Inverter circuit and inverter

Abstract

The utility model provides an inverter circuit and an inverter, and the inverter circuit comprises an inverter channel and a driving power supply. Wherein the inversion channel comprises a switch module; the driving power supply is coupled to the switch module and provides driving voltage for the switch module, so that the switch module selectively controls the current direction of the inversion channel based on the driving voltage; the driving power supply is coupled to the driving end of the switch module through a driving channel and a cut-off channel, and under the condition that the driving power supply outputs first driving voltage, driving current flows to the driving end of the switch module through the driving channel; under the condition that the driving power supply outputs the second driving voltage, the cut-off current flows out of the driving end of the switch module through the cut-off channel; wherein the driving channel comprises a driving resistor, a driving end coupled to the switch module and a driving power supply; the cut-off channel comprises a cut-off resistor, a driving end coupled to the switch module and a driving power supply. According to the scheme, the voltage stress borne by the switch module can be flexibly adjusted.

Description

Technical Field

[0001] The embodiments disclosed in this application relate to the field of inverter technology, and more specifically, to an inverter circuit and an inverter. Background Technology

[0002] The inverter circuit in an inverter can use semiconductor switches (such as IGBTs) to control the direction of current to achieve the inverter function.

[0003] The voltage stress that a semiconductor switch needs to withstand when it is turned on and off may be different, and current inverter circuits cannot flexibly adjust the voltage stress that the semiconductor switch needs to withstand.

[0004] Therefore, how to flexibly adjust the voltage stress borne by semiconductor switches has become an urgent problem to be solved. Utility Model Content

[0005] According to embodiments of this application, this application proposes an inverter circuit and inverter to flexibly adjust the voltage stress borne by the switching module.

[0006] According to one aspect of this application, an inverter circuit is disclosed, including an inverter channel and a drive power supply. The inverter channel includes a switching module; the drive power supply is coupled to the switching module and provides a drive voltage to the switching module, enabling the switching module to selectively control the current direction of the inverter channel based on the drive voltage; the drive power supply is coupled to the drive terminal of the switching module through a drive channel and a cutoff channel; when the drive power supply outputs a first drive voltage, a drive current flows through the drive channel to the drive terminal of the switching module; when the drive power supply outputs a second drive voltage, a cutoff current flows out from the drive terminal of the switching module through the cutoff channel; wherein the drive channel includes a drive resistor coupled to the drive terminal of the switching module and the drive power supply; the cutoff channel includes a cutoff resistor coupled to the drive terminal of the switching module and the drive power supply.

[0007] According to a second aspect of this application, an inverter is provided, including a control circuit and the inverter circuit described in the first aspect above.

[0008] In the above scheme, the driving power supply is coupled to the driving terminal of the switching module through a driving channel and a cutoff channel, respectively. When the driving power supply outputs a first driving voltage to turn on the switching module, the driving current flows to the driving terminal of the switching module through the driving channel. When the driving power supply outputs a second driving voltage to turn off the switching module, the driving current flows out of the driving terminal of the switching module through the cutoff channel. The driving channel includes a driving resistor, and the cutoff channel includes a cutoff resistor. Thus, when the switching module is in the on state and the cutoff state, the driving current and the cutoff current flow through the driving resistor and the cutoff resistor, respectively. By adjusting the driving resistor, the voltage at the driving terminal when the switching module is in the on state can be adjusted, and by adjusting the cutoff resistor, the voltage at the driving terminal when the switching module is in the off state can be adjusted. This facilitates flexible adjustment of the voltage stress borne by the switching module. Attached Figure Description

[0009] The present application will be further described below with reference to the accompanying drawings and embodiments. In the drawings:

[0010] Figure 1 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0011] Figure 2 This is a schematic diagram of the inverter circuit in some other embodiments of this application;

[0012] Figure 3 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0013] Figure 4 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0014] Figure 5 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0015] Figure 6 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0016] Figure 7 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0017] Figure 8 This is a schematic diagram of the inverter circuit in some embodiments of this application;

[0018] Figure 9 This is a schematic diagram of the circuit structure of the inverter circuit in some embodiments of this application;

[0019] Figure 10 This is a schematic diagram of the inverter frame in one embodiment of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0021] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless otherwise clearly indicated above. “Multiple” generally includes at least two, but does not exclude the inclusion of at least one.

