A high voltage step-up ratio multi-phase floating interleaved Boost converter and its driving method

Abstract

The present invention provides a high step-up ratio multiphase floating interleaved Boost converter and its driving method, which relates to the field of power electronics technology. The converter includes: a fixed phase and a floating phase; the input ends in the fixed phase and the floating phase each have two phases in parallel; it is set that the driving signals of each interleaved phase are mutually staggered by 90° in time sequence in the order of power switch tube S1, power switch tube S3, power switch tube S2, and power switch tube S4, and based on the duty cycle working intervals of different high step-up ratio multiphase floating interleaved Boost converters, different driving methods are adopted according to the working modes composed of the opening and closing states of four power switch tubes and four power diode. The present invention can maintain high gain characteristics in the entire working range.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a high voltage boost ratio multi-phase floating interleaved Boost converter and a driving method thereof. Background Art

[0002] Thanks to its simple topology and high conversion efficiency, the interleaved boost converter (IBC) and its derivative topologies have been widely used in power supply systems to connect energy generation or storage units, such as solar panels or fuel cells, to the power bus. However, the output voltage of fuel cells is usually low. Although it is theoretically possible to increase the duty cycle of the IBC to generate a higher voltage gain, in practice, due to the reverse recovery of the power diode in the topology and parasitic parameters, the voltage gain that the IBC can provide cannot exceed 4 times, corresponding to a duty cycle of 0.75, and as the output voltage and power level increase, the gain limit will be further reduced.

[0003] Many studies have been conducted to address the above issues, in an effort to find a power topology that is not close to the duty cycle limit in a non-isolated boost converter and can further expand the voltage gain, such as the floating interleaved boost converter (FIBC). FIBC evolved from IBC and consists of a floating phase and a fixed phase two-phase module, such as Figure 1 As shown, the two-phase input terminals are connected in parallel, the positive electrode of the floating phase output filter capacitor is connected to the positive electrode of the input terminal, and the negative electrode of the fixed phase output filter capacitor is connected to the input ground wire. Therefore, the gain between the output voltage Vo and the input voltage Vin is (1+D) / (1-D), where D is the duty cycle of the power switch tube. From the above analysis, it can be seen that the voltage gain of FIBC has been improved compared with IBC, but the improvement effect is limited. Summary of the invention

[0004] The object of the present invention is to provide a high voltage step-up ratio multi-phase floating interleaved Boost converter and a driving method thereof, so as to solve the problem that the voltage gain improvement effect of the existing Boost converter is limited.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A high voltage step-up ratio multi-phase floating interleaved Boost converter, comprising: a fixed phase and a floating phase;

[0007] The fixed phase and the floating phase each have two phases in parallel at the input end;

[0008] The fixed phase includes a filter inductor L a 、Filter inductor Lb One end of the power diode D o1 , power diode D o2 , internal output filter capacitor C1, external output filter capacitor C o1 , power switch tube S1 and power switch tube S2;

[0009] The floating phase includes a filter inductor L c 、Filter inductor L d One end of the power diode D o3 , power diode D o4 , internal output filter capacitor C2, external output filter capacitor C o2 , power switch tube S3 and power switch tube S4;

[0010] The filter inductor L a One end of the filter inductor L b One end of the external output filter capacitor C o2 The filter inductor L is connected to one end of the power switch tube S3 and the source of the power switch tube S4; a The other end of the power diode D o1 The positive electrode of the filter inductor L is connected to the drain of the power switch tube S1; b The other end of the power diode D is connected to the drain of the power switch tube S2 and one end of the internal output filter capacitor C1; o1 The cathode of the power diode D o2 The positive electrode of the power diode D is connected to the other end of the internal output filter capacitor C1; o2 The negative terminal of the external output filter capacitor C o1 and one end of the output load R0; the external output filter capacitor C o1 The other end is connected to the input voltage V in , the filter inductor L c One end of the filter inductor L d One end of is connected;

