KR102131866B1 - Single stage ac-dc converter - Google Patents

Abstract

This embodiment is a single-power stage AC-DC converter, which is connected to a three-phase or single-phase AC power source to receive AC power, and to the input filter and the input filter to improve the input power factor and total harmonic distortion of the AC power source. It includes an input rectifying unit for rectifying the AC power transmitted through a plurality of connected step-up inductors and converting it into DC power, and a DC-DC converter for converting and outputting the level of the DC power, and the DC-DC converter includes a link ( Link) a plurality of input capacitors and a plurality of switching elements, each connected in series, and one resonant tank connected to at least one of the plurality of switching elements-the resonant tank includes a transformer, a resonant capacitor and a flying capacitor. A primary circuit including a voltage applied to a secondary winding of the transformer according to an alternating switching operation of a plurality of switching elements; And it is connected to the secondary winding of the transformer provides a single power stage AC-DC converter including a secondary output rectifying unit including a plurality of diodes to rectify the resonant load current individually.

Description

Single power stage AC-DC converter {SINGLE STAGE AC-DC CONVERTER}

The present invention relates to an AC-DC converter, and more particularly, to a power factor correction (PFC) AC-DC converter having a single power stage and a method of operating the same.

The contents described in this section merely provide background information for this embodiment, and do not constitute a prior art.

Power factor correction (PFC) AC-DC converter or DC with wide input/output voltage control range in various applications such as electric vehicle charging system, wind power system, microgrid, energy storage system, etc. -The demand for DC converters is increasing.

Accordingly, recently developed and released power supply systems such as electric vehicle charging systems, interleaved PFC converters, bridgeless PFC converters, and PFC Vienna rectifiers for receiving single-phase or three-phase AC power to improve input power factor and increase conversion efficiency Topologies such as (VIENNEA Rectifier) are used. In addition, in such a power system, an insulated high-frequency DC-DC converter, an LLC resonant converter and a 3-level converter are used to receive the converted DC link voltage and charge the battery, thereby reducing size and weight.

1 is a diagram showing a 3-level converter having an input terminal diode rectifier, and FIG. 2 is a diagram showing a Vienna stage rectifier and a 2-stage DC power supply system with a 3-level DC-DC converter.

Referring first to FIG. 1, a power supply 100 composed of a three-phase (or single-phase) diode rectifier 110 and a DC-DC converter 130 insulated from the diode rectifier ( Due to rectification through D1 to D6), reactive power due to harmonic currents (e.g., 5 harmonics, 7 harmonics current, etc.) increases due to the flow of pulsed phase currents (Ia to Ic) at the input stage and the input power factor This decreases.

In addition, harmonic current and reactive power can be reduced by adding passive elements such as an inductor or a capacitor to the input terminal, but in this case, there is a problem that the size or weight of the power supply increases.

Next, referring to Figure 2, the two-stage (Two-Stage) power supply system 200, the sine input current and rectifier output voltage in response to harmonic regulations such as IEC 1000-3-2, the international harmonic management standards It includes a Vienna rectifier (210, VIENNEA Rectifier) which is an input power factor correction circuit for controlling, and a full-bridge or 3-level DC-DC converter 230 for obtaining an isolated output.

However, in this two-stage main circuit method, since each converter must be individually controlled, the control complexity increases, and the number of parts of the power supply increases and the unit cost increases due to the addition of switching elements for individual control. There is a problem.

In order to solve the problems of the power supply of FIGS. 1 and 2, as in the power supply of FIGS. 3 and 4, an input power factor improving circuit and an isolated DC-DC converter are integrated into a single power stage (Single Stage) AC -A DC converter has been announced.

3 is a diagram showing a single-phase single power stage 3-level AC-DC converter with an auxiliary winding rectifier, and FIG. 4 is a diagram showing a voltage source 3-phase single power stage 3-level AC-DC converter.

Referring first to FIG. 3, the single-phase single-power stage 3-level AC-DC converter 300 includes an input boosting center-tap rectifier including an auxiliary winding Naux for boosting the link voltage V _LINK (Auxially Rectifier) ( 310) and a secondary (N ₂ ) output rectifier (Secondary Rectifier) 330.

In the AC-DC converter 300 of FIG. 3, when the link voltage V _LINK has a wide operating range of 2 times or more, each auxiliary winding is applied to the rectifying diodes D _C1 and D _{C2 of the} input boost center-tap rectifier 310. Since the sum voltage of Naux) is applied to increase the voltage stress, there is a problem in that rectifying diodes D _C1 and D _C2 having a high rated voltage must be used.

In addition, since the AC-DC converter 300 of FIG. 3 includes an input step-up center-tap rectifier 310 of a 3-level DC-DC converter configured in series with the input voltage, the conversion efficiency is low and the ambient voltage is 2 Since the entire rated power for the vehicle side (N ₂ ) output rectifying unit 330 and the input boosting center-tap rectifying unit 310 has to be handled, there is a problem in that it is difficult to increase the integration by increasing the capacity of the peripheral voltage.

Next, referring to FIG. 4, the three-phase single power stage 3-level AC-DC converter 400 controls the input terminal link voltage V _Link and the output voltage V _O in a phase control method.

The AC-DC converter 400 of FIG. 4 is difficult to implement zero voltage switching (ZVS) of the primary-side switching elements (S ₁ to S ₄ ) when operating under light load conditions. Since the surge voltage and parasitic vibration are generated in the secondary-side output rectifiers D _R1 and D _{R2 due} to the leakage inductance of, a separate snubber is required to suppress this, resulting in lower conversion efficiency. .

In addition, the AC-DC converter 400 of FIG. 4 has a problem that high integration is difficult by using an inductor L _O at an output terminal.

This embodiment is intended to provide a highly integrated single power stage AC-DC converter having the advantages of input power factor improvement, size reduction, conversion efficiency improvement, and wide input/output voltage control range and an operation method thereof.

According to an aspect of the present embodiment, a single power stage AC-DC converter, connected to a three-phase or single-phase AC power supply to receive AC power, and an input filter for improving the input power factor and total harmonic distortion of the AC power supply; An input rectifying unit rectifying the AC power transmitted through a plurality of boosting inductors connected to the input filter and converting the AC power into DC power; And a DC-DC converter for converting and outputting the level of the DC power supply, wherein the DC-DC converter comprises a plurality of input capacitors and a plurality of switching elements connected in series to a link terminal, and the plurality of switching elements. One resonant tank connected to at least one of the switching elements of the-the resonant tank includes a transformer, a resonant capacitor and a flying capacitor, and a voltage on the secondary winding of the transformer according to the alternating switching operation of a plurality of switching elements A primary-side circuit including an application box; And it is connected to the secondary winding of the transformer provides a single power stage AC-DC converter including a secondary output rectifying unit including a plurality of diodes to rectify the resonant load current individually.

According to another aspect of the present embodiment, a single power stage AC-DC converter comprising: an input filter that receives AC power and improves the input power factor and total harmonic distortion of the AC power; An input rectifying unit rectifying AC power transmitted through a plurality of step-up inductors connected to the input filter and converting it into DC power; And a DC-DC converter for converting and outputting the level of the DC power supply, wherein the DC-DC converter comprises a plurality of input capacitors and a plurality of switching elements connected in series to a link terminal, and the plurality of switching elements. A first resonant tank and a second resonant tank connected to at least one of the switching elements of the-each of the first resonant tank and the second resonant tank includes a transformer, a resonant capacitor, and first to fourth partial pressure capacitors, and a plurality of A primary-side circuit including-applying a voltage to a secondary winding of the transformer according to an alternate switching operation and phase control of switching elements of the; And it is connected to the secondary winding of the transformer provides a single power stage AC-DC converter including a secondary output rectifying unit including a plurality of diodes to rectify the resonant load current individually.

