2025-04-30

Does the oil-immersed transformer need to be replaced?

Introduction Oil-immersed transformers are critical components in power distribution systems, relying on specialized transformer oil for insulation and cooling. This document provides detailed operational procedures to ensure optimal performance, extended service life, and enhanced safety of oil-immersed transformers in various working conditions.   Transformer Oil Maintenance Protocol 1.1 Oil Quality Management Implement a rigorous oil testing schedule using ASTM D3487 standards Conduct dielectric strength tests monthly (minimum 30kV breakdown voltage) Perform dissolved gas analysis (DGA) quarterly to detect incipient faults Maintain acid number below 0.05 mg KOH/g through regular testing   1.2 Oil Filtration and Treatment Install online filtration systems for continuous purification Schedule offline filtration every 6 months or when particulate contamination exceeds 100 ppm Utilize vacuum dehydration units when moisture content exceeds 15 ppm Employ degassing equipment when total dissolved gas exceeds 2% by volume   Comprehensive Inspection Procedures 2.1 Temperature Monitoring System Install dual redundant temperature sensors (winding and oil) Implement SCADA integration for real-time monitoring   Establish three-tier temperature thresholds: Warning level: 75°C Alarm level: 85°C Critical shutdown: 95°C   2.2 Advanced Oil Analysis Quarterly laboratory tests including: Interfacial tension measurement Oxidation stability testing Furfural analysis for paper insulation assessment Implement predictive maintenance based on oil...

2025-04-30

How to Adjust the Operation of a Three-Phase Pad-Mounted Transformer?

Three-phase pad-mounted transformer: This transformer consists of primary and secondary windings, which transfer electrical energy through magnetic coupling without direct electrical connection between the primary (center-grounded) and secondary sides. This design ensures excellent ground isolation performance.   Key Safety Features: 1.Leakage Protection: (1)If the equipment enclosure becomes live due to insulation failure, no electric shock hazard exists—regardless of which terminal of the secondary winding forms a circuit with the enclosure. (2)Both primary and secondary sides are equipped with fuses, while the transformer core and metal enclosure are reliably grounded, providing shielding and anti-interference capabilities. (3)This makes it an exceptionally safe power source for instruments, meters, and electric hand tools.   2.Voltage Flexibility: Customizable voltage configurations, including common specifications: Single-phase: 220/220V, 220/36V, 380/220V Three-phase: 380/380V, 380/220V, 380/36V   3.Usage Guidelines: (1)The total load capacity of connected devices must not exceed the transformer’s rated capacity (standard models: 0.1–15 kVA). (2)For rural households using 3-pin safety sockets, the socket’s grounding terminal must be connected to the neutral wire of the three-phase four-wire system to achieve protective neutral bonding. (3)This setup safeguards appliances (e.g., washing machines, refrigerators) operating in humid environments, where metal enclosures are prone to leakage. Note: The socket’s grounding terminal must be directly linked to the neutral wire upstream of the household entry point.   Technical Advantages Summary： Galvanic isolation ensures...

2025-03-28

Comprehensive Analysis: Isolation Transformers vs. Conventional Power Transformers

Fundamental Operational Differences Conventional Power Transformers: Core function: Voltage transformation through electromagnetic induction Configuration: Features unequal turns ratio between primary (N₁) and secondary (N₂) windings (N₁/N₂ ≠ 1) Subtypes: Includes step-up (N₂ > N₁) and step-down (N₂ < N₁) configurations Non-isolating example: Autotransformers share common winding portions   Isolation Transformers: Primary purpose: Galvanic isolation between input and output circuits Design: Implements complete DC separation through independent windings Safety feature: Maintains 1:1 turns ratio (N₁ = N₂) in standard isolation models   Technical Definitions and Standards Isolation Transformers** (IEC 61558):   Meet stringent double insulation requirements   Provide reinforced isolation (typically 4kV AC withstand voltage)   Feature capacitive shielding in medical-grade versions   Conventional Transformers (IEC 60076):   Designed for efficient power transfer (η > 95% in modern units)   Include various cooling classifications (ONAN, ONAF, OFAF)   Cover voltage classes from 400V to 765kV   Application-Specific Implementations Isolation Transformer Applications:   √ Critical care medical equipment (e.g., IEC 60601-1 compliant)   √ Sensitive laboratory instrumentation (noise reduction > 60dB)   √ Industrial control systems requiring ground loop elimination   √ IT equipment in high-noise environments   Conventional Transformer Applications:   √ Power distribution networks (33kV/11kV substations)   √ Machine tool motor controls (480V to 120V conversion)   √ Renewable energy interfaces (wind farm...

