Product profile

The main circuit of an active power filter (APF) is an IGBT power converter. Its transient-reactive-power-based detection technology allows it to track the variations in power harmonics, granting it high controllability and fast response. With the defects, e.g. poor filtration performance, resonance tendency, compensation for harmonics with fixed multiples only, of traditional passive filters conquered, the APFs have satisfying performance on filtration and compensation of the diverse transient impact loads.

The CY-APF series APF has a military-grade control chip with superior computing power and disturbance resistance, making it possible to control multiple parallel APFs with a single controller. Its self-adapting current average control algorithm in combination with the LCL topological structure eliminates the defects of wide output frequency range, filtration difficulty, interference with the grids by high-frequency harmonics, etc. in traditional hysteresis current control applications as a result of variation in switching frequency.

Naming rule

Operating principles

Filtration principles of CY-APF

The CY-APF collects real-time current signals via an external current transformer (CT), separates the harmonics therein via the internal detection circuit, and produces and inputs compensation current with equal magnitude but opposite phase of the system harmonics via the IGBT power converter to the grid, and thus filtering the harmonics.

VAR compensation principles of CY-APF

The CY-APF detects the reactive power in the system with a real-time manner, and then, through the IGBT power converter, produces capacitive or reactive fundamental current to realize dynamic, continuous VAR compensation, of which the power factor target may be specified on the operation panel.

CY-APF capacity summary

This table is for selection reference only. For particulars, the results of capacity calculation formulas shall prevail.

[Note] The APF capacity listed above is the outcomes under 80% load rate of the transformer. The actual values in practice shall be obtained by comparing the load rate with the 80% herein.