The prefabricated compact substation

The prefabricated compact substation is a type of comprehensive distribution equipment set that integrates medium voltage switchgear, low voltage switchgear, distribution transformer, energy metering devices, and reactive power compensation devices. It is designed to be assembled into one or multiple units based on a specific wiring scheme. This compact solution is well-suited for three-phase AC systems operating at rated voltages of 11KV or 33KV, facilitating the efficient transmission and distribution of electrical energy.

Due to its compact size, the prefabricated compact substation has found extensive application in all three phases of power distribution systems, supporting voltage ratings ranging from 11kV to 33kV for efficient electricity distribution. The shell component of the prefabricated compact substation incorporates cutting-edge domestic technology.

Galvanized steel plates are employed for the shell, while the frame utilizes materials and production techniques akin to standard containers. This construction ensures excellent corrosion resistance, guaranteeing a rust-free performance for up to 20 years. The equipment's operational efficiency remains unaffected by natural climatic conditions and external pollutants, ensuring reliable functionality even in harsh environments with temperatures ranging from -40°C to +40°C.

What is the Key Components of a Compact Substation?

At the heart of every compact substation lies a suite of meticulously chosen electrical components, each contributing to the seamless and reliable distribution of power:

Medium Voltage Switchgear (MV Switchgear): This critical component assumes the role of controlling and safeguarding the electrical power system at medium voltage levels. It incorporates advanced switching technologies for optimal performance and safety.

Low Voltage Switchgear (LV Switchgear): Charged with managing the distribution of electrical power at lower voltage levels, the LV switchgear ensures that power is prepared and optimized for further delivery to end-users. It often features state-of-the-art protective devices.

Distribution Transformer: The distribution transformer serves as the linchpin, adeptly stepping down voltage from medium to low levels. It features advanced insulation materials, cooling systems, and monitoring devices to ensure efficiency and reliability.

Protection and Control Devices: A sophisticated array of protection and control devices, including relays, circuit breakers, and protective relaying systems, meticulously monitor and manage electrical parameters. These devices act swiftly to ensure the safe and reliable operation of the entire substation.

Metering Devices: Precision is paramount in power distribution, and metering devices play a crucial role in measuring and recording electrical consumption. These devices are equipped with advanced technologies for accurate billing and monitoring purposes.

Reactive Power Compensation Devices: Enhancing the power factor and overall system efficiency, reactive power compensation devices include power factor correction capacitors and reactors. These components optimize the distribution network for enhanced performance.

Common Issues in Compact Substations and Solutions

Prefabricated compact substations, integral to modern power distribution networks, encounter various challenges over time. Identifying and addressing these common issues is vital to sustaining their reliability and performance.

Insulation Deterioration: A Silent Threat

Over the years, insulation materials within transformers and components may experience deterioration. This can result from temperature fluctuations, electrical stresses, and environmental factors. Diminished insulation resistance poses a risk of electrical breakdowns. Regular electrical testing and insulation monitoring are crucial for early detection and mitigation.

Contamination of Transformer Oil: Guarding the Vital Fluid

In oil-immersed transformers, the health of the transformer oil is paramount. Contamination with moisture, dirt, or impurities can compromise dielectric strength and lead to overheating. Regular oil analysis is essential to assess the condition of the oil and implement timely measures such as filtration or oil replacement.

Corrosion and Rust: Weathering the Elements

Outdoor compact substations are exposed to the elements, making them susceptible to corrosion and rust. Structural integrity may be compromised, affecting components like enclosures and support structures. Routine visual inspections, corrosion-resistant materials, and protective coatings are preventive measures against environmental wear.

Loose Electrical Connections: Bolstering Integrity

Vibrations, thermal cycling, and operational stresses can induce loosening of electrical connections. This escalates resistance, generates heat, and poses a risk of arcing. Regular tightening and torque checks, coupled with advanced monitoring technologies, help maintain secure electrical connections.

Switchgear Issues: The Heart of Operation

Switchgear malfunctions, such as circuit breaker failures or deteriorating contacts, can disrupt operations. Regular checks on mechanisms, trip circuits, and contactors ensure the smooth functioning of switchgear components. Periodic maintenance and timely replacements address potential issues before they escalate.

Transformer Overheating: Balancing the Heat

Factors like overloading or inadequate cooling can lead to transformer overheating. Monitoring temperature levels, inspecting cooling systems, and addressing issues promptly are crucial for preventing overheating and maintaining transformer efficiency.

Failure of Protective Relays: Safeguarding the System

Protective relays play a crucial role in detecting abnormal conditions and initiating protective actions. Malfunctions or incorrect settings can compromise protection. Regular testing, calibration, and adherence to relay maintenance schedules enhance the reliability of protective systems.

