An inverter, circuit and control method

Abstract

The embodiment of the application discloses an inverter, a circuit and a control method. The method comprises the following steps: assigning corresponding control signals to the switch tubes in the first bridge arm and the switch tubes in the second bridge arm respectively; in a half cycle when the inverter output voltage is positive, the first type of designated switch tubes in the second bridge arm are continuously turned on, and the designated switch tubes in the first bridge arm are complementarily turned on and turned off; in a half cycle when the inverter output voltage is negative, the second type of designated switch tubes in the second bridge arm are continuously turned on, and the designated switch tubes in the first bridge arm are complementarily turned on and turned off. The scheme provided by the application can improve the original full-bridge inverter circuit topology and provide a corresponding control method, so that the technical effect of improving the efficiency is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication technology application, and particularly relates to an inverter, a circuit and a control method. BACKGROUND

[0002] With the rapid development of information technology, in order to ensure the continuous power supply of the AC power supply of the machine room, data center and its peripheral equipment, an inverter power supply system is adopted, that is, the low-voltage DC power supply of the communication power supply is converted into AC power. In the application of the communication industry, after the low-voltage DC is boosted, the required sinusoidal AC power is obtained through the full-bridge circuit and sinusoidal pulse width modulation (SPWM).

[0003] Under the trend of green and low-carbon development of energy, the communication industry has higher requirements for the efficiency of the inverter. The traditional small and medium power single-phase full-bridge inverter usually adopts single-polarity modulation or bipolar modulation, but not limited to these two modulation methods. Compared with each other, the two have advantages and disadvantages. In the application of bipolar modulation, the efficiency of the inverter is low, the main reason of which is that each switch tube is in a high-frequency SPWM state in each cycle. With the increase of frequency, the switching loss increases accordingly, and the loss caused by the difference in the characteristics of the freewheeling diode when the switch tube is turned off. However, the output voltage harmonic content is low, the total harmonic distortion (THD) value is low, and there is no distortion problem at the zero-crossing point of the output voltage. Single-polarity modulation only needs one bridge arm to work in a high-frequency SPWM state, and the other bridge arm works in a power frequency of 50Hz state. The control method is simple and the efficiency is high, but there is a zero-crossing distortion problem. In the application of small and medium power single-phase full-bridge inverters, the main switch tubes used are two kinds: insulated gate bipolar transistors (IGBT) and metal-oxide-semiconductor field-effect transistors (MOSFET). No matter what kind of modulation method is used, the switch tube needs to work in a high-frequency state. The switching characteristics of MOSFET are better than those of IGBT, and MOSFET has an advantage in efficiency application. However, the reverse recovery characteristics of the parasitic diode of MOSFET are poor, which restricts its application in high-frequency and current flow function required topologies.

[0004] In the regulations of the communication industry for communication inverters, it is required that the communication inverter needs to have the function of driving reactive power.

[0005] In view of the above problem that the prior art cannot guarantee high conversion efficiency while also having the function of transmitting reactive power, no effective solution has been proposed. SUMMARY

[0006] To solve the above technical problems, the embodiments of the present application expect to provide an inverter, a circuit and a control method to at least solve the problem that the prior art cannot guarantee high conversion efficiency while also having the function of transmitting reactive power.

[0007] The technical solution of the present application is implemented as follows:

[0008] In a first aspect, the embodiments of the present application provide a circuit, comprising: a power supply, an inverter and a filter, wherein the power supply is connected to the input end of the inverter, the output end of the inverter is connected to the input end of the filter, wherein the inverter comprises: a first bridge arm, a second bridge arm, a diode group and an inductor, the first bridge arm is coupled to the power supply, the second bridge arm is connected in parallel with the first bridge arm, the diode group is connected with the first bridge arm and the second bridge arm respectively, the output end of the inductor is connected in series with the filter and coupled to the first bridge arm and the second bridge arm.

[0009] Optionally, the power supply comprises: a direct current power supply.

[0010] Optionally, the filter comprises: an electromagnetic interference filter.

[0011] Optionally, the first bridge arm comprises: a first MOSFET switch tube, a second MOSFET switch tube, a third MOSFET switch tube, a fourth MOSFET switch tube and a first diode group, wherein the first MOSFET switch tube, the second MOSFET switch tube, the third MOSFET switch tube and the fourth MOSFET switch tube are connected in series; the first MOSFET switch tube and the second MOSFET switch tube are connected in reverse series, the third MOSFET switch tube and the fourth MOSFET switch tube are connected in reverse series; each diode in the first diode group is connected in parallel with the first MOSFET switch tube, the second MOSFET switch tube, the third MOSFET switch tube and the fourth MOSFET switch tube respectively.

[0012] Further, optionally, the second bridge arm comprises: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch, and a second diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch are connected in series; the fifth MOSFET switch and the sixth MOSFET switch are connected in reverse series, and the seventh MOSFET switch and the eighth MOSFET switch are connected in reverse series; each diode in the second diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch, respectively.

