GO-SIN
Product Introduction
DT OIT SST DAES RMU AC LV Cabinet YBM PS ZGS ABT KYN28 |
Dry-Type Transformer
Dry-type transformers are essential equipment in modern power systems, widely used for local lighting, high-rise buildings, airports, docks, CNC machinery and other facilities. Compared with traditional oil-immersed transformers, dry-type transformers feature distinct advantages as follows.
Dry-Type Transformer Product Description
As a key component of modern power systems, dry-type transformers stand out for their superior performance and versatile applications, making them the preferred choice for numerous industrial and civil sectors. Below is the detailed product introduction.
High Safety
Adopting advanced insulating materials and structural design, dry-type transformers require no insulating oil, eliminating fire hazards caused by oil leakage. Featuring a high insulation class and strong short-circuit resistance, they guarantee stable operation of power systems.
Eco-Friendly Performance
No harmful substances are generated during operation, resulting in zero environmental pollution. The low-noise design effectively reduces noise disturbance and creates a quiet living environment for surrounding residents.
Easy Maintenance
With a simple and compact structure, the equipment is convenient for routine inspection and upkeep. Excellent heat dissipation extends service life and cuts maintenance time and costs.
High Efficiency
Thanks to sophisticated electromagnetic design and manufacturing techniques, power loss is significantly reduced for higher operational efficiency. Its compact size and light weight facilitate installation and transportation, enabling rapid deployment of power facilities.
Wide Application Range
It is ideal for space-limited areas such as basements, high-rise buildings and vessels. The oil-free design also makes it suitable for explosion-proof sites and areas with severe electromagnetic interference.
Intelligent Management
Equipped with a comprehensive temperature monitoring and protection system, the intelligent temperature control unit automatically detects and displays the operating temperature of three-phase windings in cycles. It can start and stop cooling fans automatically, and is configured with alarm and tripping functions.
Technical Parameters
Operating Frequency: 50/60Hz
No-load Current: 4%
Dielectric Withstand Voltage: 35000V/min, no breakdown
Insulation Class: Class F (Special classes available on request)
Insulation Resistance: ≥ 2MΩ
Connection Mode: Y/Y, A/Y0, Yo/A, Auto-transformer (Optional)
Permissible Coil Temperature Rise: 100K
Cooling Method: Natural air cooling or automatic temperature-controlled cooling
Noise Level: ≤ 30dB
Operating Environment
Ambient Temperature: -25-40℃
Relative Humidity: 70%
Altitude: ≤ 2500m
Keep away from rain, moisture, extreme heat and direct sunlight
Do not operate in areas with excessive corrosive liquids, gases, dust, conductive fibres or metal particles
Prohibit long-term inverted storage and transportation; avoid severe impact
Overall Dimensions & Weight
Model: BGS-333
Overall Dimensions (mm): 350 x 280 x 380
Weight (Kg): 30
With outstanding safety, environmental performance, easy maintenance and high efficiency, dry-type transformers play an increasingly vital role in power systems. Along with technological advancement and expanding application scenarios, they will see broader use and further development in the future.
Oil-Immersed Transformer
Oil-immersed transformers use oil as the cooling and insulating medium. They consist of iron core, windings, oil tank, cooling system and protection devices. Featuring excellent heat dissipation and high insulation performance, they are applicable for various voltage levels and capacity requirements.
Oil-Immersed Transformer Product Description
An oil-immersed transformer adopts oil as the cooling and insulating medium. It is composed of iron core, windings, oil tank, cooling system and protection devices. With superior heat dissipation and high insulation performance, it can meet various requirements on voltage level and capacity.
Application Scope & Performance Features
Application Scope
Suitable for power and distribution systems with capacity up to 6300 kVA and voltage up to 35 kV.
Performance Features
High Reliability: Manufactured with premium materials and advanced craftsmanship to ensure stable operation.
Low Power Loss: Adopts energy-efficient design to reduce operating costs.
Excellent Heat Dissipation: The oil-immersed structure delivers efficient heat dissipation and extends service life.
High Insulation Performance: Transformer oil serves as a reliable insulating medium for full protection.