Grounding Issues: A Foundation of Stability

Inadequate grounding or deteriorating grounding systems compromise safety and stability. Regular inspections and maintenance of grounding systems ensure effective fault current dissipation and provide a solid foundation for the substation's overall safety.

Environmental Impact: Weathering the Storm

Compact substations in harsh environments face accelerated wear. Exposure to salt, chemicals, or extreme weather conditions contributes to premature aging. Protective measures, such as corrosion-resistant materials and environmental monitoring, are essential for substations in challenging locations.

Aging Components: A Natural Progression

The aging of various components is inevitable over time. Insulation materials degrade, mechanical wear occurs, and efficiency diminishes. Proactive replacement of aging components, based on manufacturer recommendations and lifecycle assessments, mitigates the impact of aging on substation performance.

Inadequate Maintenance: A Recipe for Complications

Neglecting routine maintenance exacerbates existing issues and invites new challenges. Regular inspections, preventive maintenance, and adherence to recommended schedules are essential for identifying and addressing issues promptly, preventing the accumulation of problems.

Cybersecurity Risks: Navigating the Digital Landscape

As compact substations embrace digitization, the risk of cybersecurity threats increases. Unauthorized access, data breaches, or attacks on control systems can compromise the integrity and security of the substation. Robust cybersecurity measures, including secure communication protocols and regular assessments, are imperative in safeguarding against digital threats.

Voltage Fluctuations: Balancing Act

Voltage fluctuations, whether due to external factors or internal issues, can impact power supply stability. Monitoring and corrective measures ensure stable voltage levels, preventing equipment failures and maintaining the overall performance of the substation.

Inadequate Cooling: Cooling for Efficiency

Effective cooling is crucial to prevent overheating in transformers and components. Malfunctions in cooling systems, such as fans or cooling channel blockages, can disrupt operations. Regular checks and maintenance of cooling systems ensure efficient heat dissipation.

Lack of Spare Parts: Preparedness for Contingencies

Maintaining an inventory of critical spare parts is essential for swift recovery during maintenance or failures. Adequate spare parts reduce downtime and facilitate quick replacement, ensuring the continuous operation of the substation.

Addressing these common issues requires a proactive and systematic approach to maintenance. Regular inspections, adherence to recommended maintenance schedules, and a commitment to technological advancements contribute to the reliability and longevity of compact substations. By navigating these challenges with diligence and foresight, these substations can continue to serve as pillars of modern power distribution networks.

What are the types of compact substation?

Compact substations, marvels of engineering efficiency, come in diverse forms to cater to specific needs and applications across industries.

1. Outdoor Compact Substation:Designed for resilience in outdoor environments, these substations boast weather-resistant enclosures, ensuring the protection of critical components against the elements.

2. Indoor Compact Substation: Tailored for settings where space is limited, indoor compact substations find a home within structures, shielding their components from indoor environmental conditions.

3. Pad-Mounted Compact Substation: Mounted on concrete pads, these substations are ground-level solutions often utilized in urban areas with restricted space, delivering efficient power distribution.

4. Mobile Compact Substation: Geared for mobility and flexibility, mobile compact substations are mounted on trailers or skids, facilitating swift transportation and deployment in emergency or temporary scenarios.

5. Skid-Mounted Compact Substation: Similar to mobile counterparts, skid-mounted substations rest on skids for ease of transport. Commonly used in industrial settings, they cater to temporary power requirements.

6. Containerized Compact Substation: Housed within standard shipping containers, these substations provide a modular and portable solution, ideal for rapid deployment and transport to various locations.

7. Prefabricated Compact Substation: The epitome of efficiency, prefabricated compact substations are pre-assembled and tested units featuring key components like switchgear, transformers, and control systems.

8. Mining Compact Substation:Engineered for robustness in harsh mining environments, these substations withstand challenging conditions, providing reliable power distribution in mining operations.

9. Railway Compact Substation: Tailored for railway electrification systems, these substations meet the specific requirements of railway applications, ensuring dependable power distribution along rail lines.

10. Containerized Data Center with Substation: Integrating compact substation features with a containerized data center, this type serves as an efficient solution for supplying power to modular data center setups.

The choice of compact substation type hinges on factors such as application, available space, and specific electrical system requirements. Industries and sectors opt for particular types based on their unique needs and constraints, showcasing the adaptability and versatility of compact substations in modern power distribution networks.

Maintenance Practices for Compact Substations

Compact substations play a pivotal role in modern power distribution networks, providing efficient and reliable electricity supply. To ensure the longevity and optimal performance of these substations, systematic maintenance practices are paramount. Here, we delve into key maintenance measures that contribute to the seamless operation of compact substations.