[0013] Optionally, the diode group comprises: a first diode, a second diode, a third diode, and a fourth diode, wherein the first diode is connected in reverse parallel with the first MOSFET switch and the second MOSFET switch; the second diode is connected in reverse parallel with the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in reverse parallel with the fifth MOSFET switch and the sixth MOSFET switch; and the fourth diode is connected in reverse parallel with the seventh MOSFET switch and the eighth MOSFET switch.

[0014] Further, optionally, the first output point is located between the second MOSFET switch and the third MOSFET switch, the second output point is located between the sixth MOSFET switch and the seventh MOSFET switch, the inductor and the filter are connected in series and coupled to the first output point and the second output point.

[0015] In a second aspect, an inverter is provided, comprising: a first bridge arm, a second bridge arm, a diode group and an inductor, wherein the first bridge arm is coupled to a power supply, the second bridge arm is in parallel with the first bridge arm, the diode group is connected to the first bridge arm and the second bridge arm respectively, and the inductor is in series with a filter and coupled to the first bridge arm and the second bridge arm; the first bridge arm comprises: a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, a fourth MOSFET switch and a first diode group, wherein the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch are connected in series; the first MOSFET switch and the second MOSFET switch are connected in reverse series, and the third MOSFET switch and the fourth MOSFET switch are connected in reverse series; each diode in the first diode group is connected in parallel with the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch respectively; the second bridge arm comprises: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch and a second diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch are connected in series; the fifth MOSFET switch and the sixth MOSFET switch are connected in reverse series, and the seventh MOSFET switch and the eighth MOSFET switch are connected in reverse series; each diode in the second diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch respectively; the diode group comprises: a first diode, a second diode, a third diode and a fourth diode, wherein the first diode is connected in reverse parallel with the first MOSFET switch and the second MOSFET switch; the second diode is connected in reverse parallel with the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in reverse parallel with the fifth MOSFET switch and the sixth MOSFET switch; the fourth diode is connected in reverse parallel with the seventh MOSFET switch and the eighth MOSFET switch; a first output point is located between the second MOSFET switch and the third MOSFET switch, a second output point is located between the sixth MOSFET switch and the seventh MOSFET switch, the inductor is in series with the filter and coupled to the first output point and the second output point.

[0016] In a third aspect, the embodiments of the present application provide a control method of an inverter, applied to the above-mentioned circuit, comprising: assigning corresponding control signals to the switch tubes in the first bridge arm and the switch tubes in the second bridge arm respectively; in a half cycle in which the output voltage of the inverter is positive, the first type of designated switch tubes in the second bridge arm are continuously turned on, and the designated switch tubes in the first bridge arm are complementarily turned on and off; in a half cycle in which the output voltage of the inverter is negative, the second type of designated switch tubes in the second bridge arm are continuously turned on, and the designated switch tubes in the first bridge arm are complementarily turned on and off.

[0017] Optionally, the assigning of the corresponding control signals to the switch tubes in the first bridge arm and the switch tubes in the second bridge arm comprises: in the case where the first bridge arm comprises a first MOSFET switch tube, a second MOSFET switch tube, a third MOSFET switch tube and a fourth MOSFET switch tube, the control signal corresponding to the first MOSFET switch tube is a first control signal, the control signal corresponding to the second MOSFET switch tube is a second control signal, the control signal corresponding to the third MOSFET switch tube is a third control signal, and the control signal corresponding to the fourth MOSFET switch tube is a fourth control signal; wherein the first control signal and the third control signal are complementary, and are used to control the first MOSFET switch tube and the third MOSFET switch tube to be complementarily turned on and off; in the case where the second bridge arm comprises a fifth MOSFET switch tube, a sixth MOSFET switch tube, a seventh MOSFET switch tube and an eighth MOSFET switch tube, the control signal corresponding to the fifth MOSFET switch tube is a fifth control signal, the control signal corresponding to the sixth MOSFET switch tube is a sixth control signal, the control signal corresponding to the seventh MOSFET switch tube is a seventh control signal, and the control signal corresponding to the eighth MOSFET switch tube is an eighth control signal; wherein the fifth control signal and the seventh control signal are complementary, and are used to control the fifth MOSFET switch tube and the seventh MOSFET switch tube to be complementarily turned on and off.

[0018] Further, optionally, the first type of designated switch tubes comprise the seventh MOSFET switch tube and the eighth MOSFET switch tube, the second type of designated switch tubes comprise the fifth MOSFET switch tube and the sixth MOSFET switch tube, and the designated switch tubes in the first bridge arm comprise the first MOSFET switch tube and the third MOSFET switch tube.