Operating Conditions
Ambient Temperature: -25℃ ~ +40℃
Relative Humidity: ≤ 90%
Altitude: ≤ 1000 m
Installation Site: Locations free from fire, explosion hazards, severe pollution, chemical corrosion and intense vibration.
Structural Features & Main Functions
Iron Core: Made of high-quality cold-rolled silicon steel sheets to reduce power loss and improve efficiency.
Windings: Constructed with copper or aluminium conductors to guarantee excellent electrical conductivity.
Oil Tank: Welded from high-grade steel plates and fully filled with transformer oil for cooling and insulation.
Cooling System: Equipped with radiators and fans to ensure normal operation under high temperature conditions.
Protection Devices: Fitted with pressure relief valve, gas relay, thermometer and other components to secure safe operation.
Working Principle & Main Technical Parameters
Working Principle
Voltage transformation is realized based on the principle of electromagnetic induction. When AC power is applied to the primary winding, an alternating magnetic field is generated. The secondary winding induces electromotive force under the magnetic field to complete voltage conversion.
Main Technical Parameters
Rated Capacity: ≤ 6300 kVA
Rated Voltage: ≤ 35 kV
Rated Frequency: 50 Hz
Cooling Method: Oil Natural Cooling, Oil Forced Air Cooling
Insulation Class: Class B / Class C
Impedance Voltage: Subject to specific models and specifications
6. Installation
Transportation
Mainly transported by road or railway with the tank fully filled with transformer oil.
Lifting Method
Use four lifting lugs on the tank wall (two lugs for small-capacity units). The angle between lifting ropes and the vertical line shall not exceed 30°.
Installation Procedures
Including foundation preparation, transformer positioning, wiring and overall inspection.
7. Commissioning & Operation
Commissioning Procedures
Including visual inspection, electrical tests and oil sample analysis.
Operation Procedures
Including no-load trial operation, on-load trial operation and formal commissioning.
8. Routine Maintenance & Tests
Daily Maintenance
Check oil level, oil temperature, gas relay and other key parts regularly.
Periodic Tests
Include insulation resistance test, oil sample analysis and winding DC resistance test.
9. Drawings & Accessory List
Drawings
Transformer outline drawing, installation dimension drawing, electrical wiring diagram, etc.
Accessory List
Factory certificate, operation manual, technical documents and other attachments.
This is the complete product description of the oil-immersed transformer. Please feel free to contact our supplier or manufacturer for further inquiries and technical support.
Solid State Transformer
Solid State Transformer (SST) is an integration of power electronics and semiconductor technologies. Regarded as a smart energy router, it is poised to revolutionize traditional power systems.
Working Principle: Evolution from Iron Core to Silicon Core
Conventional transformers operate at 50Hz power frequency with iron cores and copper windings, featuring bulky size and single function. Solid State Transformer (SST) replaces traditional iron cores with power semiconductor devices such as SiC and high-frequency transformers. It firstly rectifies input AC power into DC, completes voltage conversion via high-frequency transformers (frequency ranging from several kilohertz to megahertz), and finally inverts the power to the required output.
Boosting the operating frequency by hundreds of times drastically downsizes magnetic components, which is the fundamental reason for SST's compact design.
Core Advantages: Compact Size Plus Intelligent Performance
SST delivers revolutionary advantages over traditional transformers:
Ultra-compact Structure: Under the same power rating, its volume and weight are reduced by 60% to 90%, saving considerable floor space.
High Efficiency & Energy Saving: The overall efficiency exceeds 98%. With lower power conversion losses, it can cut electricity costs by millions annually for large data centers.
Flexible Control: It enables real-time voltage regulation, harmonic filtering and reactive power compensation, and supports both AC and DC outputs, serving as an ideal interface for smart grids.
Safe & Eco-friendly: No transformer oil is required, eliminating risks of oil leakage and fire hazards.
Key Application ScenariosAI Data Centers: As the power load of single racks rises to 100kW, SST directly converts 10kV high-voltage power to 800V DC, greatly simplifying power supply circuits.
EV Ultra-fast Charging: It converts 10kV AC to 800V DC for electric vehicles, perfectly matching the demands of ultra-fast charging piles.
Renewable Energy Grid Integration: It connects directly to DC equipment like photovoltaics and energy storage systems, enabling efficient grid connection and power fluctuation stabilization.
