Inverter and control method thereof

Abstract

The invention provides an inverter and a control method. The inverter can comprise a controller, an inverter circuit and a power module. The input end of the inverter circuit is used for being connected with a direct-current port, and the output end of the inverter circuit is used for being connected with an alternating-current port. When the inverter works, the controller performs reverse charging on the corresponding switch tube in the inverter circuit by controlling the power supply module so as to control the corresponding switch tube in the inverter circuit to be switched on after charging is finished, so that the inverter circuit performs power conversion. According to the inverter, reverse charging is carried out on the corresponding switching tubes in the inverter circuit through the power supply module, soft opening of the switching tubes in the inverter is achieved, and the inverter has the advantages of being high in switching frequency and small in size.

Description

Technical Field

[0001] The present application relates to the technical field of inverters, and in particular to an inverter and a control method thereof. Background Art

[0002] With the advancement of science and technology, high frequency, miniaturization, high efficiency and low noise have become important indicators for electronic products. During the operation of the switch tube, due to the overlap of voltage and current at the switching moment, hard switching losses will inevitably occur. In practical applications, the existence of hard switching losses limits the switching frequency of the switch tube, which in turn limits the working efficiency of the inverter. Summary of the invention

[0003] In view of the above, the present application provides an inverter and a control method thereof, which are used to solve the problem that the switching frequency of the switch tube in the inverter is limited by the hard switching loss.

[0004] The first aspect of the present application provides an inverter, comprising: a controller, an inverter circuit and a power module. The input end of the inverter circuit is used to connect to a DC port, and the output end of the inverter circuit is used to connect to an AC port. The controller is used to: when the inverter is working, control the power module to reversely charge the corresponding switch tube in the inverter circuit, so as to control the corresponding switch tube in the inverter circuit to conduct after charging is completed, so that the inverter circuit performs power conversion.

[0005] By adopting the inverter of the present application, when the inverter circuit is working, the power module is used to reversely charge the corresponding switch tube in the inverter circuit, so as to control the corresponding switch tube in the inverter circuit to be turned on after the charging is completed, so that the inverter circuit performs power conversion. The inverter of the present application reversely charges the corresponding switch tube in the inverter circuit through the power module, thereby realizing soft opening of each switch tube in the inverter, and has the advantages of high switching frequency, small size and low electromagnetic compatibility.

[0006] According to some embodiments of the present application, the inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the power module includes a fifth switch tube, a sixth switch tube, a seventh switch tube and a bidirectional inductor. The first end of the first switch tube is connected to the first end of the DC port, the second end of the first switch tube is connected to the first end of the third switch tube, the second end of the third switch tube is connected to the second end of the DC port, the first end of the second switch tube is connected to the second end of the DC port, the second end of the second switch tube is connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is connected to the second end of the DC port. The first end of the fifth switch tube is connected to the connection point between the second end of the first switch tube and the first end of the third switch tube, the second end of the fifth switch tube is connected to the first end of the bidirectional inductor, the first end of the sixth switch tube is connected to the connection point between the second end of the second switch tube and the first end of the fourth switch tube, the second end of the sixth switch tube is connected to the second end of the bidirectional inductor, the third end of the bidirectional inductor is connected to the first end of the seventh switch tube, and the second end of the seventh switch tube is connected to the second end of the DC port.

[0007] According to some embodiments of the present application, the controller is used to: when the inverter performs inversion work, in the first time period of the positive half-inversion cycle, control the second switch tube, the sixth switch tube and the seventh switch tube to be turned on, in the second time period of the positive half-inversion cycle, control the second switch tube to be turned off, and in the third time period of the positive half-inversion cycle, control the first switch tube and the fourth switch tube to be turned on. When the inverter performs inversion work, in the first time period of the negative half-inversion cycle, control the first switch tube, and the seventh switch tube to be turned on, in the second time period of the negative half-inversion cycle, control the first switch tube to be turned off, and in the third time period of the positive half-inversion cycle, control the second switch tube and the third switch tube to be turned on. Wherein, the positive half-inversion cycle and the negative half-inversion cycle are one inversion cycle.

[0008] According to some embodiments of the present application, the inverter further includes an eighth switch tube, a ninth switch tube, a first inductor, and a second inductor. A first end of the eighth switch tube is connected to one end of the first inductor, the other end of the first inductor is connected to the first end of the AC port, a second end of the eighth switch tube is connected to the first end of the ninth switch tube, a second end of the ninth switch tube is connected to one end of the second inductor, and the other end of the second inductor is connected to the second end of the AC port.

[0009] According to some embodiments of the present application, the controller is used to control the ninth switch tube to turn off during the positive half-inversion cycle and the negative half-inversion cycle.