[0019] The embodiment of the present application provides a kind of inverter, circuit and control method.The corresponding control signal is respectively assigned to the switch tube in the first bridge arm and the switch tube in the second bridge arm;In the half cycle that inverter output voltage is positive, the first type designated switch tube in the second bridge arm is continuously turned on, and the designated switch tube in the first bridge arm is complementary on-off;In the half cycle that inverter output voltage is negative, the second type designated switch tube in the second bridge arm is continuously turned on, and the designated switch tube in the first bridge arm is complementary on-off, so that the original full-bridge inverter circuit topology can be improved, and the corresponding control method is provided to improve the technical effect of efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are used to provide further understanding of the present application, form part of the present application, the illustrative embodiment of the present application and its description are used to explain the present application, and do not constitute improper limitation to the present application.In the drawings:

[0021] Figure 1 A schematic diagram of a circuit provided for the first embodiment of the present application is shown in the figure;

[0022] Figure 2 A flowchart of the control method of the inverter provided for the third embodiment of the present application is shown in the figure;

[0023] Figure 3 A schematic diagram of the control timing in the control method of the inverter provided for the third embodiment of the present application is shown in the figure;

[0024] Figure 4 A schematic diagram of the timing of positive half cycle in the control method of the inverter provided for the third embodiment of the present application is shown in the figure;

[0025] Figure 5 A schematic diagram of the timing of negative half cycle in the control method of the inverter provided for the third embodiment of the present application is shown in the figure;

[0026] Figures 6A-6E A schematic diagram of the working mode of the timing in the control method of the inverter provided for the third embodiment of the present application is shown in the figure; Figure 4

[0027] Figures 7A-7D A schematic diagram of the working mode of the timing in another control method of the inverter provided for the third embodiment of the present application is shown in the figure; Figure 4

[0028] Figures 8A-8E A schematic diagram of the working mode of the timing in the control method of the inverter provided for the third embodiment of the present application is shown in the figure; Figure 5

[0029] Figures 9A-9D A schematic diagram of the working mode of the timing in the control method of the inverter provided for the third embodiment of the present application is shown in the figure.​​​Figure 5 schematic diagram of the working mode. DETAILED DESCRIPTION

[0030] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor should belong to the protection scope of the present application.

[0031] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the accompanying drawings are used to distinguish different objects, and are not used to limit a specific sequence.

[0032] It should also be noted that each of the following embodiments of the present application can be executed alone, and each of the embodiments can also be executed in combination with each other, and the embodiments of the present application do not specifically limit this.

[0033] Embodiment one

[0034] In a first aspect, the embodiments of the present application provide a circuit, Figure 1 A schematic diagram of the circuit provided by the embodiment one of the present application is shown in the figure. Figure 1 As shown, the circuit provided by the embodiments of the present application includes:

[0035] The power supply 110, the inverter 100 and the filter 140, wherein the power supply 110 is connected with the input end of the inverter 100, the output end of the inverter 100 is connected with the input end of the filter 140, wherein the inverter 100 includes: the first bridge arm 120, the second bridge arm 130, the diode group and the inductor, the first bridge arm 120 is coupled to the power supply 110, the second bridge arm 130 is connected with the first bridge arm 120 in parallel, the diode group is connected with the first bridge arm 120 and the second bridge arm 130 respectively, the output end of the inductor is connected with the filter 140 in series and is coupled to the first bridge arm 120 and the second bridge arm 130.

[0036] Optionally, the power supply 110 includes: a direct current power supply.

[0037] Optionally, the filter 140 includes: an electromagnetic interference filter.

[0038] The electromagnetic interference filter can be an EMI filter.

[0039] Optionally, the first bridge arm 120 comprises: a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, a fourth MOSFET switch and a first diode group, wherein the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch are connected in series; the first MOSFET switch and the second MOSFET switch are connected in anti-parallel, and the third MOSFET switch and the fourth MOSFET switch are connected in anti-parallel; each diode in the first diode group is connected in parallel with the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch respectively.

[0040] Further, optionally, the second bridge arm 130 comprises: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch and a second diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch are connected in series; the fifth MOSFET switch and the sixth MOSFET switch are connected in anti-parallel, and the seventh MOSFET switch and the eighth MOSFET switch are connected in anti-parallel; each diode in the second diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch respectively.

[0041] Optionally, the diode group comprises: a first diode, a second diode, a third diode and a fourth diode, wherein the first diode is connected in anti-parallel with the first MOSFET switch and the second MOSFET switch; the second diode is connected in anti-parallel with the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in anti-parallel with the fifth MOSFET switch and the sixth MOSFET switch; and the fourth diode is connected in anti-parallel with the seventh MOSFET switch and the eighth MOSFET switch.

[0042] Further, optionally, the first output point is located between the second MOSFET switch and the third MOSFET switch, the second output point is located between the sixth MOSFET switch and the seventh MOSFET switch, the inductor is connected in series with the filter and coupled to the first output point and the second output point.

