Wanlida high voltage AHF - active harmonic filter

APF Technical Principle

Active power filter (APF/AHF) is new power electronic equipment which can dynamically filter harmonic with variable amplitude and frequency and compensate reactive power, it overcome the shortages of conventional LC filter and obtained the better compensation performances than passive filter.

The right diagram is schematic diagram of active power filter (APF/AHF), where, V_s is AC power supply, nonlinear load is harmonic source, it generates harmonic and consumes reactive power. APF system is composed of instruction current operational circuit and compensation current generation circuit, the instruction current operational circuit is mainly to detect current components in harmonic current and reactive power of compensation object, and the compensation current generation circuit generates equivalent compensation current with same amplitude and inverse polarity with harmonic current to filter harmonics according to instruction signal, the main circuit adopts PWM converter. 

APF Functions

Reduce harmonic distortion

Improve power factor

Reduce line loss

Prevent neutral line from overheat

Prevent power equipments from noise, overheat and vibration like motor, transformer etc.

Prevent signal transmission equipments from data loss and interference

Prevent measurement error caused by non-sinusoidal current and voltage.

Prevent sensitive semi-conductive device from damage

Prevent circuit breaker trip.

Prevent capacitors from burn due to harmonic resonance

Ensure safety of power system and reduce energy consumption

APF Technical Features

Can filter all kinds of harmonic currents

Filtering capability >95% for aimed harmonic

Traction level IGBT module, 20KHz switching frequency    

Response time <10ms

Single capacity up to 400A

Suppress three-phase unbalance

Conform to IEEE Std. 519-1992, GB/T 14549

Can be used as harmonic source

Apply closed-loop control, and ensure filtering accuracy

Can set filtering mode and select harmonic filtering type

Adapt automatically to impedance change of power network

Can connect 690V system(CE/C-tick) and 600V system(cUL) directly

Parallel connection, easy for filtering capacity expansion

Modularized design, easy for maintenance

Perfect protection functions

Faults record and history inquire

Support multiple communication protocols

Technical Parameters 

Factory Acceptance Test Platform

We built the first-class high voltage and big capacity power electronic equipments test platform to realize Factory Acceptance Testing for whole machine before delivery. We built the first-class high voltage and big capacity power electronic equipments test platform to realize Factory Acceptance Testing for whole machine before delivery.

Model and Dimension specification

The above dimension is our standard cabinet for 400V APF (Active power filter) and the wall-mounted cabinet or other voltage level APF can be designed according to requirements of users.