Single-phase four-level rectifier circuit, power supply and electronic equipment based on pseudo-totem pole structure

Abstract

The present invention relates to a single-phase four-level rectifier circuit, power supply and electronic equipment based on a pseudo-totem pole structure, including: a pseudo-totem pole structure, a bridge arm voltage regulating module, multiple switch tubes, a fifth diode, a sixth diode and an AC power supply; the pseudo-totem pole structure includes: a first switch tube, a second switch tube, a first inductor, a second inductor, a first diode, a second diode, a third diode and a fourth diode; the bridge arm voltage regulating module and the first switch tube, the second switch tube and different combination states of multiple switch tubes constitute multiple different loops with the bridge arm to adjust the bridge arm voltage through multiple different loops. Compared with the traditional two-level or three-level rectifier power supply, the present invention has lower voltage stress on the switch tube and the diode, which helps to select devices with lower withstand voltage levels, reduce costs, and improve system reliability and efficiency. In addition, the present invention also has more level states and smaller output voltage ripple.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and more specifically, to a single-phase four-level rectifier circuit, a power supply and an electronic device based on a pseudo-totem pole structure. Background Art

[0002] The traditional two-level rectifier power supply has been used for decades, but its switching frequency is limited, and usually requires the use of large inductors and capacitors, which makes the overall size of the filter larger and reduces efficiency. In addition, the input current of the traditional two-level rectifier power supply has a large harmonic content and is seriously non-sinusoidal. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a single-phase four-level rectifier circuit, a power supply and an electronic device based on a pseudo totem pole structure in view of the problems existing in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a single-phase four-level rectifier circuit based on a pseudo-totem pole structure, including: a pseudo-totem pole structure, a bridge arm voltage regulation module, multiple switch tubes, a fifth diode, a sixth diode and an AC power supply;

[0005] The pseudo totem pole structure includes: a first switch tube, a second switch tube, a first inductor, a second inductor, a first diode, a second diode, a third diode and a fourth diode;

[0006] The first end of the AC power source is respectively connected to the second end of the first inductor and the second end of the second inductor, the first end of the first inductor is respectively connected to the anode of the second diode and the drain of the first switch tube and connected to terminal a, the first end of the second inductor is respectively connected to the cathode of the third diode and the source of the second switch tube and connected to terminal b, and the second end of the AC power source is respectively connected to the anode of the fifth diode and the cathode of the sixth diode and connected to terminal n;

[0007] The source of the first switch tube is respectively connected to the anode of the fourth diode, the anode of the sixth diode and the negative electrode of the load; the cathode of the first diode is respectively connected to the drain of the second switch tube, the cathode of the fifth diode and the positive electrode of the load;

[0008] The bridge arm voltage regulating module and the first switch tube, the second switch tube and different combination states of the multiple switch tubes form multiple different loops with the bridge arm to regulate the bridge arm voltage through the multiple different loops.

[0009] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, the bridge arm voltage regulation module includes: a first capacitor, a second capacitor and a third capacitor; the multiple switch tubes include: a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube;

[0010] The drain of the third switch tube is connected to the cathode of the second diode and the anode of the first diode, and the source of the third switch tube is connected to the drain of the fourth switch tube, the drain of the fifth switch tube, and the source of the seventh switch tube;

[0011] The source of the fourth switch tube is connected to the anode of the third diode and the cathode of the fourth diode, the source of the fifth switch tube is connected to the source of the sixth switch tube, and the drain of the sixth switch tube is connected to the negative electrode of the first capacitor and the positive electrode of the second capacitor and connected to the terminal e;

[0012] The drain of the seventh switch tube is connected to the drain of the eighth switch tube, and the source of the eighth switch tube is connected to the negative electrode of the second capacitor and the positive electrode of the third capacitor and connected to the end point f.

[0013] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, the first capacitor, the second capacitor and the third capacitor are series split capacitors.

[0014] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, the first capacitor, the second capacitor and the third capacitor are the same capacitor, and each capacitor withstands one third of the DC bus voltage.

[0015] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are any one of an insulated gate bipolar transistor, an integrated gate-commutated thyristor and a power field effect transistor.

