Basic principles of active harmonic filters

Active Harmonic Filters are new special equipment for power harmonic control made of modern power electronics technology and digital signal processing technology based on high-speed DSP devices. It consists of two main parts: the command current operation circuit and the compensation current generation circuit. The command current operation circuit monitors the current in the line in real time, converts the analog current signal into a digital signal, and sends it to the high-speed digital signal processor (DSP) for signal processing, separates the harmonics from the fundamental wave, and sends a drive pulse to the compensation current generation circuit in the form of a pulse width modulation (PWM) signal to drive the IGBT or IPM power module to generate a compensation current with the same amplitude and opposite polarity as the grid harmonic current and inject it into the grid, compensating or offsetting the harmonic current, and actively eliminating power harmonics.

Technical advantages: Green

Efficiency reaches 97.2%, which saves about 6,500kwh of electricity per year compared with active filters with an efficiency of 95%

Higher efficiency topology enhanced control algorithm

Thermal design and structural optimization based on precise models

Miniaturization

The volume is only 1/6 of similar mainstream brands, taking up less space

Adaptable to different working conditions, installation innovation, wall-mounted or rack-mounted installation uses less raw materials and protects the environment

Intelligent

Compensate for specified harmonics Adjustable inductive and capacitive reactive power compensation Compensation system Unbalanced load automatic detection, suppression of system resonance Full-function monitoring system

Modularity

N+1 redundancy significantly improves system reliability. Production line, better quality assurance. Reduce single failure points in the system. Flexible parallel connection to adapt to different working conditions.

Functional characteristics

Filter out 2~50th harmonics at the same time, or select any harmonics within 2~50th for compensation. Response time is less than 300μs

Use 3DSP+CPLD full digital control method and internationally renowned brand high-speed IGBT, closed-loop control, accurate harmonic filtering