Overview

The main circuit of Active Power Filter (APF) is an IGBT power converter, which uses detection technology based on instantaneous reactive power theory to automatically track harmonic changes in the power grid, with high controllability and fast responsiveness. Overcoming the shortcomings of traditional passive filters such as poor filtering performance, susceptibility to resonance, and limited ability to compensate for fixed harmonics, it can achieve good filtering and compensation effects for various fast transient impulsive loads.

The CY-APF series active filter adopts military grade control chips, which have strong computing and anti-interference capabilities. It can achieve centralized control of multiple active filters in parallel with one controller. The adaptive current average control algorithm and LCL topology structure are used to overcome the shortcomings of traditional hysteresis current control, such as wide output spectrum range, difficult filtering, and high-frequency harmonic interference with the power grid caused by changes in switching frequency.

工作原理

CY-APF filtering principle

CY-APF collects current signals in real time through an external transformer CT, separates the harmonic components through an internal detection circuit, and injects compensation current equal to and opposite to the system's harmonic size into the power grid through an IGBT power converter, achieving the function of filtering out harmonics.

CY-APF reactive power compensation principle

The reactive power of the CY-APF real-time detection system is generated through the IGBT power converter to generate capacitive or inductive fundamental current, achieving dynamic continuous reactive compensation. The target power factor for reactive compensation can be set through the operation panel.

 


CY-APF Capacity Quick Reference Table
This table is only for selection reference, and the specific calculation is based on the capacity calculation formula.
 


[Note] The APF capacity in the above table is obtained when the transformer load rate is 80%. In actual projects, the APF capacity is calculated proportionally by comparing the load rate value with the 80% load rate in this table.