In order to save energy, rapeseed oil is used in amorphous transformers.

Why do you want to think of rapeseed oil?

Mineral transformer insulating oil has been applied to oil-immersed transformers for nearly 100 years with its excellent electrical and thermal properties. It has been enduring for a long time with its large output, good quality and superior technical and economic indicators. However, mineral insulating oil has its own shortcomings, such as non-renewable, non-biodegradable, easy to cause environmental pollution when leakage occurs, low flash point and poor fire retardancy. At the same time, mineral transformer oil is produced from petroleum. At present, the world's petroleum resources are in short supply, and the search for alternative mineral oil products has become the main topic at present.

Talk about plant insulating oil

Plant insulating oil is prepared by crushing natural oil crops (hereinafter, taking rapeseed oil as an example), refining and modification processes, the molecules of which are triglycerides, triglycerides and three long-chain fatty acids attached to one Glycerin center composition, rapid and complete biodegradation, non-toxic in oral and aquatic biological tests, better environmental and health characteristics than mineral oil, good electrical properties, high ignition point, broad source of raw materials, renewable and biological Advantages such as degradation. At present, the United States, the European Union and Japan have begun to replace the mineral transformer oil with plant insulating oil.

What are the key points of innovation?

Innovative structural design . Plant rapeseed oil high-loading amorphous alloy transformers differ greatly in structure from conventional transformers. Since the amorphous alloy core is subjected to external stress, the loss increases by about 60%. The noise also increases, which seriously affects its performance. Therefore, the amorphous alloy core structure design is different from the core main support structure of the conventional transformer, in order to avoid the stress of the amorphous alloy core. The core of the plant rapeseed oil high-loading amorphous alloy transformer is suspended on the winding, and the oil-immersed high-voltage winding adopts a wrapped glass filament adhesive tape to heat and solidify the rigid body structure, and the axial mechanical strength thereof is high enough to "push up" the amorphous alloy core. . The windings bear the weight on the lower clamp through the spacer. In addition, since the amorphous alloy core adopts a three-phase five-column structure, the length of the transformer is determined to be large. Considering that the span of the hanging plate is too large, the lateral pulling force of the sling is greatly caused by the lifting force of the hoisting rope. Therefore, the hoisting design is to pull the upper clamping member, and the side clamping member connects the upper and lower clamping members. Therefore, the bearing strength of the upper and lower clamps is the key to structural design. The plant rapeseed oil high overload amorphous alloy transformer adopts a frame structure. The frame has two types of integral frame and connecting frame. The use of a connecting frame facilitates the control of assembly errors. The clip is designed as an everted structure.

Optimize the coil process. The product coil has a double-layer concentric rectangle and is wrapped with a non-woven glass adhesive tape. The high-voltage adopts a multi-layer concentric rectangular structure coil. The high and low voltage coils are wound together by a tension device to improve the shaping and press-fitting processes. With high temperature curing, it effectively reduces the partial discharge, increasing the mechanical strength and the ability to resist short-circuit impact.

Improved short circuit resistance. Plant insulating oil high-loading amorphous alloy transformer winding is a rectangular structure, the force is not as uniform as the circular winding, and it is easy to deform when subjected to short-circuit electric power. Moreover, the high-overload amorphous alloy transformer of plant insulating oil adopts the axial load-bearing structure of the winding. Thus, the test of the short-circuit electric power of the rectangular winding in the axial and radial directions is more severe than that of the circular winding. The product axially presses the windings into the upper and lower clips through the spacers, and the high-voltage windings are encapsulated and solidified by the epoxy glass adhesive tape, which is sufficient to withstand the core quality and the axial electric power generated during the short circuit. The low-voltage winding is wound by copper foil, the oven is solidified, and the mechanical strength is high. The rectangular winding is analyzed by Ansys structural analysis software. It is concluded that the radial deformation of the rectangular winding is the most serious when subjected to short-circuit electric power. Therefore, the long-axis and short-axis difference of the low-voltage rectangular winding should be avoided when designing. During the assembly process, the support pads are padded in the long axis and the short axis direction to increase the strength.

In addition, stainless steel is bent into a "" type oil passage to enhance the fluidity of vegetable oil.

The hysteresis noise is obvious. Plant insulating oil is used instead of traditional mineral oil. The viscosity of vegetable oil is relatively high and the fluidity is relatively poor. To some extent, the speed and frequency of sound wave propagation can be reduced to achieve the effect of hysteresis noise.

The main technical and economic indicators

1 The no-load loss of the product is more than 80% lower than that of the 11-type product, and the load loss is reduced by more than 15% compared with the 11-type product.

22 times rated load continuous running time 6 hours, 1.5 times rated load can be continuously operated for a long time, can effectively solve the transformer overload operation problem for a long time, avoiding the transformer burning phenomenon caused by short time high overload.

3 The noise level is leading domestically, which is lower than the national standard by more than 8 decibels.

Data comparison between ordinary amorphous alloy transformer and vegetable oil high overload amorphous alloy transformer:

Mainly meet the following requirements:

✔GB1094.1—2013 Power Transformers Part 1: General

✔GB1094.2—2013 Power Transformer Part 2: Temperature rise

✔GB1094.3—2003 Power transformers Part 3: Insulation level, insulation test and external insulation air gap

✔ GB/T1094.4—2005 Power transformers - Part 4: Guide to lightning impulses and operational impulses for power transformers and reactors

✔GB1094.5—2008 Power Transformers Part 5: Ability to withstand short circuits

✔GB/T1094.10—2003 Power transformers - Part 10: Sound level determination

✔GB/T25446—2010 Technical parameters and requirements for oil-immersed amorphous alloy iron core distribution transformer

✔GB20052-2013 three-phase distribution transformer energy efficiency limit value and energy efficiency rating

✔Q/GDW11190-2014 Technical Guidelines for Agricultural Network High Overload Capacity Distribution Transformers

✔DL/T1360-2014 soybean vegetable oil transformer quality standard

Rapeseed oil amorphous change hopefully

Rapeseed oil has high biodegradation rate, no harm to the environment, and meets the requirements of new environmental protection; plant rapeseed oil transformer has good flame retardancy and is suitable for areas with high fire protection requirements; plant rapeseed oil paper is better combined, electric field distribution is more uniform; The seed oil can absorb the moisture contained in the aging insulation paper, and can prevent the splitting of the long fiber molecules when the heat is contacted. These special properties increase the overload capacity and prolong the insulation life of the transformer and reduce the life cycle cost; the vegetable rapeseed oil has a wide range of sources. It can be planted on a large scale to increase production and reduce the production cost of transformers. With the further development of plant rapeseed oil technology, the unification of standards, the improvement of production, and the reduction of cost, this kind of plant insulation oil transformer that meets environmental protection requirements, is safe and reliable, and utilizes renewable resources will have a broad space for development. .