[0010] According to some embodiments of the present application, the controller is used to: when the inverter performs rectification work, and in the first time period of the positive half rectification cycle, control the first switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube to be turned on, in the second time period of the positive half rectification cycle, control the first switch tube and the seventh switch tube to be turned off, in the third time period of the positive half rectification cycle, control the ninth switch tube to be turned on, and in the fourth time period of the positive half rectification cycle, control the fifth switch tube and the ninth switch tube to be turned off. When the inverter performs rectification work, and in the first time period of the negative half rectification cycle, control the second switch tube, the sixth switch tube, the seventh switch tube and the ninth switch tube to be turned on, in the second time period of the negative half rectification cycle, control the second switch tube and the seventh switch tube to be turned off, in the third time period of the negative half rectification cycle, control the eighth switch tube to be turned on, and in the fourth time period of the negative half rectification cycle, control the sixth switch tube and the ninth switch tube to be turned off. Wherein, the positive half rectification cycle and the negative half rectification cycle are one rectification cycle.

[0011] According to some embodiments of the present application, the power module further includes a filter capacitor, a current limiting resistor and a diode. The first end of the filter capacitor is connected to the third end of the bidirectional inductor, the second end of the filter capacitor is connected to the first end of the seventh switch tube, the first end of the current limiting resistor is connected to the third end of the bidirectional inductor, the second end of the current limiting resistor is connected to the first end of the seventh switch tube, the first end of the diode is connected to the first end of the DC port, and the second end of the diode is connected to the first end of the seventh switch tube.

[0012] An embodiment of the present application provides a control method for an inverter, which is applied to the inverter. The inverter includes a controller, an inverter circuit and a power supply module. The input end of the inverter circuit is used to connect to a DC port, and the output end of the inverter circuit is used to connect to an AC port. The control method includes: when the inverter is working, controlling the power supply module to reversely charge the corresponding switch tube in the inverter circuit, so as to control the corresponding switch tube in the inverter circuit to be turned on after charging is completed, so that the inverter circuit performs power conversion.

[0013] According to some embodiments of the present application, the inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, the power module includes a fifth switch tube, a sixth switch tube, a seventh switch tube and a bidirectional inductor, the first end of the first switch tube is connected to the first end of the DC port, the second end of the first switch tube is connected to the first end of the third switch tube, the second end of the third switch tube is connected to the second end of the DC port, the first end of the second switch tube is connected to the second end of the DC port, the second end of the second switch tube is connected to the first end of the fourth switch tube, the second end of the fourth switch tube is connected to the second end of the DC port, the first end of the fifth switch tube is connected to the connection point between the second end of the first switch tube and the first end of the third switch tube, The second end of the fifth switch tube is connected to the first end of the bidirectional inductor, the first end of the sixth switch tube is connected to the connection point between the second end of the second switch tube and the first end of the fourth switch tube, the second end of the sixth switch tube is connected to the second end of the bidirectional inductor, the third end of the bidirectional inductor is connected to the first end of the seventh switch tube, and the second end of the seventh switch tube is connected to the second end of the DC port. The control method also includes: when the inverter performs inversion work, in the first time period of the negative half-inversion cycle, the second switch tube, the sixth switch tube and the seventh switch tube are controlled to be turned on, in the second time period of the positive half-inversion cycle, the second switch tube is controlled to be turned off, and in the third time period of the positive half-inversion cycle, the first switch tube and the fourth switch tube are controlled to be turned on. When the inverter performs inversion work, in the first time period of the negative half-inversion cycle, the first switch tube, the fifth switch tube and the seventh switch tube are controlled to be turned on, in the second time period of the negative half-inversion cycle, the first switch tube is controlled to be turned off, and in the third time period of the positive half-inversion cycle, the second switch tube and the third switch tube are controlled to be turned on. Wherein, the positive half-inversion cycle and the negative half-inversion cycle are one inversion cycle.

[0014] According to some embodiments of the present application, the inverter further includes an eighth switch tube, a ninth switch tube, a first inductor, and a second inductor. The first end of the eighth switch tube is connected to one end of the first inductor, the other end of the first inductor is connected to the first end of the AC port, the second end of the eighth switch tube is connected to the first end of the ninth switch tube, the second end of the ninth switch tube is connected to one end of the second inductor, and the other end of the second inductor is connected to the second end of the AC port. The control method also includes: in the positive half-inversion cycle and the negative half-inversion cycle, the ninth switch tube is controlled to be turned off; when the inverter performs rectification work, and in the first time period of the positive half-rectification cycle, the first switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube are controlled to be turned on, in the second time period of the positive half-rectification cycle, the first switch tube and the seventh switch tube are controlled to be turned off, in the third time period of the positive half-rectification cycle, the ninth switch tube is controlled to be turned on, and in the fourth time period of the positive half-rectification cycle, the fifth switch tube and the ninth switch tube are controlled to be turned off. When the inverter performs rectification work, in the first time period of the negative half rectification cycle, the second switch tube, the sixth switch tube, the seventh switch tube and the ninth switch tube are controlled to be turned on, in the second time period of the negative half rectification cycle, the second switch tube and the seventh switch tube are controlled to be turned off, in the third time period of the negative half rectification cycle, the eighth switch tube is controlled to be turned on, and in the fourth time period of the negative half rectification cycle, the sixth switch tube and the ninth switch tube are controlled to be turned off. The positive half rectification cycle and the negative half rectification cycle are one rectification cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of an inverter provided in one embodiment of the present application.

