Views:0 Author:Site Editor Publish Time: 2018-03-27 Origin:Site
Definition of polypropylene film capacitor: a "container" for storing electric charges or electric field energy. C = unit of capacitance: F, μ F, NF, PF. Capacity indication method of 1F=106 μ F=109nF=1012pF1 μ F=103nF=106pF1nF=103pF capacitors: the equivalent circuit of 1F=106 μ F=109nF=1012pF1 μ F=103nF=106pF1nF=103pF Capacity marking method for capacitors: such as: 1u0100nnn0 digital method such as: 105104102, in which: RI-capacitor insulation resistance LS- capacitor inductance CS-equivalent series capacitance RS-loss equivalent series resistance.
The energy consumed per unit time due to heat is called the loss of capacitors. In general, the loss angle is tangent to denote: TG δ = active / reactive power. Loss mainly: dielectric loss dielectric leakage current caused by the conductivity loss. Polarization loss caused by slow polarization of dielectric Ionization loss metal loss (lead,polar plate, contact between lead and polar plate) the commonly used measurement method for capacitance loss tangent of polypropylene film is 20 ℃,1 KHz polyester (CL) ≤ 0. 01 PP (CBB) ≤ 0.001 because of the difference of dielectric polarity. Therefore, the loss angle tangent of polypropylene film capacitor is much smaller than that of polyester film capacitor, especially the loss frequency characteristic of polypropylene film capacitor is much better when it is used at high frequency.
The ideal capacitor can store all the energy from the power supply in the capacitor, while the actual capacitor consumes a certain amount of energy in the circuit, that is, converting part of the stored electric energy in the capacitor into heat energy. On the one hand, the heat energy causes the capacitor to heat and the temperature rises; on the other hand, the surface of the polypropylene film capacitor is emitted into the surrounding environment.