The main transformer primarily converts the high-voltage electrical energy generated by power plants into lower-voltage electrical energy suitable for transmission, distribution, and usage. This process involves transforming from high voltage to low voltage.
Working Principle:
The main transformer operates on the principles of electromagnetic induction and voltage transformation. When the high-voltage coil is supplied with an AC power source, it generates an alternating current. This alternating current creates an alternating magnetic field in the high-voltage coil, which is then conducted to the low-voltage coil through the core. According to Faraday's law of electromagnetic induction, the alternating magnetic field in the low-voltage coil induces an electromotive force in the low-voltage coil, thereby converting electrical energy from high voltage to low voltage.
Components:
The main transformer consists of several key components: the core, the oil tank and cover, protection devices, the cooling system, and bushings. The core performs the direct electromagnetic energy conversion and comprises the iron core, coils, leads, and insulation. The oil tank and cover include the tank body, cover, base, and accessories (such as oil sample valves, oil drain plugs, grounding bolts, etc.). The protection devices comprise the conservator, oil gauge, oil purifier, flow relay, desiccator, and signal thermometer.
Applications:
Main transformers are widely used in three major areas of the power system: transmission, distribution, and utilization. Additionally, they have extensive applications in industrial sectors, construction, and residential areas, such as in power machinery, welding and arc furnaces, power supply and distribution, and indoor lighting systems.