[0016] In the single-phase four-level rectifier circuit based on the pseudo-totem pole structure described in the present invention, the single-phase four-level rectifier circuit includes: eight working modes; the eight working modes include: four working modes of the positive half cycle and four working modes of the negative half cycle; the four working modes of the positive half cycle include: a first working mode, a second working mode, a third working mode and a fourth working mode; the four working modes of the negative half cycle include: a fifth working mode, a sixth working mode, a seventh working mode and an eighth working mode.

[0017] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, when in the first working mode, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current passes through the first inductor, the second diode, the first diode, the first capacitor, the second capacitor, the third capacitor and the sixth diode in sequence to form a path; the AC power supply and the first inductor jointly charge the first capacitor, the second capacitor and the third capacitor;

[0018] When in the second working mode, the third switch tube and the fifth switch tube are turned on, the first switch tube, the second switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current passes through the first inductor, the second diode, the third switch tube, the fifth switch tube, the body diode on the sixth switch tube, the second capacitor, the third capacitor and the sixth diode in sequence to form a path; the AC power supply charges the second capacitor and the third capacitor, and the first capacitor discharges to the load;

[0019] When in the third working mode, the third switch tube and the eighth switch tube are turned on, the first switch tube, the second switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube are turned off, and the grid current forms a path through the first inductor, the second diode, the third switch tube, the body diode on the seventh switch tube, the eighth switch tube, the third capacitor and the sixth diode; the AC power supply charges the third capacitor;

[0020] When in the fourth working mode, the first switch tube is turned on, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, the grid current forms a path through the first inductor, the first switch tube and the sixth diode; the AC power supply charges the first inductor; the first capacitor, the second capacitor, the third capacitor and the load form another path; the first capacitor, the second capacitor and the third capacitor discharge to the load.

[0021] In the single-phase four-level rectifier circuit based on the pseudo totem pole structure described in the present invention, when in the fifth working mode, the second switch tube is turned on, the first switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the second switch tube and the second inductor; the AC power supply charges the second inductor; the first capacitor, the second capacitor, the third capacitor and the load form another path; the first capacitor, the second capacitor and the third capacitor discharge to the load;

[0022] When in the sixth working mode, the fourth switch tube and the sixth switch tube are turned on, the first switch tube, the second switch tube, the third switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the sixth switch tube, the body diode on the fifth switch tube, the fourth switch tube, the third diode and the second inductor; the AC power supply charges the first capacitor; the second capacitor and the third capacitor discharge to the load;

[0023] When in the seventh working mode, the fourth switch tube and the seventh switch tube are turned on, the first switch tube, the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the second capacitor, the body diode on the eighth switch tube, the seventh switch tube, the fourth switch tube, the third diode and the second inductor; the AC power supply charges the first capacitor and the second capacitor, and the third capacitor discharges to the load;

[0024] When in the eighth working mode, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the second capacitor, the third capacitor, the fourth diode, the third diode and the second inductor; the AC power supply and the second inductor charge the first capacitor, the second capacitor and the third capacitor.

[0025] The present invention further provides a single-phase four-level rectifier power supply, comprising: the above-mentioned single-phase four-level rectifier circuit based on the pseudo-totem pole structure.

[0026] The present invention further provides an electronic device, comprising: the above-mentioned single-phase four-level rectifier circuit based on the pseudo-totem pole structure.

[0027] The single-phase four-level rectifier circuit, power supply and electronic device based on the pseudo-totem pole structure of the present invention have the following beneficial effects: including: a pseudo-totem pole structure, a bridge arm voltage regulating module, multiple switch tubes, a fifth diode, a sixth diode and an AC power supply; the pseudo-totem pole structure includes: a first switch tube, a second switch tube, a first inductor, a second inductor, a first diode, a second diode, a third diode and a fourth diode; the bridge arm voltage regulating module and the first switch tube, the second switch tube and different combination states of multiple switch tubes constitute multiple different loops with the bridge arm to adjust the bridge arm voltage through multiple different loops. Compared with the traditional two-level or three-level rectifier power supply, the present invention has lower voltage stress on the switch tube and the diode, which helps to select devices with lower withstand voltage levels, reduce costs, and improve system reliability and efficiency. In addition, the present invention also has more level states and smaller output voltage ripple. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0029] Figure 1 This is a main topological structure diagram of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0030] Figure 2 It is a schematic diagram of a first working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0031] Figure 3 The present invention is a schematic diagram of a second working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure.

