500kva 630kva 20kv 400v Oil Immersed Transformer

500kva 630kva 20kv 400v Oil Immersed Transformer

1. Product Overview

The 500kva 630kva 20kv 400v Oil Immersed Transformer is a practical medium-capacity three-phase distribution transformer widely used in global 20kV medium-voltage power grid systems. Manufactured strictly in accordance with IEC 60076 international standards and GB/T 6451 industry specifications, this 20kV to 400V step-down oil immersed transformer belongs to the mature S11 and S13 low-loss transformer series. As a mainstream 20kV grade oil filled power transformer, it covers two common rated capacities of 500kVA and 630kVA, perfectly matching medium-load power supply demands that exceed 10kV grid conventional capacity and adapt to high-voltage regional power distribution requirements.

Designed with a standard 20kV high-voltage input and 400V low-voltage output configuration, this industrial oil immersed electrical transformer efficiently converts 20kV medium-voltage overhead line power into standard three-phase four-wire 400V low-voltage electricity compatible with global civil, commercial and light industrial power standards. Adopting fully sealed oil immersion cooling technology and non-PCB anti-aging mineral insulating oil, the 500kVA and 630kVA 20kV distribution transformers deliver stable continuous operation, ultra-low operational loss and excellent harsh environment resistance. Compared with traditional 10kV oil immersed transformers and indoor dry-type transformers, this 20kV high-grade power transformer features higher voltage withstand capacity, wider power coverage and stronger overload tolerance, making it the preferred equipment for new rural power grid upgrading, industrial zone power expansion and suburban high-voltage power distribution projects.

Every finished 500kva 630kva 20kv 400v oil immersed transformer undergoes comprehensive factory quality testing, including partial discharge detection, full-load temperature rise testing, short-circuit impact resistance verification and long-term aging operation inspection. With optimized electromagnetic structure, balanced three-phase output and durable anti-corrosion casing, this energy-saving oil immersed power transformer has become a hot-selling medium-capacity transformer for 20kV level power engineering construction, regional power grid optimization and medium-sized enterprise power matching worldwide.

2. Main Technical Parameters

Below are standardized industry-certified technical parameters of the 500kva 630kva 20kv 400v Oil Immersed Transformer. All performance indicators comply with 20kV grid access standards and medium-capacity power engineering acceptance norms, supporting project bidding, scheme design, on-site installation and long-term operational real-time monitoring:

3. Core Product Features

This 500kva 630kva 20kv 400v oil immersed transformer adopts upgraded S13 low-loss electromagnetic optimization technology and fully sealed corrugated oil tank structure, solving the problems of insufficient voltage resistance, high energy consumption and poor heavy-load stability of traditional 10kV transformers. With dual capacity options and excellent comprehensive performance, it adapts to diverse medium-load power distribution demands in 20kV high-voltage grid systems:

3.1 High Voltage Withstand & Ultra-low Energy Loss

Specially designed for 20kV medium-voltage grid operation, this high-grade oil immersed distribution transformer adopts high-permeability grain-oriented cold-rolled silicon steel sheets and full oblique lap core technology, which effectively suppresses magnetic flux leakage and greatly reduces no-load iron loss. The precisely wound compact copper coils lower internal resistivity significantly, cutting down copper loss during long-term full-load operation. As an energy-saving 20kV step-down transformer, both 500kVA and 630kVA models maintain ultra-low power consumption, effectively reducing grid line loss and daily operational energy costs for regional power supply systems.

3.2 Reliable ONAN Oil Immersed Cooling & Fully Sealed Insulation

Filled with environmental-friendly non-PCB anti-aging mineral insulating oil that meets international safety standards, this 20kV/400V oil filled transformer adopts standard ONAN natural air natural cooling mode. The autonomous oil circulation system continuously absorbs and dissipates heat generated by medium-load power conversion, ensuring uniform internal temperature and stable 24-hour uninterrupted operation. The fully sealed corrugated tank structure completely isolates internal insulating oil from external air, moisture and dust, preventing oil oxidation, emulsification and insulation aging. This stable sealing design ensures consistent dielectric performance in humid, dusty and open-air outdoor substation environments.

