Thai Trafo

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Established in 1986, Thai Trafo Co., Ltd. is dedicated to the manufacturing and distribution of high-quality distribution transformers for both domestic and international markets. The company operates under the leadership of experienced electrical engineers, with a commitment to professional management and continuous growth.

Driven by the vision and dedication of its executives and staff, Thai Trafo has steadily expanded its operations over the years. As the energy industry grew rapidly, increased demand outpaced the capacity of our original manufacturing facility. To meet this challenge, Thai Trafo Manufacturing Co., Ltd. was founded in 1996 with the establishment of a second plant in Rayong, Thailand—enhancing both production capacity and product quality.

Our facilities are equipped with advanced machinery, testing systems, and calibration devices. We continuously invest in the development of our team’s technical knowledge and expertise. As a result, all Thai Trafo transformers meet rigorous international standards and have successfully passed short-circuit testing, certified by ASTA, KEMA, and CESI.

Oil Type

Rate Power: 50kVA – 4000kVA

Rate Voltage: 400V – 33000V

Oil Type - Fully Sealed

The transformer body is fully enclosed, with the oil tank completely filled to ensure optimal insulation and cooling. This type of transformer utilizes a corrugated fin cooling system, where the fins are designed to expand and contract in response to the thermal expansion of the oil, enhancing heat dissipation and overall efficiency.

Dry Type

Rate Power: 100kVA – 3150kVA

Rate Voltage: 24000V

Dry Type - Cast Resin Transformer

The high-voltage coil of this dry-type transformer is constructed using high-quality metal conductors, such as copper or aluminum. These conductors are insulated with Class F insulation, capable of withstanding temperatures up to 155°C.

The insulation system is composed of resin reinforced with glass fiber, chosen for its excellent thermal stability. Since the expansion coefficients of the glass and resin are closely matched, this minimizes the risk of coil damage or cracking under high-temperature operating conditions, ensuring enhanced durability and performance.

Open-Type

Rate Power: 50kVA – 10000kVA

Rate Voltage: 400V – 33000V

Open-Type Transformer (Free-Breathing Design with Dehydrating Breather)

Dehydrating Breather System

This transformer model features a dehydrating breather, an air moisture filter that functions during both air intake and exhaust, maintaining optimal internal conditions.

The transformer is designed to accommodate oil expansion caused by heat. The space created by this expansion may be filled with air or connected to an auxiliary oil reservoir. Since the insulating oil may come into direct contact with air, this configuration is referred to as an open-type transformer.

Nitrogen-Sealed

Rate Power: 30kVA – 5000kVA

Rate Voltage: 400V – 33000V

Nitrogen-Sealed Transformer (Hermetically Sealed System for Enhanced Oil Preservation and Safety)

The void space within the oil tank is filled with nitrogen gas, creating a protective barrier that prevents direct contact between the insulating oil and atmospheric air.

In the event of a structural leak, the positive nitrogen pressure acts as a safeguard, effectively blocking external air from entering the internal components of the transformer—preserving oil quality and extending the transformer’s operational life.

Completely-Self-Protected

Rate Power: 150kVA – 225kVA

Rate Voltage: 416V – 24000V

Completely Self-Protected Transformer (CSP)

What sets this transformer apart is its built-in self-protection system designed to enhance safety and reliability.

Upon detecting an overload, the primary protection mechanism automatically disconnects the load to prevent damage. In the event of a lightning surge, a secondary protection system activates, safely diverting excessive voltage to the ground. This dual-layer protection helps shield the transformer from potential harm and ensures continued, reliable operation.

Power

Rate Power: 5000kVA – above

Rate Voltage: 22000V – above

Power Transformer

Structure
This transformer features a robust, fully enclosed or sealed design, built for high durability. It utilizes radiator fins for efficient cooling and heat dissipation under heavy-duty conditions.

Conservator
Housed within the transformer is a conservator tank, designed to accommodate oil expansion. It includes a rubber bladder to prevent direct contact between the insulating oil and atmospheric air, thereby preserving oil quality and extending service life.

On-Load Tap Changer (OLTC)
The on-load tap changer enables voltage adjustment during operation, allowing users to regulate voltage fluctuations on the primary side without interrupting the power supply.

Control Equipment
An integrated control panel allows for user operation and monitoring. It also supports remote display and control from a central control station, ensuring convenience and real-time system visibility.

TM Ecotap® VPD®

voltage-regulating distribution transformer

Rate Power: 5000kVA – above

Rate Voltage: 22000V – above

Voltage-Regulating Distribution Transformer (VRDT)

The TM Ecotap® VPD® by Thai Trafo is a voltage-regulating distribution transformer (VRDT) with an integrated Automatic Voltage Regulator (AVR), designed to automatically maintain steady voltage levels during operation—eliminating voltage sag in long-feeder networks (50–200 km) or surges from renewable energy sources.

Key Features:
On-Load Tap Changer (OLTC): Adjusts voltage without interrupting power.

Three operation modes: Manual, automatic, and remote-controlled via CAN bus.

Eco‑design: Compact size with low structural losses, matching a standard distribution transformer’s footprint.

Benefits:

Consistent Voltage Over Long Distances
This transformer ensures stable voltage levels even when distributing power across extended distances of 50 to 200 kilometers.

Automatic Voltage Regulation for Renewable Energy
It automatically adjusts elevated voltage levels, which often result from excess power generated by renewable energy sources before being transmitted to the Provincial Electricity Authority (PEA) distribution network.

Improved Efficiency and Equipment Protection
By maintaining optimal voltage, the system helps reduce electricity costs and extend the lifespan of motors and connected equipment.