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

Single-phase grounding, line break (open-phase), and resonance can all cause three-phase voltage unbalance. Correctly distinguishing among them is essential for rapid troubleshooting.Single-Phase GroundingAlthough single-phase grounding causes three-phase voltage unbalance, the line-to-line voltage magnitude remains unchanged. It can be classified into two types: metallic grounding and non-metallic grounding. Inmetallic grounding, the faulted phase voltage drops to zero, while the other two phas

Solar panel coatings are protective layers applied to the surface of photovoltaic (PV) modules, primarily designed to enhance water resistance, corrosion resistance, and UV protection. They also help reduce the negative impact of dust, haze, and other contaminants adhering to the panel surface, which can lower power generation efficiency. Solar panel coatings are typically composed of various organic or inorganic materials that protect the panel surface and improve its ability to absorb sunlight

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

How to Resolve the Islanding Lockout of Grid-Connected InvertersResolving the islanding lockout of a grid-connected inverter usually refers to situations where, despite the inverter appearing to have a normal connection to the grid, the system still fails to establish an effective connection with the grid. Below are general steps to address this issue: Check inverter settings: Verify the inverter’s configuration parameters to ensure they comply with local grid requirements and regulations, inclu

Definition of Islanding EffectWhen the utility grid power supply is interrupted due to faults, operational errors, or scheduled maintenance outages, distributed renewable energy generation systems may continue operating and supplying power to local loads, forming a self-sustained “island” that is beyond the control of the utility company.Hazards Caused by Islanding Effect Loss of Voltage and Frequency Control: The utility cannot regulate voltage and frequency within the islanded section. If thes

The selection principles and precautions for fuse-switch disconnectors are crucial to ensuring the safe and stable operation of power systems.Selection Principles for Fuse-Switch Disconnectors Rated Voltage:The rated voltage of the fuse-switch disconnector shall be equal to or greater than the rated voltage of the electrical system to ensure the equipment operates normally without damage. Rated Current:The selection of rated current should be based on the load conditions of the electrical system

Substations designed for voltage levels ranging from 55 kV to 765 kV are known as outdoor substations. This type of substation requires less construction time but occupies more space. Outdoor substations are mainly divided into pole-mounted substations and foundation-mounted substations.Pole-Mounted SubstationsThis type of substation is used to support distribution transformers with capacities up to 250 kVA. Such transformers represent the cheapest, simplest, and smallest form of distribution. A

AC load banks are electrical devices used to simulate real-world loads and are widely applied in power systems, communication systems, automation control systems, and other fields. To ensure personal and equipment safety during use, the following safety precautions and guidelines must be observed:Select an appropriate AC load bank: Choose an AC load bank that meets actual requirements, ensuring its capacity, voltage rating, and other parameters satisfy the intended application. Additionally, sel

Installation precautions for Type K thermocouples are critical to ensuring measurement accuracy and extending service life. Below is an introduction to the installation guidelines for Type K thermocouples, compiled from highly authoritative sources:1.Selection and Inspection Select the appropriate thermocouple type: Choose the right thermocouple based on the temperature range, medium properties, and required accuracy of the measurement environment. Type K thermocouples are suitable for temperatu