1. technical name

Design Technology of Green and Energy-Saving Open Three-Dimensional Wrapped Core Dry-Type Transformer

2. scope of application

A three-phase dual-winding three-dimensional wound core unencapsulated dry-type power transformer with a voltage class of 6kVA to 35kVA and a rated capacity of 30kVA to 12500kVA.

3. technical content

3.1 technical principle

The iron core is the core component of the transformer, and its structure determines the performance loss and production cost of the transformer. This technology adopts a three-dimensional rolled core structure. The three-dimensional wound core is based on the technology of planar wound core transformers, and the arrangement of the cores is optimized into a three-dimensional equilateral triangle structure, so that the three-phase core magnetic circuit is symmetrical, the magnetic circuit is shortest, the magnetic reluctance is reduced, and the excitation current, no-load loss, and operation noise are significantly reduced. It is a core component of an efficient, energy-saving and material-saving transformer obtained through technical transformation using traditional materials.

3.2 main innovations

Innovate the three-dimensional rolled iron core structure, break through the traditional plane structure, and consist of three single iron core frames wound continuously in turn through several trapezoidal material belts. The arrangement of the three core pillars is optimized into a three-dimensional equilateral triangle structure. The three-phase iron core magnetic circuit is symmetrical, with the shortest magnetic circuit and reduced magnetic reluctance. The original core structure has been completely changed. It is a high-efficiency and energy-saving transformer core that uses traditional materials but has a more reasonable structure, lower manufacturing cost, excellent performance and reliable quality.

4. Energy conservation and greenhouse gas emission reduction effects

Calculated based on the average capacity of 2500kVA, the no-load loss is 1.96kW, the load loss is 16.264kW, and the no-load current is 0.09%, which is in line with the national standard "Technical Parameters and Requirements for Dry-Type Power Transformers"( GB/T 10228-2015)(The allowable deviation of empty load is taken as 8%) Compared with each unit, each unit can save 43481kW·h of electricity per year. The life cycle of the transformer is 20 years. With 2000 units operating for 20 years, the total power saving is 1.73924 million kW·h, converted to 213,800 tons of standard coal, and at the same time, 991,900 tons of carbon dioxide and 39,300 tons of sulfur dioxide were reduced.

5. Technology demonstration

Engineering applications have been implemented in 12 projects. For example, Bourne Optics Co., Ltd. will put into use first-class energy efficiency green energy-saving open-type three-dimensional wound core dry-type transformers SGB18-RL-2500/10-NX1 (18 units) in 2021, and their performance is in line with the national standard "Dry-type Power Transformer Technical Parameters and Requirements"( GB/T 10228-2015)(The allowable deviation of empty load is 8%) Compared with 18 units with a capacity of 2500kVA, 782,700 kW·h of electricity can be saved every year; The life cycle of the transformer is 20 years, and it has been operated for 20 years. The total electricity saving is 14.3798 million kW·h, which is converted to 1,767.28 tons of standard coal. At the same time, 8,200.80 tons of carbon dioxide and 353.96 tons of sulfur dioxide are reduced.

6. investment estimation

Based on the annual output of 1200 units, the investment in infrastructure is 20 million yuan, the investment in equipment and other ancillary equipment (including installation fees) is 8 million yuan, and the investment in intangible assets is 10 million yuan. After the project is completed, it is estimated that the annual output will be 400 units in the first year, 800 units in the second year, and the planned output will be 1200 units in the third year. Through product price analysis, the project's production scale is 1200 units/year, and the annual sales revenue after reaching production capacity is 360 million yuan.

The total cost of the product at the end of production is 313.85 million yuan, of which the fixed cost is 60.35 million yuan, including new wages and welfare expenses, repair expenses, depreciation expenses, management expenses, etc.; the variable cost is 253.5 million yuan, including main raw materials, fuel and power expenses, etc.

7. investment recovery period

Based on the production scale with an annual output of 1200 units/year, the project investment payback period is approximately 3.09 years (pre-tax including construction period); the project investment payback period is approximately 3.74 years (after-tax including construction period).

8. Prospects for transformation and promotion of technological achievements

The products manufactured by this technology have been identified and have reached the international advanced level. It has significant technical performance and economic advantages in replacing traditional laminated core transformers. It can lead the industry's technological upgrading, enhance the international competitiveness of transformers, and increase foreign exchange through exports. This technology is mature and standardized, and there is a national standard "Technical Parameters and Requirements for Three-Phase Dry Three-Dimensional Winged Core Distribution Transformer"(GB/T 32825-2016). The products comply with national policies and the supply of raw materials is sufficient. At present, dry-type transformers in the market are mainly divided into resin-insulated dry-type transformers and open-type dry-type transformers. Domestic resin-insulated dry-type transformers account for about 90%, while open-type dry-type transformers only account for about 10%. This technology is expected to have a large promotion space.