US 11,757,301 B2
Carriers synchronizing method of hybrid frequency parallel inverter and system thereof
Tsai-Fu Wu, Hsinchu (TW); Temir Sakavov, Hsinchu (TW); and Yen-Hsiang Huang, Hsinchu (TW)
Assigned to NATIONAL TSING HUA UNIVERSITY, Hsinchu (TW)
Filed by NATIONAL TSING HUA UNIVERSITY, Hsinchu (TW)
Filed on Mar. 3, 2022, as Appl. No. 17/653,459.
Claims priority of application No. 110135694 (TW), filed on Sep. 24, 2021.
Prior Publication US 2023/0124942 A1, Apr. 20, 2023
Int. Cl. H02J 9/06 (2006.01); H02M 7/493 (2007.01); H02J 13/00 (2006.01)
CPC H02J 9/062 (2013.01) [H02J 9/068 (2020.01); H02M 7/493 (2013.01); H02J 13/00032 (2020.01)] 14 Claims
OG exemplary drawing
 
1. A carriers synchronizing method of a hybrid frequency parallel inverter, which is configured to synchronize a high-frequency carrier to a low-frequency carrier, the carriers synchronizing method of the hybrid frequency parallel inverter comprising:
performing an inverter paralleling step to connect a low-frequency high power inverter and a high-frequency low power inverter in parallel, wherein the low-frequency high power inverter is controlled by the low-frequency carrier, and the high-frequency low power inverter is controlled by the high-frequency carrier;
performing a low-frequency ripple simulating step to drive a high-frequency controlling unit to simulate a low-frequency ripple corresponding to the low-frequency high power inverter according to a simulating procedure, wherein the high-frequency controlling unit comprises a proportional integral controller and a period counter, and the period counter is configured to generate the high-frequency carrier;
performing an equidistant grid sampling step to drive the high-frequency controlling unit to sample a sample ripple according to an equidistant grid to generate a sample group and sample the low-frequency ripple according to the equidistant grid and a plurality of reference shifting angles to generate a plurality of low-frequency reference groups, wherein the low-frequency reference groups correspond to the reference shifting angles, respectively;
performing an actual shifting angle searching step to drive the high-frequency controlling unit to compare the sample group with the low-frequency reference groups to search an actual shifting angle between the high-frequency carrier and the low-frequency carrier from the reference shifting angles; and
performing a high-frequency carrier adjusting step to drive the proportional integral controller to calculate the actual shifting angle according to an adjusting procedure to generate a sync reference, and then drive the period counter to adjust a starting point of the high-frequency carrier according to the sync reference.