According to another aspect of the present embodiment, as a power supply device including two single power stage AC-DC converters, each of the two single power stage AC-DC converters receives AC power and input power factor of the AC power And an input filter for improving the total harmonic distortion ratio. An input rectifying unit rectifying the AC power transmitted through a plurality of boosting inductors connected to the input filter and converting the AC power into DC power; And a DC-DC converter for converting and outputting the level of the DC power supply, wherein each of the DC-DC converters includes a plurality of input capacitors and a plurality of switching elements connected in series to a Link terminal, respectively. Two resonant tanks connected to at least one of the plurality of switching elements-the resonant tank includes a transformer, a resonant capacitor, and first to fourth divided voltage capacitors, but the transformer according to an alternating switching operation of a plurality of switching elements And a secondary-side output rectifying unit including a plurality of diodes connected to the secondary-side winding of the transformer to individually rectify a resonant load current. A single single power stage AC-DC converter provides a power supply device characterized by reducing the current ripple of the input stage and the output stage by interleaved with the input filter in common.

The single-power stage 3-level AC-DC converter according to the present embodiment improves the input power factor, consists of a single power stage to achieve size reduction and conversion efficiency improvement, and can control the input/output voltage over a wide range of more than twice. It has an effect.

1 is a view showing a 3-level converter having an input terminal diode rectifier.
FIG. 2 is a view showing a two-stage power supply system to which a Vienna rectifier and a 3-level DC-DC converter are applied.
3 is a view showing a single-phase single power stage 3-level AC-DC converter having an auxiliary winding rectification unit.
4 is a diagram showing a voltage source 3-phase single power stage 3-level AC-DC converter.
5 is a diagram showing a three-phase single power stage AC-DC converter having one resonant tank circuit according to an aspect of the present embodiment.
FIG. 6 is a diagram showing an operating waveform of the three-phase single power stage AC-DC converter of FIG. 5.
7A to 7C are diagrams showing current paths in operation modes 1 to 3 of the three-phase single power stage AC-DC converter of FIG. 5.
8A to 8C are graphs showing experimental results of measuring the voltage and current of the three-phase single power stage AC-DC converter of FIG. 5.
9 is a graph showing experimental results comparing the conversion efficiency and the total harmonic distortion characteristics according to the load capacity of the three-phase single power stage AC-DC converter of FIG. 5.
10 is a view showing an example of a three-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment.
11 is a view exemplarily showing a secondary-side rectifier that can be applied to the present embodiment.
FIG. 12 is a view showing an operating waveform of the three-phase single power stage AC-DC converter of FIG. 10.
13A to 13G are diagrams showing current paths in operation modes 1 to 7 of the three-phase single power stage AC-DC converter of FIG. 10.
14A to 14C are graphs showing experimental results of measuring the voltage and current of the three-phase single power stage AC-DC converter of FIG. 10.
15 is a graph showing experimental results comparing the conversion efficiency and the total harmonic distortion characteristics according to the load capacity of the three-phase single power stage AC-DC converter of FIG. 10.
16 is a view showing an example of a single-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment.
FIG. 17 is a view showing an operating waveform of the single-phase single power stage AC-DC converter of FIG. 16.
18A to 18G are diagrams showing the current paths in operation modes 1 to 7 of the single-phase single power stage AC-DC converter of FIG. 16.
19 is a view showing an example of a three-phase single power stage AC-DC converter having a secondary-side 3-bridge rectifying diode circuit according to another aspect of the present embodiment.
FIG. 20 is a view showing an example in which the secondary-side rectifying unit of the AC-DC converter of FIG. 19 is configured with a center-tap rectifying diode circuit.
FIG. 21 is a diagram showing an operating waveform of the three-phase single power stage AC-DC converter of FIG. 19.
22A to 22G are diagrams showing current paths in operation modes 1 to 7 of the three-phase single power stage AC-DC converter of FIG. 19.
FIG. 23 is a diagram showing an application example in which two three-phase single power stage AC-DC converters of FIG. 10 are configured to alternately operate in parallel.
FIG. 24 is a diagram showing an application example in which two single-phase single power stage AC-DC converters of FIG. 16 are configured to alternately operate in parallel.
25 is a diagram showing an application example of the three-phase single power stage AC-DC converter of FIG. 5 to wireless power transmission.
26 is a diagram showing an application example of the three-phase single power stage AC-DC converter of FIG. 10 to wireless power transmission.
27 is a diagram showing an application example of the three-phase single power stage AC-DC converter of FIG. 23 to wireless power transmission.
28 is a diagram showing another example of a three-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment.
29 exemplarily shows resonant circuits that can be applied to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible, even if they are displayed on different drawings. In addition, in describing embodiments of the present invention, when it is determined that detailed descriptions of related well-known structures or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. Throughout the specification, when a part is'included' or'equipped' a component, this means that other components may be further included rather than excluded other components unless specifically stated to the contrary. . In addition, terms such as'... unit,' and'module' described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a diagram showing a three-phase single power stage AC-DC converter having one resonant tank circuit according to an aspect of the present embodiment, and FIG. 6 is a diagram showing the operating waveforms of the three-phase single power stage AC-DC converter of FIG. 5. 7A to 7C are diagrams showing current paths in operation modes 1 to 3 of the three-phase single power stage AC-DC converter of FIG. 5.

First, referring to Figure 5, the three-phase single power stage AC-DC converter 500, filter capacitors (C _Fa to C _FC ), filter inductors (L _Fa to L _Fc ), step-up inductors (L _B1 to L _B3 ) , Input rectifying diodes (D _R1 to D _R6 ) and a DC-DC converter 510.

The filter capacitors (C _Fa to C _FC ) and the filter inductors (L _Fa to L _Fc ) are connected to the three-phase input terminals (Va to Vc) to improve the input power factor and total harmonic distortion (THD). Perform.

The neutral point N of the filter capacitors C _Fa to C _FC is connected to a node a between the source of the switching element Q2 and the drain of Q3.

The DC-DC converter 510 is an insulated DC-DC converter and includes a resonance tank 511 composed of a transformer T, resonant capacitors Cr1 and Cr2, and a flying capacitor CB.

The resonant tank 511 gains on the secondary side of the resonant tank 511 according to a constant switching frequency of the switching elements Q ₂ and Q ₃ that alternately operate at a duty ratio of 50% regardless of phase control. The voltage according to the characteristics is applied. Therefore, the three-phase single power stage AC-DC converter 500 according to an aspect of the present embodiment, unlike a conventional three-level AC-DC converter, in order to respond to a wide output voltage, link voltage V through phase control _It is configured to control the voltage/current of the secondary side of the resonant tank 511 according to a certain switching frequency by controlling the _link , so that the output voltage can be extended to a wide range (e.g. 200 to 430 V without a boost converter for improving the input power factor). _DC ).

The operating waveform of the three-phase single power stage AC-DC converter 500 is as shown in FIG. 6. Referring to Figures 5 and 6, as shown in Figures 7a to 7c, the three-phase single power stage AC-DC converter 500 is summarized as follows.

't0~t1' section

In the section't0 to t1' where the switching elements Q ₁ and Q ₂ are turned on at the same time according to the phase-shifted modulation of the DC-DC converter 510, to the step-up inductors L _B1 to L _B3 . Energy is accumulated by applying a three-phase phase voltage.

't2~t3' section

In the section't2 to t3' where the switching element Q ₁ is turned off, the step-up inductors L _B1 to L _B3 link the accumulated energy to the link stage input capacitors C ₁ and C ₂ and the circulating diode D ₁ and D ₂ ), reset by discharging to the current path of the input power and the switching element, and perform a step-up operation in the Discontinuous Conduction Mode (DCM).

Hereinafter, with reference to FIGS. 7 to 9, the operation mode and experimental results of the three-phase single power stage AC-DC converter 500 according to an aspect of the present embodiment will be described in detail.

7A is a diagram showing a current path in operation mode 1 of the three-phase single power stage AC-DC converter of FIG. 5, and FIG. 7B is a current in operation mode 2 of the three-phase single power stage AC-DC converter of FIG. FIG. 7C is a diagram showing the current path in the operation mode 3 of the three-phase single power stage AC-DC converter of FIG. 5.

