DFC-F Series Reactive Power Compensation/Harmonic Filter

Overview

The traditional way for reactive power compensation is switch on the capacitors which are in parallel connection. But if load is un-liner one, which means low power factor and also the branch capacitors will cause the harmonic current to be amplified, resulting in the damage of capacitors and the power compensation cabinet can not work. The above problem can be avoided by L-C(reactance and capacitor) type filter. It is applied with capacitor branch series connection with reactors whose common reactance ratio is 5.5%, 7%, 8%, 12.5% and 14%. L-C type not only can avoid the amplification of harmonic current but also improve power factor, thus reducing energy losses on the transmission line and save energy. It is especially applied requirements for reactive power compensation mainly and suppresses harmonics secondly.

Working principle

If we call the impedance of power system is inductive Xs and that of reactive power compensation Xc, then the harmonic order of parallel resonance would be N0=Xc/Xs. So, if the same order of harmonic is included in the harmonics produced by load or other harmonic source, resonance would happen resulting in the harmonic amplification which would cause damage to capacitor and other equipments. But, install reactor of certain reactance ratio in series with capacitor in each branch can solve this issue. Generally, we choose reactance ratio of 13~14%to deal with 3rd harmonics, and reactance ratio of 5.5%,6%,7% to solve 5th and 7th harmonics, as for 11th and 13th harmonic issue, we select reactor with reactance ratio of 5.67%. This kind of design not only compensates reactive power but suppress harmonics amplification as well.

Features

*Reactive power compensation，improve power factor to＞0.95，
*Reduce energy on the transmission line to save energy
*Suppress harmonics and purify grid power, it is of high reliability
*Reactance of different resistance ratio is applied according to different harmonic in system.

Technical Parameters

* Rated voltage：0.4～1.5KV
* Capacity per unit：60～800KVar/cabinet, it can work in parallel
* Power factor after compensation:＞0.95, effectively suppress harmonic amplification and eliminate by 30～60%
* Rated measurement current: 5A
* Physical factor：cosφ，reactive power
* Protection Function：Over-Current, over- voltage, under-voltage protection
* Manual operation available, completely insulated form controller(in case controller malfunction, manual operation can also work well).