Smart Grids: Acting as an energy router, it realizes bidirectional power flow control and power quality improvement.
Core Technology: SiC Devices as the Key
The performance of SST relies heavily on third-generation semiconductors represented by Silicon Carbide (SiC). Compared with traditional silicon devices, SiC features high voltage resistance, high frequency capability and excellent heat resistance, laying a solid foundation for SST's high efficiency and power density. With the rapid cost reduction of SiC components, the total cost of SST is approaching that of conventional solutions.
Currently, high initial procurement cost and long-term reliability verification remain the main challenges for SST. Nevertheless, thanks to its outstanding strengths in efficiency, space utilization and operation & maintenance, SST has become one of the core equipment for future AI computing development and energy transition.
Distribution Area Energy Storage
Distribution area energy storage can be regarded as a "smart power bank" installed on the low-voltage side of distribution transformers. It offers a flexible and intelligent solution to common issues at the end of distribution networks, including unstable voltage, transformer overload and difficulties in new energy consumption.
Core Values
Dynamic Capacity Expansion: It discharges automatically when transformer capacity is insufficient, handling seasonal peak loads without capacity upgrade.
Voltage Stabilization: Charges to lower voltage during peak photovoltaic power generation, and discharges to raise voltage at power consumption peaks, maintaining stable voltage all the time.
Higher Energy Absorption: Stores surplus photovoltaic power to avoid solar curtailment. The energy absorption rate of some projects can rise by over 10 percentage points.
Interpretation of Key Technical Indicators (Selection Guidelines)
Four core indicators are essential:
Cycle Life: Determines long-term economic benefits. Lithium batteries boast over 6,000 cycles, while sodium-ion batteries reach 8,000 cycles, supporting a design life of more than 10 years.
Ingress Protection (IP) Rating: Outdoor units require superior weather resistance. The mainstream rating is IP54 (dust and rain proof), with some products adopting IP44.
Switching Speed: Critical for mitigating voltage sags. High-quality products achieve grid-tied/off-grid switching within 20ms to prevent equipment tripping.
Intelligent Regulation: The core function. It supports active/reactive power decoupling control to independently adjust voltage and rectify three-phase unbalance.
Two mainstream solutions are available on the market:
Integrated Energy Storage Cabinet: A compact outdoor cabinet covering only a few square meters, with power ranging from 100kW to 200kW for plug-and-play use.
Mobile Energy Storage Vehicle: Trailer-mounted for flexible deployment. It is ideal for temporary power peaks during tea-picking, tourist seasons and other scenarios.
Overall, distribution area energy storage products are evolving rapidly toward larger capacity, full liquid cooling and higher intelligence.
Ring Main Unit
A Ring Main Unit (RMU) is a set of power transmission and distribution electrical equipment housed in metal enclosures or assembled as sectional ring power supply units. Its core components consist of load switches and fuses.
1. Working Principle of Ring Network Power Supply
A ring network refers to a closed-loop distribution system. The main power lines form a complete ring. The po
wer source feeds electricity into this loop, and power is distributed to individual branches via high-voltage switches.
Core advantages: Each distribution branch can draw power from either side of the main loop. If one section of the main line fails, power supply is maintined via the other side. Though fed by a single power source, every branch achieves reliability equivalent to dual-power supply.
2. Product Classification
2.1 Classification by Insulating Medium
| Type | Characteristics | Application Scenarios |
| SF₆ Gas Insulation | Superior performance, high reliability, compact size and low maintenance. Annual SF₆ leakage rate ≤ 0.01%; insulation service life exceeds 30 years. | Widely used in urban distribution networks. SF₆-free products are required for environmentally sensitive areas. |
Eco- friendly Gas Insulation(N₂ + Dry Air) | No greenhouse gas emission; partial discharge ≤ 10 pC; stable operation at -25℃ ~ +65℃ across full temperature range. | Water source areas, scenic spots and other environmentally sensitive regions. |
| Air Insulation (HXGN Series) | Simple structure, low cost, oil-free and non-toxic; protection class IP2X. | Conventional indoor power distribution; gradually replaced by gas-insulated equipment. |
| Solid Insulation | Fully sealed structure, maintenance-free. | Severe environments such as high-altitude and humid areas. |
2.2 Classification by Structure
Common Tank Type: Multiple circuits share a single gas tank. It features a compact structure and is mostly used for outdoor ring main units.