[0016] Figure 2 It is a current path diagram of the first time period of the positive half-inversion cycle of the inverter provided in one embodiment of the present application.

[0017] Figure 3 It is a current path diagram of the second time period of the positive half-inversion cycle of the inverter provided in one embodiment of the present application.

[0018] Figure 4 It is a current path diagram of the third time period of the positive half-inversion cycle of the inverter provided in one embodiment of the present application.

[0019] Figure 5 It is a current path diagram of the first time period of the negative half-inversion cycle of the inverter provided in one embodiment of the present application.

[0020] Figure 6 It is a current path diagram of the second time period of the negative half-inversion cycle of the inverter provided in one embodiment of the present application.

[0021] Figure 7It is a current path diagram of the third time period of the negative half-inversion cycle of the inverter provided in one embodiment of the present application.

[0022] Figure 8 It is a schematic diagram of the structure of an inverter provided in another embodiment of the present application.

[0023] Fig. 9 It is a current path diagram of the first time period of the positive half rectification cycle of the inverter provided in one embodiment of the present application.

[0024] Fig.10 It is a current path diagram of the second time period of the positive half rectification cycle of the inverter provided in one embodiment of the present application.

[0025] Fig.11 It is a current path diagram of the third time period of the positive half rectification cycle of the inverter provided in one embodiment of the present application.

[0026] Fig.12 It is a current path diagram of the first time period of the negative half rectification cycle of the inverter provided in one embodiment of the present application.

[0027] Fig.13 It is a current path diagram of the second time period of the negative half rectification cycle of the inverter provided in one embodiment of the present application.

[0028] Fig.14 It is a current path diagram of the third time period of the negative half rectification cycle of the inverter provided in one embodiment of the present application.

[0029] Fig.15 It is a schematic diagram of the structure of an inverter provided in another embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] The term "and / or" in this application is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0032] In the present application, the term "plurality" refers to two or more. In addition, it should be understood that in the description of the present application, the terms "first", "second", etc. are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.

[0033] In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0034] With the advancement of science and technology, high frequency, miniaturization, high efficiency and low noise have become important indicators for electronic products. During the operation of the switch tube, due to the overlap of voltage and current at the switching moment, hard switching losses will inevitably occur. In practical applications, the existence of hard switching losses limits the switching frequency of the switch tube, which in turn limits the working efficiency of the inverter.

[0035] To this end, an embodiment of the present application provides an inverter and a control method thereof, which realizes soft opening of each switch tube in the inverter, and has the advantages of high switching frequency, small size and low electromagnetic compatibility.

[0036] See also Figure 1 , Figure 1 It is a structural schematic diagram of an inverter provided by an embodiment of the present application.

[0037] like Figure 1 As shown, the inverter includes a controller (not shown in the figure), an inverter circuit 10 and a power module 20. The input end of the inverter circuit 10 is used to connect to a DC port, and the output end of the inverter circuit 10 is used to connect to an AC port.

[0038] The controller is used to: when the inverter is working, control the power module 20 to reverse charge the corresponding switch tube in the inverter circuit 10, so as to control the corresponding switch tube in the inverter circuit 10 to be turned on after charging, so that the inverter circuit 10 performs power conversion.

[0039] In this embodiment, when the inverter circuit 10 is working, the controller controls the power module 20 to reverse charge the corresponding switch tube in the inverter circuit 10 and then controls the switch tube to be turned on to achieve soft opening of the switch tube, thereby reducing the loss of the switch tube and improving the working efficiency of the inverter. After the charging is completed, the corresponding switch tube in the inverter circuit 10 is controlled to be turned on so that the inverter circuit 10 performs power conversion. The inverter of the present application reverse charges the corresponding switch tube in the inverter circuit 10 through the power module 20, thereby achieving soft opening of each switch tube in the inverter, and has the advantages of high working efficiency, small size and low electromagnetic compatibility.

[0040] The internal structure of the inverter will be introduced in detail below.

[0041] See also Figure 1 The inverter circuit 10 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4.

[0042] The first end of the first switch tube Q1 is connected to the first end of the DC port, and the second end of the first switch tube Q1 is connected to the first end of the third switch tube Q3. The second end of the third switch tube Q3 is connected to the second end of the DC port, the first end of the second switch tube Q2 is connected to the second end of the DC port, the second end of the second switch tube Q2 is connected to the first end of the fourth switch tube Q4, and the second end of the fourth switch tube Q4 is connected to the second end of the DC port. The third end of the first switch tube Q1, the third end of the second switch tube Q2, the third end of the third switch tube Q3 and the third end of the fourth switch tube Q4 are respectively connected to the controller, that is, the controller can output corresponding driving signals to the third end of the first switch tube Q1, the third end of the second switch tube Q2, the third end of the electric switch tube and the third end of the fourth switch tube Q4, so as to respectively control the conduction or shutdown of the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4.