Visual Inspection: Eyes on Precision

Regular visual inspections are the frontline defense in the maintenance arsenal. Conducted at intervals, these inspections scrutinize external components such as enclosures, busbars, and insulators. Technicians look for signs of wear, damage, or corrosion, addressing issues before they escalate.

Electrical Testing: Safeguarding Insulation Integrity

The electrical integrity of compact substations is safeguarded through routine electrical testing. Insulation resistance tests are conducted to identify any deterioration in the insulation system, preventing potential electrical breakdowns and ensuring the substation's reliability.

Oil Analysis (if applicable): Preserving Transformer Health

For oil-immersed transformers, periodic oil analysis is indispensable. This analysis assesses the condition of the transformer oil, detecting contaminants or degradation that could compromise the transformer's efficiency. Proactive measures can then be taken to preserve the health of the transformer.

Switchgear Operation Checks: Smooth Operation, Optimal Performance

Switchgear components, including circuit breakers, disconnect switches, and contactors, undergo regular operation checks. Technicians ensure that these components function smoothly, without abnormal sounds or signs of arcing, guaranteeing the substation's optimal performance.

Transformer Inspection: Monitoring Vital Signs

A meticulous inspection of the transformer is essential for oil-immersed transformers. Technicians check for oil leaks, inspect cooling systems, monitor temperature levels, and ensure proper grounding. Any deviations from normal operating conditions are promptly addressed.

Control and Protection System Testing: Precision in Safety

Testing the control and protection systems is imperative for ensuring the safety and reliability of compact substations. Monitoring devices, relays, and protective elements undergo scrutiny to verify proper functioning. This includes testing trip circuits and confirming the integrity of alarm systems.

Cleaning: Warding Off Contaminants

Keeping compact substations clean is not just an aesthetic concern; it's crucial for efficiency. Regular cleaning of insulators, busbars, and other equipment prevents the buildup of dust, debris, and contaminants that can compromise performance.

Tightening and Torque Checks: Bolstering Connections

Periodic tightening and torque checks of electrical connections are fundamental maintenance tasks. Ensuring that bolts and nuts are properly torqued prevents the development of loose connections, reducing the risk of increased resistance and heating.

Grounding System Inspection: Ensuring Safety and Stability

A thorough inspection of the grounding system is crucial for ensuring safety and system stability. Technicians verify the effectiveness of the grounding system in providing a low-resistance path to ground, a key element in protecting both personnel and equipment.

Infrared Thermography: Identifying Hotspots

Incorporating infrared thermography into maintenance practices allows technicians to identify hotspots in electrical components. Elevated temperatures can signal issues such as loose connections or overloaded circuits, enabling proactive intervention.

Spare Parts Inventory: Preparedness for Quick Recovery

Maintaining an inventory of critical spare parts, including fuses, circuit breakers, and other components, ensures quick replacement in the event of failures. This minimizes downtime and contributes to swift recovery during maintenance activities.

Documentation and Record-Keeping: Tracking the Substation's Journey

Comprehensive record-keeping is the backbone of effective maintenance. Documenting maintenance activities, test results, and identified issues provides a historical record that aids in planning future maintenance and troubleshooting.

Training and Awareness: Empowering Maintenance Personnel

Ensuring that maintenance personnel are well-trained and aware of safety procedures is crucial. Regular training sessions keep the team updated on best practices, new technologies, and safety protocols, enhancing the effectiveness of maintenance efforts.

Environmental Monitoring: Shielding Against Adverse Conditions

Monitoring the environmental conditions around the substation is particularly important for those located in corrosive or harsh environments. Preventive measures can be implemented to protect equipment from adverse conditions, ensuring longevity and reliability.

Scheduled Outages for Maintenance: Strategic Planning for Minimal Disruption

Maintenance activities are strategically planned and scheduled during planned outages. This minimizes disruption to power supply, ensures the safety of maintenance personnel, and allows for comprehensive inspections and repairs. The reliability and longevity of compact substations hinge on a proactive and systematic approach to maintenance. From visual inspections to sophisticated infrared thermography, each maintenance practice contributes to the overall health and performance of the substation.

Prefabricated Substation Manufacturers - Why Choose Delixi?

Delixi YB series prefabricated electrical substation is a set of power distribution device, which is assembled with medium voltage switchgear, transformer, low voltage switchgear based on indicated connection. They are used for 3-phase AC system, 50Hz frequency, and capacity less than 2500kVA in the residential districts, malls, hotels, construction site, industrial & mining enterprise and temporary workplace. Generally, they are suitable for ring network power supply and redial terminal power supply.