[0032] Figure 4 It is a schematic diagram of a third working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0033] Figure 5 It is a schematic diagram of a fourth working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure according to the present invention.

[0034] Figure 6 It is a schematic diagram of the fifth working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0035] Figure 7 It is a schematic diagram of the sixth working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0036] Figure 8 It is a schematic diagram of the seventh working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure of the present invention.

[0037] Fig. 9 It is a schematic diagram of an eighth working mode of a single-phase four-level rectifier power supply based on a pseudo totem pole structure according to the present invention.

[0038] Fig.10 is the steady-state AC input voltage u of the present invention g And the steady-state AC input current i g Waveform graph.

[0039] Fig.11 is the voltage u between point a and point N in the present invention aN Steady-state waveform diagram.

[0040] Fig.12 is the voltage u between point b and point N of the present invention bN Steady-state waveform diagram.

[0041] Fig.13 is the current i of the inductor L1 of the present invention L1 Waveform graph.

[0042] Fig.14 is the current i of the inductor L2 of the present invention L2 Waveform graph.

[0043] Fig.15 The voltage u of the DC split capacitors C1, C2, and C3 of the present invention is C1 、u C2 、u C3 Waveform graph.

[0044] Fig.16 is the steady-state output voltage U of the present invention dc Waveform graph. DETAILED DESCRIPTION

[0045] 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.

[0046] refer to Figure 1 , Figure 1 This is a main topological structure diagram of a single-phase four-level rectifier circuit based on a pseudo-totem pole structure provided by the present invention.

[0047] like Figure 1As shown, the single-phase four-level rectifier circuit based on the pseudo-totem pole structure includes: a pseudo-totem pole structure, a bridge arm voltage regulation module, multiple switch tubes, a fifth diode D5, a sixth diode D6 and an AC power supply ug; the pseudo-totem pole structure includes: a first switch tube S1, a second switch tube S2, a first inductor L1, a second inductor L2, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; the bridge arm voltage regulation module includes: a first capacitor C1, a second capacitor C2 and a third capacitor C3; the multiple switch tubes include: a third switch tube S3, a fourth switch tube S4, a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7 and an eighth switch tube S8. The first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are fully controlled power switch tubes.

[0048] like Figure 1 As shown, the first diode D1, the second diode D2, the third diode D3, the fourth diode D4, the first switch tube S1, the second switch tube S2, the first inductor L1 and the second inductor L2 form a pseudo totem pole structure.

[0049] like Figure 1 As shown, the AC power supply u g The first end of the first inductor L1 is connected to the second end of the first inductor L1 and the second end of the second inductor L2 respectively. The first end of the first inductor L1 is connected to the anode of the second diode D2 and the drain of the first switch tube S1 and connected to the end point a. The first end of the second inductor L2 is connected to the cathode of the third diode D3 and the source of the second switch tube S2 and connected to the end point b. The AC power supply u g The second end of is respectively connected to the anode of the fifth diode D5 and the cathode of the sixth diode D6 and is connected to the end point n; the source of the first switch tube S1 is respectively connected to the anode of the fourth diode D4, the anode of the sixth diode D6 and the negative electrode of the load; the cathode of the first diode D1 is respectively connected to the drain of the second switch tube S2, the cathode of the fifth diode D5 and the positive electrode of the load; the bridge arm voltage regulation module and the first switch tube S1, the second switch tube S2 and different combination states of multiple switch tubes constitute multiple different loops with the bridge arm to adjust the bridge arm voltage through multiple different loops.

[0050] The drain of the third switch tube S3 is connected to the cathode of the second diode D2 and the anode of the first diode D1, the source of the third switch tube S3 is connected to the drain of the fourth switch tube S4, the drain of the fifth switch tube S5, and the source of the seventh switch tube S7; the source of the fourth switch tube S4 is connected to the anode of the third diode D3 and the cathode of the fourth diode D4, the source of the fifth switch tube S5 is connected to the source of the sixth switch tube S6, the drain of the sixth switch tube S6 is connected to the negative electrode of the first capacitor C1 and the positive electrode of the second capacitor C2, and is connected to the end point e; the drain of the seventh switch tube S7 is connected to the drain of the eighth switch tube S8, the source of the eighth switch tube S8 is connected to the negative electrode of the second capacitor C2 and the positive electrode of the third capacitor C3, and is connected to the end point f.