Mode 1 (Mode 1)-'t0~t1' section

Referring to FIG. 7A, in the operation mode 1 (Mode 1), the switching elements Q ₁ and Q ₂ are turned on so that 1/4 of the link voltage V _{Link to} the primary winding of the resonance tank 511 (ie, V _Link) /4) is applied, the three-phase single power stage AC-DC converter 500 transmits energy to the secondary-side output stage.

At this time, the filter capacitor voltages V _CFa and V _CFb are applied to the input step-up inductors L _B1 and L _B2 , and the filter filter C _Fa (C _Fb ) → the input step-up inductor L _B1 (L _B2 ) → the input rectifying diode D _R1 (D _R3 ) → switching element Q ₁ → switching element Q ₂ → current flows through the path of the filter capacitor C _Fa (C _Fb )', and energy accumulates, and the energy previously accumulated in the other input step-up inductor (L _B3 ) Is decreased and reset by the difference voltage between the input phase voltage V _C and the link voltage V _Link .

Mode 2-'t2~t3' section

Referring to FIG. 7B, in the operation mode 2 (Mode 2), the switching elements Q ₂ and Q ₄ are turned on, so that the three-phase single power stage AC-DC converter 500 transfers energy to the secondary output terminal.

At this time, the energy previously stored in the input boosting inductors L _B1 and L _B2 in the operation mode 1 _is'filter capacitor C _Fa (C _Fb ) → input boosting inductor L _B1 (L _B2 ) → input rectifying diode D _R1 (D _R3 ) → Input capacitor C1 → Circulating diode D1 → Switching element Q2 → Current flows through the path of filter capacitor C _Fa (C _Fb )'and resets, and the current flowing through the input boosting inductor L _B1 (L _B2 ) I _LB1 (I _LB2 ) decreases.

Mode 3-'t4~t5' section

Referring to FIG. 7C, in the operation mode 3 (Mode 3), the switching elements Q ₃ and Q ₄ are turned on, and a 1/4 of the link voltage V _Link is applied to the primary winding of the resonance tank 511 (that is, V _Link /4) is applied, the three-phase single power stage AC-DC converter 500 transmits energy to the secondary-side output stage.

At this time, since the switching elements Q ₃ and Q ₄ are turned on, the input step-up inductor L _B3 includes'filter capacitor C _Fc → switching element Q ₃ → switching element Q ₄ → input rectifying diode D _R6 → input step-up The current I _LB3 flows through the path of the inductor (L _B3 )', energy accumulates, and the current I _LB1 (I _LB2 ) flowing in the input boosting inductor L _B1 (L _B2 ) that was reduced in operation mode 2 is the filter capacitor. It is reset to 0 by the difference voltage between the voltage V _CFa (V _CFb ) and the link voltage V _LINK .

8A to 8C are graphs showing experimental results of measuring the voltage and current of the three-phase single power stage AC-DC converter of FIG. 5, and FIG. 9 is a load capacity of the three-phase single power stage AC-DC converter of FIG. It is a graph showing the experimental results comparing the conversion efficiency and total harmonic distortion characteristics according to.

In the experiments of FIGS. 8 and 9, the main ratings and transformer parameters are shown in Table 1.

Main rating Input line voltage (V _LL ) 220 V _AC Output voltage (V _O )/Output current (I _OMAX ) 200 V _DC /10A, 430 V _DC /4.65A (2kW) Switching frequency (fs)/resonant frequency (fr) 112.8 kHz/109.8 kHz Applied device Switching elements (Q ₁ to Q ₄ ) SCT3030AL (650 V/70 A/30 mΩ) Input rectifying diode GP2D050A120B[1200V/50A/1.6A/SIC] Primary-side circulation diodes (D ₁ to D ₂ ) GP2D050A060B[600V/50A/1.45A/SIC] Secondary output diode GP2D050A060B[600V/50A/1.45A/SIC] parameter La to Lc
C _Fa to C _Fc
L _B1 to L _B3 0.94 mH
2.86 uF
35 uH Cr1 to Cr2 / C _F 100nF / 2.2 uF Transformers 1/2 side magnetic inductance L _P /L _S 53.47 uH / 267.3 uH Equivalent leakage inductance L _eq 10.51 uH Turn-defense n _b1 (N _P1 /N _S2 ) 0.47 (8T/18T)

8A to 8C show that the inductor current (I _LB1 ), phase voltage (Va), phase current (Ia), link voltage (V _Link ) and LLC transformer of the three-phase single power stage AC-DC converter 500 are shown. The primary and secondary voltages and currents are shown, and the experimental results in FIG. 9 show the conversion efficiency characteristics and total harmonic distortion (THD) of each three-phase single power stage AC-DC converter 500 by output voltage.

In order to improve the total harmonic distortion (THD), the input step-up inductors L _B1 to L _B3 are designed to always operate in a discontinuous conduction mode (DCM).

9, 200 V _dc The maximum efficiency of a 3-phase single power stage AC-DC converter 500 at output voltage and 500 W load was measured at 94%, averaged over all output voltage (200 to 430 Vdc) and load (500 to 2000 W) ranges. Efficiency was measured at 91.58%. And, the lowest total harmonic distortion (THD) was the lowest at 1.89% at 430 Vdc output voltage and 2000 W load.

10 is a view showing an example of a three-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment, and FIG. 11 is an exemplary secondary side rectifier applicable to the present embodiment. It is a figure represented by.

First, referring to FIG. 10, the three-phase single power stage AC-DC converter 1000, unlike the three-phase single power stage AC-DC converter 500 of FIG. 5, in order to improve conversion efficiency, has two resonance tanks. (Resonant circuit 1 (Res. Tank 1), resonant circuit 2 (Res. Tank 2)). Hereinafter, the three-phase single power stage AC-DC converter 1000 according to another aspect of the present embodiment will be described based on the differences.

The three-phase single power stage AC-DC converter 1000 includes filter capacitors (C _Fa to C _FC ) and filter inductors (L _Fa to L _Fc ), step-up inductors (L _B1 to L _B3 ), and input rectifying diodes (D _R1) To D _R6 ) and a DC-DC converter 1010.

The filter capacitors (C _Fa to C _FC ) and the filter inductors (L _Fa to L _Fc ) are connected to the three-phase input terminals (Va to Vc) to improve the input power factor and total harmonic distortion (THD). Perform.

The neutral point N of the filter capacitors C _Fa to C _FC is connected to a node a between the source of the switching element Q2 and the drain of Q3.

'T0 to t1' according to the phase-shifted modulation of the DC-DC converter 1010 In the section, the switching elements Q1 and Q2 are simultaneously turned on, so that the three-phase phase voltages are applied to the boosting inductors L _B1 to L _B3 , respectively, and energy is accumulated. In addition, according to the phase control of the DC-DC converter 1010't4 ~ t5' In the section, the switching elements Q3 and Q4 are simultaneously turned on, so that a three-phase phase voltage is applied to the boosting inductors L _B1 to L _B3 , respectively, and energy is accumulated.

When the switching element Q ₁ is turned off in a period't2 to t3', the step-up inductors L _B1 to L _B3 link _pre -accumulated energy into a link stage input capacitor (C1 or C2), a circulating diode D ₁ , The switching element Q2 and the filter capacitors (C _Fa to C _Fc ) are reset by discharging to a current path, and a boost operation is performed in a Discontinuous Conduction Mode (DCM).

In addition, the three-phase single power stage AC-DC converter 1000, for the insulated DC-DC conversion, transformers (T1, T2) and resonant capacitors (C _r1 , C _r2 ), voltage divider capacitors (C _B1 to C _B4) ) Includes two resonant tanks (ie, resonant tank l (1011, Res. Tank 1), resonant tank 2 (1013, Res. Tank 2)). Here, each resonant tank (1011, 1013) is a transformer (T1, according to the constant switching frequency of switching elements Q ₁ to Q ₄ alternately operated at a duty ratio of 50% regardless of the phase control of the DC-DC converter 1010) A voltage according to the gain characteristic is applied to the secondary side of T2).

The secondary-side rectifying unit 1015 performs individual rectifying operation by each rectifying diode, but may perform stable rectifying operation without current imbalance according to a series connection operation.