[0022] It should be understood that the term "and / or" used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0023] It should be understood that the terms "comprising," "including," or any other variations used herein are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in every place in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] The inverter circuit in an inverter can use semiconductor switches (such as IGBTs) to control the direction of current to achieve the inverter function.

[0026] The voltage stress that a semiconductor switch needs to withstand when it is turned on and off may be different, and current inverter circuits cannot flexibly adjust the voltage stress that the semiconductor switch needs to withstand.

[0027] Therefore, please refer to Figure 1 This application provides an inverter circuit 100, including an inverter channel L and a drive power supply 110. The inverter channel L includes a switching module 120. A drive power supply 110 is coupled to the switching module 120 to provide a drive voltage, enabling the switching module 120 to selectively control the current direction of the inverter channel L based on the drive voltage. The drive power supply 110 is coupled to the drive terminal TD of the switching module 120 through a drive channel on_path and a cutoff channel off_path. When the drive power supply 110 outputs a first drive voltage, the drive current flows through the drive channel on_path to the drive terminal TD of the switching module 120. When the drive power supply 110 outputs a second drive voltage, the cutoff current flows out from the drive terminal TD of the switching module 120 through the cutoff channel off_path. The drive channel on_path includes a drive resistor R-on, coupled to the drive terminal TD of the switching module 120 and the drive power supply 110. The cutoff channel off_path includes a cutoff resistor R-off, coupled to the drive terminal TD of the switching module 120 and the drive power supply 110.

[0028] In the above scheme, the driving power supply 110 is coupled to the driving terminal TD of the switching module 120 through the driving channel on_path and the cutoff channel off_path, respectively. When the driving power supply 110 outputs the first driving voltage, the driving current flows to the driving terminal TD of the switching module 120 through the driving channel on_path. When the driving power supply 110 outputs the second driving voltage, the driving current flows out of the driving terminal TD of the switching module 120 through the cutoff channel off_path. The driving channel on_path includes a driving resistor R-on, and the cutoff channel off_path includes a cutoff resistor R-off. Thus, when the switching module 120 is in the on state and the cutoff state, the driving current and the cutoff current flow through the driving resistor R-on and the cutoff resistor R-off, respectively. By adjusting the driving resistor R-on, the voltage of the driving terminal TD when the switching module 120 is in the on state can be adjusted, and by adjusting the cutoff resistor R-off, the voltage of the driving terminal TD when the switching module 120 is in the cutoff state can be adjusted, which is beneficial for flexibly adjusting the voltage stress of the switching module.

[0029] from Figure 1As can be seen, when the switch module 120 is turned on or off, the drive current or cutoff current can flow in the drive channel on_path or the cutoff channel off_path, respectively. Therefore, by adjusting the drive resistor R-on or the cutoff resistor R-off, the speed of the semiconductor switching device in the switch module 120 can be adjusted, thereby adjusting the voltage stress during turn-on and turn-off, and thus optimizing the working voltage stress of the switch module.

[0030] It is understood that in this application, the switching module 120 may include a semiconductor switching device coupled in the inverter channel L, capable of controlling the on or off state of the inverter channel L. Examples include insulated-gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), and bipolar junction transistors (BJTs). For instance, in an IGBT, the switching state can be controlled by adjusting the driving voltage applied to the gate; therefore, when the switching module 120 includes an IGBT, the driving terminal TD includes the gate of the IGBT. In a MOSFET, the switching state can be controlled by adjusting the driving voltage applied to the gate; therefore, when the switching module 120 includes a MOSFET, the driving terminal TD includes the gate of the MOSFET. In a BJT, the switching state can be controlled by adjusting the driving voltage applied to the base; therefore, when the switching module 120 includes a BJT, the driving terminal TD includes the base of the BJT.

[0031] Please continue to refer to Figure 1 Those skilled in the art will understand that the inverter circuit 100 typically has multiple bridge arms, and each bridge arm typically includes upper and lower half-bridge arms. Figure 1 The diagram only shows the switching module 120 in one half-bridge arm of the inverter circuit 100. For the other arms, please refer to [reference needed]. Figure 1 The half-bridge arm shown is configured. The switching module 120 may include multiple semiconductor switching devices (e.g., IGBTs) connected in the inverter channel L to control the on / off state of its respective half-bridge arm, thereby controlling the current flow direction in the inverter channel L. For example, the switching module 120 can control the current flow from the positive bus BUS+ to the negative bus BUS-, or vice versa.