[0043] The power module 20 may include a fifth switch tube Q5 , a sixth switch tube Q6 , a seventh switch tube Q7 and a bidirectional inductor L3 .

[0044] The first end of the fifth switch tube Q5 is connected to the connection point between the second end of the first switch tube Q1 and the first end of the third switch tube Q3, the second end of the fifth switch tube Q5 is connected to the first end of the bidirectional inductor L3, the first end of the sixth switch tube Q6 is connected to the connection point between the second end of the second switch tube Q2 and the first end of the fourth switch tube Q4, the second end of the sixth switch tube Q6 is connected to the second end of the bidirectional inductor L3, the third end of the bidirectional inductor L3 is connected to the first end of the seventh switch tube Q7, and the second end of the seventh switch tube Q7 is connected to the second end of the DC port. The third end of the fifth switch tube Q5, the third end of the sixth switch tube Q6, and the third end of the seventh switch tube Q7 are respectively connected to the controller, that is, the controller can output corresponding driving signals to the third end of the fifth switch tube Q5, the third end of the sixth switch tube Q6, and the third end of the seventh switch tube Q7 to respectively control the conduction or shutdown of the fifth switch tube Q5, the sixth switch tube Q6, and the seventh switch tube Q7.

[0045] It can be understood that the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6 and the seventh switch tube Q7 in this embodiment can all be any one of a metal oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), a bipolar power transistor (Bipolar Power Transistor, BPT) or a wide bandgap semiconductor field effect transistor.

[0046] The inverter working mode of the inverter of the present application will be described in detail below.

[0047] See also Figure 2 When the inverter is in the first time period of the positive half-inverting cycle, the controller can control the second switch tube Q2, the sixth switch tube Q6 and the seventh switch tube Q7 to be in the on state, and control the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 to be turned off. The DC port will store energy in the bidirectional inductor L3 through the second switch tube Q2, the sixth switch tube Q6 and the seventh switch tube Q7, that is, the current output from the first end of the DC port flows through the second switch tube Q2 and the sixth switch tube Q6 in sequence and then flows into the second end of the bidirectional inductor L3, and then flows back to the second end of the DC port through the third end of the bidirectional inductor L3 and the seventh switch tube Q7 in sequence, so as to store energy in the bidirectional inductor L3. Its current path is as follows: Figure 2 As shown in line S21.

[0048] See also Figure 3When the inverter is in the second time period of the positive half-inversion cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 to be turned off, and control the sixth switch tube Q6 and the seventh switch tube Q7 to be turned on, so that the bidirectional inductor L3 can reversely charge the first switch tube Q1 and the fourth switch tube Q4, that is, the current output from the first end of the bidirectional inductor L3 flows through the anti-parallel diode in the fifth switch tube Q5 and the anti-parallel diode in the first switch tube Q1 in sequence, and then flows into the first end of the DC port, so as to raise the voltage of the second end of the first switch tube Q1 and reduce the voltage difference between the first end and the second end of the first switch tube Q1. The current path is as follows: Figure 3 The current output from the third end of the bidirectional inductor L3 flows through the seventh switch tube Q7, the anti-parallel diode in the fourth switch tube Q4 and the sixth switch tube Q6 in sequence, and then flows into the second end of the bidirectional inductor L3 to raise the voltage of the second end of the fourth switch tube Q4 and reduce the voltage difference between the first end and the second end of the fourth switch tube Q4. The current path is as follows: Figure 3 As shown in line S32.

[0049] See also Figure 4 , when the inverter is in the third time period of the positive half-inversion cycle, the controller can control the first switch tube Q1 and the fourth switch tube Q4 to be turned on, and control the second switch tube Q2, the third switch tube Q3, the fifth switch tube Q5, the sixth switch tube Q6 and the seventh switch tube Q7 to be turned off. At this time, the first end of the DC port outputs current, and flows into the first end of the AC port through the first switch tube Q1, and then returns to the second end of the DC port through the second end of the AC port and the fourth switch tube Q4 in sequence, wherein the current path is as follows: Figure 4 As shown in line S41 in .

[0050] See also Figure 5 When the inverter is in the first time period of the negative half-inverting cycle, the controller can control the first switch tube Q1, the fifth switch tube Q5 and the seventh switch tube Q7 to be in the on state, and control the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the sixth switch tube Q6 to be turned off. The DC port will store energy in the bidirectional inductor L3 through the first switch tube Q1, the fifth switch tube Q5 and the seventh switch tube Q7, that is, the current output from the first end of the DC port flows through the first switch tube Q1 and the fifth switch tube Q5 in sequence and then flows into the first end of the bidirectional inductor L3, and then flows back to the second end of the DC port through the third end of the bidirectional inductor L3 and the seventh switch tube Q7 in sequence, so as to store energy in the bidirectional inductor L3. Its current path is as follows: Figure 5 As shown in line S51.

