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

What Are the Differences Between Substations, Switching Stations, and Distribution Rooms?A substation is a power facility in the electric power system that transforms voltage levels, receives and distributes electrical energy, controls the direction of power flow, and adjusts voltage. It interconnects power grids of various voltage levels through its transformers. In specific applications—such as submarine power cables or long-distance transmission—some systems use high-voltage direct current (H

Power Off and Power On Sequence in the Distribution RoomPower-off sequence:When de-energizing, first disconnect the low-voltage (LV) side, then the high-voltage (HV) side. When de-energizing the LV side:First open all LV branch circuit breakers, then open the LV main breaker. Additionally, disconnect the control circuits before de-energizing the main power circuits. When de-energizing the HV side:First open the circuit breaker, then open the isolating switch (disconnector).If the HV incoming lin

Very often, the lowest-level circuit breaker does not trip, but the upstream (higher-level) one does! This causes a large-scale power outage! Why does this happen? Today, we’ll discuss this issue.Main Causes of Cascading (Unintended Upstream) Tripping The main circuit breaker’s load capacity is smaller than the total load capacity of all downstream branch breakers. The main breaker is equipped with a residual current device (RCD), while the branch breakers are not. When appliance leakage current

Essential Rules for Three-Level Power Distribution System Design1.Hierarchical and Branch Circuit Distribution(1) Power distribution from the primary main distribution board (distribution cabinet) to secondary distribution boards can be branched; that is, one main distribution board may supply power via multiple branch circuits to several secondary distribution boards.(2) Similarly, power distribution from a secondary distribution board to tertiary switch boxes can also be branched; that is, one

1.Reasonable Use of TransformersTransformers should be selected with flexible winding configurations according to the power consumption characteristics of industrial enterprises, and load adjustments should be made promptly based on each transformer’s load rate to ensure operation at optimal loading conditions. Three-phase loads on transformers should be kept as balanced as possible; unbalanced operation not only reduces output capacity but also increases losses. Energy-efficient transformers sh

What Is Common Grounding?Common grounding refers to the practice where a system’s functional (working) grounding, equipment protective grounding, and lightning protection grounding share a single grounding electrode system. Alternatively, it may mean that grounding conductors from multiple electrical devices are connected together and linked to one or more common grounding electrodes.1. Advantages of Common Grounding Simpler system with fewer grounding conductors, making maintenance and inspecti

There are many taboos and problematic practices in the installation of distribution boards and cabinets that must be noted. Especially in certain areas, improper operations during installation may lead to serious consequences. For cases where the precautions were not followed, some corrective measures are also provided here to remedy previous mistakes. Let’s follow along and take a look at common installation taboos from manufacturers regarding distribution boxes and cabinets!1. Taboo: Lighting

1. Induced Lightning OvervoltageInduced lightning overvoltage refers to the transient overvoltage generated on overhead distribution lines due to nearby lightning discharges, even when the line is not directly struck. When a lightning flash occurs in the vicinity, it induces a large amount of charge on the conductors—opposite in polarity to the charge in the thundercloud.Statistical data shows that lightning-related faults caused by induced overvoltages account for approximately 90% of total fau

Basic Composition and Function of Circuit Breaker Failure ProtectionCircuit breaker failure protection refers to a protective scheme that operates when the relay protection of a faulty electrical device issues a trip command but the circuit breaker fails to operate. It uses the protection trip signal from the faulty equipment and the current measurement from the failed breaker to determine breaker failure. The protection can then isolate other relevant breakers within the same substation in a sh

Distribution Lines: A Key Component of Power SystemsDistribution lines are a major component of power systems. On the same voltage-level busbar, multiple distribution lines (for input or output) are connected, each with numerous branches arranged radially and linked to distribution transformers. After being stepped down to low voltage by these transformers, electricity is supplied to a wide range of end users. In such distribution networks, faults such as phase-to-phase short circuits, overcurre