[0032] The type of semiconductor switching device in the switching module 120 can vary in different embodiments. For example, in some embodiments, the switching module 120 may include an N-channel IGBT, which is turned on when its gate input driving voltage is high and turned off when its gate input driving voltage is low. Correspondingly, the first driving voltage is high and the second driving voltage is low. In some embodiments, the switching module 120 may include a P-channel IGBT, which is turned on when its gate input driving voltage is low and turned off when its gate input driving voltage is high. Correspondingly, the first driving voltage is low and the second driving voltage is high. Therefore, the magnitudes of the first and second driving voltages can be determined by the selection of the semiconductor switching device, and this application does not impose any limitations on this.

[0033] In some embodiments, please refer to Figure 2 The drive channel on_path further includes a drive unidirectional conduction unit 210 coupled to the drive resistor R-on and the drive power supply 110. The drive unidirectional conduction unit 210 is configured to be turned on when the drive power supply 110 outputs the first drive voltage and turned off when the drive power supply 110 outputs the second drive voltage. The cutoff channel off_path further includes a cutoff unidirectional conduction unit 220 coupled to the cutoff resistor R-off and the drive power supply 110. The cutoff unidirectional conduction unit 220 is configured to be turned off when the drive power supply 110 outputs the second drive voltage and turned on when the drive power supply 110 outputs the first drive voltage.

[0034] It can be understood that the drive unidirectional conduction unit 210 is used to conduct when the switch module 120 is turned on in response to the first drive voltage, and the cut-off unidirectional conduction unit 220 is used to conduct when the switch module 120 is turned off in response to the second drive voltage.

[0035] The drive unidirectional conduction unit 210 and the cut-off unidirectional conduction unit 220 may include controllable semiconductor switching devices, such as BJTs and MOSFETs. Taking a MOSFET as an example, the gate of the MOSFET can be connected to the drive power supply 110, and the drain and source can be coupled to the drive power supply 110 and the drive resistor R-on / cut-off resistor R-off, respectively. Thus, when the drive power supply 110 generates the first drive voltage and the second drive voltage, the drive unidirectional conduction unit 210 and the cut-off unidirectional conduction unit 220 can be turned on or off in response to the drive voltage.

[0036] In some embodiments, the driving unidirectional conduction unit 210 and the cutting-off unidirectional conduction unit 220 may include uncontrollable semiconductor switching devices, such as diodes. Please refer to... Figure 3The drive terminal TD of the switch module 120 is coupled to the drive power supply 110 through the drive channel on_path and the cutoff channel off_path. In the drive channel on_path, the drive diode D-on is coupled to the drive resistor R-on, and the positive input terminal of the drive diode D-on is coupled to the drive power supply 110, while the negative input terminal of the drive diode D-on is coupled to the drive resistor R-on. In the cutoff channel off_path, the positive input terminal of the cutoff diode D-off is coupled to the drive terminal TD of the switch module 120, while the negative input terminal of the cutoff diode D-off is coupled to the cutoff resistor R-off.

[0037] In some embodiments, please refer to Figure 4 , Figure 4 The diagram shows the upper and lower half-arms of one of the bridge arms in the inverter circuit 100. A second switching module 440 is coupled to the upper bridge arm, and a first switching module 430 is coupled to the lower bridge arm. The upper and lower bridge arms are connected via an AC output point. The lower bridge arm forms a first inverter channel L1, and the upper bridge arm forms a second inverter channel L2. The current flows in opposite directions in the first inverter channel L1 and the second inverter channel L2, and when the first inverter channel L1 is on, the second inverter channel L2 is off. The drive power supply 110 includes a first drive power supply 410 and a second drive power supply 420. A first driving power supply 410 is coupled to the first switching module 430 and provides a driving voltage to the first switching module 430 so that the first switching module 430 selectively controls the on or off of the first inverter channel L1 based on the driving voltage; a second driving power supply 420 is coupled to the second switching module 440 and provides a driving voltage to the second switching module 440 so that the second switching module 440 selectively controls the on or off of the second inverter channel L2 based on the driving voltage.