The secondary side rectifier 1015 may be implemented in various forms, such as a half-bridge rectifier circuit (a), a full-bridge rectifier circuit (b), or a center-tap rectifier (c), as shown in FIG. 11. However, it should be noted that this is an example, and the present embodiment is not limited thereto.

In the three-phase single power stage AC-DC converter 1000 described above, i) unlike the conventional three-level AC-DC converter, the primary-side switching elements Q ₁ to Q ₄ are operated at all input voltage and load conditions. Zero Voltage Switching (ZVS) is possible, and ii) Secondary rectifier diodes (D _r1 to D _r6 ) are also capable of soft switching, so surge voltage is not applied, so snubber is not required. This makes it possible to operate at a high switching frequency and to be suitable for high integration.

In addition, the three-phase single power stage AC-DC converter 1000, the secondary side of the LLC resonant converter 1010 operating at a constant switching frequency by controlling the link voltage V _Link through a phase control to correspond to a wide output voltage range It is configured to control the voltage/current, and it has an advantage of controlling the output voltage in a wide range of 2 times or more without a step-up converter to improve the input power factor.

Hereinafter, an operation mode and an experimental result of the three-phase single power stage AC-DC converter 1000 according to another aspect of the present embodiment will be described in detail with reference to FIGS. 12 to 15.

Mode 1 (Mode 1)-'t0~t1' section

FIG. 12 is a diagram showing an operating waveform of the three-phase single power stage AC-DC converter of FIG. 10, and FIG. 13A is a diagram showing a current path in operation mode 1 of the three-phase single power stage AC-DC converter of FIG. 10. .

Referring to FIGS. 12 and 13A, in the period't0 to t1', switching elements Q ₁ and Q ₂ are turned on, so that 1/4 of the link voltage V _Link is applied to the resonance tanks 1011 and 1013, respectively. Current I _T1 , I _T2 flows.

At this time, the primary resonance current I _T1 is: i)'Capacitor C _B1 → Switching element Q ₂ → Resonant capacitor Cr1 → Winding N _P1 → Capacitor C _B1 ' path and ii)'Input capacitor C ₁ → Switching element Q _l → Switching element Q ₂ → Resonant capacitor Crl → Winding N _P1 → Capacitor C _B2 → Circulating diode D ₂ → It flows in the path of input capacitor C _l '.

The primary resonant current I _T2 is: i) the difference between the capacitor C _B3 voltage (ie, V _Link /2) and the capacitor C _B1 voltage (ie, V _Link /4),'Capacitor C _B3 → switching element Q ₁ → capacitor C _B1 → winding N _P2 → resonant capacitor Cr2 → path of capacitor C _B3 ' and ii) link voltage V _Link and capacitor C _B1 voltage (ie, V _Link /4) and capacitor C _B4 voltage (V _Link /2 ), the input voltage is different from the sum voltage of'Input Capacitor C ₁ → Switching Element Q ₁ → Capacitor C _B1 → Winding N _P2 → Resonant Capacitor Cr2 → Capacitor C _B4 → Input Capacitor C ₂ '.

The secondary-side output rectifier 1015, depending on the polarity of the transformer secondary-side individual windings (N _Sl , N _S2 ), i) In the secondary-side winding N _Sl ,'winding N _S1 → rectifying diode D _r3 → output capacitor C _O1 → winding N _S1 ', the resonant load current flows to charge the output capacitor C _O1 , and ii) the secondary winding N _S2 has'winding N _S2 → rectifying diode D _r5 → output capacitor C _O and load → rectifying diode D _r1 → output The load resonant current flows through the path of the capacitor C _O2 → winding N _S2 ′, but at this time, the voltage of the output capacitor C _O2 and the secondary winding N _{S2 as} the secondary output rectifier 1015 is configured in series connection. Voltage is applied and load current is supplied.

In the step-up inductors L _B1 and L _B2 , since the switching elements Q ₁ and Q ₂ are turned on, the filter capacitor voltages V _CFa and V _CFb are applied, respectively, and the filter filter C _Fa (C _Fb ) → step-up inductor L _B1 (L _B2 ) → Input rectifying diode → Switching element Q ₁ → Switching element Q ₂ → Filter capacitor C _Fa (C _Fb )'flows current and accumulates energy.

The step-up inductor L _B3 is reset by discharging the previously accumulated energy to 0 by the difference voltage between each line voltage (Vca, Vcb) and the link voltage (V _Link ).

Mode 2-'t1~t2' section

13B is a diagram showing a current path in operation mode 2 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13B, when the switching element Q ₁ is turned off at the time't1', the parasitic output capacitance C of the switching elements Q ₁ and Q ₄ is driven by the primary-side resonance currents I _T1 and I _T2 . _0SS ) is charged/discharged. At the same time, the junction parasitic capacitance C _JD1 of the circulating diode D ₁ starts discharging, and the junction parasitic capacitance C _JD2 of the circulating diode D ₂ starts charging.

The voltage of the parasitic output capacitance (C _0SS ) of the switching element Q ₁ and the voltage of the junction parasitic capacitance (C _JD2 ) of the circulating diode D _{2 reach} 1/2 of the link voltage (that is, V _Link /2), and the switching element Q The voltage of the parasitic output capacitance (C _0SS ) of ₄ and the voltage of the parasitic capacitance (C _JD2 ) of the circulating diode D ₁ decreases to 0 voltage, and thereafter, when the current starts to flow through the anti-parallel diode of the switching element Q ₄ 2 ends.

At this time, the resonant tank 2 (1013) has a polarity change (-l/4) V _Link voltage is applied, so the secondary winding N _S2 also changes polarity to transmit an idle current to the output rectifier 1015 and energy to the secondary output terminal Begins to deliver.

Mode 3-'t2~t3' section

13C is a diagram showing a current path in operation mode 3 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13c, the switching element Q ₄ is turned on at a zero voltage at the time't2', and (l/4)V _Link as before in the resonance tank 1 (1011) in the period't2 to t3' The voltage is applied, and the resonant tank 2 (1013) is supplied with a (-l/4) V _Link voltage with a reversed polarity. At this time, the winding of the secondary side with the reversed polarity N _S2 is'winding N _S2 → output capacitor C _O1 → rectification. Diode D _r4 → Output capacitor C ₀ → Rectifying diode D _r6 → Winding Resonant current flows in the path of N _S2 ′, and output capacitor C _O1 voltage and secondary winding as secondary output rectifier 1015 is configured in series connection The sum voltage of N _S2 voltage is applied and supplies the load resonance current.

In addition, the energy stored in the input step-up inductors L _B1 and L _B2 in the previous operation mode 1 _is'filter capacitor C _Fa (C _Fb ) → step-up inductor L _Bl (L _B2 ) → input rectifying diode → capacitor C ₁ → Circulating diode D ₁ → Switching element Q ₂ → Current flows through the path of filter capacitor C _Fa (C _Fb )'to reset, and the currents I _LB1 and I _LB2 flowing through the input step-up inductor gradually decrease.

Mode 4-'t3~t4' section

FIG. 13D is a diagram showing the current path in operation mode 4 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13d, the switching element Q2 is turned off at the't3' time, and the parasitic output capacitance of the switching elements Q ₂ and Q ₃ by the resonance current I _T1 of the primary resonance tank 1 1011 ( C _OSS ) is charged/discharged.

At this time, the polarity of the secondary winding N _S1 is also changed because the (-l/4) V _Link voltage with the changed polarity is applied to the resonance tank 1 1011.

When the voltage is reduced to zero voltage of the switching element Q ₃ parasitic output capacitance (C _OSS) of, and after a current starts flowing through the antiparallel diode of the switching element Q ₃ operation mode 4 is terminated.

