TW398110B - Adjustable 3-phase voltage buck-and-boost AC/DC converter - Google Patents

Abstract

This invented device consists of a conventionally used power semi-conductor switch, electric inductor, capacitor and a set of converter control circuit. It converts the input 3 phase AC power source to a DC voltage output. Another feature is the utilization of balanced 3-phase voltage. Its 120-degree phase shift to each other different six zones for the balanced 3-phase voltage within one cycle the positive and negative peak voltages for each phase. According to the characteristic for the different zones, the conductive status of the six semi-conductor switching elements for 3 phase full bridge type inverter structure is determined. Input side 3 phase currents are all sinusoidal waves with unit power factors that obtains a voltage DC output voltage.

Description

A7 B7 Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs V. Invention Description (1) One of the main motivations for the application of this invention was one of the applicants. In view of the current state's vigorous promotion of the concept of intellectual property rights, and the domestic industry Due to the great oppression from abroad, in particular, some of the results of the doctoral students under their guidance are applied before they are published in international academic journals, which will help to establish localized technology, and at the same time, from the perspective of education This view allows students to understand the process of patent application, and by letting them share the results, they can also inspire their creativity and invention ability in the future, so that they can apply for the invention. The invention relates to a three-phase AC-to-DC converter, in particular to a three-phase step-up / step-down AC-to-DC converter that can obtain high efficiency by using a single-stage converter, especially having both phases of current Both are sine waves and are unit power factor. The three-phase AC-to-DC converter with unit power factor mentioned here is used in, for example, a DC motor driver, a DC-link type AC-to-AC converter, or a stage that requires a stable DC power supply. Generally used three-phase AC to DC converter, its power factor often changes greatly due to the difference in load and heavy harmonics. If it needs to have the function of step-up / step-down, it usually requires two-stage conversion. Devices are connected in series to achieve. That is, the first stage performs rectification and power factor correction first, and the second stage is another DC / DC converter (DC / DC CONVERTER) for the DC voltage with step-up / step-down function, so it is difficult to achieve high efficiency. . Figure 1 shows the single-phase three-phase step-down / boost AC-to-DC converter architecture commonly used in related literature. The waveforms of the input voltage of phase a and the input current without high-frequency filter are shown in Figure 2. Although this type of three-phase AC to DC converter also has a step-up / step-down function, because the input a-current works in discontinuous mode, each component must have a higher rated voltage and current peak stress. Paper size is applicable to Chinese National Standard (CNS) A4 (210X297mm) J --------- \ installation— (please read the precautions on the back before filling this page). Central Bureau of Standards, Ministry of Economic Affairs A7 B7 printed by Beigong Cooperative Co., Ltd. 5. Description of the invention (2) As a result, the effective utilization of each component is low and serious electromagnetic interference. Harmonic pollution and low power factor. In addition, additional high-frequency input filters and auxiliary switching circuits are required to avoid the short circuit of the power supply when the switching elements (such as S1 and S3) are turned on simultaneously. Therefore, the present invention addresses the above-mentioned disadvantages and further improves it, thereby developing the device of the present invention. (Explanation of the invention) The main object of the present invention is to provide a three-phase AC-to-DC converter device to improve the shortcomings of the existing three-phase AC-to-DC converter, and by a simple and practical circuit device, In order to supply a stable and step-up / step-down DC voltage, and at the same time achieve the effect of high efficiency, unit power factor and three-phase input current are sine waves, and the semiconductor power components can be fully utilized. First, by using the characteristic that the balanced three-phase voltages are phase-shifted by 120 degrees with each other, one cycle of the balanced three-phase voltages can be divided into six different intervals according to the most positive or negative of the voltage of each phase. Cooperate with the common sine pulse modulation (SPWM) technology to control the on-state of the six switching elements of the inverter architecture. When the control signals of the upper or lower arm switching elements of the three arms of the inverter architecture are turned on at the same time, the energy at the input end is stored in the three-phase full-bridge inverter through the three-phase full-bridge inverter architecture. Three inductors between the inductor architecture and the input. At the same time, the energy stored in the capacitor is discharged to the filter capacitor and the load through a filter inductor. And when the control signals of the upper or lower arm switching elements of the three arms of the inverter architecture are not on at the same time, the energy stored in the three-phase inductor is discharged to the capacitor through the power diode; at the same time stored in the filter inductor The energy of the device is also discharged to the filter capacitor and the load through the same power diode. Its characteristics are the three-phase power supply (please read the precautions on the back before filling this page)