[0043] Specifically, as shown in FIG. 1, the first bridge arm 120 comprises: a first MOSFET switch Q1, a second MOSFET switch Q2, a third MOSFET switch Q3, a fourth MOSFET switch Q4 and a first diode group D1, wherein the first MOSFET switch Q1, the second MOSFET switch Q2, the third MOSFET switch Q3 and the fourth MOSFET switch Q4 are connected in series; the first MOSFET switch Q1 and the second MOSFET switch Q2 are connected in anti-parallel, and the third MOSFET switch Q3 and the fourth MOSFET switch Q4 are connected in anti-parallel; each diode in the first diode group D1 is connected in parallel with the first MOSFET switch Q1, the second MOSFET switch Q2, the third MOSFET switch Q3 and the fourth MOSFET switch Q4 respectively. Figure 1As shown, the first MOSFET switch is denoted as S1, the second MOSFET switch is denoted as S2, the third MOSFET switch is denoted as S3, the fourth MOSFET switch is denoted as S4, the fifth MOSFET switch is denoted as S5, the sixth MOSFET switch is denoted as S6, the seventh MOSFET switch is denoted as S7, and the eighth MOSFET switch is denoted as S8; the first diode is denoted as D1, the second diode is denoted as D2, the third diode is denoted as D3, and the fourth diode is denoted as D4; wherein S1 and S2 are connected in reverse series, D1 is connected in reverse parallel with S1 and S2; S3 and S4 are connected in reverse series, D2 is connected in reverse parallel with S3 and S4; S5 and S6 are connected in reverse series, D3 is connected in reverse parallel with S5 and S6; S7 and S8 are connected in reverse series, and D4 is connected in reverse parallel with S7 and S8.

[0044] The first output point is denoted as point a, the second output point is denoted as point b, and the inductor is denoted as L1, wherein the first output point a is located between the second MOSFET switch S2 and the third MOSFET switch S3 of the first bridge arm, the second output point b is located between the sixth MOSFET switch S6 and the seventh MOSFET switch S7 of the second bridge arm, the inductor L1 is connected in series with the EMI filter 140 and is coupled to the first output point a and the second output point b.

[0045] In the embodiment of the present application, the first type of diode is located in the first bridge arm 120, and each diode in the first type of diode is connected in parallel with the corresponding S1-S4; the second type of diode is located in the second bridge arm 130, and each diode in the second type of diode is connected in parallel with the corresponding S5-S8.

[0046] The circuit provided by the embodiment of the present application realizes the full-bridge inverter by applying MOSFET through additional circuit design, realizes the purpose of reactive and active output through external diodes, realizes the optimization of the freewheeling path by reversely connecting low-voltage MOSFET switches, avoids the freewheeling path through the body diode of the main MOSFET switch, effectively reduces the switching loss generated when applying MOSFET, and optimizes the efficiency of the inverter.

[0047] The embodiment of the present application provides a circuit. The circuit comprises a power supply, an inverter and a filter, wherein the power supply is connected with the input end of the inverter, the output end of the inverter is connected with the input end of the filter, wherein the inverter comprises a first bridge arm, a second bridge arm, a diode group and an inductor, the first bridge arm is coupled to the power supply, the second bridge arm is connected in parallel with the first bridge arm, the diode group is connected with the first bridge arm and the second bridge arm respectively, and the output end of the inductor is connected in series with the filter and is coupled to the first bridge arm and the second bridge arm, so that the original full-bridge inverter circuit topology can be improved, and the corresponding control method is provided to improve the technical effect of efficiency.

[0048] Embodiment two

[0049] In a second aspect, the embodiments of the present application provide an inverter, comprising: a first bridge arm, a second bridge arm, a diode group and an inductor, wherein the first bridge arm is coupled to a power supply, the second bridge arm is connected in parallel with the first bridge arm, the diode group is connected with the first bridge arm and the second bridge arm respectively, and the inductor is connected in series with a filter and coupled to the first bridge arm and the second bridge arm; the first bridge arm comprises: a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, a fourth MOSFET switch and a first diode group, wherein the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch are connected in series; the first MOSFET switch and the second MOSFET switch are connected in reverse series, and the third MOSFET switch and the fourth MOSFET switch are connected in reverse series; each diode in the first diode group is connected in parallel with the first MOSFET switch, the second MOSFET switch, the third MOSFET switch and the fourth MOSFET switch respectively; the second bridge arm comprises: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch and a second diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch are connected in series; the fifth MOSFET switch and the sixth MOSFET switch are connected in reverse series, and the seventh MOSFET switch and the eighth MOSFET switch are connected in reverse series; each diode in the second diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch and the eighth MOSFET switch respectively; the diode group comprises: a first diode, a second diode, a third diode and a fourth diode, wherein the first diode is connected in reverse parallel with the first MOSFET switch and the second MOSFET switch; the second diode is connected in reverse parallel with the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in reverse parallel with the fifth MOSFET switch and the sixth MOSFET switch; the fourth diode is connected in reverse parallel with the seventh MOSFET switch and the eighth MOSFET switch; a first output point is located between the second MOSFET switch and the third MOSFET switch, a second output point is located between the sixth MOSFET switch and the seventh MOSFET switch, the inductor is connected in series with the filter and coupled to the first output point and the second output point.

