Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Transformer Fault Diagnosis Methods1. Ratio Method for Dissolved Gas AnalysisFor most oil-immersed power transformers, certain combustible gases are produced in the transformer tank under thermal and electrical stress. The combustible gases dissolved in oil can be used to determine the thermal decomposition characteristics of the transformer oil-paper insulation system based on their specific gas content and ratios. This technology was first used for fault diagnosis in oil-immersed transformers.

1 Why must the transformer core be grounded?During normal operation of power transformers, the core must have one reliable ground connection. Without grounding, a floating voltage between the core and ground would cause intermittent breakdown discharge. Single-point grounding eliminates the possibility of floating potential in the core. However, when two or more grounding points exist, uneven potentials between core sections create circulating currents between grounding points, causing multi-poi

1. Project BackgroundDistributed photovoltaic (PV) and energy storage projects are developing rapidly across Vietnam and Southeast Asia, yet face significant challenges:1.1 Grid Instability:Vietnam's power grid experiences frequent fluctuations (particularly in northern industrial zones). In 2023, coal power shortages triggered large-scale blackouts, resulting in daily losses exceeding USD 5 million. Traditional PV systems lack effective neutral grounding management capabilities, making equipmen

Transformer Testing Procedures and Requirements1. Non-Porcelain Bushing Tests1.1 Insulation ResistanceSuspend the bushing vertically using a crane or support frame. Measure the insulation resistance between the terminal and the tap/french using a 2500V megohmmeter. The measured values should not significantly deviate from factory values under similar environmental conditions. For capacitive-type bushings rated 66kV and above with tap bushings, measure the insulation resistance between the "small

Transformer Core Inspection and Assembly Requirements The iron core should be flat with intact insulation coating, tightly stacked laminations, and no curling or waviness at the edges of silicon steel sheets. All core surfaces must be free of oil, dirt, and impurities. There should be no short circuits or bridging between laminations, and joint gaps must meet specifications. Good insulation must be maintained between the core and upper/lower clamping plates, square iron pieces, pressure plates,

Power Transformers: Short Circuit Risks, Causes, and Improvement MeasuresPower transformers are fundamental components in power systems that provide energy transmission and are crucial induction devices ensuring safe power operation. Their structure consists of primary coils, secondary coils, and an iron core, utilizing the principle of electromagnetic induction to alter AC voltage. Through long-term technological improvements, the reliability and stability of power supply have continuously enha

Growing Requirements for Power Transformer Cooling Systems and the Function of CoolersWith the rapid development of power grids and the increase in transmission voltage, power grids and electricity users are demanding increasingly higher insulation reliability for large power transformers. Since partial discharge testing is non-destructive to insulation yet highly sensitive, effectively detecting inherent defects in transformer insulation or safety-threatening defects generated during transporta

General Requirements for Power Transformer Cooling Systems All cooling devices shall be installed in accordance with the manufacturer's specifications; The cooling system with forced oil circulation must have two independent power supplies with automatic switching capability. When the working power supply fails, the standby power supply shall be automatically activated while emitting audible and visual signals; For transformers with forced oil circulation, when a faulty cooler is disconnected, a

1. OverviewDue to global warming, reducing greenhouse gas emissions is a critical issue. A significant portion of losses in power transmission systems comes from power transformers. To reduce greenhouse gas emissions in power systems, more efficient transformers must be installed. However, more efficient transformers often require more manufacturing materials. To determine the optimal loss ratio and manufacturing price of transformers, the Total Cost of Ownership (TCO) method is the industry sta

1.Neutral Point Establishment and System StabilityIn photovoltaic power stations, grounding transformers effectively establish a system neutral point. According to relevant power regulations, this neutral point ensures the system maintains certain stability during asymmetric faults, functioning like a "stabilizer" for the entire power system.2.Overvoltage Limitation CapabilityFor photovoltaic power stations, grounding transformers can effectively limit overvoltages. Generally, they can control o