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

1. Methods for Detecting Busbar Discharge1.1 Insulation Resistance TestThe insulation resistance test is a simple and commonly used method in electrical insulation testing. It is highly sensitive to through-type insulation defects, overall moisture absorption, and surface contamination—conditions that typically result in significantly reduced resistance values. However, it is less effective in detecting localized aging or partial discharge faults.Depending on the equipment’s insulation class and

1. Purpose of Handling Total Substation BlackoutA total blackout at a 220 kV or higher substation may lead to widespread power outages, significant economic losses, and instability in the power grid, potentially causing system separation. This procedure aims to prevent voltage loss in main grid substations rated 220 kV and above.2. General Principles for Handling Total Substation Blackout Establish contact with dispatch as soon as possible. Restore station service power promptly. Quickly restore

The Role of Harmonic Detection in Ensuring Power System Stability1. Importance of Harmonic DetectionHarmonic detection is a critical method for assessing the level of harmonic pollution in power systems, identifying harmonic sources, and predicting the potential impact of harmonics on the grid and connected equipment. With the widespread use of power electronics and the increasing number of nonlinear loads, harmonic pollution in power grids has become increasingly severe. Harmonics not only disr

The table below covers key decision criteria from requirements to implementation in the core dimensions of solid-state transformer selection, which you can compare item by item. Evaluation Dimension Key Considerations & Selection Criteria Explanation & Recommendations Core Requirements and Scenario Matching Primary Application Objective: Is the goal to achieve extreme efficiency (e.g., AIDC), require high power density (e.g., microgrid), or improve power quality (e.g., s

Purpose of Grounding System Functional Grounding (Working Grounding):In power systems, grounding is required for normal operation, such as neutral point grounding. This type of grounding is known as working grounding. Protective Grounding:The metal enclosures of electrical equipment may become energized due to insulation failure. To prevent electric shock hazards to personnel, grounding is provided and is referred to as protective grounding. Overvoltage Protection Grounding:Grounding is installe

How to Select and Set Circuit Breakers1. Types of Circuit Breakers1.1 Air Circuit Breaker (ACB)Also known as a molded frame or universal circuit breaker, all components are mounted within an insulated metal frame. It is typically open-type, allowing easy replacement of contacts and parts, and can be equipped with various accessories. ACBs are commonly used as main power supply switches. Overcurrent trip units include electromagnetic, electronic, and intelligent types. They provide four-stage pro

Optimization and Key Considerations for Operation and Maintenance Management of Low-Voltage Distribution NetworksWith the rapid development of China's power industry, operation and maintenance (O&M) management of low-voltage distribution networks has become increasingly important. A low-voltage distribution network refers to the power supply lines between a power transformer and end-user equipment, forming the most fundamental and critical part of the power system. To ensure its normal opera

Differences Between Rectifier Transformers and Power TransformersRectifier transformers and power transformers both belong to the transformer family, but they differ fundamentally in application and functional characteristics. The transformers commonly seen on utility poles are typically power transformers, while those supplying electrolytic cells or electroplating equipment in factories are usually rectifier transformers. Understanding their differences requires examining three aspects: working

The 110kV substation at our plant was constructed and put into operation in February 2005. The 110kV system employs ZF4-126\1250-31.5 type SF6 GIS (Gas-Insulated Switchgear) from Beijing Switchgear Factory, comprising seven bays and 29 SF6 gas compartments, including five circuit breaker compartments. Each circuit breaker compartment is equipped with an SF6 gas density relay. Our plant uses the MTK-1 model oil-filled density relays manufactured by Shanghai Xinyuan Instrument Factory. These relay

1.Rectifier Transformer: Principle and OverviewA rectifier transformer is a specialized transformer designed to supply rectifier systems. Its working principle is the same as that of a conventional transformer — it operates based on electromagnetic induction and is used to transform alternating voltage. A typical transformer has two electrically isolated windings — primary and secondary — wound around a common iron core.When the primary winding is connected to an AC power source, alternating cur