[0050] In particular, the inverter provided by the embodiments of the present application can be the inverter 100 in Embodiment 1.

[0051] The embodiment of the present application provides an inverter. The first bridge arm is coupled to the power supply, the second bridge arm is parallel to the first bridge arm, the diode groups are connected with the first bridge arm and the second bridge arm respectively, and the output end of the inductor is connected with the filter in series and is coupled to the first bridge arm and the second bridge arm, so that the original full-bridge inverter circuit topology can be improved, and the corresponding control method is provided to improve the technical effect of efficiency.

[0052] Embodiment three

[0053] In a third aspect, the embodiment of the present application provides an inverter control method applied to the circuit in the above-mentioned embodiment 1. Figure 1 Figure 2 A flowchart of the inverter control method provided by the third embodiment of the present application is shown in FIG. 3. Figure 2 The inverter control method provided by the embodiment of the present application comprises the following steps.

[0054] In step S202, the switch tubes in the first bridge arm and the switch tubes in the second bridge arm are respectively assigned corresponding control signals.

[0055] Optionally, in step S202, the switch tubes in the first bridge arm and the switch tubes in the second bridge arm are respectively assigned corresponding control signals, including: in the case that the first bridge arm comprises a first MOSFET switch tube, a second MOSFET switch tube, a third MOSFET switch tube and a fourth MOSFET switch tube, the control signal corresponding to the first MOSFET switch tube is a first control signal, the control signal corresponding to the second MOSFET switch tube is a second control signal, the control signal corresponding to the third MOSFET switch tube is a third control signal, and the control signal corresponding to the fourth MOSFET switch tube is a fourth control signal; wherein the first control signal and the third control signal are complementary and are used for controlling the first MOSFET switch tube and the third MOSFET switch tube to be complementary on and off; in the case that the second bridge arm comprises a fifth MOSFET switch tube, a sixth MOSFET switch tube, a seventh MOSFET switch tube and an eighth MOSFET switch tube, the control signal corresponding to the fifth MOSFET switch tube is a fifth control signal, the control signal corresponding to the sixth MOSFET switch tube is a sixth control signal, the control signal corresponding to the seventh MOSFET switch tube is a seventh control signal, and the control signal corresponding to the eighth MOSFET switch tube is an eighth control signal; wherein the fifth control signal and the seventh control signal are complementary and are used for controlling the fifth MOSFET switch tube and the seventh MOSFET switch tube to be complementary on and off.

[0056] Specifically, the inverter control method provided by the embodiment of the present application can be applied to the circuit in the embodiment 1. When working, the power supply 110 provides a direct current voltage Vdc. Figure 3 ​A schematic diagram of a control timing of a control method of an inverter provided for Embodiment Three of the present application can control the inverter according to the control timing as shown in Figure 3 The control signals G1-G8 (i.e., the first control signal to the eighth control signal in the present application) control the MOSFET switch tubes S1-S8 (i.e., the first MOSFET switch tube to the eighth MOSFET switch tube in the present application) respectively. The first control signal G1 and the second control signal G2 can be controlled to synchronize the first and second MOSFET switch tubes, or the first control signal G1 and the second control signal G2 can be controlled to make the first MOSFET switch on before the second MOSFET switch off, so that the second MOSFET realizes soft switching. The control signals G3 and G4, G5 and G6, G7 and G8 of S3 and S4, S5 and S6, S7 and S8 are similar to the above.

[0057] The first control signal G1 and the third control signal G3 are complementary to each other, so that the two MOSFET switch tubes S1 and S3 are complementary on and off; the fifth control signal G5 and the seventh control signal G7 are complementary to each other, so that the two MOSFET switch tubes S5 and S7 are complementary on and off.

[0058] In step S204, in the half cycle in which the output voltage of the inverter is positive, the first type of specified switch tube in the second bridge arm is continuously turned on, and the specified switch tube in the first bridge arm is complementary on and off.

[0059] The first type of specified switch tube includes the seventh MOSFET switch tube and the eighth MOSFET switch tube; the specified switch tube in the first bridge arm includes the first MOSFET switch tube and the third MOSFET switch tube.

[0060] Specifically, as shown in Figure 3 In the half cycle in which the output voltage of the inverter is positive, the seventh MOSFET switch tube and the eighth MOSFET switch tube are continuously turned on. The first MOSFET switch tube and the third MOSFET switch tube are complementary on and off.

[0061] In step S206, in the half cycle in which the output voltage of the inverter is negative, the second type of specified switch tube in the second bridge arm is continuously turned on, and the specified switch tube in the first bridge arm is complementary on and off.

[0062] The second type of specified switch tube includes the fifth MOSFET switch tube and the sixth MOSFET switch tube; the specified switch tube in the first bridge arm includes the first MOSFET switch tube and the third MOSFET switch tube.

[0063] Specifically, as shown in Figure 3As shown, in the half cycle in which the inverter output voltage is negative, the fifth MOSFET switch and the sixth MOSFET switch are continuously turned on. The first MOSFET switch and the third MOSFET switch are complementary turned on and off.