[0011] The filter inductor L c The other end of the power diode D o3 The negative electrode of the filter inductor L is connected to the source of the power switch tube S3; d The other end of the power diode D is connected to the source of the power switch tube S4 and one end of the internal output filter capacitor C2; o3 The positive electrode of the internal output filter capacitor C2 and the other end of the power diode D o4 The negative electrode of the power diode Do4 The positive terminal of the external output filter capacitor C o2 The other end of and the other end of the output load R0 are connected;

[0012] The driving signals of the interleaved phases are set to be staggered by 90° in timing in the order of the power switch tube S1, the power switch tube S3, the power switch tube S2 and the power switch tube S4, and based on the working range of the duty cycle of the multi-phase floating interleaved Boost converter with different high boost ratios, different driving modes are adopted according to the working mode composed of the on-off states of the four power switch tubes and the four power diodes.

[0013] Optionally, the working mode specifically includes: 10 modes;

[0014] Mode I is when the power switch tube S1 is closed and the power diode D o2 , the power diode D o3 And the power diode D o4 Forward conduction, or the power switch tube S3 is closed, the power diode D o1 , the power diode D o2 And the power diode D o4 Forward conduction;

[0015] Mode II is when the power switch tube S2 is closed and the power diode D o1 , the power diode D o3 And the power diode D o4 Forward conduction, or the power switch tube S4 is closed, the power diode D o1 , the power diode D o2 And the power diode D o3 Forward conduction;

[0016] Mode III is when the power switch tube S1 and the power switch tube S3 are closed, and the power diode D o2 And the power diode D o4 Forward conduction;

[0017] Mode IV is when the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o1 And the power diode D o3 Forward conduction;

[0018] Mode V is when the power switch tube S1 and the power switch tube S2 are closed, and the power diode D o3 And the power diode D o4Forward conduction, or, the power switch tube S3 and the power switch tube S4 are closed, the power diode D o1 And the power diode D o2 Forward conduction;

[0019] Mode VI is when the power switch tube S1 and the power switch tube S4 are closed, and the power diode D o2 And the power diode D o3 Forward conduction, or, the power switch tube S2 and the power switch tube S3 are closed, the power diode D o1 And the power diode D o4 Forward conduction;

[0020] Mode VII is when the power switch tube S1, the power switch tube S2 and the power switch tube S3 are closed, and the power diode D o4 The power diode D o2 Forward conduction;

[0021] Mode VIII is when the power switch tube S1, the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o3 The power diode D o1 Forward conduction;

[0022] Mode IX is when the power switch tube S1, the power switch tube S2, the power switch tube S3 and the power switch tube S4 are closed;

[0023] Mode X is the power diode D o1 , the power diode D o2 , the power diode D o3 And the power diode D o4 Positive conduction.

[0024] Optionally, when the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter is in the range of 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes;

[0025] When the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter is within the range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5.

[0026] Optionally, when 0.75≤D<1, within one switching cycle, the working sequence is mode IX→mode VIII→mode IX→mode VII→mode IX→mode VII→mode IX→mode VIII.

[0027] Optionally, when 0.5≤D<0.75, within one switching cycle, the working order is mode VIII→mode VI→mode VII→mode III→mode VII→mode VI→mode VIII→mode IV.

[0028] Optionally, when 0<D<0.25, within one switching cycle, the working sequence is mode VI→mode III→mode I→mode VI→mode II→mode IV.

[0029] Optionally, when 0.25≤D<0.5, within one switching cycle, the working sequence is mode VI→mode II→mode I→mode X→mode II→mode II.

[0030] A driving method of a high voltage boost ratio multi-phase floating interleaved Boost converter, comprising:

[0031] Based on the duty cycle working range of a high-boost ratio multi-phase floating interleaved Boost converter, different driving modes are adopted according to the working mode composed of the on-off states of four power switches and four power diodes; the driving modes include symmetrical driving modes and asymmetrical driving modes.