Operation Mode 5 (Mode 5)-'t4~t5' section

13E is a diagram showing the current path in operation mode 5 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13e, since the switching element Q ₃ is turned on at a zero voltage at the time't4', and the switching elements Q ₃ and Q ₄ at a period't4 to t5' are turned on, the resonance tank ( 1011, 1013) is applied with 1/4 of the link voltage V _Link (that is, -V _Link /4), respectively, and the resonant currents I _T1 and I _T2 flow. At this time, the primary resonant current I _T1 is: i)'Reel N _S1 → Resonant Capacitor Crl → Switching Element Q ₃ → Capacitor C _B2 → Winding N _S1 ' path and ii) Capacitor C ₂ voltage (i.e., V _Link / 2) According to the differential voltage of the capacitor C _B1 voltage (that is, V _Link /4),'input capacitor C ₂ → circulating diode D ₁ → capacitor C _B1 → winding N _P1 → resonant capacitor Crl → switching element Q ₃ → switching element Q ₄ → It flows in the path of the input capacitor C ₂ ′.

At the same time, the primary resonant current I _T2 is: i)'winding N _P2 → capacitor C _B2 → switching element Q ₄ → capacitor C _B4 → path of resonant capacitor Cr2 → winding N _P2 ' and ii) link voltage V _Link and capacitor C Input the input capacitor C ₁ → Capacitor C _B3 → Resonant capacitor Cr2 → Winding N _P2 by the difference voltage from the sum voltage of C _B3 voltage (that is, V _Link /2) and capacitor C _B2 voltage (that is, V _Link /4) → Capacitor C _B2 → Switching element Q ₄ → Resonant current flows in the path of input capacitor C ₂ ′.

Secondary output rectifier 1015, depending on the polarity of the individual windings of the transformer secondary (N _S1 ,N _S2 ), i) In the secondary winding N _S1 ,'winding N _S1 → output capacitor C _O2 → rectifying diode Dr2 → winding N _S1 ', the resonant load current flows to charge the output capacitor C _O2 , and ii) on the secondary winding (N _S2 ), the'winding N _S2 → output capacitor C _O1 → rectifying diode Dr4 → output capacitor C _O → rectifying diode D _r6 → Resonant load current flows in the path of winding N _S2 ′, but at this time, as the secondary output rectifier 1015 is configured in series connection, the sum voltage of the output capacitor C _O1 voltage and the secondary winding N _S2 voltage is applied. Supply load current.

In addition, since the switching elements Q ₃ and Q ₄ are turned on, the step-up inductor L _B3 is referred to as a path of'filter capacitor C _Fc → switching element Q ₃ → switching element Q ₄ → input rectifying diode → step-up inductor L _B3 '. The current I _LB1 and I _LB2 of the boosting inductors L _B1 and L _{B2 where} the current I _B3 flows, accumulates energy, and is previously reduced, decreases the filter capacitor voltage V _CFa (V _CFb ) and the link voltage (V _Link ). It is reset to zero by the difference voltage.

Operation mode 6 (Mode 6)-'t5~t6' section

13F is a diagram showing the current path in operation mode 6 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13f, the switching element Q ₄ is turned off at the't5' time, and the parasitic output capacitance of the switching elements Q ₄ and Q ₁ by the resonance current I _T2 of the primary resonance tank 2 1013 (C _OSS ) is charged/discharged.

If 't6' the voltage of the parasitic output capacitance (C _OSS) of the switching element Q ₁ decreased to 0 voltage at the time, and a current starts flowing after via the switching antiparallel diode of device Q ₁ operation mode 6 is terminated.

Operation Mode 7-'t6~t7' section

13G is a diagram showing the current path in operation mode 7 of the three-phase single power stage AC-DC converter of FIG. 10.

12 and 13g, the switching element Q ₁ is turned on at a zero voltage at the time't6', and the switching elements Q ₁ and Q ₃ are turned on during the period't6 to t7' (T ₁ and T ₂ ), a 1/4 of the link voltage (that is, V _Link /4) is applied to the primary winding, and power is transmitted to the secondary output terminal 1015. In addition, since the switching elements Q ₂ and Q ₃ are turned on, the energy of the step-up inductor L _B3 accumulated in the previous mode _is'filter capacitor C _Fc → switching element Q ₃ → circulating diode D ₂ → capacitor C ₂ → input Rectifier diode → current I _B3 flows through the path of step-up inductor L _B3 ′ and is reset.

14A to 14C are respective experimental operation waveforms when controlling output voltages of 200 Vdc, 300 Vdc, and 430 Vdc at 2 kW output load conditions, and the voltage of the three-phase single power stage AC-DC converter of FIG. 10 and It is a graph showing the experimental results of measuring the current, and FIG. 15 is a graph showing the experimental results comparing the conversion efficiency and the total harmonic distortion characteristics according to the load capacity of the three-phase single power stage AC-DC converter of FIG. 10.

In the experiments of FIGS. 14 and 15, the main ratings and transformer parameters are shown in Table 2.

Main rating Input line voltage (V _LL ) 220 V _AC Output voltage (V _O )/Output current (I _OMAX ) 200 V _DC /10A, 430 V _DC /4.65A (2kW) Switching frequency (fs)/resonant frequency (fr) 108.28 kHz/106.6 kHz Applied device Switching elements (Q ₁ to Q ₄ ) SCT3030AL (650 V/70 A/30 mΩ) Input rectifying diode GP2D050A120B[1200V/50A/1.6A/SIC] Primary-side circulation diodes (D ₁ to D ₂ ) GP2D050A060B[600V/50A/1.45A/SIC] Secondary output diode GP2D050A060B[600V/50A/1.45A/SIC] parameter La to Lc
C _Fa to C _Fc
L _B1 to L _B3 0.94 mH
2.86 uF
35 uH Cr1 to Cr2 / C _F 200nF / 2.2 uF Transformers 1/2 side magnetic inductance L _P /L _S 55.6 uH / 56.1 uH Equivalent leakage inductance L _eq 56.1 uH Turn-defense n _b1 (N _P1 /N _S2 ) 1 (8T/8T)

14A to 14C show the step-up inductor current (I _LB1 ), the phase voltage (Va), the phase current (Ia), the link voltage (V _Link ) and the LLC transformer of the three-phase single power stage AC-DC converter 1000. The primary and secondary voltages/currents of FIG. 15 and the experimental results of FIG. 15 indicate conversion efficiency characteristics and total harmonic distortion (THD) of each three-phase single power stage AC-DC converter 1000 by output voltage.

14A to 14C, referring to each (a), in the three-phase single power stage AC-DC converter 1000, the step-up inductor current I _LB1 is the control range of all output voltages (200 to 430 V _dc for improving the input power factor). ) And a phase current operated in Discontinuous Conduction Mode (DCM) at rated load and filtered through input filters (i.e., filter capacitors (C _Fa to C _Fc ) and filter inductors (L _Fa to L _Fc )) Ia) is a sinusoidal current waveform, and it can be seen that the input phase voltage Va and phase current Ia are controlled in phase.

Also, referring to (b) of each of FIGS. 14A to 14C, the primary terminal voltage V _ac and current I _T1P of the transformer T ₁ , the secondary terminal voltage V _fg and current I _T1S ), it can be seen that the switching element is soft-switched.

In order to improve the total harmonic distortion (THD), the boosting inductors L _B1 to L _B3 are designed to always operate in the Discontinuous Conduction Mode (DCM).

15, the maximum efficiency of the three-phase single power stage AC-DC converter 1000 at 200 V _dc output voltage and 500 W load condition was measured to be 94%, and all output voltages (200 to 430 Vdc) and load The average efficiency in the range (500 to 2000 W) was measured to be 91.58%. In addition, the lowest total harmonic distortion rate THD was the lowest at 1.89% at 430 Vdc output voltage and 2000 W load.

16 is a view showing an example of a single-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment.

Referring to FIG. 16, the single-phase single-power stage AC-DC converter 1600 is not a three-phase input power source, unlike the three-phase single-power stage AC-DC converter 1000 of FIG. 10 to improve conversion efficiency. The main difference is that it operates from a single-phase input power supply, and the overall operation mode and characteristics are the same. Hereinafter, a single phase single power stage AC-DC converter 1600 according to another aspect of the present embodiment will be described based on the differences.