[0051] See also Figure 6When the inverter is in the second time period of the negative half-inverting cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4 and the sixth switch tube Q6 to be turned off, and control the fifth switch tube Q5 and the seventh switch tube Q7 to be turned on, so that the bidirectional inductor L3 can reversely charge the second switch tube Q2 and the third switch, that is, the current output from the third end of the bidirectional inductor L3 flows through the seventh switch tube Q7, the anti-parallel diode in the third switch tube Q3 and the fifth switch tube Q5 in sequence, and then flows into the first end of the DC port, so as to raise the voltage of the second end of the third switch tube Q3 and reduce the voltage difference between the first end and the second end of the third switch tube Q3. The current path is as follows: Figure 6 The current output from the second end of the bidirectional inductor L3 flows through the anti-parallel diode in the sixth switch tube Q6 and the anti-parallel diode in the second switch tube Q2 in sequence and then flows into the first end of the DC port to raise the voltage of the second end of the second switch tube Q2 and reduce the voltage difference between the first end and the second end of the second switch tube Q2. The current path is as follows: Figure 6 As shown in line S62.

[0052] See also Figure 7 , when the inverter is in the third time period of the negative half-inversion cycle, the controller can control the second switch tube Q2 and the third switch tube Q3 to be turned on, and control the first switch tube Q1, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6 and the seventh switch tube Q7 to be turned off. At this time, the first end of the DC port outputs current and flows into the second end of the AC port through the second switch tube Q2, and then returns to the second end of the DC port through the first end of the AC port and the third switch tube Q3 in sequence. The current path is as follows: Figure 7 As shown in line S71 in .

[0053] Among them, the positive half-inversion cycle and the negative half-inversion cycle constitute one inversion cycle.

[0054] It is understandable that Figure 8 As shown, in some optional embodiments, the inverter may further include an eighth switch tube Q8, a ninth switch tube Q9, a first inductor L1, and a second inductor L2. A first end of the eighth switch tube Q8 is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to the first end of the AC port, a second end of the eighth switch tube Q8 is connected to the first end of the ninth switch tube Q9, a second end of the ninth switch tube Q9 is connected to one end of the second inductor L2, and the other end of the second inductor L2 is connected to the second end of the AC port.

[0055] It can be understood that the eighth switch tube Q8 and the ninth switch tube Q9 in this embodiment can be any one of a metal oxide semiconductor field effect tube, an insulated gate bipolar transistor, a bipolar power transistor or a wide bandgap semiconductor field effect tube. One of the eighth switch tube Q8 and the ninth switch tube Q9 is selected as a normally open switch tube. In the embodiment of the present application, the eighth switch tube Q8 is used as a normally open switch tube for example description.

[0056] Specifically, in the positive half-inversion cycle and the negative half-inversion cycle of the inverter, the ninth switch tube Q9 is controlled to be turned off, so as to prevent the ninth switch tube Q9 from affecting the working state of the inverter.

[0057] The rectification working mode of the inverter of the present application will be described in detail below.

[0058] See also Fig. 9 When the inverter is in the first time period of the positive half-rectification cycle, the controller can control the first switch tube Q1, the fifth switch tube Q5, the seventh switch tube Q7 and the eighth switch tube Q8 to be in the on state, and control the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the sixth switch tube Q6 and the ninth switch tube Q9 to be turned off, and the AC port will store energy in the bidirectional inductor L3 through the fifth switch tube Q5 and the seventh switch tube Q7, that is, the current output from the first end of the AC port flows into the first end of the bidirectional inductor L3 through the fifth switch tube Q5, and then flows back to the second end of the AC port through the third end of the bidirectional inductor L3, the seventh switch tube Q7 and the anti-parallel diode of the fourth switch tube Q4 in sequence, so as to store energy for the bidirectional inductor L3, and the current output from the first end of the AC port flows into the first end of the DC port through the first switch tube Q1, and then flows back to the second end of the AC port through the anti-parallel diode of the fourth switch tube Q4 in sequence, and its current path is as follows: Fig. 9 As shown in line S91.

[0059] See also Fig.10 When the inverter is in the second time period of the positive half-rectification cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the sixth switch tube Q6, the seventh switch tube Q7 and the ninth switch tube Q9 to be turned off, and control the fifth switch tube Q5 and the eighth switch tube Q8 to be turned on, so that the bidirectional inductor L3 can reversely charge the ninth switch tube Q9, that is, the current output from the second end of the bidirectional inductor L3 flows through the anti-parallel diode in the sixth switch tube Q6, the anti-parallel diode in the ninth switch tube Q9, the eighth switch tube Q8 and the fifth switch tube Q5 in sequence, and then flows into the first end of the bidirectional inductor L3, so as to raise the voltage of the second end of the ninth switch tube Q9 and reduce the voltage difference between the first end and the second end of the ninth switch tube Q9. The current path is as follows: Figure 6 As shown in line S101.

