US 11,757,375 B2
DC-AC inverter system using state observer and control method thereof
Wan-Pei Chen, Qionglin Township (TW); Yoshihiro Konishi, Zhubei (TW); Kuan-Wen Chen, New Taipei (TW); Yeh-Hsiang Ho, Jhongpu Township (TW); and Wan-Ju Ho, New Taipei (TW)
Assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE, Hsinchu (TW)
Filed by INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE, Hsinchu (TW)
Filed on Apr. 13, 2022, as Appl. No. 17/719,789.
Claims priority of provisional application 63/293,852, filed on Dec. 27, 2021.
Claims priority of application No. 111108083 (TW), filed on Mar. 4, 2022.
Prior Publication US 2023/0208318 A1, Jun. 29, 2023
Int. Cl. H02M 7/5387 (2007.01); H02M 1/00 (2006.01); H02M 1/14 (2006.01)
CPC H02M 7/53871 (2013.01) [H02M 1/0009 (2021.05); H02M 1/14 (2013.01); H02M 7/53873 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A control method of a DC-AC inverter system, comprising:
receiving, by a state observer, a DC link voltage at a current sampling time and a filter-capacitor-voltage actual value at the current sampling time;
outputting, by the state observer, a filter-capacitor-current estimation value at a next sampling time according to the DC link voltage at the current sampling time and the filter-capacitor-voltage actual value at the current sampling time, wherein the filter-capacitor-current estimation value at the next sampling time is an average current value without ripple;
receiving, by an inductor current calculator, a filter-inductor-current actual value at the current sampling time;
outputting, by the inductor current calculator, a filter-inductor-current estimation value at the next sampling time according to the DC link voltage at the current sampling time and the filter-inductor-current actual value at the current sampling time;
comparing the filter-inductor-current estimation value at the next sampling time with the filter-capacitor-current estimation value at the next sampling time to obtain a load current estimation value at the next sampling time;
outputting, by an inductor voltage estimator, a filter-inductor-voltage estimation value at the next sampling time according to the load current estimation value at the next sampling time; and
performing a feed-forward control according to the filter-inductor-voltage estimation value at the next sampling time.