[0064] When the controller controls the turning on and off of the switch, the inverter works in different working modes. Figure 4 A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figure 5 A timing diagram of a negative half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figures 6A-6E A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figure 4 A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figures 7A-7D A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figure 4 A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figures 8A-8E A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figure 5 A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figures 9A-9D A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in Figure 5 A timing diagram of a positive half cycle in a control method of an inverter according to Embodiment Three of the present application is shown in

[0065] wherein Figures 6A-6E is the first and second working modes, Figures 7A-7D is the third and fourth working modes; Figures 8A-8E is the fifth and sixth working modes, Figures 9A-9D is the seventh and eighth working modes.

[0066] Referring to Figure 4 , Figure 6A In the first working mode, the first MOSFET switch S1 and the seventh MOSFET switch S7 are first turned on. At this time, the current passes through the first MOSFET switch S1, the body diode of the second MOSFET switch S2, the inductor L1, the EMI filter 150, the seventh MOSFET switch S7 and the body diode of the eighth MOSFET switch S8.

[0067] Referring to Figure 4 , Figure 6B, the first MOSFET switch S1, the second MOSFET switch S2, the seventh MOSFET switch S7 and the eighth MOSFET switch S8 are all turned on, at this time, the current passes through the path of the first MOSFET switch S1, the second MOSFET switch S2, the inductor L1, the EMI filter 150, the seventh MOSFET switch S7 and the eighth MOSFET switch S8. The second MOSFET switch and the eighth MOSFET switch form natural commutation with their respective body diodes, and belong to soft turn-on.

[0068] With reference to Figure 4 , Figure 6C , the second MOSFET switch S2 is turned off earlier than the first MOSFET switch S1, and belongs to soft turn-off.

[0069] With reference to Figure 4 , Figure 6D , in the second working mode, all the MOSFET switches of the first bridge arm 120 are in the off state, and the seventh MOSFET switch S7 and the eighth MOSFET switch S8 of the MOSFET switches of the second bridge arm 130 are in the on state. At this time, the inductor current flows through the path of the inductor L1, the EMI filter 140, the seventh MOSFET switch S7, the eighth MOSFET switch S8 and the second diode D2, forming a first freewheeling path.

[0070] With reference to Figure 4 , Figure 6E , in the first working mode or the second mode, when the inverter switches from the positive half cycle to the negative half cycle, the eighth MOSFET switch is turned off earlier than the seventh MOSFET switch, and belongs to soft turn-off.

[0071] With reference to Figure 4 , Figure 7A , in the third working mode, the third MOSFET switch is turned on, and the seventh MOSFET switch S7 and the eighth MOSFET switch S8 are in the on state, at this time, the inductor current flows through the path of the inductor L1, the third MOSFET switch, the fourth MOSFET switch body diode, the eighth MOSFET switch, the seventh MOSFET switch and the EMI filter 140.

[0072] With reference to Figure 4 , Figure 7B, the third MOSFET switch S3, the fourth MOSFET switch S4, the seventh MOSFET switch S7 and the eighth MOSFET switch S8 are all turned on, at this time, the current passes through the third MOSFET switch S3, the fourth MOSFET switch S4, the eighth MOSFET switch S8, the seventh MOSFET switch S7, the EMI filter 140 and the inductor L1. The fourth MOSFET switch S4 and its body diode form natural commutation, which is soft turn-on.

[0073] Referring to Figure 4 , Figure 7C , the fourth MOSFET switch S4 is turned off earlier than the third MOSFET switch S3, which is soft turn-off.

[0074] Referring to Figure 4 , Figure 7D , in the fourth working mode, all the MOSFET switches of the first bridge arm 120 are in the off state, and the seventh MOSFET switch S7 and the eighth MOSFET switch S8 of the MOSFET switches of the second bridge arm 130 are in the on state. At this time, the current passes through the eighth MOSFET switch, the seventh MOSFET switch, the EMI filter 140, the inductor L1 and the first diode D1, forming a second freewheeling path.

[0075] Referring to Figure 5 , Figure 8A , in the fifth working mode, the third MOSFET switch S3 and the fifth MOSFET switch S5 are turned on first, at this time, the current passes through the fifth MOSFET switch S5, the body diode of the sixth MOSFET switch S6, the EMI filter 150, the inductor L1, the third MOSFET switch S3 and the body diode of the fourth MOSFET switch S4.

[0076] Referring to Figure 5 , Figure 8B , the third MOSFET switch S3, the fourth MOSFET switch S4, the fifth MOSFET switch S5 and the sixth MOSFET switch S6 are all turned on, at this time, the current passes through the fifth MOSFET switch S5, the sixth MOSFET switch S6, the EMI filter 150, the inductor L1, the third MOSFET switch S3 and the fourth MOSFET switch S4. The fourth MOSFET switch and the sixth MOSFET switch and their respective body diodes form natural commutation, which is soft turn-on.

