Granted Patent B2

US 12,249,925 · App. 18/606,916 · Granted Mar 11, 2025

Inventors: Yeong-Hoon Sohn (Sokcho-si, KR); Se-Hong Park (Busan, KR); Sae-Hoon Uhm (Hwaseong-si, KR)

Assignee: EN2CORE TECHNOLOGY, INC.

H02M7/537H02M1/38H02M7/5387H03H7/38H05H1/4652

Abstract

Claims (58)

1. A voltage supply applying an AC voltage to a variable load, the voltage supply comprising:

an inverter applying an AC voltage to the variable load and having at least two switches electrically interposed between terminals which are connected to (i) the variable load and (ii) a DC power source,

wherein the AC voltage has a frequency determined by operation of the at least two switches; and

a controller generating a switching signal which controls the operation of the at least two switches,

wherein the controller is configured to:

transmit a first switching signal which controls at least one of the at least two switches such that a first AC voltage having a first frequency is applied to the variable load during a first time duration,

wherein the first frequency is higher than or equal to a resonant frequency of the variable load,

determine a second frequency of a second AC voltage to be applied to the variable load during a second time duration after the first time duration based on transition in a physical characteristic of the variable load,

transmit a second switching signal which controls at least one of the at least two switches such that the second AC voltage having the second frequency is applied to the variable load during the second time duration,

wherein the controller is further configured to:

detect an output current which is output from the inverter to the variable load used for determining whether the physical characteristic of the variable load is transitioned during the first time duration,

acquire, based on it being determined that the physical characteristic of the variable load was transitioned within the first time duration using the detected output current, a first phase information of the output current used for determining the second frequency of the second AC voltage to be applied to the variable load during the second time duration,

acquire a second phase information of an output voltage which is transmitted from the inverter to the variable load based on the first switching signal,

detect a first delay time between the output current and the output voltage using the first phase information and the second phase information,

acquire N first delay times by repeating N times the acquisition of the first phase information, the acquisition of the second phase information, and the detection of the first delay time,

calculate a first representative value of the N first delay times, wherein N is a positive integer greater than or equal to 2,

determine the second frequency to be same with the first frequency based on the first representative value being included in a preconfigured range, and

determine the second frequency higher or lower than the first frequency based on the first representative value being not included in the preconfigured range.

2. The voltage supply of claim 1 , wherein the controller is further configured to:

acquire a third phase information of the first switching signal, and

acquire the second phase information of the output voltage using the third phase information.

3. The voltage supply of claim 1 , wherein the controller is further configured to

acquire a fourth phase information of the output current used for determining a third frequency of a third AC voltage to be applied to the variable load during a third time duration after the second time duration,

acquire a fifth information of the output voltage based on the first switching signal,

detect a second delay time between the output current and the output voltage using the fourth phase information and the fifth phase information,

acquire N second delay times by repeating N times the acquisition of the fourth phase information, the acquisition of the fifth phase information, and the detection of the second delay time,

calculate a second representative value of the N second delay times,

determine the third frequency to be same with the second frequency based on the second representative value being included in the preconfigured range, and

determine the third frequency higher or lower than the second frequency based on the second representative value being not included in the preconfigured range.

4. The voltage supply of claim 1 , wherein the first representative value is an average value of the N first delay times.

5. The voltage supply of claim 1 , wherein N is a predetermined value.

6. A method of applying an AC voltage to a variable load by a voltage supply, wherein the voltage supply comprises an inverter applying an AC voltage to the variable load and having at least two switches electrically interposed between terminals which are connected to (i) the variable load and (ii) a DC power source, the method comprising:

transmitting a first switching signal which controls at least one of the at least two switches such that a first AC voltage having a first frequency is applied to the variable load during a first time duration,

wherein the first frequency is higher than or equal to a resonant frequency of the variable load;

determining a second frequency of a second AC voltage to be applied to the variable load during a second time duration after the first time duration based on transition in a physical characteristic of the variable load;

transmitting a second switching signal which controls at least one of the at least two switches such that the second AC voltage having the second frequency is applied to the variable load during the second time duration;

wherein the determining the second frequency comprising:

detecting an output current which is output from the inverter to the variable load used for determining whether the physical characteristic of the variable load is transitioned during the first time duration;

acquiring, based on it being determined that the physical characteristic of the variable load was transitioned within the first time duration using the detected output current, a first phase information of the output current used for determining the second frequency of the second AC voltage to be applied to the variable load during the second time duration;

acquiring a second phase information of an output voltage which is transmitted from the inverter to the variable load based on the first switching signal;

detecting a first delay time between the output current and the output voltage using the first phase information and the second phase information;

acquiring N first delay times by repeating N times the acquisition of the first phase information, the acquisition of the second phase information, and the detection of the first delay time;

calculating a first representative value of the N first delay times, wherein N is a positive integer greater than or equal to 2;

determining the second frequency to be same with the first frequency based on the first representative value being included in a preconfigured range; and

determining the second frequency higher or lower than the first frequency based on the first representative value being not included in the preconfigured range.

7. The method of claim 6 , wherein the acquiring the second phase information comprising:

acquiring a third phase information of the first switching signal; and

acquiring the second phase information of the output voltage using the third phase information.

8. The method of claim 6 , further comprising:

acquiring a fourth phase information of the output current used for determining a third frequency of a third AC voltage to be applied to the variable load during a third time duration after the second time duration;

acquiring a fifth information of the output voltage based on the first switching signal;

detecting a second delay time between the output current and the output voltage using the fourth phase information and the fifth phase information;

acquiring N second delay times by repeating N times the acquisition of the fourth phase information, the acquisition of the fifth phase information, and the detection of the second delay time;

calculating a second representative value of the N second delay times;

determining the third frequency to be same with the second frequency based on the second representative value being included in the preconfigured range; and

determining the third frequency higher or lower than the second frequency based on the second representative value being not included in the preconfigured range.

9. The method of claim 6 , wherein the first representative value is an average value of the N first delay times.

10. The method of claim 6 , wherein N is a predetermined value.

Priority Claims (1)

Continuity (4)

References Cited (40)