[0032] Optionally, when the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter is in the range of 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes;

[0033] Filter inductor L a 、Filter inductor L b 、Filter inductor L c 、Filter inductor L d The inductor voltages all satisfy the volt-second balance relationship within one switching cycle;

[0034] The volt-second balance relationship is:

[0035]

[0036] The output voltage is:

[0037]

[0038] Among them, V c1 is the voltage across the internal output filter capacitor C1, V c2 is the voltage across the internal output filter capacitor C2, V co1 is the external output filter capacitor C o1 The voltage across the terminals, V co2 is the external output filter capacitor C o2 The voltage across the terminals, V o is the output voltage, V in is the input voltage.

[0039] Optionally, when the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter is in the operating range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5; wherein D is the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes;

[0040] Filter inductor L a 、Filter inductor L b 、Filter inductor L c 、Filter inductor L d The inductor voltages all satisfy the volt-second balance relationship within one switching cycle;

[0041] The volt-second balance relationship is:

[0042]

[0043] The output voltage is:

[0044]

[0045] Among them, V c1 is the voltage across the internal output filter capacitor C1, V c2 is the voltage across the internal output filter capacitor C2, V co1 is the external output filter capacitor C o1 The voltage across the terminals, V co2 is the external output filter capacitor C o2 The voltage across the terminals, V o is the output voltage, V in is the input voltage.

[0046] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the present invention provides a high boost ratio multi-phase floating interleaved Boost converter, based on the topological structure of the high boost ratio multi-phase floating interleaved Boost converter, based on the working range of different duty cycles of the high boost ratio multi-phase floating interleaved Boost converter, and driven in different ways according to the working mode composed of the on and off states of four power switching tubes and four power diodes, so that the high boost ratio multi-phase floating interleaved Boost converter can maintain high gain characteristics in the entire working range. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 It is the existing FIBC topology diagram;

[0049] Figure 2 A topology diagram of a high voltage step-up ratio multi-phase floating interleaved Boost converter provided by the present invention;

[0050] Figure 3 A topological diagram of HGFIBC in mode I provided by the present invention;

[0051] Figure 4 A topological diagram of the HGFIBC in mode II provided by the present invention;

[0052] Figure 5 A topological diagram of HGFIBC in mode III provided by the present invention;

[0053] Figure 6 A topological diagram of the HGFIBC in mode IV provided by the present invention;

[0054] Figure 7 A topological diagram of the HGFIBC in mode V provided by the present invention;

[0055] Figure 8 A topological diagram of HGFIBC in mode VI provided by the present invention;

[0056] Fig. 9 A topological diagram of HGFIBC in mode VII provided by the present invention;

[0057] Fig.10A topological diagram of the HGFIBC in mode VIII provided by the present invention;

[0058] Fig.11 A topological diagram of HGFIBC in mode IX provided by the present invention;

[0059] Fig.12 A topological diagram of HGFIBC in mode X provided by the present invention;

[0060] Fig.13 This is a key point waveform diagram of the HGFIBC provided by the present invention when 0.75≤D<1;

[0061] Fig.14 This is a key point waveform diagram of the HGFIBC provided by the present invention when 0.5≤D<0.75;

[0062] Fig.15 This is a key point waveform diagram of the HGFIBC provided by the present invention when 0<D<0.25;

[0063] Fig.16 This is a key point waveform diagram of the HGFIBC provided by the present invention when 0.25≤D<0.5;

[0064] Fig.17 This is a comparison chart of the boost ratio of HGFIBC and IBC under different driving modes. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] The object of the present invention is to provide a high voltage step-up ratio multi-phase floating interleaved Boost converter and a driving method thereof, which can maintain high gain characteristics in the whole working range.

[0067] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0068] Example 1

[0069] like Figure 2 As shown, the present invention provides a high boost ratio multi-phase floating interleaved Boost converter, comprising: a fixed phase and a floating phase;

[0070] Assume that a high gain float interleaved boost converter (HGFIBC) operates in a continuous conduction mode (CCM), wherein two phases are connected in parallel at the input ends of the fixed phase and the floating phase respectively.

