and quickly.
Isn’t that amazing?
That process will guarantee the normal and flawless operation of the equipment.
It will also limit the incident to the minimum range.
Therefore, it will offer the stability of the power system.
Ultimately, it will guarantee the security of electricity consumption.
Some of the cause of this fault in compact substation includes:
To fix your problem, you can check the opening point with a multimeter.
Make sure that you also find out the cause of the trip and press the reset button after troubleshooting.
Don’t forget to check the manual or electric energy storage as well.
The apparent cause for this substation fault might be the insufficient release after tripping.
It might also be that the circuit breaker is with under voltage coil.
Thus, it doesn’t have the power supply at the incoming end.
To solve these types of faults in the substation, you need to identify the cause of tripping and reset after troubleshooting.
If you observe the electrification of incoming line, you can reset the handle and then close.
The only cause for this is there’s a short circuit in the outlet loop.
The solution to this is not to switch on repeatedly. You need to determine the substation fault.
Then you can get rid of them before closing.
If your capacitor switchgear can’t compensate automatically, it might be because the power supply of the control loop is not there.
It might also be because the existing signal line isn’t connected appropriately.
Do you think what the solution to this?
Well, it’s straightforward.
You can check the control loop and restore the power supply.
Alternatively, you can also connect the signal line correctly.
Compact Substation Maintenance
When is the perfect time to conduct a maintenance schedule for your compact substation?
Well, in case you didn’t know yet, your compact substation must be maintained on a regular basis.
It should not be less than a month.
That time frame is according to the inspection and maintenance cycle.
You also need to bear in mind that temperature at the junction of the cable terminal should be tested.
The operation of the equipment should also be checked as well.
The face test is performed if needed.
High voltage switchgear maintenance
Following are the general items you need to check if you’re carrying out your maintenance inspection:
Prefabricated compact substation has transformed over the past 20 years.
It evolved to such a level which they can almost be sought as a standard product line.
What was once a phase deemed as the hugely complicated task has now become standard practice by different compact substation manufacturers.
Compact substations that comply completely along with the standard specification of IEC have transformed into an acceptable option to traditional substations.
That’s because they deliver the needed:
These days, there are ever increasing prices of performing site work.
That’s particularly true in remote locations.
Therefore, this alternative is likely to become more frequently referred by the majority of end users.
Now, are questions been answered about:
We hope all of this is now clear to you!
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