Modular Unit Type: Each circuit is equipped with an independent gas tank. It offers high flexibility and easy expansion.
2.3 Comparison of Common Models
| Model Series | Insulation Type | Structural Features |
| HXGN-10 | Air Insulation | Gas-generating load switch, fixed structure |
| XGN-15 SF₆ | SF₆ Gas Insulation | Modular design, expandable |
| AGH-12 | SF₆-free Eco-friendly Gas (N₂ + Dry Air) | Ideal for new energy project |
3. Structural Composition
| Compartment | Main Equipment | Function Description |
| Switch Compartment | Load switch, earthing switch, busbar | Core components enclosed in metal housing. The load switch is typically a three-position type (Close - Open - Earth). |
| Fuse Compartment | High-voltage current-limiting fuse | Installed in epoxy resin insulated enclosure. When blown, the fuse activates a striker to trip the load switch. |
| Operating Mechanism Compartment | Spring energy-stored mechanism, interlocking device | Located at the front. Realizes manual/electric operation and five-prevention interlock. |
| Cable Compartment | Cable accessories, current transformer | Situated at the lower part of the cabinet for connecting incoming and outgoing cables. |
4. Core Technical Solution: Combined Load Switch and Fuse
Ring main units are featured with combined load switch and fuse apparatus in place of circuit breakers:
Load switch: Handles normal load current (breaking capacity ≤ 630 A) and overload current.
Fuse: Interrupts short-circuit current to protect transformers.
Combined performance: Satisfies routine operation and fault protection requirements of distribution systems at a much lower cost than circuit breaker switchgears.
5. Reference Technical Parameters
(Typical 12 kV Ring Main Unit)
| Parameter Item | Typical Value |
| Rated Voltage | 12 kV (24 kV / 40.5 kV optional) |
| Rated Current | 630 A (main busbar), 125 A (fuse circuit) |
| Rated Short-time Withstand Current | 20 kA/3 s (max. 31.5 kA/3 s) |
| Rated Short-circuit Making Current (Peak) | 50 kA (max. 75 kA) |
| Power Frequency Withstand Voltage (1 min) | 42 kV (phase-to-earth / phase-to-phase), 48 kV (isolating fracture) |
| Lightning Impulse Withstand Voltage | 75 kV (phase-to-earth / phase-to-phase), 85 kV (isolating fracture) |
| Mechanical Endurance | ≥ 2000 operations |
| Protection Class | Enclosure: IP4X; Gas tank: IP67 (outdoor type) |
| Dimensions (Width × Depth × Height) | 600× 900 × 1800 mm (side-mounted load switch) |
6. Application Scenarios & Selection Guidelines
Typical Application Scenarios
Urban residential communities & high-rise buildings: Installed in power distribution rooms or box-type substations
Industrial parks & commercial centers: Used as ring network power supply nodes
Photovoltaic & wind power (new energy): For grid connection of collector lines
Box-type substations: Serves as high-voltage distribution unit
Selection Guidelines
Insulation type: SF₆ gas insulation for general use; eco-friendly gas insulated units for environmentally sensitive areas.
Operating environment: Outdoor units shall adopt IP67 protection class for moisture and dust resistance.
Transformer capacity: Fuse protection is applicable to transformers with capacity ≤ 1600 kVA.
Intelligent requirements: Check if automatic interfaces (remote switching, condition monitoring) are required.
Structure type: Modular unit type for indoor installation; common tank type for outdoor installation.
7. Comparison with Traditional High-Voltage Switchgear (KYN28)
Ring main units adopt a combination of load switches and fuses as the main switching device, while KYN28 withdrawable switchgears are equipped with vacuum circuit breakers.
For short-circuit protection, fuses used in ring main units are disposable components, whereas circuit breakers can perform opening and closing operations repeatedly.
In terms of rated current, the value of ring main units is generally no more than 630 A, while KYN28 switchgears cover a range from 630 A to 4000 A.
Ring main units feature lower cost and a compact design with a width of 600 mm. By contrast, KYN28 switchgears cost more and have a larger overall size, with the width ranging from 800 mm to 1000 mm.