[0051] In an embodiment of the present invention, the first capacitor C1, the second capacitor C2 and the third capacitor C3 are series split capacitors. Optionally, the first capacitor C1, the second capacitor C2 and the third capacitor C3 are the same capacitors, and each capacitor withstands one-third of the DC bus voltage. The bridge arm voltage regulation module composed of the first capacitor C1, the second capacitor C2 and the third capacitor C3 and the different combination states of the first switch tube S1 to the eighth switch tube S8 can form multiple different loops with the bridge arm, thereby changing the bridge arm voltage. When the bridge arm current loop only flows through one of the three split capacitors, the bridge arm voltage is ±1 / 3U dc， Realize ±1 / 3U in four-level dc Similarly, when the bridge arm current loop flows through different numbers of split capacitors, the four levels of 0, ±2 / 3U are realized respectively. dc , ±U dc .

[0052] Optionally, in an embodiment of the present invention, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are any one of an insulated gate bipolar transistor, an integrated gate commutated thyristor and a power field effect transistor. Among them, different combination states of the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 can produce multiple level outputs in conjunction with three split capacitors. By controlling the conduction and shutdown of these switch tubes, the bridge arm voltage can be converted into a plurality of different levels of DC voltage outputs, so as to be closer to the ideal sinusoidal voltage. Moreover, the switch tube cooperates with energy storage elements such as inductors and capacitors to realize energy conversion and transmission, ensuring that the load can obtain a stable DC voltage and power supply.

[0053] The specific parameters of the line can be: AC power supply u gThe effective value of the voltage is 220V, the frequency is 50Hz, and the DC side output voltage U dc =400V, inductor L1=L2=2mH, capacitor C1=C2=C3=4700μF, switching frequency fs=20kHz, load R L =50Ω.

[0054] The first diode D1 generates +U for the bridge arm voltage in the positive half cycle of the AC. dc The second diode D2 generates +1 / 3U for the bridge arm voltage in the positive half cycle of the AC. dc 、+2 / 3U dc The third diode D3 generates -1 / 3U for the bridge arm voltage in the negative half cycle of the AC. dc 、-2 / 3U dc , -U dc The fourth diode D4 generates -U for the bridge arm voltage in the negative half cycle of the AC. dc The level forms a loop; at the same time, the bridge arm voltage generates -1 / 3U dc 、-2 / 3U dc The fifth diode D5 blocks the reverse current in the negative half cycle of the AC power supply u g The negative electrode provides a path for outflow; the bridge arm voltage generates a 0 level to charge the inductor L2; at the same time, the bridge arm voltage generates +U dc The sixth diode D6 generates 0 and +U for the bridge arm voltage in the positive half cycle of AC. dc 、+2 / 3U dc 、+1 / 3U dc The voltage level forms a loop; the bridge arm voltage generates a 0 level to charge the inductor L1; at the same time, the bridge arm voltage generates -1 / 3U dc 、-1 / 3U dc When the voltage is high, the reverse current is blocked.

[0055] The single-phase four-level rectifier circuit based on the pseudo-totem pole structure has the functions of boosting and rectifying. The three equal-value capacitors on the DC side are connected in series to realize the four-level circuit. The voltage stress of the power device is low, and low-cost switching devices can be selected to reduce costs. Among them, the boost function is realized by the first inductor L1 and the second inductor L2. The inductor has an energy storage function. The energy stored in the inductor flows on the AC input side. After the inductor stores energy, it is connected in series with the power supply and acts on the output end to boost the voltage. The rectification function can be realized by the first switch tube S1 to the eighth switch tube S8 and the first diode D1 to the sixth diode D6.