[0071] Ignoring the parasitic parameters in the topology, we use L a ~L d They represent the four-phase filter inductors, S1~S4 represent the four-phase power switch tubes, and D o1 ~D o4 They represent the four-phase power diodes, C1 and C2 represent the internal output filter capacitors of the fixed phase and floating phase respectively, and C o1 , C o2 Respectively represent the external output filter capacitors of the fixed phase and floating phase, with R o Indicates the output load, i La ~i Ld Respectively represent the current flowing through each inductor, V c1 、V c2 、V co1 and V co2 Represents the voltage across each capacitor respectively.

[0072] Wherein, the fixed phase includes a filter inductor L a 、Filter inductor L b One end of the power diode D o1 , power diode D o2 , internal output filter capacitor C1, external output filter capacitor C o1 , power switch tube S1 and power switch tube S2.

[0073] The floating phase includes a filter inductor L c 、Filter inductor L d One end of the power diode D o3 , power diode D o4 , internal output filter capacitor C2, external output filter capacitor C o2 , power switch tube S3 and power switch tube S4.

[0074] The filter inductor L a One end of the filter inductor L b One end of the external output filter capacitor C o2 The filter inductor L is connected to one end of the power switch tube S3 and the source of the power switch tube S4; a The other end of the power diode D o1The positive electrode of the filter inductor L is connected to the drain of the power switch tube S1; b The other end of the power diode D is connected to the drain of the power switch tube S2 and one end of the internal output filter capacitor C1; o1 The cathode of the power diode D o2 The positive electrode of the power diode D is connected to the other end of the internal output filter capacitor C1; o2 The negative terminal of the external output filter capacitor C o1 and one end of the output load R0; the external output filter capacitor C o1 The other end is connected to the input voltage V in , the filter inductor L c One end of the filter inductor L d The input voltage V in This is the input voltage of the input power supply.

[0075] The filter inductor L c The other end of the power diode D o3 The negative electrode of the filter inductor L is connected to the source of the power switch tube S3; d The other end of the power diode D is connected to the source of the power switch tube S4 and one end of the internal output filter capacitor C2; o3 The positive electrode of the internal output filter capacitor C2 and the other end of the power diode D o4 The negative electrode of the power diode D o4 The positive terminal of the external output filter capacitor C o2 and the other end of the output load R0 are connected.

[0076] The driving signals of the interleaved phases are set to be staggered by 90° in timing in the order of the power switch tube S1, the power switch tube S3, the power switch tube S2 and the power switch tube S4, and based on the working range of the duty cycle of the multi-phase floating interleaved Boost converter with different high boost ratios, different driving modes are adopted according to the working mode composed of the on-off states of the four power switch tubes and the four power diodes.

[0077] In practical applications, the working modes specifically include: 10 modes.

[0078] like Figure 3 As shown, mode I is when the power switch tube S1 is closed and the power diode D o2 , the power diode D o3 And the power diode D o4Forward conduction, or the power switch tube S3 is closed, the power diode D o1 , the power diode D o2 And the power diode D o4 Positive conduction.

[0079] like Figure 4 As shown, mode II is when the power switch tube S2 is closed and the power diode D o1 , the power diode D o3 And the power diode D o4 Forward conduction, or the power switch tube S4 is closed, the power diode D o1 , the power diode D o2 And the power diode D o3 Positive conduction.

[0080] like Figure 5 As shown, mode III is when the power switch tube S1 and the power switch tube S3 are closed, and the power diode D o2 And the power diode D o4 Positive conduction.

[0081] like Figure 6 As shown, mode IV is when the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o1 And the power diode D o3 Positive conduction.