Printed by the Central Standards Bureau of the Ministry of Economic Affairs, Shellfish Consumer Cooperative A7 _B7_ V. Description of the invention (3) Six semiconductor switching elements of a three-phase full-bridge inverter architecture are appropriately controlled so that the current of the three-phase power supply is a sine wave And achieve the effect of the unit power factor, at the same time have the function of raising or lowering the DC output voltage. Other objects and advantages of the present invention can be understood with reference to the following detailed description of the accompanying drawings. (Illustration) First, the description of each figure is shown as follows: Figure 1: Single-phase three-phase buck / boost AC to DC: converter (buckboost type) architecture commonly used in related literature. Figure 2: Waveform of input voltage a and input current without high-frequency filter in phase 1. Figure 3: A block diagram showing a schematic system of the present invention. Figure 4: A detailed physical structure diagram of the present invention. Figure 5: A functional block diagram of the controller of the present invention. < Figure 6: Schematic diagram showing the three-phase input voltage waveform. Figure 7: The device of the present invention selects control strategy 1 (ie, control signal G = 1) and is in interval 2 (ie, control signals Fa = 1, Fb = 0, Fc = 0) and control signals Ca = l, Cb = When 0, Cc = 0, the semiconductor switching elements SI, S4, and S6 are turned on; 5 This paper size applies the Chinese National Standard (CNS) A4 specification (21〇 '乂 297 mm) 1.1 ... ^ ----- install ------- Order ---.----- line (please read the precautions on the back before filling this page) Printed by the Central Standards Bureau of the Ministry of Economy, Shellfish Consumer Cooperative, A7 _ B7___; _ V. Invention Explanation (4) S2, S3, and S5 are truncated. At this time, the equivalent circuit of the circuit of the device of the present invention. Figure 8: The device of the present invention selects control strategy 1 (ie, control signal G = 1) and is in interval 2 (ie, control signals Fa = 1, Fb = 0, Fc = 0) and control signals Ca = l, Cb = 〇, Cc = 1, the semiconductor switching elements SI, S4 and S5 are turned on; S2, S3 and S6 are cut off, and the equivalent circuit of the circuit of the device is invented at this time. Figure 9: The device of the present invention selects the control strategy U, that is, the control signal G = 1) and is in the interval 2 of Figure 6: (that is, the control signals Fa = 1, Fb = 0, Fc = 0) and the control signals Ca = 1, Cb = l, when Cc = 0, the semiconductor switching elements S1, S3, and S6 are turned on; S2, S4, and S5 are turned off, and the equivalent circuit of the circuit of the device of the present invention at this time. Figure 10: The device of the present invention selects control strategy 1 (that is, the control signal G = 1) and is in the interval 2 of FIG. 6 (that is, the control gun number Fa = 1, Fb = 0, Fc = 0) and the control signals Ca = 1, Cb When = 1, Cc = l, the semiconductor switching elements S1, S3, and S5 are turned on; S2, S4, and S6 are turned off, and the equivalent circuit of the circuit of the device of the present invention at this time. Figure 11: The device of the present invention selects control strategy 1 (ie, control signal G = 1) and is in interval 2 (ie, control signals Fa = 1, Fb = 0, Fc = 0) and control signals C a = 0, When C b = 1 (or C b = 0) and Γ c = 1 (or C c = 0), the semiconductor switching elements SI, S2, S3, S4, S5, and S6 are turned on. At this time, the present invention_6_ This paper The scale is applicable to China National Standard (CNS) A4 specification (210X297 mm) ------- ^ ----------- Order -------- line (please read the first Note this page, please fill out this page) B7 V. Description of the invention (5) Equivalent circuit of the device circuit. Fig. 12: Three-phase current measurement waveform diagram of the device of the present invention. Fig. 13: Measured waveforms of phase a voltage and current of the device of the present invention. The numbers of the block diagrams in the above figures are not as follows. 11: Represents a three-phase high-frequency LC filter. 12,74: Represents the architecture of a three-phase full-bridge inverter. 13,71,72,73,77: Indicates inductors. 14,76: power diode. 15,78: Represents a filter capacitor. 16,79: indicates the load. 75: indicates a capacitor. Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the notes on the back before filling out this page) (Detailed description of the invention) This paper size applies the Chinese National Standard (CNS) A4 (210X297 mm) Central Standard of the Ministry of Economics A7__B7__ printed by the local shellfish consumer cooperative V. Description of the invention (6) First, please refer to FIG. 3 which is a schematic system block diagram of the present invention. As shown in Figure 3, the energy of the input three-phase AC power supply (212) is transferred to the DC voltage Vo output terminals (79a, 79b) through a controlled three-phase AC-DC converter (211). A load (79) is connected in parallel to the output terminals (79a, 79b) to obtain the required energy. The present invention further includes a converter control circuit (213), and its detailed functional block diagram is shown in Figure 5. The working principle of the present invention can be understood from the following description. The detailed description of the converter control circuit (213) in the third figure is shown in Figure 5. The inverting input terminal of the adder (26) in Fig. 5 is a signal indicating the size of the converter output voltage, and the non-inverting input terminal of the adder is the reference signal F of the output voltage. , #. The adder (26) generates a voltage error signal & controls an output voltage to a set value through an output voltage regulator (30) (e.g., a PI controller). Whether the voltage error is positive or negative determines that the converter works in rectification or power return mode. The control signal and the three-phase unit phase voltage V% detected by the voltage detector (36), and vOT are sent to the multipliers (27), (28), and (29), respectively. The phase reference current commands <, <, (after that, they are sent to the non-inverting input terminals of the adders (23), (24) and (25) respectively. At the same time, the adders (23), (24) and ( The reverse input terminals of 25) respectively receive the three-phase actual current signals L44, and then the adders (23), (24), and (25) generate the current error signal cores, respectively, and the cores are sent to the current regulators (30), (3 1) and (32) (for example, PI controller), the output signals of the current regulators (30), (31), and (32) are passed through the high-frequency triangle wave generated by the high-frequency triangle wave generator (50) respectively. The comparators (51), (52), and (53) compare and generate control signals Ca, Cb, and Cc, and then send them to the input terminals 3d: 3e, 3f of a drive signal selector (33). At the same time, the voltage detection The three-phase phase voltages va „, ve„ detected by the tester (36) are sent to the three-phase zero-point detection circuit (60), and the output is 8_ This paper size is applicable to the Chinese national standard (CNS) A4 specification (210X297mm) I—I II and order line (please read the notes on the back before filling this page) A7 B7 V. Description of the invention (7) The access signals Fa, Fb and Fc, also separately Send to the input terminals 3a, 3b, 3c of the drive signal selection controller (33). At the same time, the output signal command (G) of the control strategy selector (44) is also sent to the input terminal 3 of the drive signal selection controller (3 3) g. The driving signal selection controller (33) determines the driving signals of the six power semiconductor switching elements (81, 32, 83, 84, 35, 86) via the driving signal selector (3 3) according to the state of the control signal G. , And then send them into the conventional three-phase power semiconductor switch driver (34) to control the on / off action of six power semiconductor switching elements (31, 32, 83, 84, 85, 86), thus completing the entire converter It can be seen from the above description that the entire working principle is not complicated, and the physical production is quite easy. The main circuit of the adjustable three-phase step-up / step-down AC / DC converter used in the device of the present invention is shown in the fourth figure. The trigger circuit of each semiconductor switching element is a conventional one. The wide modulation circuit has the advantages of simple control and fixed switching frequency. As for the switching decision of the six semiconductor switching elements of the three-phase full-bridge inverter architecture, the balanced three-phase voltage is shifted by 120 degrees from each other. One cycle of the balanced three-phase voltage can be divided into six different intervals as shown in Figure 6 according to the most positive or negative voltage of each phase, and then according to the characteristics of the different intervals and the actual feedback current error. (Please read the notes on the back before filling in this note), -rr Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. Cb, Cc, Fa, Fb, Fc and G are expressed as follows: 9 This paper size is applicable to China Standard (CNS) A4 specification (21 × 29 < 7 mm) Α7 Β7 Five 'invention description (8)