[0038] The first driving power supply 410 is coupled to the driving terminal TD of the first switching module 430 through the first driving channel on_path1 and the first cutoff channel off_path1. When the first driving power supply 410 outputs the first driving voltage, the first driving current flows to the driving terminal TD of the first switching module 430 through the first driving channel on_path1. When the first driving power supply 410 outputs the second driving voltage, the first cutoff current flows out from the driving terminal TD of the first switching module 430 through the first cutoff channel off_path1. The second driving power supply 420 is coupled to the driving terminal TD of the second switching module 440 through the second driving channel on_path2 and the second cutoff channel off_path2. When the second driving power supply 420 outputs the first driving voltage, the second driving current flows to the driving terminal TD of the second switching module 440 through the second driving channel on_path2. When the second driving power supply 420 outputs the second driving voltage, the second cutoff current flows out from the driving terminal TD of the second switching module 440 through the second cutoff channel off_path2.

[0039] Those skilled in the art will understand that Figure 4 This only shows the circuit framework of one bridge arm of the inverter circuit 100. The inverter circuit 100 typically has multiple bridge arms (e.g., 2 or 3), and each bridge arm's switching module 120 requires a drive power supply 110 to operate. To reduce the number of drive power supplies 110, switching modules 120 sharing a common ground can use the same drive power supply 110; however, switching modules 120 not sharing a common ground (e.g.) Figure 4 The first switch module 430 and the second switch module 440 in the process cannot be driven by the same power supply 110.

[0040] To further reduce the number of drive power supplies 110, please refer to... Figure 5 The inverter circuit 100 further includes a bootstrap drive power supply 510 connected to the first drive power supply 410 and the second switching module 440. The bootstrap drive power supply 510 provides the second drive voltage to the second switching module 440 when the first drive power supply 410 outputs the first drive voltage, so that the second switching module 440 is turned off based on the second drive voltage; and provides the first drive voltage to the second switching module 440 when the first drive power supply 410 outputs the second drive voltage, so that the second switching module 440 is turned on based on the first drive voltage.

[0041] In some embodiments, a switch (not shown) may be provided between the bootstrap power supply 510 and the drive terminal TD of the second switching module 440. This switch is configured to be turned on when the bootstrap power supply 510 needs to output a first drive voltage to the second switching module 440, and turned off when the bootstrap power supply 510 needs to output a second drive voltage to the second switching module. For example, it can be turned off when the bootstrap power supply 510 needs to output a second drive voltage to the second switching module to ground the drive terminal TD of the second switching module 440, thereby achieving the effect of the bootstrap power supply 510 outputting a second drive voltage to the second switching module 440. Specifically, this switch can be a controllable semiconductor switching device, such as a BJT.

[0042] exist Figure 5 In the illustrated embodiment, the bootstrap power supply 510 stores the electrical energy provided by the first power supply 410 when the first power supply 410 outputs the first power supply voltage, thereby establishing a first power supply voltage for subsequent supply to the second switch module 440, and outputs the first power supply voltage to the second switch module 440 when the first power supply 410 outputs the second power supply voltage. This realizes the use of the first power supply 410 to provide the drive voltage to the second switch module 440, which helps to reduce the number of power supplies 110.

[0043] In some embodiments, please refer to Figure 6 The bootstrap power supply 510 includes a bootstrap capacitor C-rise, which has a first terminal 1T and a second terminal 2T. The first terminal 1T is connected to the first power supply 410 and the drive terminal TD of the second switch module 440. When the first power supply 410 outputs the first drive voltage, the voltage difference between the first terminal 1T and the second terminal 2T of the bootstrap capacitor C-rise gradually increases, and the voltage of the first terminal 1T is greater than the voltage of the second terminal 2T. The bootstrap capacitor C-rise provides the second drive voltage to the second switch module 440 so that the second switch module 440 is turned off based on the second drive voltage. When the first power supply 410 outputs the second drive voltage, the bootstrap capacitor C-rise provides the first drive voltage to the second switch module 440 so that the second switch module 440 is turned on based on the first drive voltage.

[0044] Those skilled in the art will understand that Figure 6 The structure of the bootstrap power supply 510 shown is only illustrative. In practical applications, the number of bootstrap capacitors (C-rise) in the bootstrap power supply 510 can be selected according to the actual application scenario, and the specific circuit topology can also be expanded according to actual needs, and is not limited to... Figure 6 What is shown.