[0077] Referring to Figure 5 , Figure 8CThe fourth MOSFET switch S4 is turned off earlier than the third MOSFET switch S3, which belongs to soft turn-off.

[0078] With reference to Figure 5 , Figure 8D In the sixth working mode, all the MOSFET switches of the first bridge arm 120 are turned off, and the fifth MOSFET switch S5 and the sixth MOSFET switch S6 of the MOSFET switches of the second bridge arm 130 are turned on. At this time, the flow path of the inductor current is the EMI filter 140, the inductor L1, the first diode D1, the fifth MOSFET switch S5, and the sixth MOSFET switch S6, forming a third freewheeling path.

[0079] With reference to Figure 5 , Figure 8E In the fifth working mode or the sixth mode, when the inverter switches from the positive half cycle to the negative half cycle, the sixth MOSFET switch is turned off earlier than the fifth MOSFET switch, which belongs to soft turn-off.

[0080] With reference to Figure 5 , Figure 9A In the seventh working mode, the first MOSFET switch S1 is turned on, and the fifth MOSFET switch S5 and the sixth MOSFET switch S6 are turned on. At this time, the flow path of the inductor current is: the first MOSFET switch S1, the second MOSFET switch body diode, the inductor L1, the EMI filter 140, the fifth MOSFET switch S5, and the sixth MOSFET switch S6.

[0081] With reference to Figure 5 , Figure 9B The first MOSFET switch S1, the second MOSFET switch S2, the fifth MOSFET switch S5, and the sixth MOSFET switch S6 are all turned on. At this time, the current passes through the path: the first MOSFET switch S1, the second MOSFET switch S2, the inductor L1, the EMI filter 140, the sixth MOSFET switch S6, and the fifth MOSFET switch S5. The second MOSFET switch S2 and its body diode form a natural commutation, which belongs to soft turn-on.

[0082] With reference to Figure 5 , Figure 9C The second MOSFET switch S2 is turned off earlier than the first MOSFET switch S1, which belongs to soft turn-off.

[0083] With reference to Figure 5 , Figure 9DIn the eighth working mode, all the MOSFET switches of the first bridge arm 120 are in the off state, and the fifth MOSFET switch S5 and the sixth MOSFET switch S6 of the MOSFET switches of the second bridge arm 130 are in the on state. At this time, the circulation path of the inductor current is: the second diode D2, the inductor L1, the EMI filter 140, the sixth MOSFET switch S6, and the fifth MOSFET switch S5, forming the fourth freewheeling path.

[0084] The embodiment of the present application provides a control method. By assigning corresponding control signals to the switches in the first bridge arm and the switches in the second bridge arm respectively; in the half cycle in which the inverter output voltage is positive, the first type of designated switches in the second bridge arm are continuously turned on, and the designated switches in the first bridge arm are complementarily turned on and off; in the half cycle in which the inverter output voltage is negative, the second type of designated switches in the second bridge arm are continuously turned on, and the designated switches in the first bridge arm are complementarily turned on and off, so that the original full-bridge inverter circuit topology can be improved, and the corresponding control method is provided to improve the efficiency.

[0085] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks Figure 1 The functions specified in one or more flows and / or blocks

[0086] These computer program instructions can also be stored in a computer-readable memory that can guide the computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction devices that implement the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks Figure 1 The functions specified in one or more flows and / or blocks

[0087] These computer program instructions can also be loaded into a computer or other programmable data processing device, so that a series of operation steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks Figure 1steps of the functions specified in the one or more blocks.

[0088] The above descriptions are merely specific embodiments of the application, but not intended to limit the protection scope of the application.

Claims

1. A circuit, characterized in that, include: Power supply, inverter, and filter, among which, The power supply is connected to the input terminal of the inverter, and the output terminal of the inverter is connected to the input terminal of the filter. The inverter includes a first bridge arm, a second bridge arm, a diode group, and an inductor. The first bridge arm is coupled to the power supply, the second bridge arm is connected in parallel with the first bridge arm, the diode group is connected to the first bridge arm and the second bridge arm respectively, and the output terminal of the inductor is connected in series with the filter and coupled to the first bridge arm and the second bridge arm. The first bridge arm includes: a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, a fourth MOSFET switch, and a first type of diode group, wherein the first MOSFET switch, the second MOSFET switch, the third MOSFET switch, and the fourth MOSFET switch are connected in series sequentially; the first MOSFET switch and the second MOSFET switch are connected in series in reverse, and the third MOSFET switch and the fourth MOSFET switch are connected in series in reverse; each diode in the first type of diode group is connected in parallel with the first MOSFET switch, the second MOSFET switch, the third MOSFET switch, and the fourth MOSFET switch, respectively. The second bridge arm includes: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch, and a second type of diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch are connected in series sequentially; the fifth MOSFET switch and the sixth MOSFET switch are connected in series in reverse, and the seventh MOSFET switch and the eighth MOSFET switch are connected in series in reverse; each diode in the second type of diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch, respectively. The diode group includes: a first diode, a second diode, a third diode, and a fourth diode, wherein the first diode is connected in reverse parallel to the first MOSFET switch and the second MOSFET switch; the second diode is connected in reverse parallel to the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in reverse parallel to the fifth MOSFET switch and the sixth MOSFET switch; and the fourth diode is connected in reverse parallel to the seventh MOSFET switch and the eighth MOSFET switch. The first output point is located between the second MOSFET switch and the third MOSFET switch, and the second output point is located between the sixth MOSFET switch and the seventh MOSFET switch. The inductor is connected in series with the filter and coupled to the first output point and the second output point.