[0082] like Figure 7 As shown, mode V is when the power switch tube S1 and the power switch tube S2 are closed, and the power diode D o3 And the power diode D o4 Forward conduction, or, the power switch tube S3 and the power switch tube S4 are closed, the power diode D o1 And the power diode D o2 Positive conduction.

[0083] like Figure 8 As shown, mode VI is when the power switch tube S1 and the power switch tube S4 are closed, and the power diode D o2 And the power diode D o3 Forward conduction, or, the power switch tube S2 and the power switch tube S3 are closed, the power diode D o1 And the power diode D o4 Positive conduction.

[0084] like Fig. 9As shown, mode VII is that the power switch tube S1, the power switch tube S2 and the power switch tube S3 are closed, and the power diode D o4 The power diode D o2 Positive conduction.

[0085] like Fig.10 As shown, mode VIII is when the power switch tube S1, the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o3 The power diode D o1 Positive conduction.

[0086] like Fig.11 As shown, in mode IX, the power switch tube S1, the power switch tube S2, the power switch tube S3 and the power switch tube S4 are closed.

[0087] like Fig.12 As shown, mode X is the power diode D o1 , the power diode D o2 , the power diode D o3 And the power diode D o4 Positive conduction.

[0088] In practical applications, when the duty cycle working range of the high boost ratio multi-phase floating interleaved Boost converter is 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes.

[0089] Furthermore, the duty cycle interval is divided into two categories: 0.75≤D<1 and 0.5≤D<0.75.

[0090] When 0.75≤D<1, the key waveforms of current and voltage are as follows Fig.13 As shown, Fig.13 In the working condition shown, within one switching cycle, the working sequence is mode IX→mode VIII→mode IX→mode VII→mode IX→mode VII→mode IX→mode VIII.

[0091] When 0.5≤D<0.75, the key waveforms of current and voltage are as follows Fig.14 As shown, Fig.14In the working condition shown, within one switching cycle, the working sequence is mode VIII→mode VI→mode VII→mode III→mode VII→mode VI→mode VIII→mode IV.

[0092] In the above two cases, the inductor voltage v La ~v Ld The volt-second balance relationship is satisfied within one switching cycle, that is:

[0093]

[0094] From formula (1), we can get that the output voltage V o The expression is:

[0095]

[0096] In practical applications, when the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter is in the range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5.

[0097] Furthermore, when 0<D<0.5, if the above-mentioned method of driving HGFIBC with equal duty ratios of each phase is continued, when the duty ratio continues to decrease to D<0.5, the inductor voltage v La ~v Ld The volt-second balance relationship is still satisfied within a switching cycle, that is:

[0098] V in D=(V co1 -V in )(1-2D)+(V c1 -V in )D

[0099] V in D=(V co1 -V in -V c1 )(1-D) (3)

[0100] Then from formula (3) we can get:

[0101]

[0102] At this time, the output voltage V o The expression is:

[0103]

[0104] Comparing equation (2) with equation (5), it can be seen that the boost ratio decreases sharply at this time.

[0105] In order to maintain the high step-up ratio advantage of HGFIBC, the present invention adopts an asymmetric driving method to solve the above problem, that is, when the duty cycle gradually decreases, D2 and D4 are fixed when they are as low as 0.5, and D1 and D3 are used to adjust the voltage V in With V o Similarly, if the driving signals are staggered by 90° in the order of S1, S3, S2 and S4, the duty cycle interval can be divided into two categories: 0<D<0.25 and 0.25≤D<0.5.

[0106] Furthermore, when 0<D<0.25, the key waveforms of current and voltage are as follows: Fig.15 As shown by Fig.15 In the working condition shown, within one switching cycle, the working order is mode VI→mode III→mode I→mode VI→mode II→mode IV.

[0107] Furthermore, when 0.25≤D<0.5, the key waveforms of current and voltage are as follows: Fig.16 As shown by Fig.16 In the working condition shown, within one switching cycle, the working sequence is mode VI→mode II→mode I→mode X→mode II→mode II.