In practical application, ring main units are mainly applied to terminal power distribution and ring network nodes. KYN28 switchgears are suitable for main power distribution and large-capacity outgoing circuits.
AC Low-voltage Switchgear
AC low-voltage switchgear is core equipment in power systems. It distributes, controls and protects electric power at 380V/400V, and is widely used in industrial and civil power distribution.
Classification and Introduction of AC Low-Voltage Switchgear
AC low-voltage switchgear is mainly categorized into three mainstream types, including fixed type, draw-out type and standard models.
1. Main Model Classification & Selection ComparisonLow-voltage distribution switchgears are primarily divided into three classic series: GGD (fixed type), GCS and MNS (draw-out type). There are also improved models such as GCD.
1.1 GGD Series (Fixed Type) — Cost-effective & Reliable WorkhorseGGD is the most widely used fixed switchgear currently. All components are fixedly installed, featuring simple structure and low cost.
Core Features
Natural ventilation & heat dissipation: Vent slots are arranged on the top and bottom of the cabinet. Convection is formed by the upward flow of hot air, requiring no forced air cooling.
Fixed installation: Flexible configuration and easy visual maintenance. Ideal for projects with infrequent operation or cost constraints.
Technical Parameters & ClassificationThe series is divided into three sub-models by short-circuit withstand capacity:
GGD1: Maximum rated current 1000A, 1s short-time withstand current 15kA. Applied to small workshops and residential branch power distribution.GGD2: Maximum rated current 1600A, 1s short-time withstand current 30kA. Applied to commercial complexes and general factories.GGD3: Maximum rated current 3150A, 1s short-time withstand current 50kA. Applied to large workshops and main distribution in substations.
GGD1/2/3 represent different cabinet frame grades corresponding to varying short-time withstand current. The current of outgoing circuits inside the same cabinet is optional, such as 630A and 400A.
1.2 Draw-out Series (GCS / MNS) — High-Reliability Intelligent SolutionSwitch units are designed as drawer modules. Modules can be pulled out and replaced directly during maintenance without interrupting power supply to other circuits, delivering superior power supply reliability.
GCS (Mainstream domestic model)Developed in accordance with standards for low-voltage switchgear and controlgear, it features high modularity, strong unit interchangeability, and a maximum of 22 outgoing circuits per cabinet.
MNSAdopts C-section steel frame with a module pitch of 25mm for flexible assembly. Each draw-out unit has three working positions: Connected, Test and Isolated. The protection class remains effective at any position of the drawer.
GCD SeriesAn upgraded version based on GCS and MNS. It supports PROFIBUS fieldbus and realizes four remote functions: remote control, remote regulation, remote measurement and remote signalling.
Selection AdviceDraw-out switchgears are preferred for scenarios requiring high power supply continuity, such as data centers and precision manufacturing workshops, or projects with limited on-site maintenance manpower. Fixed GGD cabinets are a more cost-effective choice for budget-limited projects with convenient maintenance conditions.
2. Interpretation of Key Technical ParametersRated insulation voltage (Ui): Normally 660V or 1000V, which defines the insulation level of the cabinet.
Rated current of horizontal busbar: Refers to the total current carried by the main busbar. Common ratings include 1000A, 1600A, 2500A and 4000A, with the maximum range reaching 5000A to 7000A.
Rated short-time withstand current (Icw): A core indicator reflecting the cabinet’s resistance to short-circuit impact. GGD cabinets generally reach 15–50kA, while MNS and GCS can achieve 50–80kA, and higher values for high-end products.
Protection class (IP)
IP30: For conventional indoor distribution rooms, preventing ingress of solid objects larger than 2.5mm.
IP40: For environments with stricter dust prevention requirements.
IP41 / IP54: Mostly adopted by MNS and similar models with special ventilated top plates, suitable for occasions requiring drip-proof performance.
3. Internal Structure & Functional Zoning
A standard low-voltage switchgear consists of four physically isolated compartments:
Busbar compartment: Located at the cabinet top, for installation of three-phase horizontal main busbars (Phase A, B, C, Neutral and Protective Earth).
Component / Functional unit compartment: The core area. Equipped with moulded case circuit breakers for fixed cabinets or drawer units for draw-out cabinets.
