What are the application advantages and development trends of pad-mounted transformers?

In the reconstruction and expansion of modern urban power grids, to optimize the power supply layout, it is required that high - voltage directly enters urban areas, medium - voltage penetrates deep into load centers to shorten the low - voltage power supply radius, and underground cable laying is mostly adopted for urban main roads. Electrical equipment needs to meet the requirements of intelligence, miniaturization, high reliability and aesthetics. The compact substation is widely used in urban distribution networks and load - intensive places due to its economy, convenience and high efficiency.

The compact substation integrates devices such as transformers, high - voltage power - receiving side equipment, and low - voltage power distribution. It is fully sealed and insulated, with a compact and beautiful structure. There is no need for a separate power distribution room, and it can be flexibly installed. It has both the function of power supply and environment embellishment; it supports the rapid conversion of power supply modes to ensure reliable and flexible power supply; it adopts double - fuse protection, special cable heads and high - quality distribution transformers to reduce costs and improve performance.

Structure and Characteristics

It is composed of electrical units such as the high - voltage switch system and is arranged in a fully enclosed and movable steel structure box. The characteristics are as follows:

• Compact and Space - saving: Integrate high - voltage equipment, reduce the insulation distance, and compress the occupied area and space.

• Quick Installation: Design and select the type according to requirements. The manufacturer completes the installation and commissioning, and it can be put into operation directly after being placed on - site.
  Low Cost: The equipment cost, pre - investment cost and operation and maintenance cost are all low, with remarkable economy.

• Flexible Combination: A single box can form a system, and the components have strong universality and interchangeability, which is convenient for maintenance and upgrading.

• Safe and Reliable: The internal equipment is fully enclosed. The box has anti - corrosion properties and is equipped with an environment - regulating device. There are no exposed conductors, avoiding safety risks.

• High Automation: Equipped with a microcomputer protection system, it realizes the "four - remote" functions (remote measurement, remote signaling, remote control, remote adjustment), and can perform intelligent regulation, monitoring and alarming.

• Aesthetic and Adaptable: Small in size, beautifully designed, and can be integrated with the environment by selecting appropriate colors, suitable for urban construction.

Operation Specifications

• Parallel Operation: Meet the conditions of the same wiring group, the same voltage ratio, and the same impedance voltage; check the load and perform phase verification before operation, and record the results in the switching operation ticket.

• Power - on and Power - off Operation: Consider the neutral point switching before power - on and power - off; for power - off, first turn off the low - voltage side, then the medium - voltage side, and finally the high - voltage side. First open the circuit breakers on each side, and then open the disconnectors on each side from low to high (for the main transformer disconnector, first pull the transformer side, then the bus side); the power - on sequence is the opposite.

• On - load Tap - changing Operation: Voltage regulation is required to stabilize the voltage. According to the operation duration and the number of switching times of the tap - changer, oil sample testing, oil replacement, and core - lifting inspection are required.

Conclusion

Following the concept of environmental protection and conservation, the compact substation integrates the traditional transformer into a box - type shell. With the advantages of small size, light weight, low noise, low loss and high reliability, it is widely used in load - intensive places such as industrial and mining enterprises and ports. It effectively optimizes the power supply layout in the urban power grid. Through the optimization of structure and performance, it improves the reliability of power supply and the convenience of operation and maintenance, enhances corrosion resistance and prolongs the service life. It provides strong support for the sustainable development of offshore wind farms and urban distribution networks, and meets the development needs of the modern power system for high efficiency, intelligence and environmental protection.