Ca if (0-^ (0

Cb

Cc | 〇ifVtrig ^ t) > ic if Vojg (t) < Jc \ t) -icU) 0 ifVan (t) < 〇 ---------- Product—— (Please read the back first (Notes for filling in this page)

Fb

rl i / Vin (0 > 〇 〇 ifVbn (t) < Q (5) order

Fc Ί i / Vcn (t) > 〇〇 ifKA〇 < 〇 (6) line

G fl selects control strategy 1 0 selects control strategy 2 (7) Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs and then considers the selection of control strategy 1 (G = 1) and the interval 2B # in FIG. Circuit working status. Observing Figure 6 shows that when the three-phase input power is in interval 2, Ka (0 is positive 値 and K ⑴ and K ⑴ are negative 因此. Therefore, we can know that the control signals Fa = 1, Fb = 0, and Fc = 0. Consider again The status of the control signals Ca, Cb, Cc, we can determine 10 paper sizes applicable to the Chinese National Standard (CNS) A4 specifications (210X 297 mm) Printed by the Bayer Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Explanation (9) The six semiconductor switching elements of the three-phase full-bridge inverter architecture are turned on or off. Therefore, we can obtain the following five working modes: Mode 1-1: The control strategy of the device of the present invention is 1 (ie When the control signal G = 1 and the interval 2 in FIG. 6 (that is, the control signals Fa = 1, Fb = 0, Fc = 0) and the control signals Ca = 1, Cb = 0, and Cc = 0, the semiconductor switching element S1 , S4, and S6 are on: S2, S3, and S5 are cut off. At this time, the equivalent circuit of the device of the present invention. (Shown in Figure 7) Mode 1-2: The device of the present invention selects control strategy 1 (ie, control signal G) = l) and in the interval 2 in FIG. 6 (that is, the control signals Fa = 1, Fb = 0, Fc = 0) and the control signals Ca = 1, Cb = 0, and Cc = 1, the semiconductor switches on. The components SI, S4 and S5 are turned on; S2 'S3 and S6 are cut off. At this time, the equivalent circuit of the device of the present invention. (Shown in Figure 8) Mode 1-3: The device of the present invention selects control strategy 1 (ie, control signal) .G = l) and in the interval 2 of FIG. 6 (that is, 'control signal Fa = 1, Fb = 0, Fc = 0) and control signal Ca = 1, Cb = 1, Cc = 0, the semiconductor switching element S1 , To be connected to S6; S2, S4, and S5 are cut off, at this time the equivalent circuit of the device of the present invention. (Shown in Figure 9) Mode 1-4: The device of the present invention selects control strategy 1 (that is, the control signal 0 = 1) When interval 2 in FIG. 6 (that is, control signals Fa = 1, Fb = 〇, Fc = 〇) and control signals Ca = 1, Cb = 1, and Cc = 1, the semiconductor switching elements Si, s3, and S5 are turned on. ; S2, S4 and S6 are cut off. At this time, the equivalent circuit of the circuit of the device of the present invention. (As shown in Fig. 10) η__ This paper size applies the Chinese National Standard (CNS) A4 specification (210 × 297 mm); Line 7 (Please read the notes on the back before filling out this page) A7 B7 Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (i〇) Mode 1-5: The invention Set control strategy 1 (ie control signal G = 1) and select interval 2 (ie control signals Fa = 1, Fb = 0, Fc = 0) and control signals Ca = 0, Cb = .l (or Cb = 0), Cc = 1 (or Cc = 0), the semiconductor switching elements SI, S2, S3, S4, S5 and S6 are turned on. At this time, the equivalent circuit of the circuit of the device of the present invention. (As shown in Figure i) Because the working modes of interval 1, 3, 4, 5, and 6 in the sixth diagram are similar to interval 2, and the principle is almost the same, it is easy to understand, so the work of each interval is no longer Another pattern-praise. Next, consider the use of control strategy 2 (G = 0) and the state of the circuit of the device of the present invention when interval 2 in Fig. 7 is selected. In the same way, we can know that the control signals Fa = 1, Fb = 0, and Fc = 0. Considering the states of the control signals Ca, Cb, and Cc, we can determine whether the six semiconductor switching elements of the three-phase full-bridge inverter architecture are turned on or off. Therefore, we can obtain the following four working modes: Mode 2-1: The device of the present invention selects control strategy 1 (that is, the control signal G = 0) and is in the interval 2 of FIG. 6 (that is, the control signals Fa = 1 and Fb = 0. , Fc = 0) and control signals Ca = 1, Cb = 0, Cc = 0, the semiconductor switching elements S1, S4, and S6 are turned on; S2, S3, and S5 are cut off, at this time, the electric circuit of the device of the present invention is equivalent to Effective circuit. (As shown in Figure 7) Mode 2-2: The device of the present invention selects control strategy 1 (that is, the control signal G = 0) and is in interval 2 in FIG. 6 (that is, the control signals Fa = 1, Fb = 0, and Fc = 0) And control signals Ca = 1, Cb = 0, Cc = 1, the semiconductor switching elements SI, S4, and ___12 This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X 297 mm) innn ϋ ni — an > nn · ndm T m κ. II n --- coupons, \ §.-collapse {Please read the notes on the back before filling out this page} A7 B7 printed by the Shellfish Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs 5. Description of the invention (Li) S5 is on; S2, S3, and S6 are cut off. At this time, the equivalent circuit of the circuit of the device of the present invention. (As shown in Figure 8) Mode 2_3: The device of the present invention selects control strategy 1 (that is, control signal G = 0) and is in interval 2 (that is, control signals Fa = 1, Fb = 0, Fc = 0) and control When the signals Ca = 1, Cb = 1, and Cc = 0, the semiconductor switching elements S1, S3, and S6 are turned on; S2, S4, and S5 are cut off. At this time, the equivalent circuit of the circuit of the device of the present invention. (As shown in Figure 9) Mode 2-4: The device of the present invention selects control strategy 1 (that is, the control signal G = 0) and is in: interval 2 in FIG. 6 (that is, the control signals Fa = 1, Fb = 0, and Fc = 0 ) And control signals

