In the power transformer manufacturing process, Vacuum Pressure Impregnation (VPI) equipment is the key equipment that determines coil insulation quality. With the rapid development of new energy, smart grids, and UHV power transmission, the transformer industry has put forward higher requirements for insulation treatment processes. Choosing an efficient and stable vacuum pressure impregnation system directly affects the transformer's service life, operational safety, and overall performance.
1. Why Does the Transformer Industry Need Vacuum Pressure Impregnation Equipment?
1.1 Limitations of Traditional Impregnation Processes
Traditional impregnation processes have multiple issues that affect transformer quality. First, impregnation is insufficient, and air gaps easily exist inside the coil, leading to reduced insulation strength. Second, the varnish film is uneven, which increases the risk of partial discharge and shortens product life. Third, curing is incomplete, and the heat resistance level may not meet design requirements. Finally, production efficiency is low, batch cycles are long, and production capacity is limited.
1.2 Core Advantages of VPI Technology
Vacuum pressure impregnation equipment achieves multiple technical breakthroughs through the process cycle of "vacuum degassing, pressure impregnation, and curing molding." In terms of deep penetration, air inside the coil is excluded under vacuum conditions, allowing the insulating varnish to fully penetrate every gap. Regarding bubble-free defects, pressure impregnation ensures the varnish completely fills all spaces, eliminating air gaps and voids. For uniform varnish film, a dense and uniform insulation protective layer is formed, improving the voltage resistance level. In terms of efficient production, automated control shortens the process cycle and improves production capacity utilization.
2. Core Technology of Our Vacuum Pressure Impregnation Equipment
2.1 Equipment Structure Composition
The Vacuum Pressure Impregnation VPI system consists of multiple core modules, including the impregnation tank, vacuum system, pressure system, varnish supply system, heating system, control system, safety protection, and recovery system. All systems work together to ensure the stability and reliability of the impregnation process.
2.2 Key Technical Parameters (Customizable)
The standard configuration of tank effective volume is 1000L to 5000L, with an optional range from 500L to 20000L. The standard vacuum degree configuration is less than or equal to 50 Pa, and the high-end version can reach less than or equal to 10 Pa. The standard working pressure configuration is 0.6 MPa, with an optional range of 0.3 to 0.8 MPa. The standard working temperature configuration is room temperature to 150°C, with an optional range of room temperature to 200°C. The control method adopts PLC plus touch screen, supporting MES and ERP system integration. The safety level complies with ASME and GB standards, and PED and CE certification is available.
2.3 Intelligent Control System
The human-machine interface uses a 10 to 15-inch industrial touch screen with visual display of process parameters. The data recording function completely records the vacuum degree, pressure, and temperature curves for each batch. The abnormal alarm system monitors in real-time, automatically stops and prompts in case of abnormalities. Remote operation and maintenance support IoT access, enabling remote diagnosis and maintenance.
3. Transformer VPI Impregnation Process Flow
The process flow is divided into six main steps. Step 1: Pre-baking, temperature 120 to 140°C, taking 2 to 4 hours. Step 2: Vacuum degassing, vacuum degree less than or equal to 50 Pa, taking 30 to 60 minutes. Step 3: Impregnation, inject insulating varnish to submerge the coil. Step 4: Pressure penetration, pressure 0.4 to 0.6 MPa, taking 30 to 90 minutes. Step 5: Varnish dripping and recovery, recover excess varnish, taking 15 to 30 minutes. Step 6: Curing, temperature 130 to 160°C, taking 4 to 8 hours.
Process Key Points Explanation
Pre-baking treatment removes moisture and volatiles inside the coil, improving impregnation effects. Vacuum degassing excludes air gaps in a high vacuum environment, creating conditions for varnish penetration. Vacuum impregnation injects insulating varnish under vacuum conditions to avoid bubble formation. Pressure penetration applies pressure to drive the varnish deep into tiny gaps inside the coil. Varnish dripping and recovery automatically recovers excess varnish, reducing material loss. High-temperature curing forms a hard and dense insulating varnish film.
4. Five Reasons to Choose Us
Reason 1: Rich Industry Experience
We have been deeply engaged in transformer insulation treatment equipment for more than 15 years, serving over 300 customers, covering fields such as electric power, new energy, and rail transit.
Reason 2: Customized Design Capability
Based on customer coil dimensions, production capacity requirements, and factory conditions, we provide one-on-one customized solutions.
Reason 3: Complete Quality Certifications
We have passed ISO9001 quality management system certification, and our equipment complies with GB, ASME, PED, and other standards.
Reason 4: Full Lifecycle Service
From solution design, installation and commissioning to after-sales maintenance, we provide 7×24 hour technical support.
Reason 5: Attractive Investment Return
Equipment life exceeds 10 years, energy consumption is reduced by 20%, varnish utilization rate is increased by 15%, and investment is recovered within 18 to 24 months.
5. Frequently Asked Questions (FAQ)
Question 1: What types of transformers are suitable for VPI equipment?
Suitable for insulation treatment of various electrical equipment such as dry-type transformers, oil-immersed transformer coils, reactors, and instrument transformers.
Question 2: What vacuum degree can the equipment achieve?
Standard configuration is less than or equal to 50 Pa, and the high-end version can reach less than or equal to 10 Pa, customizable according to product requirements.
Question 3: How many coils can one equipment process per day?
It depends on coil size and process cycle. Taking medium-sized transformer coils as an example, a single-tank system can process approximately 8 to 12 batches per day.
Question 4: Do you provide insulating varnish supporting services?
We can recommend cooperative suppliers and provide varnish and equipment matching debugging services.
Question 5: What is the delivery cycle?
Standard equipment takes 60 to 90 days, customized equipment takes 90 to 120 days, specific according to configuration.
Vacuum pressure impregnation equipment is an indispensable core equipment in transformer manufacturing. Choosing a professional VPI system supplier can not only improve product insulation quality but also enhance enterprise core competitiveness. We look forward to working with you to create high-quality transformer products and contribute to the green development of the power industry.