Abstract
Current harmonic is an important factor in power converters' DC-link design. Its accurate derivation is conducive to estimating the reliability of DC-link capacitors. In active power filter (APF), due to its wide output bandwidth, the DC link suffers current harmonics on a broader spectrum, and the coupling effects among compensated harmonics make the derivation in this application more complex. However, the traditional methods in voltage source inverters (VSIs) usually assume the output current to be a simple sinusoid, or only calculate the root mean square (RMS) values. They cannot readily illustrate the coupling effect, nor discriminate between different modulation strategies. This paper presents a general method for APF to solve the DC-link current harmonics under any operation condition. Using Double-Fourier theory, a new variable called ‘harmonic factor’ is defined to describe the coupling effect among compensated harmonics. Then the DC-link current spectrum is quantitatively derived with the low-frequency compensated harmonics and the switching-frequency ripple currents. Finally, the simulation and experiment of a 2-level 100-A APF verify the theoretical analysis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