Ca = l, Cb = l, Cc = l (or (Ca = 0, Cb = 0, Cc = 0); or (Ca = 0, Cb = 0, Cc = l); or (Ca = 0, Cb = (1, Cc = 0); (Ca = 0, Cb = 1, Cc = 1)), the semiconductor switching elements SI, S2, S3, S4, S5, and S6 are turned on, and the equivalent circuit of the circuit of the device of the present invention at this time . (As shown in Figure 11) •. • Because the working modes of interval 1, 3, 4, 5, and 6 in the sixth diagram are similar to interval 2, and the principle is almost the same, it is easy to understand, so it is no longer The working mode of the interval again-praise. The waveform diagram of the three-phase input current of the device of the present invention measured by the implementation circuit and a. ‘Phase input voltage and current measured waveform diagrams are shown in FIGS. 12 and 13 respectively. From the results of Figures 12 to 13, it is easy to understand that in addition to the single-stage conversion function, the device of the present invention can obtain a three-phase input current with a unit power factor and a clean sine wave. As for this issue 13__ This paper size applies to Chinese National Standards (CNS) Standard 4 ^ 210 X 297 mm) M. ------- IT-^ -----. ^-(Please read the back first (Notes for filling in this page)

141,142,143 144 145 146 147 14 8 1 4 Q A7 B7 V. Description of the invention (i2) The adjustment of the output DC voltage of the device is achieved by using the feedback control of the voltage loop and the adjustable circuit architecture of the device of the invention. The fourteenth figure is a structural diagram of a second embodiment according to the basic configuration of the present invention shown in the fourth figure. In the fourteenth figure, an inductor is shown. Represents a three-phase full-bridge inverter architecture. Represents a capacitor. Represents an inductor. : Power Diode. Represents a filter capacitor. Represents the load. Comparing the fourth diagram and the fourteenth diagram, it can be seen that the biggest difference between the first embodiment and the second embodiment of the present invention lies in the power diode (76) and the inductor (77) in the fourth diagram. In the figure, _ is replaced by an inductor (146) and a power diode (147), respectively. Since the working modes of the fourteenth diagram are similar to that of the fourth diagram, and the principle is almost the same, it is easy to understand, so I will not repeat the details of each mode. The fifteenth figure shows a third embodiment of the present invention (the isolated structure of the fourth figure). In the fifteenth figure, 1 5 1, 1 5 2, 1 5 3: represents an inductor. ‘154: Represents a three-phase full-bridge inverter architecture. ____14 This paper size is applicable to China National Standard (CNS) A4 specification (210X297 mm) --------- ^ ------, order --------- ^ (Please read first Note on the back, please fill in this page again.) Printed by the Shellfish Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs. 5. Description of the invention (l3) A7 B7. 15 6: indicates a high-frequency transformer. 15 8: Power diode. 1 59: indicates an inductor. 170: indicates a filter capacitor. 17 1: indicates load. · Comparing the fifteenth figure and the fourth figure, it can be seen that in the fifteenth figure, only the DC-to-DC converter (ie, C'uk converter) in the second half of the fourth figure is replaced with its conventional isolation type. 2. As the working principle of the fifteenth figure is almost the same as that of the fourth figure, it will not be repeated for each working mode. The sixteenth figure shows the fourth embodiment of the present invention (that is, the isolated structure of the fourteenth figure). In the sixteenth figure, _,. 16 1,162,163 represent inductors. 164 indicates a three-phase full-bridge inverter architecture. 1 65 indicates a capacitor. ‘1 66 represents a high-frequency transformer. 1 67 Power diode. 16 8 represents a chirped wave capacitor. 1 69: indicates the load. 15 Private paper standards are applicable to China National Standard (CNS) A4 specifications (21〇 < 297 public products) -----------, 4J ------ iT—lll · ·-^ 1) 1 (Please read the notes on the back before filling out this page) A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (14) Comparing the sixteenth and fourteenth pictures, you can see in the tenth In the sixth figure, only the inductor (146) of the fourteenth figure is replaced by a high-frequency transformer (166) to achieve the effect of power supply and load isolation. Since the working principles of Figure 16 and Figure 14 are almost the same, and it is easy to understand, the detailed description of each working mode will not be repeated. If so, the present invention has the following characteristics: (1) The present invention can achieve the required function only by a single-stage converter, so it is easy to obtain high efficiency. (2) The voltage and current of each phase of the input three-phase AC power supply are sine waves and in phase, so it can achieve high performance with unit power factor and no harmonic pollution. (3) The input three-phase AC current of each phase works in continuous mode, so the current stress of each switching element is small, which can reduce equipment cost and is suitable for high-power applications. (4) The output DC voltage of this converter has the function of stepping up / down. (5) This converter has a fixed switching frequency, so the filter design is easy. The above-mentioned points, before showing that the present invention can indeed achieve the intended purpose and efficacy, have never been seen in any domestic or foreign publications or publicly used before application, and are in line with the invention patent application. 16 This paper size is applicable to China National Standard (CNS) Person 4 specifications (210X 297 mm) (Please read the precautions on the back before filling this page) Order-Embroidery

