SINEXCEL Active Harmonic Filter

1. Working principle

External CT detects the load current, DSP tracks instruction current and calculates the harmonic content through Intelligent Fast Fourier algorithm. Then DSP sends PWM signal to IGBT driving board which can control IGBT turning on and off to generate opposite phase of compensation harmonic current. At the same time CT detects the output current and compensation result is fed back to DSP, then the next round of logic control is carried out to realize stable power grid.

2. Advantage

Three level topology (less switching loss & higher switching frequency)

Compared to two-level topology, Sinexcel AHF adopts three-level topology which has twice the IGBT modules guarantees 35kHz switching frequency, and with two IGBT in each bridge arm to share the DC bus voltage instead of one, the switching losses is reduced. And three-level inverter uses multiple levels to synthesize stepped waves to approximate the sinusoidal output voltage. As there is one more output level than a two-level inverter, its output PWM wave is closer to the sinusoidal waveform with less ripple content which guarantees the output  compensation current without attenuation.

Intelligent Fast Fourier algorithm (avoid resonance and more accurate compensation)

Sinexcel AHF adopts Intelligent Fast Fourier algorithm instead of FFT-Fast Fourier Transform as unique intelligent FFT can automatically study system impedance, identify feature of individual harmonic order to regulate the distribution of compensation capacity, if program detects some harmonic order has resonance, it stops outputting at the order but continuous compensates the others, otherwise outputs all capacity that system needs within 5 mins. If resonance changes to the other harmonic order, the next round of self-learning is carried out to prevent system from resonance.

Module design (small size)

Sinexcel AHF is in an ultra-compact design which means it can be easy installed and replaced. Wall-mounted and rack-mounted design with compact footprint make it flexible to be integrated into the system, 5 pcs modules can be put into one single cabinet with maximum capacity 750A and plug-type module can be also a choice which saves a lot space and more convenient.

3. Application

Commercial infrastructure: hospital, railway station, airport, commercial building, theme park, wharf, IDC, etc.

Industrial: water treatment, drilling systems, oil & gas, food processing, car accessories manufacturer,power supply manufacturer, irrigation, etc.

4. Qualifications: