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

1. IntroductionDue to long - term operation, faults and accidents of distribution transformers in rural power grids cannot be completely avoided. These faults and accidents are caused by a multitude of factors, such as external forces like damage and impact, and irresistible natural disasters such as lightning strikes. Meanwhile, in some rural areas, the low - voltage lines are inadequately maintained, frequently resulting in overloading and short - circuits, which cause distribution transformer

1. Wiring Forms of Ring - Main Unit1.1 Composition of Ring - Main UnitThe Ring - Main Unit (RMU) is composed of compartments. Generally, it has at least three compartments, including two compartments for ring cable entry and exit and one compartment for the transformer circuit.1.2 Configuration of Protection Modes for Ring - Main UnitBoth the ring cable feeder compartments and the transformer feeder compartments adopt load switches, usually three - position load switches with functions of making

In recent years, with the rapid development of the urban rail transit scale in China, the power and lighting load of subways has increased rapidly, and the problem of electric energy consumed by the self - losses of distribution transformers has become increasingly prominent. Against the backdrop of the country's advocacy for energy conservation and environmental protection, amorphous alloy core transformers, which use amorphous alloy strips with excellent magnetic conductivity as the magnetic -

Introduction to Fuses of American-style Box TransformersAmerican-style box transformers generally use a combination of plug-in fuses and backup protection fuses in series to provide protection. The protection principle is advanced and reliable, and the operation is simple. The backup protection fuse is an oil-immersed current-limiting fuse, usually installed inside the box transformer. It will operate only when a fault occurs inside the box transformer, and it is used to protect the high-voltage

Fault Causes of Distribution TransformersFaults Caused by Temperature RiseImpact on Metal MaterialsWhen a transformer is in operation, if the current is too large, causing the customer load to exceed the rated capacity of the transformer, the temperature of the transformer will rise, which in turn softens the metal materials and significantly reduces their mechanical strength. Take copper as an example. If it is exposed to a high - temperature environment above 200 °C for a long time, it

An indoor substation refers to a type of substation where all apparatus is installed within the substation building. Typically, this kind of substation is designed for voltages up to 11,000 volts. However, in environments where the surrounding air is contaminated by substances such as metal - corroding gases, fumes, and conductive dust, its applicable voltage range can be extended to 33,000 to 66,000 volts.As illustrated in the diagram below, an indoor substation is divided into multiple compart

An outdoor substation is one that accommodates all voltage levels ranging from 55 KV to 765 KV. This type of substation generally requires less construction time but occupies more space. Outdoor substations are primarily categorized into two types: pole - mounted substations and foundation - mounted substations.Pole - Mounted SubstationPole - mounted substations are utilized to support distribution transformers with a capacity of up to 250 KVA. These transformers are among the most cost - effect

Five core functions of Distribution automation systems①Fault IsolationFast isolation of fault section,reduce the scope of power cuts,avoid overridetrip and expand the outage scope.②Fault locationLocate fault section accurately,shorten the time of troubleshooting.③Alarm PushPush the fault type,fault time and switch position to the responsible person'smobile phone and monitoring center in time.④Monitoring AnalysisReal-time monitoring of load current,voltage,switch state,three-phaseunbalance,overlo

In-depth Analysis and Key Considerations for Load Characteristic EvaluationLoad characteristic evaluation is a cornerstone of distribution transformer design, directly influencing capacity selection, loss distribution, temperature rise control, and operational economy. The evaluation must be conducted across three dimensions:load type,temporal dynamics, andenvironmental coupling, with a refined model established based on actual operating conditions.1. Refined Analysis of Load Types Classificatio

The substation automation system (SAS), as its name implies, is distinguished by its capacity to substitute automated functions for manual operator tasks. Automated operations play a crucial role in guaranteeing the safe and reliable operation of electric power transmission and distribution. Its functions include, but are not limited to, monitoring, data collection, protection, control, and remote communication.Previously, Remote Terminal Units (RTUs) were solely employed as intermediaries betwe