Claims (1)

A8 B8 C8 D8 VI. Patent Application Printed by the Central Standards Bureau of the Ministry of Economic Affairs, Printed by Shellfish Consumer Cooperatives1. An adjustable three-phase step-up / step-down AC-to-DC converter, characterized by three inductors connected in series to the power supply Connect a series circuit composed of a capacitor and a power diode in parallel with the input terminal of the conventional three-phase full-bridge inverter architecture and the output of the three-phase full-bridge inverter architecture in parallel. A series circuit composed of a filter inductor and a filter capacitor is connected in parallel at both ends of the power diode, and the load resistor is connected in parallel to the filter capacitor. 2 · The adjustable three-phase step-up / step-down AC-to-DC converter according to the first item of the scope of the patent application, wherein the power diode and the filter inductor are sequentially divided into a filter inductor and a power two pole, respectively. Instead, it forms another type of adjustable three-phase step-up / step-down AC-to-DC converter. 3 · According to the adjustable three-phase step-up / step-down AC-to-DC converter described in the first item of the scope of patent application, the left circuit contains three-phase inductors, inverters and capacitors connected in series with the rear two The right circuit of the polar part is divided into two circuits, and then the left circuit is cascaded-the primary side of the high-frequency transformer, and the secondary side of the high-frequency transformer is connected in series with another capacitor and then connected in parallel to the aforementioned The separated right circuit part forms another adjustable three-phase step-up / step-down AC-to-DC converter. 4 · The adjustable three-phase step-up / step-down AC-to-DC converter according to the third item of the scope of the patent application, wherein the secondary winding of the high-frequency transformer is replaced by a multi-winding, and The output end is added with the same two as the original single winding (please read the precautions on the back before filling this page).., Ιτ PJ ·: 17 Paper size: Chinese national standard (CNS) A4 specification (210X297 mm) A8 B8 C8 D8 VI. Patent application scope Secondary side circuit architecture, forming another isolated multi-output adjustable three-phase step-up / step-down AC-to-DC converter. 5 · According to the adjustable three-phase step-up / step-down AC-to-DC converter described in the second item of the patent application scope, wherein the filter inductor is replaced by a high-frequency transformer to achieve the effect of isolating the power source from the load. Another type of adjustable three-phase step-up / step-down AC-to-DC converter. 6. The adjustable three-phase step-up / step-down AC-to-DC converter according to item 5 of the scope of the patent application, wherein the secondary winding of the high-frequency transformer is replaced by a multi-winding and The output side is added with the same secondary circuit structure as the original single winding, and forms another isolated multi-output adjustable three-phase step-up / step-down AC-to-DC converter. 7. The adjustable three-phase step-up / step-down AC-to-DC converter according to the first to sixth items of the scope of the patent application, wherein the three-phase full-bridge inverter architecture is soft-switched. The three-phase full-bridge inverter architecture was replaced to form another six adjustable three-phase step-up / down AC-to-DC converters. I --- ^ ----- f --- (Please read the notes on the back before filling out this page) Order printed by the Central Consumers Bureau of the Ministry of Economic Affairs, Consumer Cooperatives This paper is sized for China National Standard (CNS) A4 (210X297 mm)