[0056] In addition, the front end of the single-phase four-level rectifier circuit based on the pseudo-totem pole structure of the present invention adopts a pseudo-totem pole structure, and two identical inductors are connected in parallel in the circuit to boost the voltage, which reduces the nominal value and volume of the boost inductor and the output capacitor, and the overall design of the AC side filter composed of the first inductor L1 and the second inductor L2 and the DC side filter composed of the first capacitor C1, the second capacitor C2 and the third capacitor C3 can be modularized in a small volume, which is more conducive to installation and application. Among them, the first inductor L1 and the second inductor L2 are two equal-value inductors, which can filter out high-order harmonic components. Specifically, when the input voltage is not directly applied to both ends of the inductor, in order to maintain its current unchanged, the inductor will generate an induced electromotive force so that the inductor current can continue to flow. It is in the same direction as the input voltage. After the two are connected in series, they act together on the output end, thereby achieving boost; the inductor L1 and the inductor L2 store energy, release energy, and superimpose this part of energy on the input voltage, so that the output voltage is higher than the input voltage, and the output voltage U is increased. dc The DC side filter composed of the first capacitor C1, the second capacitor C2 and the third capacitor C3 mainly filters out the DC pulsating voltage component.

[0057] Furthermore, the four-level rectifier circuit used in the present invention is advantageous for reducing the volume of the filter inductor, reducing the harmonic content, achieving a higher power level, and realizing power output in any fault state compared to the traditional two-level rectifier circuit and the three-level rectifier circuit, thereby improving the reliability of the topology to a certain extent. For example, in a three-level rectifier power supply, the maximum voltage borne by the switch tube is half of the bus voltage, but the freewheeling diode needs to withstand the total bus voltage at most, while in a four-level rectifier power supply, the voltage stress borne by the switch tube and the diode is further reduced, which helps to select devices with a lower withstand voltage level, thereby reducing costs and improving the reliability and efficiency of the system; the output voltage of the four-level rectifier power supply has more level states, and its output voltage ripple is smaller than that of the three-level rectifier power supply. Smaller output voltage ripple means that the output voltage is more stable, which can provide a better quality power supply for the subsequent circuit, reduce the impact of voltage fluctuations on the performance of the subsequent circuit, and is particularly suitable for applications with high requirements for power supply stability.

[0058] At the same time, the present invention also retains the advantages of the pseudo-totem pole power factor correction circuit, such as no bridge arm direct-through hidden danger, no switch tube body diode reverse recovery problem, high reliability, high efficiency, etc.

[0059] In an embodiment of the present invention, a single-phase four-level rectifier circuit includes: eight working modes; the eight working modes include: four working modes of a positive half cycle and four working modes of a negative half cycle; the four working modes of the positive half cycle include: a first working mode, a second working mode, a third working mode and a fourth working mode; the four working modes of the negative half cycle include: a fifth working mode, a sixth working mode, a seventh working mode and an eighth working mode.

[0060] Specifically, refer to Figures 2 to 9 , which are different working modes of the single-phase four-level rectifier circuit based on the pseudo totem pole structure provided by the present invention under CCM mode operation.

[0061] The first working mode: the circuit works in the positive half cycle of the grid voltage. Figure 2 As shown, when in the first working mode, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current passes through the first inductor L1, the second diode D2, the first diode D1, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the sixth diode D6 in sequence to form a path; the AC power supply u g , the first inductor L1 together charges the first capacitor C1, the second capacitor C2 and the third capacitor C3. At this time, the charging current is i g -i dc , the load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =+U dc , voltage u between endpoint b and endpoint N bN =u g .

[0062] The second working mode: the circuit works in the positive half cycle of the grid voltage. Figure 3 As shown, when in the second working mode, the third switch tube S3 and the fifth switch tube S5 are turned on, the first switch tube S1, the second switch tube S2, the fourth switch tube S4, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current passes through the first inductor L1, the second diode D2, the third switch tube S3, the fifth switch tube S5, the body diode on the sixth switch tube S6, the second capacitor C2, the third capacitor C3 and the sixth diode D6 in sequence to form a path; the AC power supply u g The second capacitor C2 and the third capacitor C3 are charged, and the first capacitor C1 is discharged to the load. The charging current is equal to i g -i dc , the load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =+2Udc / 3, voltage u between endpoint b and endpoint N bN =u g .