[0045] In the above embodiment, by setting a bootstrap drive power supply 510 in the inverter circuit 100, the bootstrap drive power supply 510 converts the drive voltage provided by the first drive power supply 410 into a drive voltage usable by the second switching module 440. This helps to further reduce the number of drive power supplies 110, simplify the transformer design in the inverter, and thus simplify the wiring in the inverter.

[0046] In some embodiments, please refer to Figure 7 The inverter circuit 100 further includes a negative voltage generation module 710, which is coupled to the drive terminal TD of the switch module 120 and the drive power supply 110 through the drive channel on_path and the cutoff channel off_path. The negative voltage generation module 710 includes a first terminal 1D and a second terminal 2D. The first terminal 1D is coupled to the drive power supply 110, and the second terminal 2D is coupled to the drive terminal TD of the switch module 120. The negative voltage generation module 710 is configured to store energy such that the voltage of the first terminal 1D is greater than the voltage of the second terminal 2D when the drive power supply 110 outputs the first drive voltage, and to maintain the voltage of the first terminal 1D greater than the voltage of the second terminal 2D when the drive power supply 110 outputs the second drive voltage.

[0047] In some embodiments, the negative pressure generation module 710 may include components such as capacitors and Zener diodes.

[0048] In some embodiments, the negative voltage generation module 710 includes a negative voltage generation capacitor (not shown). The first terminal 1D of the negative voltage generation capacitor is coupled to the driving power supply 110, and the second terminal 2D of the negative voltage generation capacitor is coupled to the driving terminal TD of the switching module 120. When the driving power supply 110 outputs the first driving voltage, the negative voltage generation capacitor stores energy to make the voltage of the first terminal 1D greater than the voltage of the second terminal 2D. When the driving power supply 110 outputs the second driving voltage, the first terminal 1D voltage is kept greater than the second terminal 2D voltage.

[0049] like Figure 7As shown, when the driving power supply 110 outputs the first driving voltage (e.g., a high-level voltage), the negative voltage generation module 710 stores energy, so that the voltage of its first terminal 1D is higher than the voltage of its second terminal 2D and the voltage difference gradually increases until the maximum value (which depends on the capacitance of the negative voltage generation capacitor); when the driving power supply 110 outputs the second driving voltage (e.g., a low-level voltage), assuming that the semiconductor switching device in the switching module 120 is an IGBT, the negative voltage generation capacitor can form a current loop through the off-path, the gate and emitter of the IGBT, and at this time, the voltage of the first terminal 1D of the negative voltage generation capacitor is clamped to a low level (e.g., ground voltage, i.e., the voltage of the negative bus BUS-). Since the voltage of the first terminal 1D of the negative voltage generation capacitor is higher than the voltage of its second terminal 2D, the voltage of the second terminal 2D (equivalent to the voltage of the driving terminal TD of the switching module 120) is lower than the ground voltage, so that the gate voltage of the IGBT is lower than the emitter voltage, thereby forming a negative voltage to reliably turn off the IGBT.

[0050] In the above embodiments, by setting a negative pressure generation module 710, the switching module 120 can be reliably turned off when the driving power supply 110 outputs the second driving voltage, thereby reducing the possibility that the switching modules 120 of the upper and lower bridge arms are simultaneously turned on, and thus improving the reliability of the inverter.

[0051] In some embodiments, please refer to Figure 8 The inverter circuit 100 also includes a drive module 810, which is coupled to the drive power supply 110 and the switch module 120, and provides a drive voltage to the switch module 120 based on the drive power supply 110.

[0052] In some embodiments, please combine Figure 5 and Figure 8 When the inverter circuit 100 has both a bootstrap power supply 510 and a drive module 810, the drive module 810 corresponding to the second switch module 440 in the upper bridge arm can be connected to the bootstrap power supply 510 and obtain the drive voltage from the bootstrap power supply 510. This will be explained in detail in subsequent embodiments.

