In a generator, the exciter serves the crucial role of providing the initial electromagnetic field necessary for the generation of electrical power. Specifically, it supplies direct current (DC) to the rotor windings of the generator, creating a magnetic field. This magnetic field induces voltage in the stator windings as the rotor rotates, thereby generating electrical … Read more
Magnetizing current in a transformer is non-sinusoidal due to the non-linear nature of the transformer’s magnetic core. The core material exhibits a non-linear B-H (magnetic flux density versus magnetic field strength) characteristic, meaning that as the magnetic field strength increases, the magnetic flux does not increase proportionally. This non-linearity causes distortion in the magnetizing current, … Read more
A digital thermometer works by using electronic sensors to measure temperature and then converting that temperature into a digital display. Inside the thermometer, there is a sensor probe that detects temperature changes. This sensor is typically a semiconductor device such as a thermistor or a temperature-sensitive resistor. When the sensor detects a change in temperature, … Read more
A DC motor draws a high inrush current when starting because the initial back EMF (electromotive force) is zero. Back EMF is generated by the rotating armature and opposes the applied voltage, reducing the net voltage across the armature. At startup, the armature is stationary, so no back EMF is generated, resulting in the full … Read more
Hydrogen is used for generator cooling primarily because of its excellent heat transfer properties and low density compared to air. Hydrogen has a high thermal conductivity, meaning it can efficiently carry away heat generated during the operation of large generators. This efficient heat transfer helps maintain lower operating temperatures in the generator components, reducing thermal … Read more
A diode is called a rectifier because it has the ability to convert alternating current (AC) into direct current (DC). This process is known as rectification. In its simplest form, a diode allows current to pass through it in one direction only, blocking current flow in the opposite direction. This directional behavior is ideal for … Read more
The relation between holding current and latching current in a Silicon Controlled Rectifier (SCR) is essential to understanding its operational characteristics. Latching current is the minimum current required to initially trigger the SCR into the conducting state. Once triggered, the SCR will continue to conduct even if the gate current is removed, as long as … Read more
If you connect a switch and a capacitor in a circuit, the behavior of the capacitor depends on the state of the switch. When the switch is closed, the capacitor will start to charge if connected to a voltage source. The current will flow through the circuit, causing the voltage across the capacitor to increase … Read more
Wind turbine inverters and photovoltaic (solar) inverters differ primarily in their design and operational characteristics tailored to the specific requirements of each renewable energy source. A wind turbine inverter is designed to convert the variable frequency AC output from a wind turbine’s generator into grid-compatible AC electricity. Wind turbines generate electricity through the rotation of … Read more
A transformer will not work with DC because it relies on a changing magnetic field to induce voltage in the secondary winding. DC provides a constant current and does not create the alternating magnetic field needed for transformer operation. Without this alternating field, no voltage is induced in the secondary winding, rendering the transformer ineffective … Read more