POWER CONVERSION APPARATUS AND POWER CONVERSION METHOD THEREOF

• US 20120230075A1
• Filed: 03/06/2012
• Published: 09/13/2012
• Est. Priority Date: 03/08/2011
• Status: Active Grant

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: LEE, JAE HO
• Granted Patent: US 8,837,186 B2
• Time in Patent Office: Days
• US Class Current: 363/128
• CPC Class Codes: H02M 1/0085 Partially controlled bridges
• CPC Class Codes: H02M 1/081 wherein the phase of the control voltage is adjustable with reference to the AC source
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 7/00 Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic
• CPC Class Codes: H02M 7/1557 with automatic control of the output voltage or current
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

An apparatus/method is provided. The power conversion apparatus includes: a rectifying unit including a silicon-controlled rectifier thyristor (SCR) for rectifying single-phase power externally inputted; a power factor correcting unit configured to correct a power factor of the power rectified by the rectifying unit; and a control signal generating unit configured to detect a zero-crossing point based on the single-phase power inputted and generate a pulse single of which a width increases as time elapses based on the detected zero-crossing point. The rectifying unit rectifies the single-phase power by using the pulse signal inputted to a gate terminal of the SCR.

Claims

1. A power conversion apparatus comprising:

a rectifying unit comprising a silicon-controlled rectifier thyristor (SCR) for rectifying single-phase power externally inputted;

a power factor correcting unit configured to correct a power factor of the power rectified by the rectifying unit; and

a control signal generating unit configured to detect a zero-crossing point based on the single-phase power inputted and generate a pulse single of which a width increases as time elapses based on the detected zero-crossing point,

wherein the rectifying unit rectifies the single-phase power by using the pulse signal inputted to a gate terminal of the SCR.

2. The power conversion apparatus according to claim 1, wherein the control signal generating unit comprises:

a signal detector configured to detect the single-phase power;

a single-phase PLL configured to detect the zero-crossing point based on the single-phase power detected by the signal detector and generate a carrier signal based on the detected zero-crossing point; and

a PWM generator configured to compare a reference signal with the carrier signal generated and generate the pulse signal of which the width increases as time elapses.

3. The power conversion apparatus according to claim 2, wherein the single-phase PLL detects first and second zero-crossing points and generates the carrier signal which increases as time elapses based on the first and second zero-crossing points detected.

4. The power conversion apparatus according to claim 3, wherein the first zero-crossing point represents a zero-crossing point where the single-phase power is changed from positive to negative, and the second zero-crossing point represents a zero-crossing point where the single-phase power is changed from negative to positive.

5. The power conversion apparatus according to claim 1, wherein the carrier signal comprises a first carrier signal and a second carrier signal, wherein the first carrier signal is generated when the first zero-crossing point is detected and is reset when the second zero-crossing point is detected, and the second carrier signal is generated when the second zero-crossing point is detected and is reset when the first zero-crossing point is detected.

6. The power conversion apparatus according to claim 2, wherein the PWM generator generates the pulse signal while the carrier signal is greater than the reference signal.

7. The power conversion apparatus according to claim 5, wherein the PWM generator compares the first carrier signal with the reference signal to generate a first pulse signal while the first carrier signal is greater than the reference signal, and compares the second carrier signal with the reference signal to generate a second pulse signal while the second carrier signal is greater than the reference signal.

8. The power conversion apparatus according to claim 7, wherein the SCR comprises:

a first SCR of which a gate terminal is connected to the first pulse signal outputted from the PWM generator; and

a second SCR of which a gate terminal is connected to the second pulse signal outputted from the PWM generator.

9. The power conversion apparatus according to claim 8, wherein the first and second SCRs output currents of which intensities are proportional to the widths of the first and second pulse signals by using the first and second pulse signals inputted to the gate terminals, wherein the intensities of the currents increase as time elapses.

10. The power conversion apparatus according to claim 1, comprising a reference signal generator configured to generate the reference signal, wherein the reference signal decreases as time elapses.

11. A power conversion method of a power conversion apparatus, the power conversion method comprising:

detecting single-phase power inputted;

generating a carrier signal by using a zero-crossing point of the single-phase power detected;

generating a pulse signal by comparing the carrier signal with a reference signal; and

rectifying the single-phase power inputted by using the pulse signal.

12. The power conversion method according to claim 11, wherein the generating of the carrier signal comprises:

detecting a plurality of zero-crossing points; and

generating the carrier signal which increases as time elapses base on the plurality of zero-crossing points detected.

13. The power conversion method according to claim 12, wherein the detecting of the plurality of zero-crossing points comprises:

detecting a first zero-crossing point where the single-phase power is changed from positive to negative; and

detecting a second zero-crossing point where the single-phase power is changed from negative to positive.

14. The power conversion method according to claim 13, wherein the generating of the carrier signal comprises:

generating a first carrier signal which is generated when the first zero-crossing point is detected and is reset when the second zero-crossing point is detected; and

generating a second carrier signal which is generated when the second zero-crossing point is detected and is reset when the first zero-crossing point is detected,

wherein the first and second carrier signals generated increase as time elapses.

15. The power conversion method according to claim 11, wherein the generating of the pulse signal comprises generating the pulse signal while the carrier signal is greater than the reference signal according to a result of the comparison between the carrier signal and the reference signal.

16. The power conversion method according to claim 13, wherein the generating of the pulse signal comprises:

comparing the first carrier signal with the reference signal and generating a first pulse signal while the first carrier signal is greater than the reference signal; and

comparing the second carrier signal with the reference signal and generating a second pulse signal while the second carrier signal is greater than the reference signal.

17. The power conversion method according to claim 16, wherein the rectifying comprises:

inputting the first pulse signal to a gate terminal of a first SCR connected to a positive terminal of the single-phase power;

rectifying the single-phase power according to a width of the first pulse signal inputted to the gate terminal of the first SCR;

inputting the second pulse signal to a gate terminal of a second SCR connected to a negative terminal of the single-phase power; and

rectifying the single-phase power according to a width of the second pulse signal inputted to the gate terminal of the second SCR.

18. The power conversion method according to claim 17, wherein the rectifying of the single-phase power comprises outputting currents of which intensities are proportional to the widths of the first and second pulse signals by using the first and second pulse signals inputted to the gate terminals of the first and second SCRs, wherein the intensities of the currents increase as time elapses.

19. The power conversion method according to claim 11, comprising generating and outputting the reference signal, wherein the reference signal decreases as time elapses.