[0053] The following reference Figure 9 The working principle of the inverter circuit provided in some embodiments of this application is explained below:

[0054] The first switching module in the first inverter channel L1 ( Figure 9 (not shown) may include a controllable switch (e.g.) Figure 9 The controllable switch Q1 in the middle, Figure 9 In the middle, the controllable switch Q1 is an IGBT; the second switch module in the second inverter channel L2 ( Figure 9 (not shown) may include a controllable switch (e.g.) Figure 9 The controllable switch Q2 in the middle, Figure 9 In this configuration, the controllable switch Q2 is an IGBT; the first drive module 910 and the second drive module 920 provide drive voltages (e.g., a first drive voltage and a second drive voltage) for the controllable switches Q1 and Q2, respectively. Both the first drive module 910 and the second drive module 920 obtain the drive voltages for driving the controllable switches Q1 and Q2 from the first drive power supply 410, thereby reducing the number of drive power supplies. The first control signal DRV1 is used to control the transistor Q3 to switch between on and off, and the second control signal DRV2 is used to control the transistor Q4 to switch between on and off. The ANODE pin and CATHODE pin of the first drive module 910 and the second drive module 920 are coupled to the power supply +V (the power supply voltage can be +5V, +3.3V, etc., which is not limited in this application). When transistor Q3 is turned on, the CATHODE pin is directly grounded through transistor Q3 or Q4, thus forcibly pulling the CATHODE pin voltage down to ground. The output VOUT of the first drive module 910 or the second drive module 920 outputs a low level (e.g., equal to the voltage at ground VEE). When transistor Q3 is turned off, the CATHODE pin is connected to the +V power supply through resistor R1 or R2, thus pulling the CATHODE pin voltage up to the power supply voltage (e.g., +5V). The output VOUT of the first drive module 910 or the second drive module 920 outputs a high level (e.g., equal to the voltage at the power input VCC). Therefore, the drive voltage output at the output VOUT of the first drive module 910 and the second drive module 920 can be controlled by the first control signal DRV1 and the second control signal DRV2, respectively, thereby controlling the on and off states of controllable switches Q1 and Q2.

[0055] The following explanation uses the driving process of controllable switch Q1 as an example. The driving process of controllable switch Q2 is basically the same as that of controllable switch Q1, and will not be repeated here.

[0056] For example, when the first control signal DRV1 is high, the controllable switch Q3 is turned on, and the output terminal VOUT of the first drive module 910 outputs a high-level first drive voltage, which is equal to the voltage provided by the first drive power supply 410. The drive current flows through the negative voltage generating capacitor C5, the first drive diode D-on, the first drive resistor R-on, the resistor R7, and the diode D3 to the negative terminal BUS- of the bus, causing the voltage of the negative voltage generating capacitor C5 to rise. The voltage across the negative voltage generating capacitor C5 is clamped by the Zener diode D2. The gate voltage of the controllable switch Q1 is equal to the voltage provided by the first drive power supply 410 minus the voltage across the negative voltage generating capacitor C5. Furthermore, the Zener diode D1 clamps the gate voltage under abnormal conditions, preventing the drive voltage from exceeding the maximum gate voltage of the controllable switch Q1. The controllable switch Q1 is then driven to turn on by the first drive voltage.

[0057] In some embodiments, the first drive power supply can also be coupled to the negative terminal BUS- of the bus for filtering via capacitors C6, C7 and C8 to improve the quality of the drive voltage.

[0058] The first driving power supply is also connected to the power input terminal VCC of the second driving module and the bootstrap driving module (not shown in the figure) including capacitors C1, C2, and C3 through diode D4 and resistor R5. One end of capacitors C1, C2, and C3 is coupled to the first driving power supply, and the other end is coupled to the AC output terminal OP. When the first driving power supply outputs the first driving voltage, it charges capacitors C1, C2, and C3 through diode D4 and resistor R5, thereby establishing the first driving voltage for driving the controllable switch Q2.

[0059] When the controllable switch Q1 is turned on, the bootstrap drive module establishes a first drive voltage for driving the controllable switch Q2 through the first drive power supply. Therefore, when the second control signal DRV2 is high, the first drive voltage output by the output terminal VOUT of the second drive module 920 can be provided by the bootstrap drive module, thus further reducing the number of drive power supplies.

[0060] When the first control signal DRV1 is low, transistor Q3 is turned off, and the output VOUT of the first drive module 910 outputs a low level, pulling the potential down to the voltage of the ground terminal VEE. The cutoff current flows from the gate of the controllable switch Q1 through the cutoff resistor R-off, the cutoff diode D-off, and the negative voltage generating capacitor C5. Due to the reverse cutoff of diode D3, the charge stored in the negative voltage generating capacitor C5 during the conduction of the controllable switch Q1 cannot be released through resistor R7. Therefore, when the controllable switch Q1 is turned off, the charge in the negative voltage generating capacitor C5 is only lost from the charge stored in the junction capacitance of the controllable switch Q1. Since the charge stored in the negative voltage generating capacitor C5 is much greater than the energy stored in the junction capacitance of the controllable switch Q1, the negative voltage generating capacitor C5 only loses a small amount of voltage during the turn-off phase of the controllable switch Q1. Therefore, a negative voltage is formed, that is, the gate voltage of the controllable switch Q1 is equal to the negative voltage across the negative voltage generating capacitor C5.