[0060] See also Fig.11 When the inverter is in the third time period of the positive half-rectification cycle, the controller can control the ninth switch tube Q9 to be turned on, so as to store energy in the first inductor L1 and the second inductor L2 through the ninth switch tube Q9, that is, the current output from the first end of the AC port stores energy in the first inductor L1, flows through the anti-parallel diode in the eighth switch tube Q8 and the ninth switch tube Q9 in sequence, and then flows into the second inductor L2 to store energy in the second inductor L2, and then flows into the second end of the AC port. The current path is as follows: Fig.11 As shown in line S112.

[0061] See also Fig.11 , when the inverter is in the fourth time period of the positive half-rectification cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the ninth switch tube Q9 to be turned off. At this time, the first end of the AC port outputs current, and flows into the first end of the DC port through the first inductor L1 and the anti-parallel diode of the first switch tube Q1 in sequence, and then returns to the second end of the DC port through the second end of the DC port, the anti-parallel diode of the fourth switch tube Q4 and the second inductor L2 in sequence. The current path is as follows: Fig.11 As shown in line S111 in .

[0062] See also Fig.12 When the inverter is in the first time period of the negative half-rectification cycle, the controller can control the second switch tube Q2, the sixth switch tube Q6, the seventh switch tube Q7 and the ninth switch tube Q9 to be in the on state, and control the first switch tube Q1, the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 to be turned off. The AC port will store energy in the bidirectional inductor L3 through the sixth switch tube Q6 and the seventh switch tube Q7, that is, the current output from the second end of the AC port flows into the second end of the bidirectional inductor L3 through the sixth switch tube Q6, and then flows back to the first end of the bidirectional inductor L3 through the third end of the bidirectional inductor L3, the seventh switch tube Q7 and the anti-parallel diode of the third switch tube Q3 in sequence, so as to store energy in the bidirectional inductor L3, and the current output from the second end of the AC port flows into the first end of the DC port through the second switch tube Q2, and then flows back to the first end of the AC port through the anti-parallel diode of the third switch tube Q3. The current path is as follows: Fig.12 As shown in line S121.

[0063] See also Fig.13When the inverter is in the second time period of the negative half-rectification cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the sixth switch tube Q6 and the seventh switch tube Q7 to be turned off, and control the sixth switch tube Q6 and the ninth switch tube Q9 to be turned on, so that the bidirectional inductor L3 can reversely charge the eighth switch tube Q8, that is, the current output from the first end of the bidirectional inductor L3 flows through the anti-parallel diode in the fifth switch tube Q5, the anti-parallel diode in the eighth switch tube Q8, the ninth switch tube Q9 and the sixth switch tube Q6 in sequence, and then flows into the second end of the bidirectional inductor L3, so as to raise the voltage of the first end of the eighth switch tube Q8 and reduce the voltage difference between the first end and the second end of the eighth switch tube Q8. The current path is as follows: Fig.13 As shown in line S131.

[0064] See also Fig.14 When the inverter is in the third time period of the negative half-rectification cycle, the controller can control the eighth switch tube Q8 to be turned on, so as to store energy in the first inductor L1 and the second inductor L2 through the eighth switch tube Q8, that is, the current output from the second end of the AC port stores energy in the second inductor L2, flows through the anti-parallel diode in the ninth switch tube Q9 and the eighth switch tube Q8 in sequence, and then flows into the first inductor L1 to store energy in the first inductor L1, and then flows into the first end of the AC port. The current path is as follows: Fig.14 As shown in line S142.

[0065] See also Fig.14 , when the inverter is in the fourth time period of the negative half-rectification cycle, the controller can control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the ninth switch tube Q9 to be turned off. At this time, the second end of the AC port outputs current, and flows into the first end of the DC port through the second inductor L2 and the anti-parallel diode of the second switch tube Q2 in sequence, and then returns to the second end of the DC port through the second end of the DC port, the anti-parallel diode of the third switch tube Q3 and the first inductor L1 in sequence. The current path is as follows: Fig.14 As shown in line S141 in .

[0066] Among them, the positive half rectification cycle and the negative half rectification cycle constitute one rectification cycle.

[0067] It is understandable that Fig.15As shown, in some optional embodiments, the inverter may further include a filter capacitor C1, a current limiting resistor R1 and a diode D1. The first end of the filter capacitor C1 is connected to the third end of the bidirectional inductor L3, the second end of the filter capacitor C1 is connected to the first end of the seventh switch tube Q7, the first end of the current limiting resistor R1 is connected to the third end of the bidirectional inductor L3, the second end of the current limiting resistor R1 is connected to the first end of the seventh switch tube Q7, the first end of the diode D1 is connected to the first end of the DC port, and the second end of the diode D1 is connected to the first end of the seventh switch tube Q7.

