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

Electromagnets vs. Permanent Magnets: Understanding the Key DifferencesElectromagnets and permanent magnets are the two primary types of materials that exhibit magnetic properties. While both generate magnetic fields, they differ fundamentally in how these fields are produced.An electromagnet generates a magnetic field only when an electric current flows through it. In contrast, a permanent magnet inherently produces its own persistent magnetic field once it has been magnetized, without requirin

Working VoltageThe term "working voltage" refers to the maximum voltage that a device can withstand without sustaining damage or burning out, while ensuring the reliability, safety, and proper operation of both the device and associated circuits.For long-distance power transmission, the use of high voltage is advantageous. In AC systems, maintaining a load power factor as close to unity as possible is also economically necessary. Practically, heavy currents are more challenging to handle than hi

Pure Resistive AC CircuitA circuit containing only a pure resistanceR(in ohms) in an AC system is defined as a Pure Resistive AC Circuit, devoid of inductance and capacitance. Alternating current and voltage in such a circuit oscillate bidirectionally, generating a sine wave (sinusoidal waveform). In this configuration, power is dissipated by the resistor, with voltage and current in perfect phase—both reaching their peak values simultaneously. As a passive component, the resistor neit

Pure Capacitor CircuitA circuit comprising only a pure capacitor with capacitanceC(measured in farads) is termed a Pure Capacitor Circuit. Capacitors store electrical energy within an electric field, a characteristic known ascapacitance(alternatively referred to as a "condenser"). Structurally, a capacitor consists of two conductive plates separated by a dielectric medium—common dielectric materials include glass, paper, mica, and oxide layers. In an ideal AC capacitor circuit, the cur

Resistance SwitchingResistance switching refers to the practice of connecting a fixed resistor in parallel with the contact gap or arc of a circuit breaker. This technique is applied in circuit breakers with high post-arc resistance in the contact space, primarily to mitigate re-striking voltages and transient voltage surges.Severe voltage fluctuations in power systems arise from two main scenarios: interrupting low-magnitude inductive currents and breaking capacitive currents. Such overvoltages

The Biot-Savart Law is employed to determine the magnetic field intensity dHnear a current-carrying conductor. In other words, it describes the relationship between the magnetic field intensity generated by a source current element. This law was formulated in 1820 by Jean-Baptiste Biot and Félix Savart. For a straight wire, the direction of the magnetic field adheres to the right-hand rule. The Biot-Savart Law is also referred to as Laplace’s law or Ampère&rsq

DefinitionThe maximum value of the reverse voltage that a PN junction or diode can withstand without damage is termed thePeak Inverse Voltage (PIV). This PIV rating is specified and explained in the datasheet provided by the manufacturer.However, if the voltage across the junction under reverse bias exceeds this specified value, the junction will be damaged.As shown in the figure above, a PN junction or diode is commonly used as a rectifier, i.e., to convert alternating current (AC) to direct cu

Definition: When the resistance of certain metals and semiconductor materials changes in the presence of a magnetic field, this phenomenon is referred to as the magnetoresistance effect. The components that exhibit this effect are called magnetoresistors. Put simply, a magnetoresistor is a type of resistor whose resistance value fluctuates with the strength and direction of an external magnetic field.Magnetoresistors play a crucial role in detecting the presence of a magnetic field, measuring it

Methods of Voltage Control in Power SystemThe voltage within a power system is subject to variation in accordance with load fluctuations. Typically, the voltage is elevated during light - load periods and reduced under heavy - load conditions. To maintain the system voltage within acceptable limits, additional equipment is necessary. This equipment serves to increase the voltage when it is low and decrease it when it is overly high. The following are the methods employed in power systems for vol