Introduction and classification of power capacitors

Power capacitors, capacitors for power systems and electrical equipment. Any two metal conductors separated by an insulating medium constitute a capacitor. The size of the capacitor capacitance is determined by its geometry and the characteristics of the dielectric between the two plates. When a capacitor is used under an AC voltage, the capacity of the capacitor is often expressed in terms of its reactive power, and the unit is either deficient or deficient.

Power capacitors can be divided into 8 types according to their use:

• 1.shunt capacitor. Originally called phase shift capacitor. It is mainly used to compensate the reactive power of the inductive load of the power system to improve the power factor, improve the voltage quality and reduce the line loss.
• 2.series capacitors. It is connected in series in the power frequency high-voltage transmission and distribution lines to compensate the distribution inductance of the line, improve the static and dynamic stability of the system, improve the voltage quality of the line, lengthen the power transmission distance and increase the transmission capacity.
• 3.coupling capacitors. It is mainly used for high-frequency communication, measurement, control, protection of high-voltage power lines and components used in devices for extracting electric energy.
• 4.circuit breaker capacitors. Originally known as equalizing capacitors. The voltage equalization is applied in parallel on the fracture of the ultra-high voltage circuit breaker, so that the voltage between the fractures is uniform during the breaking process and the disconnection, and the arc-extinguishing characteristics of the circuit breaker can be improved, and the breaking capacity can be improved.
• 5.electric heating capacitors. It is used in electric heating equipment systems with a frequency of 40~24000 Hz to improve the power factor and improve the voltage or frequency of the circuit.
• 6.pulse capacitor. It mainly functions as a storage energy, and is used as a basic energy storage component such as a surge voltage generator, an inrush current generator, and an oscillation circuit for a circuit breaker test.
• 7.DC and filter capacitors. It is used in high voltage DC devices and high voltage rectifier filter devices.
• 8.standard capacitors. It is used in the power frequency high voltage measurement dielectric loss circuit as a standard capacitor or as a capacitor voltage divider for measuring high voltage.

High-voltage power capacitors (above 6KV) and low-voltage power capacitors (400V) in the power system

The low-voltage power capacitors are classified into oil-impregnated paper power capacitors and self-healing power capacitors according to their properties, and are classified into ordinary power capacitors and smart power capacitors according to functions.