Substation Selection: A Key Decision Affecting Power Supply Reliability and Project Investment

Against the advancement of the "Dual Carbon" goals and accelerated construction of the new power system, distributed photovoltaic power, energy storage systems, and charging piles have been connected to the grid on a large scale, driving faster progress in urban power grid renovation and new energy projects. As the core hub for power conversion and distribution, properly selected substations directly determine power supply reliability, construction investment and long-term operation & maintenance costs. Among all types, box-type substations integrate high-voltage power reception, transformer step-down and low-voltage power distribution into one unit. Prefabricated in factories and delivered as a whole unit, they are currently the most widely adopted compact substation solution.

I. Core Functional Value of Substations

1. Voltage Conversion & Power Collection: It converts grid voltage to user-side distribution voltage, and undertakes step-up collection, grid connection and power delivery for new energy projects such as photovoltaic and wind power plants.
2. Power Distribution & Loop Power Supply: Acting as a power distribution hub, it distributes electricity to various loads including residential quarters, commercial zones, factories and charging stations.
3. Protection & Control: It quickly breaks and isolates circuits during short-circuit and overload faults to prevent fault escalation and protect equipment and personnel safety.
4. Unattended Operation & Intelligent O&M: Matched with microcomputer integrated automation systems, it supports remote data uploading, automatic fault alarming and remote switching on/off control.

II. Classification of Mainstream Substation Types

1. Traditional Civil Engineering Substations

They feature large capacity and strong expandability, yet come with long construction cycles, large land occupation and high investment. They are mostly adopted for regional hub stations and main grid nodes.

2. Box-type Substations (European & American Types)

High-voltage switchgear, transformers and low-voltage distribution devices are integrated inside a fully enclosed, movable steel structure cabinet. Prefabricated in factories and ready for immediate installation, they occupy small land areas and enable fast construction. The fully insulated design eliminates electric shock risks, and the whole station operates oil-free. Their limitation lies in relatively limited single-unit capacity, making them suitable for urban grid renovation, industrial parks, residential communities and temporary power supply projects.

3. Prefabricated Cabin Substations

Modular cabins are prefabricated in factories and assembled on site. With high integration and relocatable design, they feature short construction cycles and are widely used in new energy power stations, energy storage projects, rail transit and other engineering works.

III. Intelligent Upgrade: Complete Solutions for Unattended Substations

The industry generally promotes integrated solutions combining primary equipment and intelligent secondary systems, integrated with microcomputer integrated automation systems, intelligent distribution terminals, as well as temperature and partial discharge monitoring units. These systems realize real-time remote upload of operational data, automatic fault alarming & positioning, remote switching control and early warning of abnormal conditions.

Note: Intelligent secondary components are purchased supporting parts. Deyan Electric is responsible for cabinet structural design, complete assembly of primary equipment, wiring integration and overall commissioning before delivery.

IV. Key Factors to Be Considered in Substation Selection

• Application scenarios and load characteristics: Urban distribution networks, industrial parks, and new energy stations have distinct demand profiles.
• Land occupation and environmental conditions: Box-type substations or prefabricated cabins are preferred for space-constrained urban areas; higher protection grades are required for coastal environments with high humidity and salt fog.
• Balance between construction cycle and investment: Civil engineering substations require long cycles and high investment, while box-type and prefabricated cabin substations can be put into service rapidly. The full life-cycle cost shall be comprehensively calculated.
• Electrical parameters and environmental requirements: Transformer capacity, short-circuit breaking capacity, protection grade, as well as requirements for oil-free operation and eco-friendly gas insulation shall be verified in accordance with engineering specifications.

Appropriate type selection balances upfront investment and long-term operation & maintenance costs, ensuring stable equipment operation for more than a decade.

About Zhejiang Deyan Electric Co., Ltd.

Located in the Economic Development Zone of Yueqing City, Zhejiang Province, Zhejiang Deyan Electric Co., Ltd. specializes in the R&D, production, sales and service of industrial electrical appliances, and is a large-scale industrial enterprise above designated size in Yueqing. Its core products include gas-insulated switchgears, ring main units, box-type substations, high & low voltage switch cabinets, cable branch boxes, outdoor switching stations and more. Its box-type substations adopt aluminum zinc steel plate cabinets and standard container manufacturing techniques, featuring full enclosure, mobility, unattended operation and oil-free full-station operation. The DYHB-12 eco-friendly gas-insulated metal-enclosed switchgear meets the demands of new energy and environmentally oriented projects.

The company's products are widely deployed in urban power grid upgrading, industrial and commercial park power distribution, distributed photovoltaic power stations, energy storage projects, rail transit, municipal infrastructure and other scenarios. Customized primary schemes, integrated assembly and overall factory commissioning services are available. If you have inquiries about procurement and scheme consultation for substations and complete power distribution equipment, please feel free to contact Deyan Electric.