Cable compartment: For connection of incoming and outgoing cables, fitted with current transformers.
Instrument compartment: Situated on the upper front of the cabinet, accommodating smart meters, indicator lights, push buttons, PLC and communication modules (essential for intelligent switchgears).4. Common Functional Cabinet Types
A complete low-voltage distribution system is composed of the following types of switchgears:
Incoming cabinet: Receives power output from the low-voltage side of transformers and is equipped with air circuit breakers.
Capacitor compensation cabinet: Built with contactors and capacitor banks for power factor correction.
Feeder / Outgoing cabinet: Distributes power to various branch loads.
Motor Control Center (MCC): Dedicated to controlling the start, stop, forward and reverse operation of motors.
Coupling cabinet: Used for connection or sectional operation between two sets of busbars.YBM Prefabricated Substation
A prefabricated substation (abbreviated as box substation) is a complete set of prefabricated power distribution equipment. It integrates high-voltage switchgear, distribution transformers and low-voltage distribution devices into an enclosed cabinet in accordance with specific wiring schemes.
Like a factory-assembled and movable "mini substation", it can be directly installed at power load centers.
Core Advantages
1. European Type Prefabricated Substation
Prefabricated substations boast remarkable strengths compared with traditional masonry substations:
Ultra-compact & space-saving: Its volume is only 1/5 to 1/10 of a conventional substation with the same capacity. It can be installed in narrow spaces such as roadsides and green belts.
Cost-effective & fast deployment: The overall investment can be cut by 40% to 50%. No dedicated distribution room is required, and only cable connection is needed on site, leading to an extremely short construction period.
Safe & eco-friendly: Adopting fully insulated and fully sealed design with no exposed live parts. Some models use dry-type transformers with zero oil leakage risks.
Strong environmental adaptability: The enclosure is made of special metallic or non-metallic materials, featuring moistureproof, dustproof, anticorrosive and heat insulation performance. It can operate under extreme temperatures ranging from -40℃ to 40℃.Three Main Categories: European Type, American Type & Chinese Type
European and American types are the mainstream products on the market. The Chinese type, which combines the merits of the former two, has emerged in recent years. Their differences and selection suggestions are as follows:
Structure & Features: Adopts I-shaped or triangular layout with separate high-voltage compartment, transformer compartment and low-voltage compartment. It has a relatively larger size yet ample internal space, allowing installation of standard switchgears and offering strong expandability. Dry-type transformers are commonly equipped for excellent fire resistance.
Application Scenarios: High-rise buildings, residential communities, commercial centers, data centers and other sites requiring high power supply reliability.
Selection Tips: Prioritize this type. It is the optimal choice for urban core areas, densely populated zones, or projects with strict requirements on distribution automation and fire protection.
2. American Type Prefabricated SubstationStructure & Features: Integrated design. High-voltage load switches and fuses are directly immersed in the transformer oil tank. Its volume is merely 1/3 to 1/5 of the European type with an ultra-compact structure. Equipped with oil-immersed transformers featuring strong overload capacity.
Application Scenarios: Sites with strict space limits and moderate requirements for power supply reliability, including industrial parks, temporary construction power supply, wind/PV power step-up stations and road lighting systems.
Selection Tips: Choose this type when space is limited. Note that there is no visible isolation point on the high-voltage side, so extra caution is required during maintenance. Early models may generate a small amount of harmful gas as switches operate in oil, while modern products have been greatly improved.
3. Chinese Type Prefabricated SubstationStructure & Features: It integrates the advantages of European and American types. The high-voltage compartment is independent, while the transformer compartment adopts the exposed radiator design of American oil-immersed transformers, delivering good heat dissipation at a reasonable cost.
Application Scenarios: New energy projects such as photovoltaic and wind power stations, as well as sites demanding cost performance and superior heat dissipation.
Key Technical Selection GuidelinesTransformer: As the core component accounting for most of the total cost. Select dry-type transformers for fire-risk areas such as basements; choose cost-effective oil-immersed transformers for open outdoor areas. For residential communities with long-duration light load at night, amorphous alloy transformers are recommended, whose no-load loss is 80% lower than that of conventional S13 transformers.
High-voltage Protection: Most prefabricated substations adopt combined load switch and fuse instead of costly high-voltage circuit breakers. This combination can switch normal load current and protect against short circuits with outstanding cost performance.