2025-03-28

Do Transformers Emit Radiation?

First, it’s important to clarify a fundamental concept for the public: in discussions about electromagnetic environments and public health, the terms “electric field” and “magnetic field”—not “electromagnetic radiation”—are the correct ways to describe the effects of transformers and other power transmission facilities.     Why “Electromagnetic Radiation” Is a Misnomer “Electromagnetic radiation” is a specialized term used in radio communications and electromagnetic compatibility engineering. It refers to energy emitted as electromagnetic waves from a source into space. However, applying this term to power transmission facilities is inappropriate because these systems are designed for energy transfer—not electromagnetic wave propagation. The correct terms for the phenomena around transmission equipment are “electric field,” “magnetic field,” or collectively, “electromagnetic field.”     ZG Power Automation: A Platform for Knowledge Exchange ZG Power Automation serves not only as a communication network for power professionals but also as a platform for technology enthusiasts and students to showcase their expertise. Compared to traditional knowledge-sharing platforms, it offers:   – Faster access to information   – Broader content coverage   – Enhanced interactivity   – Lower costs     By leveraging these advantages, ZG Power Automation bridges connections among industry peers, fostering collaboration, skill development, and technological advancement....

2025-02-28

Single Phase Pad Mounted Transformer: The Core Equipment of the Power Distribution System

Introduction The Singe Phase Pad Mounted Transformer is a compact power distribution device that converts high-voltage electrical energy into low-voltage electrical energy and is widely used in the power system. Its core function is to achieve the conversion of voltage levels through a transformer, thus providing stable and reliable low-voltage electrical energy for end users. Due to its compact structure, flexible installation, and simple operation and maintenance, the Single Phase Pad Mounted Transformer occupies an important position in the modern power distribution system, especially suitable for scenarios where the load is scattered and the power supply distance is long.   Basic Principles of the Single Phase Pad Mounted Transformer The working principle of the Single Phase Pad Mounted Transformer is based on the law of electromagnetic induction, and the conversion of electrical energy from the high-voltage side to the low-voltage side is achieved through a transformer. Its core structure includes key components such as a transformer, a high-voltage load switch, a fuse, and a low-voltage power distribution unit. The high-voltage electrical energy is connected to the primary winding of the transformer through the high-voltage load switch. Through the action of electromagnetic induction, the voltage is reduced to the required low-voltage level, and then...

2025-02-28

Rectifier Transformer: A Key Device in the Power System

Introduction The rectifier transformer is a special transformer that converts alternating current (AC) into direct current (DC). It is widely used in power systems and industrial fields. Through the rectifier circuit, it converts the input AC into DC, providing a stable DC power source for industrial applications such as electrochemistry, traction, and electroplating. In modern power electronics technology, the rectifier transformer is an essential and key device.   Basic Principles of the Rectifier Transformer The working principle of the rectifier transformer is based on the combination of electromagnetic induction and the rectifier circuit. Its core structure includes the iron core, windings, and cooling system. The iron core is usually made of silicon steel sheets with high magnetic permeability, which is used to transmit the magnetic field; the windings achieve the conversion of voltage through electromagnetic induction. The rectification process depends on the rectifier circuit. Common rectification methods include single-phase bridge rectification and three-phase bridge rectification. In single-phase rectification, the bridge circuit composed of four diodes converts AC into pulsating DC; while in three-phase rectification, the circuit composed of six diodes can output a smoother DC.   Types of Rectifier Transformers According to their uses, rectifier transformers can be divided into...