Model designation

Normal sercice condition

1. Ambient temperature:-25°C -+40 C

2. The altitude should not be over 1000m and if use special transformer and LV components the altitude can up to 3800m.

3. Installation condition should not be severe shake and impact and the vertical lean angle should not be over 5°C;

4. The air humidity should not be over 90%(+25°C )

5. The speed of outdoor wind should not be over 35m/s

Designation characteristics

1. The shell is designed in terms of advanced technology and actual situation. It has advantages of fastness, heat reduction by ventilation, good performance, dust prevention, small animal prevention, moisture prevention, good appearance and convenient maintenance. There are several kinds of material for choosing, for example, aluminum alloy plate, steel plate, composite plate, stainless steel plate, non- metallic material.

2. The HV side usually uses load switch or vacuum circuit breaker, with a completed set of anti-misperation functions. If the ring main unit switchgear (short as RMU) is selected as XGN20-12L SF6 RMU, HXGN15A, HXGN17, KYN28A, the transformer can be oil-immersed, full-sealed or dry type transformer.

3. The substation has perfect protection performance, easy operation, and optional HV&LV measurement. The automatic reactive power compensation device is able to be installed required by customer.
4 The cover of the substation is made of double layers. The gap between the two layers filled with foamed plastics to prevent heat. There are independent separators inside the HV&LV room. In the transformer room, there are condensation prevention device, automatic temperature monitor and heating & cooling devices.

Tank is designed as natural ventilation, also the forced ventilation equipment can be installed. The door and side plate opposite the shutter should be fitted with anti-dust device.

Main technical parameters

YB 22 series pre-fabricated substation disposition scheme

HV typical single wire diagram

LV wire connection

Aluminum-plastic Panel, Color Steel Plate Shell

Pre-fabricated Substation

General introduction

This series of products are more and more widely used since they have advantages of good appearance, good heat insulation performance. This pre-fabricated substation uses u-steel as the base, angle steel as the substation framework (the substation employs double-layeredcolor steel plate). The appearance materials are imported composite plate and aluminum-plastic plate, with has a strong ability of corrosion resistance, no rust, and fastness, with a simple structure, good rigidity, light weight and good heat insulation performance. This substation is widely used in residential area, malls, streetlight project, scenic place and wind power generation. The color of shell is optional by customer

Metal Shell Pre-fabricated Substation

General introduction

This China prefabricated substation made of base, side plate, separate board, door and top roof. Inside the substation, there are HV room, transformer room and LV room. The protection level of the substation is IP33. The close board, separate board, door and top roof above the base, all of them are processed by cold-roll steel sheets, connected together by welding or fasteners. Each face of components is covered by durable protective layer after spraying.

Non-metal Shell Pre-fabricated Substation

General introduction

This series of products are suitable for single-transformer or double-transformer pre-fabricated substation. There are two types of
substatios, such as above the ground and under the ground.

The shell are made of glass fiber cement, it has,

1 Strong mechanical shock resistance and change resistance.

2 Strong sun resistance, crack resistance, radiation resistance and heat insulation
characteristic.

3 Good ability of antifreeze, anti-cracking, anti-corrosion, moisture proof and anti-flaming.

4 Can be used for the whole year.
(The color of the shell is optional by customer)

Underground Pre-fabricated Substation

General introduction

For the underground type substation, the HV equipment, LV equipment and transformer are placed underground. During the maintenance, the top roof can be removed, then the staff can access to the inner substation through the entrance. Generally, they are used for square grass area, park, which will not destroy the beautiful environment. Customers can choose half-underground or wholeunderground substation according to different places.

Diagram of half-burried substation

Diagram of whole-burried substation

Stainless Shell Pre-fabricated Substation

General introduction

For the stainless shell type substation, the shells are made of high quality stainless sheets. The substation has a good designation and exquisite workmanship. With special honey comb structure, solid shell, heat insulation, heat dissipation, good appearance and high protective grade, the substation shows advantage of the stainless material.

Minimized Intelligent Pre-fabricated Substation

General introduction

Since the series of the substation fitting with the imported FLUSARC SF6 ring main unit as the HV income, the network power supply can be achieved easily. Also, the fault site can be indicated easier, power cutting area is minimized, which make it convenient for maintenance. Micro electronics technology makes it possible to monitor intensively, test periodically, operate remotely and communicate easily. This substation adopts automatic system. These functions are called five remotes, including remote test, remote communication, remote control, remote adjust and remote monitor. It gathers protection, test, monitor, condensation prevention, and communication, to achieve working without human in attendance.

The volume of the substation is quite small (Length2500 x Width 1600 x Height1700), with nice appearance, which is suitable for public place.

Economy Pre-fabricated Substation

General introduction

This type substation uses steel or aluminum alloys composite sheets. The inner and outer surfaces of the substation are sprayed to form a durable protective layer. The HV side adopts frame structure with
reliable"five-defence"functions. It makes convenient to install electric devices.