Low-voltage Configuration: Confirm the installation of reactive power compensation devices to improve power factor and avoid penalties, as well as multiple outgoing switches to meet power demand of terminal loads.
Enclosure Material & Craft: 304 stainless steel or special non-metallic enclosures are recommended for coastal areas or heavily polluted environments; aluzinc steel plates are applicable for general environments. The protection class shall be no lower than IP33.
Intelligent Interface: Mainstream products in 2026 are equipped with automation interfaces to support unattended four-remote functions (remote measurement, remote signalling, remote control and remote regulation), facilitating connection to the power grid dispatching system in the future.
ZGS American-style Prefabricated Substation
The full name of American-style prefabricated substation is American-type box substation, also known as combined transformer. It is a highly integrated device where the transformer, high-voltage switches and protection units are enclosed in a single oil tank, featuring an ultra-compact structure.
The fundamental difference from European-style prefabricated substations lies in their structural design. In American-type units, switches and fuses are submerged inside the transformer oil tank with a fully insulated and fully sealed integrated structure. By contrast, a European-type substation is like a small enclosure housing standard switchgears and a transformer, with the three functional sections completely separated from one another.
English Translation (Power Industry Standard Terminology)
American-style Prefabricated Substation
Floor area: Around 1/4 of a European-type unit with the same capacity.
Overall volume: Approximately 1/5 to 1/3 of the European type.
Weight: Lightweight structure with low requirements for foundation construction.
Structural Introduction: Triangular Layout
The full name is American-type box substation, also referred to as combined transformer. It is a highly integrated piece of equipment with the transformer, high-voltage switches and protection devices housed inside one single oil tank, delivering an extremely compact structure.
Its core difference from the European-style counterpart lies in structural design. Switches and fuses of the American type are placed inside the transformer oil tank, adopting an integrated design with full insulation and full sealing. The European-style substation is more like a compact building accommodating standard switchgears and a transformer, with the three functional units completely separated.
Core Feature: Ultra-Compact SizeSmall footprint is the most prominent advantage of American-style prefabricated substations.
The interior is divided into three main sections in a triangular arrangement:
Transformer Compartment (Rear Section)As the core part, it contains iron cores, windings, high-voltage load switches and fuses all sealed within the oil tank. Transformer oil acts as both insulation and heat dissipation medium.
High-voltage Compartment (Front Side)It is used for connecting high-voltage incoming cables. Fully insulated elbow cable connectors are adopted for safe operation, and live plugging and unplugging is available.
Low-voltage Compartment (Other Front Side)Equipped with main low-voltage switches and outgoing switches. Metering and reactive power compensation devices are generally added to comply with domestic standards.
Core Protection: Dual Fuse System
The safety performance relies on a reliable dual-fuse protection solution:
Backup fuse: Serves as ultimate protection against severe internal faults such as short circuits inside the transformer, which rarely operates under normal conditions.
Plug-in dual-element fuse: Protects the secondary side against overload and short circuit. It can sense both current and oil temperature for comprehensive protection and is replaceable externally.
Application Scenarios: Flexible Power Distribution Nodes
It is ideal for sites with limited space and requirements for rapid power supply:
New energy power generation: Used as step-up equipment for wind and photovoltaic power stations, widely deployed in fields and hills.
Temporary power supply: Construction sites, temporary exhibitions and other occasions. The unit can be hoisted and reused after service.
Urban power distribution: Renovation of old residential communities, street lighting and other areas where land resources are tight.
Advantages, Limitations & Selection Guidelines
AdvantagesCompact structure with small size and floor area for flexible installation.
Strong overload capacity: It can operate at twice the rated load for 2 hours with high durability.
Fast commissioning: No dedicated distribution room is required. It can be put into service simply after cable connection.
Full insulation design: No exposed live high-voltage parts to ensure public safety.
LimitationsNo visible isolation point: Since switches are immersed in oil, operators cannot directly observe the disconnection state during maintenance. Safety depends strictly on standard operating procedures.
Poor expandability: The rated capacity is restricted by the enclosure. A complete unit replacement is usually required for capacity upgrade.