[0061] As can be seen from the above process of the controllable switch Q1 turning on and off, the paths of the cutoff current and the drive current are different. When the controllable switch Q1 is on, the drive current flows through the drive resistor R-on, and its magnitude is limited by the drive resistor R-on. When the controllable switch Q1 is off, the cutoff current flows through the cutoff resistor R-off, and its magnitude is limited by the cutoff resistor R-off. Therefore, the speed at which the controllable switch Q1 turns on and off can be adjusted by changing the values ​​of the drive resistor R-on and the cutoff resistor R-off, thereby optimizing the operating voltage stress of the controllable switch Q1.

[0062] Therefore, in some embodiments of this application, by setting a negative voltage generation module, a negative voltage can be generated at the drive terminal of the switch module when the switch module on a certain inverter channel (e.g., the first inverter channel L1) needs to be turned off, thereby reducing the risk of interconnection between the upper and lower bridge arms due to the Miller effect; by setting the cutoff channel and the drive channel respectively, the drive resistor and the cutoff resistor can be flexibly adjusted, thereby optimizing the voltage stress waveform of the switch module; by setting a bootstrap drive module, it is beneficial to further reduce the number of drive power supplies and simplify circuit routing.

[0063] The second aspect of this application also provides an inverter 1000, please refer to... Figure 10 The inverter 1000 includes a control circuit 1001 and an inverter circuit 100 in any of the above embodiments.

[0064] In the above scheme, the driving power supply is coupled to the driving terminal of the switching module through a driving channel and a cutoff channel, respectively. When the driving power supply outputs a first driving voltage to turn on the switching module, the driving current flows to the driving terminal of the switching module through the driving channel. When the driving power supply outputs a second driving voltage to turn off the switching module, the driving current flows out of the driving terminal of the switching module through the cutoff channel. The driving channel includes a driving resistor, and the cutoff channel includes a cutoff resistor. Thus, when the switching module is in the on state and the cutoff state, the driving current and the cutoff current flow through the driving resistor and the cutoff resistor, respectively. By adjusting the driving resistor, the voltage at the driving terminal when the switching module is in the on state can be adjusted, and by adjusting the cutoff resistor, the voltage at the driving terminal when the switching module is in the off state can be adjusted. This facilitates flexible adjustment of the voltage stress borne by the switching module.

[0065] The control circuit 1001 may include a CPU coupled to the inverter circuit 100, used to generate control signals, such as a first control signal DRV1, a second control signal DRV2, etc. (see details) Figure 9 ), to control the inverter circuit 100 to generate the required alternating current.

[0066] Those skilled in the art will readily recognize that numerous modifications and variations can be made to the apparatus and method while maintaining the teachings of this application. Therefore, the above disclosure should be considered limited only by the scope of the appended claims.

Claims

1. An inverter circuit, characterized by comprising: include: Inverter channel, including switching module; A drive power supply, coupled to the switching module, provides a drive voltage to the switching module so that the switching module selectively controls the current direction in the inverter channel based on the drive voltage; The driving power supply is coupled to the driving terminal of the switching module through a driving channel and a cutoff channel. When the driving power supply outputs a first driving voltage, the driving current flows to the driving terminal of the switching module through the driving channel. When the driving power supply outputs the second driving voltage, the cutoff current flows out from the driving terminal of the switching module through the cutoff channel; The driving channel includes a driving resistor, which is coupled to the driving terminal of the switching module and the driving power supply. The cut-off channel includes a cut-off resistor, coupled to the drive terminal of the switching module and the drive power supply.

