US 12,143,024 B2
Sensorless prediction method of overcurrent in isolated bidirectional DC-DC converter
Byung Hwan Jeong, Gwacheon-si (KR); Byeng Joo Byen, Suwon-si (KR); and Joo Yeon Lee, Seoul (KR)
Assigned to HYOSUNG Corporation, Anyang-si (KR)
Appl. No. 17/623,408
Filed by HYOSUNG Corporation, Anyang-si (KR)
PCT Filed Dec. 30, 2020, PCT No. PCT/KR2020/019407
§ 371(c)(1), (2) Date Dec. 28, 2021,
PCT Pub. No. WO2021/141321, PCT Pub. Date Jul. 15, 2021.
Claims priority of application No. 10-2020-0003398 (KR), filed on Jan. 9, 2020.
Prior Publication US 2022/0360160 A1, Nov. 10, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/32 (2007.01)
CPC H02M 3/33573 (2021.05) [H02M 1/32 (2013.01); H02M 3/33584 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A sensorless prediction method of an overcurrent in an isolated bidirectional DC-DC converter, the converter comprising a first capacitor configured to charge an input voltage, a first switching unit composed of a plurality of switches and converting and outputting the input voltage charged in the first capacitor through a switching operation, a transformer having a primary side connected to output terminals of the first switching unit, a second switching unit connected to a secondary side of the transformer and composed of a plurality of switches, and a second capacitor configured to store an output voltage of the second switching unit, the method comprising:
modeling a current waveform for an inductor current of the transformer according to a step-down condition or a step-up condition of the converter using a plurality of input values;
deriving a current value at inflection points of the modeled current waveform;
calculating an average value (IL_ave) of the inductor current according to the step-down condition or the step-up condition by using the derived inflection point current values;
calculating a secondary side output current average value (I2) by comparing a current average value (Ic_ave) of the second capacitor when the converter is at no load with the average value (IL_ave) of the inductor current;
calculating an error between the secondary side output current average value (I2) and a secondary side output current (I2);
updating the current value at the inflection points of the modeled current waveform by outputting a gain (k) for reducing the error through PI control and using the gain (k); and
predicting an overcurrent of the inductor current using the updated current value.