3.3 Accurate Voltage Regulation & Strong Anti-interference Performance

Equipped with ±2×2.5% and ±5% off-load tapping adjustment functions, this three-phase oil immersed electrical transformer accurately calibrates 20kV input voltage deviation caused by long-distance transmission loss and seasonal peak load fluctuation, ensuring stable and standard 400V low-voltage output. The optional Dyn11 vector group effectively balances three-phase current, suppresses grid harmonic interference and unbalanced load impact, while the Yyn0 configuration adapts to conventional balanced municipal grid scenarios. It effectively avoids power supply instability and terminal equipment damage caused by voltage surge and three-phase imbalance in medium-load power distribution systems.

3.4 Excellent Outdoor Adaptability & Structural Durability

The whole machine adopts thickened steel plate welding and multi-layer pickling, phosphating and electrostatic anti-corrosion spray treatment, featuring outstanding waterproof, rust-proof, dust-proof and anti-aging capabilities. This 20kV grade oil immersed power transformer supports both pole-mounted and ground-mounted outdoor installation, and can operate stably in suburban high-voltage power districts, industrial parks, rural open-air substations and coastal humid environments all year round. The reinforced internal core and winding structure enhances vibration resistance and short-circuit impact resistance, lowering daily equipment failure rate and improving overall operational safety and stability.

3.5 Dual Capacity Options & High Comprehensive Cost Performance

Available in 500kVA and 630kVA two mainstream medium capacities, this 20kV oil immersed transformer can flexibly match different power load demands, avoiding capacity waste or insufficient power supply. Designed with a robust and simple mechanical structure, it has no vulnerable precision parts and requires minimal routine maintenance. The fully sealed maintenance-free design extends the insulating oil replacement cycle, greatly reducing on-site inspection workload and later operational and maintenance costs. Compared with high-capacity 20kV transformers and imported power equipment, it features lower procurement cost and wider application flexibility, achieving ultra-high comprehensive cost performance for medium-load power engineering projects.

3.6 Low-noise Operation & Complete Safety Protection

Optimized core lamination and high-strength winding fixing technology effectively weaken operating vibration and running noise, fully meeting urban and industrial environmental protection noise standards. Equipped with standard oil level gauge, real-time temperature detector, oil drain valve and automatic pressure relief valve, the transformer supports real-time monitoring of operating status. In case of overload, overheating or internal short-circuit faults, the pressure relief device releases internal pressure timely to avoid equipment damage, ensuring safe and stable operation of the entire 20kV power distribution network.

4. Core Product Uses

As essential medium-capacity power transformation equipment for 20kV high-voltage power grid systems, the 500kva 630kva 20kv 400v Oil Immersed Transformer undertakes core functions of high-voltage step-down conversion, regional medium-load power distribution and power quality optimization, ensuring safe, efficient and stable power supply for various civil and industrial medium-load scenarios:

20kV to 400V High-precision Step-down Voltage Conversion: The core function is to convert 20kV medium-voltage high-grade grid power into standard 400V three-phase low-voltage power, realizing safe and accurate voltage matching between high-voltage main transmission lines and terminal medium-load electrical equipment.

Regional Medium-load Decentralized Power Distribution: This oil immersed power transformer undertakes centralized power distribution tasks for suburban areas, township industrial zones and large residential clusters, reasonably distributing 20kV grid power according to peak and valley load demand, balancing three-phase current and reducing long-distance transmission line loss and voltage drop.

Power Supply Quality Stabilization & Grid Optimization: By adjusting off-load tap positions, the equipment calibrates voltage deviation caused by long-distance transmission and load fluctuation, stabilizes terminal 400V voltage within standard range, suppresses grid harmonics and three-phase unbalance, and comprehensively improves regional medium-load power supply quality and grid stability.

High-voltage Grid Fault Isolation & Safety Protection: It effectively isolates the upper 20kV medium-voltage main grid and lower 400V low-voltage load system, preventing high-voltage fault surges from spreading to user terminals, limiting grid fault scope and reducing medium-load equipment batch damage risks.