Single-phase single power stage AC-DC converter 1600, filter capacitors (C _Fa and C _Fb ) and filter inductors (L _Fa and L _Fb ), step-up inductors (L _B1 and L _B2 ), input rectifying diodes (D _R1 to D _R4 ) and a DC-DC converter 1610.

The filter capacitors (C _Fa and C _Fb ) and the filter inductors (L _Fa and L _Fb ) are connected to a single-phase input terminal (Vac) to improve input power factor and total harmonic distortion (THD).

The neutral point N of the filter capacitors C _Fa and C _Fb is connected to a node a between the source of the switching element Q2 and the drain of Q3.

In addition, the single-phase single-power stage AC-DC converter 1600, for insulated DC-DC conversion, transformers (T1, T2) and resonant capacitors (C _r1 , C _r2 ), voltage divider capacitors (C _B1 to C _B4 ) It comprises two resonant tanks (ie, resonant tank l (1611, Res. Tank 1), resonant tank 2 (1613, Res. Tank 2)). Here, each resonant tank (1611, 1613) is a transformer (T1, according to the constant switching frequency of switching elements Q ₁ to Q ₄ alternately operated at a duty ratio of 50% regardless of the phase control of the DC-DC converter 1610) A voltage according to the gain characteristic is applied to the secondary side of T2).

The secondary-side rectifying unit 1615 performs individual rectifying operations by each rectifying diode, but may perform stable rectifying operations without current imbalance depending on a series connection operation.

The secondary side rectifying unit 1615 may be implemented in various forms, such as a half-bridge rectifying circuit (a), a full-bridge rectifying circuit (b), and a center tap rectifying circuit (c), as described above with reference to FIG. 11. have. However, it should be noted that this is an example, and the present embodiment is not limited thereto.

In the single-phase single power stage AC-DC converter 1600 described above, i) Unlike the conventional three-level AC-DC converter, the primary switching elements Q ₁ to Q ₄ are operated at all input voltage and load conditions. Voltage Switching (ZVS) is possible, and ii) secondary rectifier diodes (D _r1 to D _r6 ) are also capable of soft switching, so surge voltage is not applied, so snubber is unnecessary. It has the advantage that it can be operated at a high switching frequency and is suitable for high integration.

In addition, the single-phase single power stage AC-DC converter 1600 controls the link voltage V _Link through a phase control to correspond to a wide output voltage range, and the secondary side voltage of the LLC resonant converter 1610 operating at a constant switching frequency. / By configuring to control the current, there is an advantage of controlling the output voltage in a wide range of 2 times or more without a step-up converter to improve the input power factor.

The operation mode of the single-phase single power stage AC-DC converter 1600 according to another aspect of this embodiment is as illustrated in FIG. 17. Specifically, FIGS. 18A to 18G show current paths in operation modes 1 to 7 of the single-phase single power stage AC-DC converter of FIG. 16.

The operation mode of the single-phase single power stage AC-DC converter 1600 is similar to the operation mode of the three-phase single power stage AC-DC converter 1000 described above with reference to FIG. 10, and zero voltage switching (ZVS) ) The operation mode (ie, operation modes 1, 3, and 5) of the remaining sections except for the dead time period in which the operation occurs will be described in detail.

Operation mode 1(Mode 1)-'t0~t1' section

FIG. 17 is a diagram showing an operating waveform of the single-phase single power stage AC-DC converter of FIG. 16, and FIG. 18A is a diagram showing a current path in operation mode 1 of the single-phase single power stage AC-DC converter of FIG. 16.

Referring to FIGS. 17 and 18A, since switching elements Q ₁ and Q ₂ are turned on in a period't0 to t1', the resonant tanks 1611 and 1613 have l/4 of the link voltage (ie, V _Link / 4) Resonant currents (I _T1 , I _T2 ) flow through each applied, and resonant current flows individually through the secondary-side output rectifier 1615, but the secondary-side rectifier consists of a series connection, so the secondary-side output without current imbalance Power is delivered to. Further, the switching elements Q ₁ and Q ₂ is turned on, because they are on the boost inductor (L _B1) is applied to the filter capacitor voltage V _CFa 'filter capacitor C _Fa → boost inductor L _B1 → input rectifier diode → the switching element Q ₁ → switching element Q ₂ → current flows through the path of the filter capacitor C _Fa ′, and energy is accumulated in the boost inductor (L _B2 ) _.The accumulated voltage of the filter capacitors (V _CFa +V _CFb ) and the link voltage ( V _Link ) is reduced to 0 by the differential voltage and reset.

Operation mode 3(Mode 3)-'t2~t3' section

FIG. 18C is a diagram showing the current path in operation mode 3 of the single-phase single power stage AC-DC converter of FIG. 16.

Referring to FIGS. 17 and 18C, the switching element Q ₄ is turned on at a zero voltage at the time't2', and the resonance tank 1 (1611) in the section't2 to t3' is (l/4)V _Link as before. Although a voltage is applied, the polarity of the resonance tank 2 1613 changes (-l/4) V _Link voltage to transmit an idle current to the secondary output rectifier 1615 and energy to the secondary output terminal.

At this time, the energy stored in step-up inductor L _B1 in operation mode 1 _is'filter capacitor C _Fa → step-up inductor L _B1 → input rectifying diode → capacitor C1 → circulating diode D1 → switching element Q ₂ → filter capacitor C _Fa The current flows through the path of and is reset.

In addition, the energy previously stored in the step-up inductor L _B2 is reduced to zero by the difference voltage between the sum voltage (V _CFa +V _CFb ) of the filter capacitors and the link voltage (V _Link ) and is reset.

Operation mode 5(Mode 5)-'t4~t5' section

FIG. 18E is a diagram showing the current path in operation mode 5 of the single-phase single power stage AC-DC converter of FIG. 16.

17 and 18E, the switching element Q ₃ is turned on at a zero voltage at the time't4', and the switching elements Q ₃ and Q ₄ are turned on at the period't4 to t5', which is the primary side. The resonant tanks 1611 and 1613 are supplied with 1/4 of the link voltage (that is, V _Link /4) and power is transmitted to the secondary output terminal.

At this time, since the switching elements Q ₃ and Q ₄ are turned on, the step-up inductor L _B2 is the path of the filter filter C _FB → the switching element Q ₃ → the switching element Q ₄ → the input rectifying diode → the step-up inductor L _B2 '. The current I _LB1 of the step-up inductor L _B1 is reduced to zero and reset by the difference voltage between the sum voltage (V _FCa +V _FCB ) and the link voltage (VLink) of the filter capacitors as the current I _B2 flows.

19 is a view showing an example of a three-phase single power stage AC-DC converter to which a secondary-side 3-bridge rectifying diode circuit according to another aspect of the present embodiment is applied, and FIG. 20 is 2 of the AC-DC converter of FIG. It is a diagram showing an example in which the rectifier of the vehicle side is constituted by a center-tap rectifying diode circuit.

First, referring to FIG. 19, the three-phase single power stage AC-DC converter 1900, in order to expand the output voltage control range and improve conversion efficiency, the three-phase single power stage AC-DC converter 1000 of FIG. Unlike ), a 3-bridge rectifier diode is used as the secondary-side output rectifier diode circuit configuration. The three-phase single power stage AC-DC converter 1900 not only changes the link stage voltage (V _LINK ) according to the phase shift D of the primary three-level converter, but also the voltage of the secondary three-bridge diode rectifier ( Since V _o ) can also be changed to control the gain, the output voltage (V _o ) control range can be further extended. Accordingly, the three-phase single power stage AC-DC converter 1900 can apply a lower link stage voltage (V _LINK ) than the AC-DC converters illustrated in FIGS. 5 and 10, so that the input stage boost inductors L _B1 to L _B3 ) Can be designed and applied with a large value, thus improving efficiency can be expected. The three-phase single power stage AC-DC converter 1900 has a phase difference (G _Q1 /G _Q2 , G _Q4 /G _Q3 ) of the gate driving signal of the switching element when compared with the AC-DC converters of FIGS. 5 and 10. Phase Shift) The overall operation mode and characteristics are the same, including the characteristics of the primary operation mode, except that the operation characteristics of the secondary 3-bridge rectifying diode rectifying unit according to D control are different.

