An Active Noise Cancellation Method for Low-Order Harmonic Mitigation Based on Multiple-Expansion Converters

In the era of smart grid development, China's photovoltaic household policies encourage consumers to participate in flexible electricity transactions. To facilitate the surplus solar energies, more and more multiple-expansion converters are applied for modular managements. However, these energies contain low-order harmonics which are difficult to filter with ordinary passive filters, while active filters are too expensive for home use only. Thus, an Active Noise Cancellation (ANC) method for low-order harmonic mitigation is proposed. By calculating the target harmonics, a series signals with the same amplitude and opposite phase as the original harmonics is approached via Integral Reset Core (IRC) and distributively injected into the control core of each expansion module. The ANC method substitutes the active filter tools with mere algorithms, without additional circuits nor intrusive measurements for expansion modules, which makes the total cost as low as possible. The feasibility and performance of the proposed method is validated by experimental studies on a 3 kVA on-grid solar system hardware platform based on the real developed in laboratory.