[0063] The third working mode: the circuit works in the positive half cycle of the grid voltage. Figure 4 As shown, when in the third working mode, the third switch tube S3 and the eighth switch tube S8 are turned on, the first switch tube S1, the second switch tube S2, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6 and the seventh switch tube S7 are turned off, and the grid current forms a path through the first inductor L1, the second diode D2, the third switch tube S3, the body diode on the seventh switch tube S7, the eighth switch tube S8, the third capacitor C3 and the sixth diode D6; the AC power supply u g The third capacitor C3 is charged. The charging current is equal to i g -i dc , the load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =+1U dc / 3, voltage u between endpoint b and endpoint N bN =u g .

[0064] The fourth working mode: the circuit works in the positive half cycle of the grid voltage. Figure 5 As shown, when in the fourth working mode, the first switch tube S1 is turned on, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current forms a path through the first inductor L1, the first switch tube S1 and the sixth diode D6; the AC power supply u g The first inductor L1 is charged; the first capacitor C1, the second capacitor C2, the third capacitor C3 and the load form another path; the first capacitor C1, the second capacitor C2 and the third capacitor C3 discharge to the load. The load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =0, voltage u between endpoint b and endpoint N bN =u g .

[0065] The fifth working mode: the circuit works in the negative half cycle of the grid voltage. Figure 6 As shown, when in the fifth working mode, the second switch tube S2 is turned on, the first switch tube S1, the third switch tube S3, the fourth switch tube S4, the fifth switch tube S=, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current forms a path through the fifth diode D5, the second switch tube S2 and the second inductor L2; the AC power supply u gThe second inductor L2 is charged; the first capacitor C1, the second capacitor C2, the third capacitor C3 and the load form another path; the first capacitor C1, the second capacitor C2 and the third capacitor C3 discharge to the load. The load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =u g , voltage u between endpoint b and endpoint N bN =0.

[0066] The sixth working mode: the circuit works in the negative half cycle of the grid voltage. Figure 7 As shown, when in the sixth working mode, the fourth switch tube S4 and the sixth switch tube S6 are turned on, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fifth switch tube S5, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current forms a path through the fifth diode D5, the first capacitor C1, the sixth switch tube S6, the body diode on the fifth switch tube S5, the fourth switch tube S=, the third diode D3 and the second inductor L2; the AC power supply u g The first capacitor C1 is charged; the second capacitor C2 and the third capacitor C3 are discharged to the load. The load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =u g , voltage u between endpoint b and endpoint N bN =-1U dc / 3.

[0067] The seventh working mode: the circuit works in the negative half cycle of the grid voltage. Figure 8 As shown, when in the seventh working mode, the fourth switch tube S4 and the seventh switch tube S7 are turned on, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fifth switch tube S5, the sixth switch tube S6 and the eighth switch tube S8 are turned off, and the grid current forms a path through the fifth diode D5, the first capacitor C1, the second capacitor C2, the body diode on the eighth switch tube S8, the seventh switch tube S7, the fourth switch tube S=, the third diode D3 and the second inductor L2; the AC power supply u g The first capacitor C= and the second capacitor C2 are charged, and the third capacitor C3 is discharged to the load. The load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =u g , voltage u between endpoint b and endpoint N bN =-2U dc / 3.

[0068] The eighth working mode: the circuit works in the negative half cycle of the grid voltage. Fig. 9As shown, when in the eighth working mode, the first switch tube S=, the second switch tube S2, the third switch tube S3, the fourth switch tube S=, the fifth switch tube S5, the sixth switch tube S=, the seventh switch tube S7 and the eighth switch tube S8 are turned off, and the grid current forms a path through the fifth diode D=, the first capacitor C=, the second capacitor C2, the third capacitor C3, the fourth diode, the third diode D3, and the second inductor L2; the AC power supply u g The second inductor L2 charges the first capacitor C1, the second capacitor C2 and the third capacitor C=. The load current is equal to i dc In this working mode, the voltage u between terminal a and terminal n is aN =u g , voltage u between endpoint b and endpoint N bN =-U dc .

[0069] Different switch states are combined to obtain 8 modes (i.e. 8 working modes), and each mode corresponds to a level, as shown in Table 1. In the table, "1" represents on and "0" represents off.

