Comparison of harmonic detection methods applied in a photovoltaic inverter during harmonic current compensation

An improved harmonics detection method based on sliding disrete Fourier transform for three-phase grid-tie inverter system

“…It can be seen that the proposed harmonic detection method has a great advantage, the memory space occupied by the processor will be greatly reduced, which is 1 9 of the traditional SDFT method. At the same time, the calculated phase will be reduced to 2 3 , which makes the number of calculations to achieve greatly reduced.…”

“…In the complex frequency domain, the periodic signal can be expressed as a complex exponential series of equation (1).…”

“…Various harmonic detection methods have been researched in the literatures [1,2,3,4,5,6,7,8,9,10,11,12], which can be generally categorized into timedomain and frequency-domain methods. Typical time-domain methods based on the instantaneous reactive power theory (pq-theory), which only estimate the fundamental signal and detect the rest harmonics as a whole.…”

“…Therefore, it is not flexible to detection a single harmonic component. [1,2] A CDSC based methods is proposed in [3], which constructe by a series of DSC operators and consists of high-order delay buffers. For extracting each harmonic, different sets of DSC operators are required, which can increase the system complexity, computational effort and storage memory overhead especially when many harmonic components are to be extracted in applications like the selective active power filter.…”