Transformer Protection Units
-- Steady & Reliable Manufacturer --
Product Overview
Transformer Protection Units are the "Dedicated Guardians" for the most expensive asset in your substation. At DSJ Electrical, our protection units provide a comprehensive defense against both internal and external faults. We utilize high-speed differential protection (87T) to detect internal winding short-circuits, as well as Restricted Earth Fault (REF) and Buchholz relay monitoring for oil-filled units. Our digital protection logic also covers thermal overloading, over-excitation, and through-fault current limitations. By integrating temperature sensors and pressure relief signals into a unified control interface, DSJ Transformer Protection Units ensure that your power transformer operates within safe limits, preventing catastrophic fires and extending the lifespan of the equipment by decades.
Electrical Partner
At DSJ, we transform complexity into reliability. With 42+ years of expertise in power distribution systems, our turnkey service integrates every phase – from regulatory compliance to final commissioning – ensuring seamless project execution for global clients. Whether it is the initial design or the final handover, we will strictly control every detail to ensure that the final delivered products perfectly meet your expectations. With us, you can focus on your core business with peace of mind, knowing that your project is in the hands of professional and reliable partners.
Introduction
The Transformer Protection Unit line from DSJ Electrical Co., Ltd is built for "Asset Integrity." We recognize that a transformer failure is not just an outage—it is a massive financial loss. Our introduction of this series focuses on "Multi-Harmonic Restraint" and "Instantaneous Fault Clearing." Our digital relays are programmed to distinguish between the normal "Inrush Current" when a transformer is energized and an actual internal fault, preventing nuisance tripping.
Innovation at DSJ involves "Dissolved Gas Analysis (DGA) Integration." Our high-end protection panels can interface with DGA sensors to monitor the health of the transformer oil in real-time, identifying "Trending Faults" before they become critical. We prioritize "Sequence of Events" logging, ensuring that if a trip occurs, you have a high-resolution millisecond-by-millisecond report of exactly what happened. At DSJ, we provide these units as standalone cubicles or integrated into the main HV switchgear, customized for the specific vector group and capacity of your transformer. Choosing our protection units means choosing the "Life Insurance" your transformer needs. We provide the "Sensitive Shield" that reacts in milliseconds to keep your core assets safe.
Applications
- Utility Power Transformers: Main protection for grid-level step-down stations.
- Industrial Sub-stations: Protecting captive power transformers in factories.
- Renewable Energy: Guarding the step-up transformers in wind/solar parks.
- Oil & Gas: Specialized protection for transformers in hazardous zones.
- Mining Operations: Ruggedized units for mobile substation transformers.
- Railway Traction: High-reliability protection for trackside transformers.
Specifications
| Technical Feature | Protection Unit Spec |
|---|---|
| Protection Functions | 87T, 50/51, 64REF, 49 (Thermal), 59N |
| Relay Type | High-Speed Microprocessor (Digital) |
| Interface | HMI with Vector Diagram Display |
| Input Channels | Multiple CT/VT inputs for differential zones |
| Analog Monitoring | 4-20mA for Temperature and Pressure |
| Protocol | IEC 61850, Modbus TCP/IP |
| Standard | IEC 60255 / IEEE C37.91 |
Why Choose Us
DSJ Electrical is a "Critical Asset Specialist." We provide deep technical support for "Differential Coordination," ensuring your protection settings perfectly match your transformer's nameplate data. Our units are the industry benchmark for reliability in harsh industrial grids.
- Q: What is "Differential Protection"?
- A: it compares the current entering and leaving the transformer to find internal leaks.
- Q: Can this unit monitor transformer temperature?
- A: Yes, it has dedicated inputs for winding and oil temperature probes.
Advantages
- Extreme Sensitivity: Detects internal winding faults at the earliest stage.
- Zero Nuisance Tripping: Advanced algorithms ignore inrush currents.
- Predictive Health: Monitors oil levels and winding heat trends.
- Data Transparency: Full fault oscillography for remote analysis.
- Robust Interlocking: Ensures safe operation of tap changers.
- Compact Integration: Combines all secondary controls in one panel.
Standards & Certifications
Our units are compliant with IEC 60255 and IEEE C37.91. We hold CE and ISO 9001 certifications. Every unit undergoes a relay-logic simulation test using secondary injection to ensure 100% accuracy of the differential curves.
Payment & Shipping
Protection units are shipped in anti-vibration crates. We offer air-freight for urgent replacement needs. Lead times: 5-7 weeks.
DSJ Story
about DSJ
Building Power, Building Trust
Founded in 1983, DSJ is a leader in China's power distribution equipment. Headquartered in Beijing as the top-selling enterprise, we integrate manufacturing with trade and maintain full in-house capabilities in R&D, production, and sales. This enables efficient fulfillment of custom orders with industry-leading speed.
As a producer of distribution system, transformer, generator and photovoltaic products exceeding Chinese/international standards, DSJ supplies medium/low-voltage electrical equipment, and PV systems. For over four decades, we have delivered high-safety electrical solutions globally to public infrastructure, corporations, and households – achieving the industry's lowest return rate.
Committed to "meeting diverse needs through quality", DSJ leverages expert teams to provide one-stop services: pre-sales consultation & customization, flexible logistics/payment options, and reliable maintenance – ensuring seamless producer-maintainer-customer collaboration.
+86 18513032986 
FLC Center, Chaoyang District, Beijing, China