[0068] In this embodiment, the filter capacitor C1 is used to filter out the noise in the current output from the third end of the bidirectional inductor L3 to prevent the noise from affecting the shutdown of the seventh switch tube Q7, and the current output from the bidirectional inductor L3 is limited by the current limiting resistor R1 to prevent the current output from the third end of the bidirectional inductor L3 from being too large to damage the seventh switch tube Q7, and the voltage output from the bidirectional inductor L3 is limited by the diode D1 to prevent the voltage output from the third end of the bidirectional inductor L3 from being too large to damage the seventh switch tube Q7.

[0069] By adopting the inverter of the present application, when the inverter circuit 10 is working, the power module 20 is used to reversely charge the corresponding switch tube in the inverter circuit 10, so as to control the corresponding switch tube in the inverter circuit 10 to be turned on after the charging is completed, so that the inverter circuit 10 performs power conversion. The inverter of the present application reversely charges the corresponding switch tube in the inverter circuit 10 through the power module 20, thereby realizing the soft opening of each switch tube in the inverter, and has the advantages of high switching frequency, small size and low electromagnetic compatibility.

[0070] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive, and the scope of the present application is defined by the attached claims rather than the above description, and therefore it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application.

Claims

1. An inverter, characterized in that: include: Controller, inverter circuit and power module; The input end of the inverter circuit is used to connect to a DC port, and the output end of the inverter circuit is used to connect to an AC port; The controller is used to: When the inverter is working, the power module is controlled to reversely charge the corresponding switch tube in the inverter circuit, so that the corresponding switch tube in the inverter circuit is controlled to be turned on after charging is completed, so that the inverter circuit performs power conversion.

2. The inverter according to claim 1, characterized in that: The inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, and the power module includes a fifth switch tube, a sixth switch tube, a seventh switch tube and a bidirectional inductor; The first end of the first switch tube is connected to the first end of the DC port, the second end of the first switch tube is connected to the first end of the third switch tube, the second end of the third switch tube is connected to the second end of the DC port, the first end of the second switch tube is connected to the second end of the DC port, the second end of the second switch tube is connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is connected to the second end of the DC port; The first end of the fifth switch tube is connected to a connection point between the second end of the first switch tube and the first end of the third switch tube, the second end of the fifth switch tube is connected to the first end of the bidirectional inductor, the first end of the sixth switch tube is connected to a connection point between the second end of the second switch tube and the first end of the fourth switch tube, the second end of the sixth switch tube is connected to the second end of the bidirectional inductor, the third end of the bidirectional inductor is connected to the first end of the seventh switch tube, and the second end of the seventh switch tube is connected to the second end of the DC port.

3. The inverter according to claim 2, characterized in that: The controller is used to: The inverter performs an inversion operation, and in a first time period of a positive half-inversion cycle, controls the second switch tube, the sixth switch tube, and the seventh switch tube to be turned on, in a second time period of the positive half-inversion cycle, controls the second switch tube to be turned off, and in a third time period of the positive half-inversion cycle, controls the first switch tube and the fourth switch tube to be turned on; The inverter performs an inversion operation, and in a first time period of a negative half-inversion cycle, the first switch tube, the fifth switch tube, and the seventh switch tube are controlled to be turned on, in a second time period of the negative half-inversion cycle, the first switch tube is controlled to be turned off, and in a third time period of a positive half-inversion cycle, the second switch tube and the third switch tube are controlled to be turned on; The positive half inversion cycle and the negative half inversion cycle constitute one inversion cycle.

4. The inverter according to claim 3, characterized in that: The inverter further includes an eighth switch tube, a ninth switch tube, a first inductor and a second inductor; A first end of the eighth switch tube is connected to one end of the first inductor, the other end of the first inductor is connected to the first end of the AC port, a second end of the eighth switch tube is connected to the first end of the ninth switch tube, the second end of the ninth switch tube is connected to one end of the second inductor, and the other end of the second inductor is connected to the second end of the AC port.

5. The inverter according to claim 4, characterized in that: The controller is used to: In the positive half-inversion cycle and the negative half-inversion cycle, the ninth switch tube is controlled to be turned off.

6. The inverter according to claim 4, characterized in that: The controller is used to: The inverter performs rectification work, and in a first time period of a positive half rectification cycle, the first switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube are controlled to be turned on, in a second time period of the positive half rectification cycle, the first switch tube and the seventh switch tube are controlled to be turned off, in a third time period of the positive half rectification cycle, the ninth switch tube is controlled to be turned on, and in a fourth time period of the positive half rectification cycle, the fifth switch tube and the ninth switch tube are controlled to be turned off; The inverter performs rectification work, and in a first time period of a negative half rectification cycle, the second switch tube, the sixth switch tube, the seventh switch tube and the ninth switch tube are controlled to be turned on, in a second time period of the negative half rectification cycle, the second switch tube and the seventh switch tube are controlled to be turned off, in a third time period of the negative half rectification cycle, the eighth switch tube is controlled to be turned on, and in a fourth time period of the negative half rectification cycle, the sixth switch tube and the ninth switch tube are controlled to be turned off; The positive half rectification period and the negative half rectification period constitute one rectification period.

