Film capacitor is a capacitor made of metal foil as electrode, and plastic film such as polyethyl ester, polypropylene or polystyrene overlapping from both ends, inductive or non-inductive winding. Because it is made of plastic film and polyethyl ester, polypropylene or polystyrene as the dielectric, so it is also called plastic film capacitor.

Thin film capacitor is used in many industries such as electronics, household appliances, communications, electric power and so on, because of its high insulation impedance, good frequency characteristics, non-polarity, and small dielectric loss. It is also used in high-frequency filtering, high-frequency bypass and analog circuits. So what do thin film capacitors do in different circuits? Let's take a look.

Thin film capacitance

(1) Parallel film capacitors, also known as moving film capacitors, are mainly used to compensate the reactive power of the inductive load of the power system, improve the power factor, improve the voltage quality and reduce the line loss in the circuit.

(2) Series film capacitors, series in power frequency high-voltage transmission and distribution lines, used to compensate the distributed reactance of the line, improve the static stability and dynamic stability of the system, improve the voltage quality of the line, greatly increase the transmission distance and improve the transmission capacity.

(3) Electric film capacitor, used in the frequency of 40 ~ 24000 Hertz electric heating equipment system, in order to improve the power factor, improve the circuit voltage or frequency characteristics.

(4) Coupled film capacitors, mainly used for high frequency communication, measurement, control and protection of high voltage power lines.

(5) Circuit breaker film capacitor, the original name is called voltage balancing capacitor, parallel in the high voltage circuit breaker break to play the role of voltage balancing, so that the voltage between the high voltage circuit breaker each break in the process of segmentation and disconnect uniform, can improve the arc extinguishing characteristics of the circuit breaker, improve the breaking capacity.