[0108] In the above two cases, the inductor voltage v La ~v Ld The volt-second balance relationship is satisfied within one switching cycle, that is:

[0109] V in D=(V co1 -V in )(0.5-D)+0.5(V c1 -V in )

[0110] 0.5V in =(V co1 -V in -V c1 )D+(V co1 -V in -V c1 )(0.5-D)(6)

[0111] Then from formula (6) we can get:

[0112]

[0113] From formula (7), we can get the output voltage V o The expression is:

[0114]

[0115] By comparing equation (5) with equation (8), it can be seen that when 0<D<0.5, the asymmetric driving method can ensure that the HGFIBC has high gain characteristics in the full range.

[0116] In summary, when using the HGFIBC proposed by the present invention, the driving signals of the interlaced phases are set to be staggered 90° in the order of S1, S3, S2 and S4. When 0.5≤D<1, a symmetrical driving mode is adopted in which the duty ratios D1 to D4 of the four power switches are equal, that is, D1=D2=D3=D4=D; when 0<D<0.5, the duty ratios D2 and D4 of the four power switches are fixed when they are as low as 0.5, and an asymmetrical driving mode is adopted in which the voltage is adjusted by D1 and D3, that is, D1=D3=D, D2=D4=0.5. This ensures that the HGFIBC maintains a high gain characteristic of (3+D) / (1-D) in the full working range.

[0117] The voltage gain of conventional IBC is limited, e.g. Fig.17 In order to improve the converter gain, the present invention proposes a topological structure of HGFIBC, as shown in the red solid line in FIG. Figure 2 As shown in the figure, the analysis results show that if the topology adopts symmetrical drive in the whole working range, it can maintain a high gain when 0.5≤D<1, but there will be a gain drop problem when 0<D<0.5, such as Fig.17 As shown by the blue dotted line in . Accordingly, the present invention proposes an asymmetric driving method for HGFIBC, that is, when 0.5≤D<1, a symmetric driving method is adopted in which the duty ratios D1~D4 of the four power switch tubes are equal, that is, D1=D2=D3=D4=D; when 0<D<0.5, the duty ratios D2 and D4 of the four power switch tubes are fixed as low as 0.5, and an asymmetric driving method is adopted to adjust the voltage with D1 and D3, that is, D1=D3=D, D2=D4=0.5. This ensures that the HGFIBC maintains a high gain characteristic of (3+D) / (1-D) in the entire operating range, as shown in Fig.17 As shown by the green dashed line in .

[0118] Embodiment 2

[0119] A driving method of a high voltage boost ratio multi-phase floating interleaved Boost converter, comprising:

[0120] Based on the duty cycle working range of a high-boost ratio multi-phase floating interleaved Boost converter, different driving modes are adopted according to the working mode composed of the on-off states of four power switches and four power diodes; the driving modes include symmetrical driving modes and asymmetrical driving modes.

[0121] In practical applications, when the duty cycle working range of the high boost ratio multi-phase floating interleaved Boost converter is 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes.

[0122] Filter inductor L a 、Filter inductor L b 、Filter inductor L c 、Filter inductor L d The inductor voltage satisfies the volt-second balance relationship within one switching cycle.

[0123] The volt-second balance relationship is:

[0124]

[0125] The output voltage is:

[0126]

[0127] Among them, V c1 is the voltage across the internal output filter capacitor C1, V c2 is the voltage across the internal output filter capacitor C2, V co1 is the external output filter capacitor C o1 The voltage across the terminals, V co2 is the external output filter capacitor C o2 The voltage across the terminals, V o is the output voltage, V in is the input voltage.

[0128] In practical applications, when the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter works in the range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5; wherein D is the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes.