Simplified low-voltage functions: Early models have no independent low-voltage compartment. Domestic improved versions come with compact low-voltage cabinets and a limited number of outgoing circuits.
Potential environmental issues (old models): A small amount of harmful gas may be generated when load switches break current in oil. Modern products have been optimized effectively.
Selection Guidelines
American-style prefabricated substations are the preferred choice for outdoor sites with extremely limited space (e.g. green belts, roadsides), temporary power projects and new energy power plants.
For densely populated urban core areas, basements of high-rise buildings or projects with high requirements for automation, European-type substations are more recommended. They feature regular layout, obvious isolation points and support larger rated capacity.
KYN28
The KYN28 switchgear is the most widely used high-voltage switchgear in current 10kV distribution networks. Its full name is Indoor Metal-clad Withdrawable Switchgear. Fully enclosed by metal plates, it acts as a high-voltage power control center. The core component, the circuit breaker, can be pulled out like a drawer for maintenance.
1. Model Definition
Each letter in the model KYN28 has a specific definition:
K: Metal-clad type, fully enclosed with metal cladding
Y: Withdrawable type, featuring removable core components
N: Indoor type, designed for indoor installation
28: Design serial number
2. Core Structure: Four Compartments & One TrolleyThe KYN28 switchgear adopts an all-metal clad structure. Earthed metal partitions divide the cabinet into four independent compartments.
The mid-mounted circuit breaker compartment is located at the cabinet center and equipped with a circuit breaker trolley that can be extracted for operation and maintenance. The busbar compartment is set at the upper rear part, housing main busbars and branch busbars that run through the entire bank of switchgears to collect and distribute electric power. The cable compartment lies at the lower rear, fitted with current transformers, earthing switches, surge arresters and outgoing cables. This area serves as the cable access space and can accommodate up to six connected cables. The relay and instrument compartment is arranged at the upper front, used for mounting secondary control and protection components including protection devices, meters and control buttons.
This equipment adopts a mid-mounted structure. The circuit breaker trolley is installed in the middle of the cabinet and slides in and out along guide rails. It can be switched between the service position with closed and energized contacts, and the test or disconnect position with open and de-energized contacts.
The five-prevention interlock is the core safety mechanism. It prevents five typical misoperations: accidental closing or opening of the circuit breaker, trolley movement under load, closing the earthing switch when the circuit is live, switching on power while the earthing switch remains closed, and entering energized compartments by mistake.
3. Technical Parameters & SpecificationsElectrical ParametersRated voltage: 3.6kV / 7.2kV / 12kV
Rated current: 630A ~ 4000A. For 4000A operation, forced air cooling is mandatory.
Rated short-circuit breaking current: 20kA ~ 50kA
Power frequency withstand voltage: 42kV for 1 minute
Lightning impulse withstand voltage: 75kV
Overall DimensionsWidth: 650mm / 800mm / 1000mm. Cabinets are wider for higher current levels.
Depth: 1200mm ~ 1660mm
Height: 2200mm ~ 2300mm
Protection DegreeOverall enclosure: IP4X, protecting against solid objects with diameter no less than 1mm
With the circuit breaker compartment door open: IP2X, preventing finger access to internal live parts
4. Main Application Scenarios
With extensive applicability, KYN28 switchgear is the primary equipment for 10kV power distribution rooms.It is applied in substations for power incoming and outgoing of secondary power substations. For industrial and mining enterprises, it undertakes plant power distribution and the startup of large high-voltage motors. In power plants, it is deployed in auxiliary power distribution systems. It also serves as the power center for high-rise buildings and residential communities in commercial and residential areas. Additionally, it is widely used for grid connection of photovoltaic and wind power in the new energy sector.
5. Cabinet Types & ConfigurationsCommon functional cabinet types include incoming cabinet, also known as main incoming cabinet, outgoing cabinet or feeder cabinet, sectionalizer cabinet and tie cabinet, PT cabinet, isolator cabinet, capacitor compensation cabinet, as well as station service transformer cabinet.
In conclusion, featuring rational structure, high safety and reliability, easy maintenance and good interchangeability, KYN28 switchgear has become the de facto standard configuration for 10kV power distribution applications.
Case Studies
Dry-Type Transformer Oil-Immersed Transformer More cases |
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Jiangsu Guoxin Electric