[0070] Table 1 Combinations of eight modal switch states

[0071]

[0072] Fig.10 To convert the alternating current i g The AC input current and AC input voltage waveform after multiplying the gain by 10 times, the steady-state AC input current i g The waveform follows the steady-state AC input voltage ug waveform and changes sinusoidally, achieving the purpose of power factor correction.

[0073] Fig.11 , Fig.12 is the steady-state output voltage u of the present invention aN 、u bN From the waveform diagram, it can be seen that the topology of the present invention realizes a four-level waveform in a steady state.

[0074] Fig.13 , Fig.14 are the currents i of the two inductors L1 and L2 of the present invention respectively. L1 、i L2 Waveform diagram. Current i L1 The waveform is 0 in the negative half cycle, that is, the first inductor L1L1 does not work in the negative half cycle, and the current i of the second inductor L2L2 L2 The waveform is 0 in the positive half cycle, that is, the second inductor L2L2 does not work in the positive half cycle. g =i L1 +i L2 , i.e. i L1 、iL2 After the confluence g Can achieve sinusoidal waveform.

[0075] Fig.15 The voltage U of the DC split capacitors C1, C2, and C3 of the present invention is C1 , U C2 , U C3 Waveform diagram. It can be seen from this that the voltage of each series capacitor on the DC side of the present invention can be stabilized at around 133V, and can achieve self-balancing, without the need for an additional voltage self-balancing circuit.

[0076] Fig.16 is the steady-state output voltage U of the present invention dc Waveform, DC output voltage U dc It stabilizes at around 400V, achieving stable DC voltage output.

[0077] The present invention further provides a single-phase four-level rectifier power supply, comprising a single-phase four-level rectifier circuit based on a pseudo-totem pole structure disclosed in an embodiment of the present invention.

[0078] The present invention further provides an electronic device, comprising the single-phase four-level rectifier circuit based on the pseudo-totem pole structure disclosed in an embodiment of the present invention.

[0079] The present invention adopts the four-level technology to enable each switch device to withstand one-third of the bus voltage when the rectifier power supply is running, and under the same DC side voltage conditions, the voltage change rate of the power switch tube in the rectifier power supply with a four-level structure is smaller, and the system fluctuation is smoother. Therefore, the use of a four-level structure helps to make the rectifier power supply more resistant to high voltage, lower cost, and can also output a stable DC voltage with good stability.

[0080] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0081] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0082] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0083] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A single-phase four-level rectifier circuit based on a pseudo-totem pole structure, characterized in that: include: A pseudo totem pole structure, a bridge arm voltage regulating module, a plurality of switch tubes, a fifth diode, a sixth diode and an AC power supply; The pseudo totem pole structure includes: a first switch tube, a second switch tube, a first inductor, a second inductor, a first diode, a second diode, a third diode and a fourth diode; The first end of the AC power source is respectively connected to the second end of the first inductor and the second end of the second inductor, the first end of the first inductor is respectively connected to the anode of the second diode and the drain of the first switch tube and connected to terminal a, the first end of the second inductor is respectively connected to the cathode of the third diode and the source of the second switch tube and connected to terminal b, and the second end of the AC power source is respectively connected to the anode of the fifth diode and the cathode of the sixth diode and connected to terminal n; The source of the first switch tube is respectively connected to the anode of the fourth diode, the anode of the sixth diode and the negative electrode of the load; the cathode of the first diode is respectively connected to the drain of the second switch tube, the cathode of the fifth diode and the positive electrode of the load; The bridge arm voltage regulating module and the first switch tube, the second switch tube and different combination states of the multiple switch tubes form multiple different loops with the bridge arm to regulate the bridge arm voltage through the multiple different loops.

2. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 1, characterized in that: The bridge arm voltage regulation module includes: a first capacitor, a second capacitor and a third capacitor; the multiple switch tubes include: a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube; The drain of the third switch tube is connected to the cathode of the second diode and the anode of the first diode, and the source of the third switch tube is connected to the drain of the fourth switch tube, the drain of the fifth switch tube, and the source of the seventh switch tube; The source of the fourth switch tube is connected to the anode of the third diode and the cathode of the fourth diode, the source of the fifth switch tube is connected to the source of the sixth switch tube, and the drain of the sixth switch tube is connected to the negative electrode of the first capacitor and the positive electrode of the second capacitor and connected to the terminal e; The drain of the seventh switch tube is connected to the drain of the eighth switch tube, and the source of the eighth switch tube is connected to the negative electrode of the second capacitor and the positive electrode of the third capacitor and connected to the end point f.

3. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 2, characterized in that: The first capacitor, the second capacitor and the third capacitor are series split capacitors.

4. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 2, characterized in that: The first capacitor, the second capacitor and the third capacitor are the same capacitor, and each capacitor bears one third of the DC bus voltage.

5. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 2, characterized in that: The first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are any one of insulated gate bipolar transistors, integrated gate-commutated thyristors and power field effect transistors.

6. The single-phase four-level rectifier circuit based on the pseudo-totem pole structure according to claim 2, characterized in that: The single-phase four-level rectifier circuit includes: eight working modes; the eight working modes include: four working modes of the positive half cycle and four working modes of the negative half cycle; the four working modes of the positive half cycle include: a first working mode, a second working mode, a third working mode and a fourth working mode; the four working modes of the negative half cycle include: a fifth working mode, a sixth working mode, a seventh working mode and an eighth working mode.

7. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 6, characterized in that: When in the first working mode, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current passes through the first inductor, the second diode, the first diode, the first capacitor, the second capacitor, the third capacitor and the sixth diode in sequence to form a path; the AC power supply and the first inductor jointly charge the first capacitor, the second capacitor and the third capacitor; When in the second working mode, the third switch tube and the fifth switch tube are turned on, the first switch tube, the second switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current passes through the first inductor, the second diode, the third switch tube, the fifth switch tube, the body diode on the sixth switch tube, the second capacitor, the third capacitor and the sixth diode in sequence to form a path; the AC power supply charges the second capacitor and the third capacitor, and the first capacitor discharges to the load; When in the third working mode, the third switch tube and the eighth switch tube are turned on, the first switch tube, the second switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube are turned off, and the grid current forms a path through the first inductor, the second diode, the third switch tube, the body diode on the seventh switch tube, the eighth switch tube, the third capacitor and the sixth diode; the AC power supply charges the third capacitor; When in the fourth working mode, the first switch tube is turned on, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, the grid current forms a path through the first inductor, the first switch tube and the sixth diode; the AC power supply charges the first inductor; the first capacitor, the second capacitor, the third capacitor and the load form another path; the first capacitor, the second capacitor and the third capacitor discharge to the load.

8. The single-phase four-level rectifier circuit based on the pseudo totem pole structure according to claim 6, characterized in that: When in the fifth working mode, the second switch tube is turned on, the first switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the second switch tube and the second inductor; the AC power supply charges the second inductor; the first capacitor, the second capacitor, the third capacitor and the load form another path; the first capacitor, the second capacitor and the third capacitor discharge to the load; When in the sixth working mode, the fourth switch tube and the sixth switch tube are turned on, the first switch tube, the second switch tube, the third switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the sixth switch tube, the body diode on the fifth switch tube, the fourth switch tube, the third diode and the second inductor; the AC power supply charges the first capacitor; the second capacitor and the third capacitor discharge to the load; When in the seventh working mode, the fourth switch tube and the seventh switch tube are turned on, the first switch tube, the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the second capacitor, the body diode on the eighth switch tube, the seventh switch tube, the fourth switch tube, the third diode and the second inductor; the AC power supply charges the first capacitor and the second capacitor, and the third capacitor discharges to the load; When in the eighth working mode, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are turned off, and the grid current forms a path through the fifth diode, the first capacitor, the second capacitor, the third capacitor, the fourth diode, the third diode and the second inductor; the AC power supply and the second inductor charge the first capacitor, the second capacitor and the third capacitor.

9. A single-phase four-level rectifier power supply, characterized in that: include: A single-phase four-level rectifier circuit based on a pseudo-totem pole structure as described in any one of claims 1 to 8.

10. An electronic device, characterized in that: include: A single-phase four-level rectifier circuit based on a pseudo-totem pole structure as described in any one of claims 1 to 8.

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