[0129] Filter inductor L a 、Filter inductor L b 、Filter inductor L c 、Filter inductor L d The inductor voltages all satisfy the volt-second balance relationship within one switching cycle;

[0130] The volt-second balance relationship is:

[0131]

[0132] The output voltage is:

[0133]

[0134] The present invention proposes different driving modes for HGFIBC, that is, when 0.5≤D<1, a symmetrical driving mode in which the duty ratios D1-D4 of the four power switch tubes are equal is adopted, that is, D1=D2=D3=D4=D; when 0<D<0.5, an asymmetrical driving mode in which the duty ratios D2 and D4 of the four power switch tubes are fixed as low as 0.5 and the voltage is adjusted by D1 and D3, that is, D1=D3=D, D2=D4=0.5. In this way, the high gain characteristic of (3+D) / (1-D) is maintained in the full working range of HGFIBC.

[0135] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0136] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high voltage step-up ratio multi-phase floating interleaved Boost converter, characterized in that: include: Stationary phase and floating phase; The fixed phase and the floating phase each have two phases in parallel at the input end; The fixed phase includes a filter inductor L a , filter inductor L b One end of the power diode D o1 , power diode D o2 , internal output filter capacitor C1, external output filter capacitor C o1 , power switch tube S1 and power switch tube S2; The floating phase includes a filter inductor L c , filter inductor L d One end of the power diode D o3 , power diode D o4 , internal output filter capacitor C2, external output filter capacitor C o2 , power switch tube S3 and power switch tube S4; The filter inductor L a One end of the filter inductor L b One end of the external output filter capacitor C o2 The filter inductor L is connected to one end of the power switch tube S3 and the source of the power switch tube S4; a The other end of the power diode D o1 The positive electrode of the filter inductor L is connected to the drain of the power switch tube S1; b The other end of the power diode D is connected to the drain of the power switch tube S2 and one end of the internal output filter capacitor C1; o1 The cathode of the power diode D o2 The positive electrode of the power diode D is connected to the other end of the internal output filter capacitor C1; o2 The negative terminal of the external output filter capacitor C o1 and one end of the output load R0; the external output filter capacitor C o1 The other end is connected to the input voltage V in , the filter inductor L c One end of the filter inductor L d One end of is connected; The filter inductor L c The other end of the power diode D o3 The negative electrode of the filter inductor L is connected to the source of the power switch tube S3; d The other end of the power diode D is connected to the source of the power switch tube S4 and one end of the internal output filter capacitor C2; o3 The positive electrode of the internal output filter capacitor C2 and the other end of the power diode D o4 The negative electrode of the power diode D o4 The positive terminal of the external output filter capacitor C o2 The other end of and the other end of the output load R0 are connected; The driving signals of the interleaved phases are set to be staggered by 90° in the order of the power switch tube S1, the power switch tube S3, the power switch tube S2 and the power switch tube S4, and different driving modes are adopted according to the working range of the duty cycle of the multi-phase floating interleaved Boost converter with different high boost ratios and the working mode composed of the on-off states of the four power switch tubes and the four power diodes; When the duty cycle of the high boost ratio multi-phase floating interleaved Boost converter is within the range of 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle when the duty cycles of all power switch tubes are equal, D1~D4 can be referred to as D; D1~D4 are the duty cycles of four power switch tubes; When the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter is in the range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5; When 0.75≤D<1, in one switching cycle, the working order is mode IX→mode VIII→mode IX→mode VII→mode IX→mode VII→mode IX→mode VIII; When 0.5≤D<0.75, in one switching cycle, the working order is mode VIII→mode VI→mode VII→mode III→mode VII→mode VI→mode VIII→mode IV; When 0<D<0.25, within one switching cycle, the working order is mode VI→mode III→mode I→mode VI→mode II→mode IV; When 0.25≤D<0.5, within one switching cycle, the working sequence is mode VI→mode II→mode I→mode X→mode II→mode II.