Hereinafter, the three-phase single power stage AC-DC converter 1900 to which the three-bridge output rectifying diode is applied will be described based on the above-described differences.

The three-phase single power stage AC-DC converter 1900 includes filter capacitors (C _Fa to C _FC ) and filter inductors (L _Fa to L _Fc ), step-up inductors (L _B1 to L _B3 ), and input rectifying diodes (D _R1) To D _R6 ) and a DC-DC converter 1910. The filter capacitors (C _Fa to C _FC ) and the filter inductors (L _Fa to L _Fc ) are connected to the three-phase input terminals (Va to Vc) to improve input power factor and total harmonic distortion. The neutral point N of the filter capacitors C _Fa to C _FC is connected to a node a between the source of the switching element Q2 and the drain of Q3.

In addition, the three-phase single power stage AC-DC converter 1900, for the insulated DC-DC conversion, transformers (T1, T2) and resonant capacitors (C _r1 , C _r2 ), voltage divider capacitors (C _B1 to C _B4) ) Includes two resonance tanks, namely, resonance tank l (1911) and resonance tank 2 (1913). The voltage polarity applied to the transformers T1 and T2 of the resonant tank 1 (1911) and the resonant tank 2 (1913) is changed according to the phase shift D control of the primary-side 3-level converter. The secondary winding of the transformer connected to the 3-bridge rectifier diode circuit operates as a series connection or parallel connection, and a load resonance current is supplied to the output terminal. In this case, the load resonance current is transmitted to the secondary 3-bridge rectifying diode as a series connection or parallel connection, but the secondary 3-bridge rectifying diode can perform a stable rectifying operation without current imbalance.

The three-phase single power stage AC-DC converter 1900 described in FIG. 19 can be applied by configuring the secondary-side rectifier as a center-tap rectifying diode circuit as shown in FIG. 20, except for the secondary-side rectifier circuit configuration. Since the overall operation mode and characteristics are the same, a separate description will be omitted.

The three-phase single power stage AC-DC converter 1900 to which the three-bridge output rectifying diode described above is applied, i) Unlike the conventional three-level AC-DC converter, primary-side switching elements (Q ₁ to Q ₄ ) They are capable of zero voltage switching (ZVS) under all input voltage and load conditions, and ii) Secondary 3-bridge output rectifying diodes (D _r1 to D _r6 ) and soft switching are also possible, resulting in surge Since a voltage is not applied, a snubber is unnecessary, and thus it is possible to operate at a high switching frequency and is suitable for high integration.

In addition, the three-phase single-power stage AC-DC converter 1900 to which the 3-bridge output rectifying diode is applied has a link voltage V _Link and a secondary side 3-bridge output rectifier voltage through phase D control to correspond to a wide output voltage range. By controlling V _o together, it is configured to control the secondary side voltage/current of the AC-DC converter 1910 operating at a constant switching frequency, so that it can be operated in a wider range of 2 times or more without a boost converter to improve the input power factor. There is an advantage that can control the output voltage.

Hereinafter, with reference to FIGS. 21, 22A to 22G, the operation mode of the three-phase single power stage AC-DC converter 1900 to which the secondary-side three-bridge rectifying diode is applied according to another aspect of the present embodiment will be described in detail. I will explain.

For reference, the operation mode of the three-phase single power stage AC-DC converter 1900 to which the secondary three-bridge rectifier diode is applied is the operation of the three-phase single power stage AC-DC converter 1000 described above with reference to FIG. 10. Since it is similar to the mode, the operation mode (that is, operation) of the output terminal of the secondary 3-bridge rectifier circuit is excluded, except for the dead time period where the zero voltage switching (ZVS) operation occurs and the primary boosting inductor operation and the resonance current operation mode. Modes 1, 3, and 5) will be mainly described.

Operation mode 1(Mode 1)-'t0~t1' section

21 is a diagram showing the operating waveforms of the three-phase single power stage AC-DC converter of FIG. 19, and FIG. 22A is a diagram showing the current path in operation mode 1 of the three phase single power stage AC-DC converter of FIG. 19. . The operation of the 3-bridge diode rectifying circuit will be briefly described.

21 and 22A, since switching elements Q ₁ and Q ₂ are turned on in a period't0 to t1', resonant tanks 1911 and 1913 have l/4 of link voltage (ie, V _Link / 4) Resonant current (I _T1 , I _T2 ) flows through each, and'winding N _S2 → winding N _S1 → rectifying diode D _r1 → output capacitor through output rectifier 1915 with secondary 3-bridge rectifying circuit C _O and load → Rectifying diode D _r6 → Winding resonant current flows in the path of N _S2 '. At this time, according to the polarity of the individual windings of the secondary side (N _Sl , N _S2 ), since the secondary side rectifier is configured in series, power can be transmitted to the secondary side output terminal without current imbalance.

Operation mode 3(Mode 3)-'t2~t3' section

22C is a diagram showing the current path in operation mode 3 of the three-phase single power stage AC-DC converter of FIG. 19.

Referring to FIGS. 21 and 22C, the switching element Q ₄ is turned on at a zero voltage at the time't2', and the resonance tank 1 (1911) in the section't2 to t3' is (l/4)V _Link as before. The voltage is applied, but the resonant tank 2 (1913) is reversed in polarity, and a (-l/4) V _Link voltage is applied to transmit an idle current to the secondary-side output rectifier 1915 and energy to the secondary-side 3-bridge rectifier circuit output terminal. To pass.

At this time, the secondary side rectifying unit 1915 having a 3-bridge diode rectifying circuit according to the polarity of the individual windings of the secondary side (N _Sl , N _S2 ) i)'winding N _S1 → rectifying diode D _r1 → output capacitor C _O and Load → Rectifying diode D _r4 → Path of winding N _S1 ′, ii)'Reel N _S2 → Rectifying diode D _r5 → Output capacitor C _O and Load → Rectifying diode D _r4 → Winding N _S2 ' Resonant current flows. However, since it has been previously operated in series, power is transferred to the secondary output without significant current imbalance.

Operation mode 5(Mode 5)-'t4~t5' section

22E is a diagram showing the current path in the operation mode 5 of the three-phase single power stage AC-DC converter of FIG. 19.

Referring to FIGS. 21 and 22E, the switching element Q ₃ is turned on at zero voltage at the time't4', and the switching elements Q ₃ and Q ₄ are turned on in the period't4 to t5' as the primary side resonance. Tanks 1911 and 1913 are supplied with 1/4 of the link voltage (that is, -V _Link /4), resonant currents (I _T1 and I _T2 ) flow, and power is transferred to the output terminals of the secondary 3-bridge rectifier circuit. .

At this time, in the output rectifying unit 1915 having a secondary-side three-bridge diode rectifying circuit, according to the polarity of the secondary individual windings of the transformer (N _S1 ，N _S2 ),'winding N _S1 → winding N _S2 → rectifying diode D _r5 → Output capacitor C _O and load → Rectifying diode D _r2 → Winding resonance current flows in the path of winding N _S1 '. Depending on the polarity of the individual windings of the secondary side (N _Sl , N _S2 ), the secondary side rectifier is configured in series, so power can be transmitted to the secondary side output terminal without current imbalance.

Hereinafter, application examples of AC-DC converters according to the present embodiment will be described with reference to FIGS. 23 to 27.

23 shows an application example of the three-phase single power stage AC-DC converter 1000 of FIG. 10 as a three-phase input interleaved single power stage AC-DC converter capable of selective multiload control, and FIG. 24 shows a single phase capable of selective multiload control The input interleaved single power stage AC-DC converter shows an application example of the single phase single power stage AC-DC converter 1600 of FIG. 16.

FIG. 25 shows an application example of the three-phase single power stage AC-DC converter 500 of FIG. 5 to wireless power transmission, and FIG. 26 shows the wireless power of the three phase single power stage AC-DC converter 1000 of FIG. 10. An application example for transmission is shown. In particular, in the application example of FIG. 26, non-contact transformers wound at right angles (Np1/Np2, NS1/NS2) may be applied to the primary and secondary ferrite cores, respectively. 27 shows an application example of the three-phase single power stage AC-DC converter 2300 of FIG. 23 to wireless power transmission.