2. The circuit according to claim 1, characterized in that, The power source includes: a DC power source.

3. The circuit according to claim 1, characterized in that, The filter includes an electromagnetic interference filter.

4. An inverter, characterized in that, include: The first bridge arm, the second bridge arm, the diode group, and the inductor, among which... The first bridge arm is coupled to the power supply, the second bridge arm is connected in parallel with the first bridge arm, the diode group is connected to the first bridge arm and the second bridge arm respectively, and the output terminal of the inductor is connected in series with the filter and coupled to the first bridge arm and the second bridge arm. The first bridge arm includes: a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, a fourth MOSFET switch, and a first type of diode group, wherein the first MOSFET switch, the second MOSFET switch, the third MOSFET switch, and the fourth MOSFET switch are connected in series sequentially; the first MOSFET switch and the second MOSFET switch are connected in series in reverse, and the third MOSFET switch and the fourth MOSFET switch are connected in series in reverse; each diode in the first type of diode group is connected in parallel with the first MOSFET switch, the second MOSFET switch, the third MOSFET switch, and the fourth MOSFET switch, respectively. The second bridge arm includes: a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, an eighth MOSFET switch, and a second type of diode group, wherein the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch are connected in series sequentially; the fifth MOSFET switch and the sixth MOSFET switch are connected in series in reverse, and the seventh MOSFET switch and the eighth MOSFET switch are connected in series in reverse; each diode in the second type of diode group is connected in parallel with the fifth MOSFET switch, the sixth MOSFET switch, the seventh MOSFET switch, and the eighth MOSFET switch, respectively. The diode group includes: a first diode, a second diode, a third diode, and a fourth diode, wherein the first diode is connected in reverse parallel to the first MOSFET switch and the second MOSFET switch; the second diode is connected in reverse parallel to the third MOSFET switch and the fourth MOSFET switch; the third diode is connected in reverse parallel to the fifth MOSFET switch and the sixth MOSFET switch; and the fourth diode is connected in reverse parallel to the seventh MOSFET switch and the eighth MOSFET switch. The first output point is located between the second MOSFET switch and the third MOSFET switch, and the second output point is located between the sixth MOSFET switch and the seventh MOSFET switch. The inductor is connected in series with the filter and coupled to the first output point and the second output point.

5. A control method for an inverter, characterized in that, Applied to the circuit according to any one of claims 1 to 3, comprising: The corresponding control signals are distributed to the switching transistors in the first bridge arm and the second bridge arm, respectively; During the half-cycle when the inverter output voltage is positive, the first type of designated switch in the second bridge arm is continuously turned on, and the designated switches in the first bridge arm are complementary in turning on and off. During the half-cycle when the inverter output voltage is negative, the second type of designated switch in the second bridge arm remains on, while the designated switches in the first bridge arm are complementary in switching on and off.

6. The control method according to claim 5, characterized in that, The process of distributing corresponding control signals to the switching transistors in the first bridge arm and the second bridge arm includes: When the first bridge arm includes a first MOSFET switch, a second MOSFET switch, a third MOSFET switch, and a fourth MOSFET switch, the control signal corresponding to the first MOSFET switch is a first control signal, the control signal corresponding to the second MOSFET switch is a second control signal, the control signal corresponding to the third MOSFET switch is a third control signal, and the control signal corresponding to the fourth MOSFET switch is a fourth control signal; wherein, the first control signal and the third control signal are complementary and are used to control the first MOSFET switch and the third MOSFET switch to be turned on and off complementaryly; When the second bridge arm includes a fifth MOSFET switch, a sixth MOSFET switch, a seventh MOSFET switch, and an eighth MOSFET switch, the control signal corresponding to the fifth MOSFET switch is the fifth control signal, the control signal corresponding to the sixth MOSFET switch is the sixth control signal, the control signal corresponding to the seventh MOSFET switch is the seventh control signal, and the control signal corresponding to the eighth MOSFET switch is the eighth control signal; wherein, the fifth control signal and the seventh control signal are complementary and are used to control the complementary on / off of the fifth MOSFET switch and the seventh MOSFET switch.

7. The control method according to claim 6, characterized in that, The first category of designated switches includes: the seventh MOSFET switch and the eighth MOSFET switch; the second category of designated switches includes: the fifth MOSFET switch and the sixth MOSFET switch; the designated switches in the first bridge arm include: the first MOSFET switch and the third MOSFET switch.

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