2. The high voltage step-up ratio multi-phase floating interleaved Boost converter according to claim 1, characterized in that: The working modes specifically include: 10 modes; Mode I is when the power switch tube S1 is closed and the power diode D o2 , the power diode D o3 And the power diode D o4 Forward conduction, or the power switch tube S3 is closed, the power diode D o1 , the power diode D o2 And the power diode D o4 Forward conduction; Mode II is when the power switch tube S2 is closed and the power diode D o1 , the power diode D o3 And the power diode D o4 Forward conduction, or the power switch tube S4 is closed, the power diode D o1 , the power diode D o2 And the power diode D o3 Forward conduction; Mode III is when the power switch tube S1 and the power switch tube S3 are closed, and the power diode D o2 And the power diode D o4 Forward conduction; Mode IV is when the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o1 And the power diode D o3 Forward conduction; Mode V is when the power switch tube S1 and the power switch tube S2 are closed, and the power diode D o3 And the power diode D o4 Forward conduction, or, the power switch tube S3 and the power switch tube S4 are closed, the power diode D o1 And the power diode D o2 Forward conduction; Mode VI is when the power switch tube S1 and the power switch tube S4 are closed, and the power diode D o2 And the power diode D o3 Forward conduction, or, the power switch tube S2 and the power switch tube S3 are closed, the power diode D o1 And the power diode D o4 Forward conduction; Mode VII is when the power switch tube S1, the power switch tube S2 and the power switch tube S3 are closed, and the power diode D o4 The power diode D o2 Forward conduction; Mode VIII is when the power switch tube S1, the power switch tube S2 and the power switch tube S4 are closed, and the power diode D o3 The power diode D o1 Forward conduction; Mode IX is when the power switch tube S1, the power switch tube S2, the power switch tube S3 and the power switch tube S4 are closed; Mode X is the power diode D o1 , the power diode D o2 , the power diode D o3 And the power diode D o4 Positive conduction.

3. A driving method of a high voltage step-up ratio multi-phase floating interleaved Boost converter, characterized in that: include: Based on the duty cycle operating range of the high boost ratio multi-phase floating interleaved Boost converter described in any one of claims 1-2, different driving methods are adopted according to the working mode composed of the on and off states of four power switching tubes and four power diodes; the driving method includes a symmetrical driving method and an asymmetrical driving method.

4. The driving method of the high voltage step-up ratio multi-phase floating interleaved Boost converter according to claim 3, characterized in that: When the duty cycle of the high voltage boost ratio multi-phase floating interleaved Boost converter is within the working range of 0.5≤D<1, a symmetrical driving mode is adopted; the symmetrical driving mode is D1=D2=D3=D4=D; wherein D is the duty cycle of the high voltage boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes; Filter inductor L a , filter inductor L b , filter inductor L c , filter inductor L d The inductor voltages all satisfy the volt-second balance relationship within one switching cycle; The volt-second balance relationship is: The output voltage is: Among them, V c1 is the voltage across the internal output filter capacitor C1, V c2 is the voltage across the internal output filter capacitor C2, V co1 is the external output filter capacitor C o1 The voltage across the terminals, V co2 is the external output filter capacitor C o2 The voltage across the terminals, V o is the output voltage, V in is the input voltage.

5. The driving method of the high voltage step-up ratio multi-phase floating interleaved Boost converter according to claim 3, characterized in that: When the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter is in the working range of 0<D<0.5, an asymmetric driving mode is adopted; the asymmetric driving mode is D1=D3=D, D2=D4=0.5; wherein D is the duty cycle of the high-boost ratio multi-phase floating interleaved Boost converter, and D1~D4 are the duty cycles of the four power switch tubes; Filter inductor L a , filter inductor L b , filter inductor L c , filter inductor L d The inductor voltages all satisfy the volt-second balance relationship within one switching cycle; The volt-second balance relationship is: The output voltage is: Among them, V c1 is the voltage across the internal output filter capacitor C1, V c2 is the voltage across the internal output filter capacitor C2, V co1 is the external output filter capacitor C o1 The voltage across the terminals, V co2 is the external output filter capacitor C o2 The voltage across the terminals, V o is the output voltage, V in is the input voltage.

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