Since the single power stage AC-DC converter proposed in the present invention basically controls the power through phase control at a constant switching frequency near the resonance frequency based on the 3-level LLC resonance converter, load dependence on the resonance gain characteristics It is small and easy to increase capacity. In addition, the single power stage AC-DC converter proposed in the present invention has the advantage of being capable of high-efficiency high-frequency switching operation by performing zero voltage switching of the primary-side switching element and zero current switching of the secondary-side rectifying diode.

23 and 24, the application circuits 2300 and 2400 of the single power stage AC-DC converters have two single power stage AC-DC converters operating in separate current discontinuous mode (DCM) for high integration. By interleaved, I _A (I _B1 +I _B4 ), I _B (I _B2 +I _B5 ), and I _C (I _B3 +I _B6 ), which are the total currents of each converter, operate in the same way as the current continuous mode. , It has the advantage of reducing the size of the input filter (ie, filter capacitor and filter inductor) and improving the waveform of the AC input current (ie, Ia to Ic).

In summary, the single power stage AC-DC converter according to the embodiments of the present invention may be applied to a power supply device to which a contact transformer is applied as in the application examples of FIGS. 23 and 24, and FIGS. 25 to 27 As an application example, it may be applied to a power supply device for wireless power transmission to which a non-contact transformer is applied.

28 is a diagram showing another example of a three-phase single power stage AC-DC converter having two resonant tank circuits according to another aspect of the present embodiment.

28, the three-phase single power stage AC-DC converter 2800, unlike the three-phase single power stage AC-DC converter 1000 of FIG. 10, has two resonant capacitors Cr1 and Cr2, Cr3, and Cr4) is implemented by two resonant tanks (Resonant Circuit 1 (Res. Tank 1), Resonant Circuit 2 (Res. Tank 2)).

In each resonant tank 2811, 2813, two resonant capacitors are commonly connected to one end of the resonant tank. And, the flying capacitor C _B is a node between the source terminal of the first switching element Q1 and the drain terminal of the second switching element Q2, and the source terminal of the third switching element Q3 and the fourth switching It is connected between nodes between the drain ends of the device Q4.

Except for these matters, the operation contents of the three-phase single power stage AC-DC converter 2800 of FIG. 28 are the same as the three-phase single power stage AC-DC converter 1000 of FIG. 10, so a separate description is omitted. Shall be

In embodiments and applications of the present invention, the resonant tank of the single power stage AC-DC converter, as shown in FIG. 29, is a series resonant circuit (a), a series-parallel resonant circuit (b) and a parallel-parallel It may be implemented using various resonant circuits such as the resonant circuit (c). However, it should be noted that this is exemplary and does not limit the present embodiment.

The above description is merely illustrative of the technical idea of the present embodiment, and those skilled in the art to which this embodiment belongs will be capable of various modifications and variations without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical spirit of the present embodiment, but to explain, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of the present embodiment should be interpreted by the claims below, and all technical spirits within the equivalent range should be interpreted as being included in the scope of the present embodiment.

Claims (17)

delete delete delete delete delete Single power stage AC-DC converter,
An input filter connected to a three-phase or single-phase AC power to receive AC power, and to improve the input power factor and total harmonic distortion of the AC power;
An input rectifying unit rectifying AC power transmitted through a plurality of step-up inductors connected to the input filter and converting it into DC power; And
It includes a DC-DC converter for converting and outputting the level of the DC power,
The DC-DC converter,
A plurality of input capacitors and a plurality of switching elements respectively connected in series to a link terminal, a first resonant tank and a second resonant tank connected to at least one of the plurality of switching elements-the first resonant tank and Each of the second resonant tanks includes a transformer, a resonant capacitor, and first to fourth voltage divider capacitors, and applies voltage to a secondary winding of the transformer according to alternating switching operations and phase control of a plurality of switching elements. Primary circuit; And
And a secondary output rectifying unit including a plurality of diodes that are connected to the secondary winding of the transformer and rectify the resonance load current individually.
Single power stage AC-DC converter. The method of claim 6,
The plurality of boosting inductors,
In order to improve the input power factor, a step-up operation is performed in a Discontinuous Conduction Mode (DCM).
Single power stage AC-DC converter. The method of claim 6,
The plurality of switching elements,
Characterized in that it performs a soft switching operation under all input voltage and load conditions.
Single power stage AC-DC converter. The method of claim 6,
The input capacitors include a first input capacitor and a second input capacitor,
The common end of the first input capacitor and the second input capacitor is connected to at least one of the plurality of switching elements through each of the first and second cyclic diodes.
Single power stage AC-DC converter. The method of claim 9,
The plurality of switching elements include first to fourth switching elements,
The cathode of the first circulation diode is connected to a node between a source terminal of the first switching element and a drain terminal of the second switching element,
The anode of the second circulation diode is connected to a node between the source terminal of the third switching element and the drain terminal of the fourth switching element.
Single power stage AC-DC converter. The method of claim 9,
The input filter includes a filter capacitor and a filter inductor,
The midpoint N of the filter capacitor is connected to a node between the source terminal of the second switching element and the drain terminal of the third switching element.
Single power stage AC-DC converter. The method of claim 10,
The first voltage divider capacitor, one end is connected to a node between the source end of the first switching element and the drain end of the second switching element, the other end is connected to the common end of the first resonant tank and the second resonant tank And
The second voltage divider capacitor has one end connected to a node between a source end of the third switching element and a drain end of the fourth switching element, and the other end is connected to a common end of the first resonant tank and the second resonant tank. And
The third voltage dividing capacitor, one end is connected to the drain end of the first switching element, the other end is commonly connected to one end of the second resonant tank and one end of the fourth voltage dividing capacitor,
The fourth voltage divider capacitor is characterized in that one end is connected to the source end of the fourth switching element, and the other end is commonly connected to one end of the third voltage divider capacitor and one end of the second resonant tank.
Single power stage AC-DC converter. The method of claim 6,
The secondary output rectifying unit,
Parallel to both ends of the output voltage VBAT,
Characterized in that it comprises an output capacitor, a load resistor, the first to fourth diodes connected in series and the fifth and sixth diodes connected in series.
Single power stage AC-DC converter. The method of claim 6,
The secondary output rectifying unit,
Characterized in that it is implemented as one of three-bridge rectifier circuit, half-bridge rectifier circuit, full-bridge rectifier circuit and center tap rectifier circuit.
Single power stage AC-DC converter. A power supply including two single power stage AC-DC converters,
Each of the two single power stage AC-DC converters,
An input filter for receiving AC power and improving the input power factor and total harmonic distortion of the AC power;
An input rectifying unit rectifying the AC power transmitted through a plurality of boosting inductors connected to the input filter and converting the AC power into DC power; And
It includes a DC-DC converter for converting and outputting the level of the DC power,
Each of the DC-DC converter,
A plurality of input capacitors and a plurality of switching elements connected in series to a link terminal, and two resonant tanks connected to at least one of the plurality of switching elements-the resonant tank includes a transformer, a resonant capacitor and A primary circuit including a first to fourth voltage dividing capacitors, wherein voltage is applied to a secondary winding of the transformer according to an alternate switching operation of a plurality of switching elements;
And a secondary output rectifying unit connected to the secondary winding of the transformer and including a plurality of diodes that individually rectify the resonant load current,
The two single power stage AC-DC converters,
It characterized in that to reduce the current ripple (ripple) of the input terminal and the output terminal by interleaved (interleaved) operation in common with the input filter
Power supply. The method of claim 15,
The plurality of boosting inductors,
In order to improve the input power factor, a step-up operation is performed in a Discontinuous Conduction Mode (DCM).
Power supply. The method of claim 15,
The transformer,
Characterized in that it is a loosely coupled transformer for contact power transmission and wireless power transmission.
Power supply.

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