Long-term Medium-load Continuous Power Guarantee: Relying on excellent heat dissipation performance and strong overload resistance, both 500kVA and 630kVA models support 24-hour uninterrupted operation, meeting stable power demand for medium-scale industrial production and municipal public infrastructure.

5. Wide Application Scenarios

With dual capacity options, high 20kV voltage resistance, stable medium-load performance and strong environmental adaptability, the 500kva 630kva 20kv 400v Oil Immersed Transformer is widely applied in 20kV level grid construction, industrial power supply, municipal infrastructure and new energy supporting projects worldwide:

5.1 20kV Urban & Rural Power Grid Upgrading

This 20kV/400V oil immersed transformer is the core equipment for new 20kV standard power grid construction, old urban high-voltage grid renovation and rural high-grade power network upgrading. It effectively solves the problem of insufficient voltage grade and low power supply capacity of traditional 10kV grid equipment, improving regional power grid carrying capacity and power supply reliability.

5.2 Medium-sized Industrial Park Power Supply

Suitable for medium-scale manufacturing parks, food processing bases, textile industrial zones, building material factories and mechanical processing workshops. The 500kVA and 630kVA medium capacities perfectly match continuous power consumption of medium-sized production lines and auxiliary mechanical equipment, ensuring stable and uninterrupted industrial production power supply.

5.3 Large Municipal & Public Infrastructure

Widely used for power distribution of large residential communities, township central hospitals, campus clusters, regional water pump stations and urban scenic area supporting facilities. Its low-noise, energy-saving and stable operation adapts to long-term unattended operation needs of public infrastructure, meeting high-standard municipal power supply requirements.

5.4 Distributed New Energy Grid Connection Projects

Applicable for voltage conversion and grid connection of medium-scale distributed photovoltaic power stations and decentralized wind power generation systems. It stabilizes fluctuating new energy output, balances medium-load grid load and ensures safe and smooth grid connection of green power equipment in 20kV power grid systems.

5.5 Key Regional Engineering Power Guarantee

With excellent outdoor weather resistance and stable medium-load operation performance, this 20kV oil immersed electrical transformer is commonly used for fixed power guarantee of suburban construction projects, rural infrastructure renovation and regional transportation supporting projects, providing reliable long-term power support for key medium-scale engineering operations.

6. Frequently Asked Questions (FAQ)

Q1: What is the difference between 500kVA and 630kVA 20kV 400V oil immersed transformers in actual use?

Both models adopt the same 20kV high-voltage grade and structural design, with consistent insulation level, cooling mode and safety performance. The core difference lies in load capacity and applicable scenarios. The 500kVA oil immersed transformer is suitable for relatively stable medium-small load scenarios such as community power supply and small-scale light industrial workshops. The 630kVA model features larger load capacity and stronger overload resistance, more suitable for medium-sized industrial parks and new energy grid connection projects with fluctuating peak loads. Users can select the corresponding capacity according to actual on-site maximum load and future power expansion demand.

Q2: Why choose 20kV grade oil immersed transformer instead of traditional 10kV transformer for regional power grid construction?

The 20kV medium-voltage grid has wider power transmission coverage and lower line loss than traditional 10kV grids, which is more suitable for suburban expansion and rural large-area power supply. This 500kva 630kva 20kv 400v oil immersed transformer has higher voltage withstand strength and better insulation performance, effectively avoiding breakdown and aging problems caused by long-term high-voltage operation. Adopting mature ONAN oil cooling technology and fully sealed structure, it runs stably in harsh outdoor environments with lower failure rate, making it the mainstream upgrade replacement equipment for new-generation high-standard power grid projects.

Q3: What daily maintenance is required for the 20kV 500kVA/630kVA oil immersed transformer?

This fully sealed 20kV oil immersed power transformer is designed for low-maintenance unattended outdoor operation. Daily routine work only includes regular visual inspection of oil tank sealing condition to prevent insulating oil leakage, and cleaning radiator surface dust to ensure unobstructed heat dissipation. Long-term full-load or overload operation should be reasonably controlled to delay insulation aging. Professional inspection of insulating oil quality and internal operating parameters is recommended every 2 to 3 years. With standardized simple maintenance, the equipment can achieve a 25-year design service life and maintain stable medium-load operation performance.