7. The inverter according to claim 2, characterized in that: The power module also includes a filter capacitor, a current limiting resistor and a diode; The first end of the filter capacitor is connected to the third end of the bidirectional inductor, the second end of the filter capacitor is connected to the first end of the seventh switch tube, the first end of the current limiting resistor is connected to the third end of the bidirectional inductor, the second end of the current limiting resistor is connected to the first end of the seventh switch tube, the first end of the diode is connected to the first end of the DC port, and the second end of the diode is connected to the first end of the seventh switch tube.

8. A control method for an inverter, characterized in that: The control method is applied to an inverter, wherein the inverter includes a controller, an inverter circuit and a power module, wherein the input end of the inverter circuit is used to connect to a DC port, and the output end of the inverter circuit is used to connect to an AC port; the control method includes: When the inverter is working, the power supply module is controlled to reversely charge the corresponding switch tube in the inverter circuit, so as to control the corresponding switch tube in the inverter circuit to be turned on after charging is completed, so that the inverter circuit performs power conversion.

9. The inverter control method according to claim 8, characterized in that: The inverter circuit includes a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, the power module includes a fifth switch tube, a sixth switch tube, a seventh switch tube and a bidirectional inductor, the first end of the first switch tube is connected to the first end of the DC port, the second end of the first switch tube is connected to the first end of the third switch tube, the second end of the third switch tube is connected to the second end of the DC port, the first end of the second switch tube is connected to the second end of the DC port, the second end of the second switch tube is connected to the first end of the fourth switch tube, the second end of the fourth switch tube is connected to the second end of the DC port, the first end of the fifth switch tube is connected to the connection point between the second end of the first switch tube and the first end of the third switch tube, the second end of the fifth switch tube is connected to the first end of the bidirectional inductor, the first end of the sixth switch tube is connected to the connection point between the second end of the second switch tube and the first end of the fourth switch tube, the second end of the sixth switch tube is connected to the second end of the bidirectional inductor, the third end of the bidirectional inductor is connected to the first end of the seventh switch tube, and the second end of the seventh switch tube is connected to the second end of the DC port, and the control method further includes: The inverter performs an inversion operation, and in a first time period of a positive half-inversion cycle, controls the second switch tube, the sixth switch tube, and the seventh switch tube to be turned on, in a second time period of the positive half-inversion cycle, controls the second switch tube to be turned off, and in a third time period of the positive half-inversion cycle, controls the first switch tube and the fourth switch tube to be turned on; The inverter performs an inversion operation, and in a first time period of a negative half-inversion cycle, the first switch tube, the fifth switch tube, and the seventh switch tube are controlled to be turned on, in a second time period of the negative half-inversion cycle, the first switch tube is controlled to be turned off, and in a third time period of a positive half-inversion cycle, the second switch tube and the third switch tube are controlled to be turned on; The positive half inversion cycle and the negative half inversion cycle constitute one inversion cycle.

10. The inverter control method according to claim 9, characterized in that: The inverter further includes an eighth switch tube, a ninth switch tube, a first inductor, and a second inductor; a first end of the eighth switch tube is connected to one end of the first inductor, the other end of the first inductor is connected to the first end of the AC port, a second end of the eighth switch tube is connected to the first end of the ninth switch tube, a second end of the ninth switch tube is connected to one end of the second inductor, and the other end of the second inductor is connected to the second end of the AC port, and the control method further includes: In the positive half-inversion cycle and the negative half-inversion cycle, controlling the ninth switch tube to turn off; The inverter performs rectification work, and in a first time period of a positive half rectification cycle, the first switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube are controlled to be turned on, in a second time period of the positive half rectification cycle, the first switch tube and the seventh switch tube are controlled to be turned off, in a third time period of the positive half rectification cycle, the ninth switch tube is controlled to be turned on, and in a fourth time period of the positive half rectification cycle, the fifth switch tube and the ninth switch tube are controlled to be turned off; The inverter performs rectification work, and in a first time period of a negative half rectification cycle, the second switch tube, the sixth switch tube, the seventh switch tube and the ninth switch tube are controlled to be turned on, in a second time period of the negative half rectification cycle, the second switch tube and the seventh switch tube are controlled to be turned off, in a third time period of the negative half rectification cycle, the eighth switch tube is controlled to be turned on, and in a fourth time period of the negative half rectification cycle, the sixth switch tube and the ninth switch tube are controlled to be turned off; The positive half rectification period and the negative half rectification period constitute one rectification period.

Images