2. The inverter circuit according to claim 1, characterized in that, The drive channel also includes: A unidirectional conduction unit is coupled to the drive resistor and the drive power supply. The unidirectional conduction unit is configured to conduct when the drive power supply outputs the first drive voltage and to turn off when the drive power supply outputs the second drive voltage. The cutoff channel also includes: A unidirectional conduction cutoff unit is coupled to the cutoff resistor and the drive power supply. The unidirectional conduction cutoff unit is configured to turn off when the drive power supply outputs the second drive voltage and to turn on when the drive power supply outputs the first drive voltage.

3. The inverter circuit according to claim 1 or 2, characterized in that, The inverter channel includes: The first inverter channel includes a first switching module; The second inverter channel includes a second switching module; the current flows in opposite directions in the first inverter channel and the second inverter channel, and when the first inverter channel is turned on, the second inverter channel is turned off; The driving power supply includes: A first driving power supply is coupled to the first switching module to provide a driving voltage to the first switching module, so that the first switching module selectively controls the conduction or cutoff of the first inverter channel based on the driving voltage. A second driving power supply is coupled to the second switching module to provide a driving voltage to the second switching module, so that the second switching module selectively controls the conduction or cutoff of the second inverter channel based on the driving voltage.

4. The inverter circuit according to claim 3, characterized in that, The first driving power supply is coupled to the driving terminal of the first switching module through the first driving channel and the first cutoff channel. When the first driving power supply outputs the first driving voltage, the first driving current flows to the driving terminal of the first switching module through the first driving channel. When the first driving power supply outputs the second driving voltage, the first cutoff current flows out from the driving terminal of the first switching module through the first cutoff channel; The second driving power supply is coupled to the driving terminal of the second switching module through the second driving channel and the second cutoff channel. When the second driving power supply outputs the first driving voltage, the second driving current flows to the driving terminal of the second switching module through the second driving channel. When the second driving power supply outputs the second driving voltage, the second cutoff current flows out from the driving terminal of the second switching module through the second cutoff channel.

5. The inverter circuit according to claim 3, characterized by Also includes: A bootstrap power supply is connected to the first power supply and the second switching module. When the first power supply outputs the first driving voltage, the bootstrap power supply provides the second driving voltage to the second switching module so that the second switching module is turned off based on the second driving voltage. When the first driving power supply outputs the second driving voltage, the first driving voltage is provided to the second switching module so that the second switching module is turned on based on the first driving voltage.

6. The inverter circuit according to claim 5, characterized in that, The bootstrap power supply includes: A bootstrap capacitor includes a first terminal and a second terminal. The first terminal is connected to the first driving power supply and the driving terminal of the second switching module. When the first driving power supply outputs the first driving voltage, the voltage difference between the first terminal and the second terminal of the bootstrap capacitor gradually increases, and the voltage at the first terminal is greater than the voltage at the second terminal, and the second driving voltage is provided to the second switching module so that the second switching module is turned off based on the second driving voltage. When the first driving power supply outputs the second driving voltage, the bootstrap capacitor provides the first driving voltage to the second switching module so that the second switching module is turned on based on the first driving voltage.

7. The inverter circuit of claim 1, wherein Also includes: The negative pressure generation module is coupled to the drive terminal of the switch module and the drive power supply through the drive channel and the cut-off channel; The negative pressure generating module includes a first terminal and a second terminal. The first terminal is coupled to the driving power supply, and the second terminal is coupled to the driving terminal of the switching module. The negative pressure generating module is configured to store energy such that the voltage of the first terminal is greater than the voltage of the second terminal when the driving power supply outputs the first driving voltage, and to maintain the voltage of the first terminal being greater than the voltage of the second terminal when the driving power supply outputs the second driving voltage.

8. The inverter circuit according to claim 7, characterized by The negative voltage generation module includes a negative voltage generation capacitor. The first end of the negative voltage generation capacitor is coupled to the driving power supply, and the second end of the negative voltage generation capacitor is coupled to the driving end of the switching module. When the driving power supply outputs the first driving voltage, the negative voltage generation capacitor stores energy to make the voltage at the first end greater than the voltage at the second end. When the driving power supply outputs the second driving voltage, the first end voltage is kept greater than the second end voltage.

9. The inverter circuit of claim 1, wherein, Also includes: The drive module is coupled to the drive power supply and the switch module, and provides a drive voltage to the switch module based on the drive power supply.

10. The inverter circuit of claim 1, wherein, The switching module includes IGBTs.

11. An inverter comprising a control circuit, characterized in that Also included is an inverter circuit according to any one of claims 1 to 10.

Images