Discharge control circuit and inverter

Abstract

The invention provides a discharge control circuit and an inverter, and relates to the technical field of capacitor discharge, the discharge control circuit comprises a bleeder resistor, a switch module and a first control module, the bleeder resistor, the switch module and a bus capacitor of the inverter form a loop, and the first control module is electrically connected with the switch module. And the first control module is electrically connected with the power supply end of the inverter, and the switch module is controlled to be switched off through the first control module under the condition that the power supply end is powered on, so that the loop is switched off, the situation that a bleeder resistor of a bus capacitor consumes power under the condition that the inverter is powered on but a switching power supply in the inverter stops working is avoided, and the electric energy consumption is reduced.

Description

Technical Field

[0001] The present application belongs to the field of capacitor discharge technology, and specifically relates to a discharge control circuit and an inverter. Background Art

[0002] After the inverter is powered off, in order to ensure safety, the bus capacitor in the inverter is discharged through the discharge resistor to discharge the electrical energy of the bus capacitor, so that the voltage of the bus capacitor is reduced to below the safe voltage.

[0003] In the related art, in order to avoid power consumption of the bleeder resistor when the inverter is powered on, a switching power supply (SPS) in the inverter is controlled to disconnect the bleeder resistor from the bus capacitor when the inverter is powered on.

[0004] However, when the inverter is powered on but the switching power supply stops working, the bleeder resistor still consumes power. For example, when the inverter's power-on voltage is lower than the switching power supply's starting voltage, the switching power supply is in the off state, or the switching power supply has not entered the working state after just starting. Summary of the Invention

[0005] The present application aims to provide a discharge control circuit and an inverter, which at least solve the problem in the related art that the discharge resistor of the bus capacitor consumes power when the inverter is powered on but the switching power supply in the inverter stops working.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] In a first aspect, an embodiment of the present application provides a discharge control circuit, comprising: a discharge resistor, a switch module, and a first control module;

[0008] The bleeder resistor, the switch module and the bus capacitor of the inverter form a loop;

[0009] The first control module is electrically connected to the switch module. The first control module is used to be electrically connected to the power supply end of the inverter and control the switch module to be disconnected when the power supply end is powered, so that the loop is disconnected.

[0010] Optionally, the first control module includes a first control submodule and a second control submodule; the first control submodule is electrically connected to the switch module, and the first control submodule is used to be electrically connected to the power supply end, and control the switch module to disconnect when the power supply end is powered on and the voltage at the power supply end is less than or equal to a voltage threshold; the second control submodule is electrically connected to the switch module, and the second control submodule is used to be electrically connected to the power supply end, and control the switch module to disconnect when the power supply end is powered on and the voltage at the power supply end is greater than a voltage threshold; wherein, when the voltage at the power supply end is less than or equal to the voltage threshold, the switching power supply of the inverter is turned off; when the voltage at the power supply end is greater than the voltage threshold, the switching power supply is started.

[0011] Optionally, the first control submodule includes a first switch unit, a second switch unit, a third switch unit and a fourth switch unit; the first switch unit is used to be electrically connected to the power supply end, and is disconnected when the power supply end is powered on and the voltage at the power supply end is less than or equal to the voltage threshold; the second switch unit is electrically connected to the first switch unit, and the second switch unit is used to be electrically connected to the power supply end, and is turned on when the first switch unit is disconnected; the third switch unit is electrically connected to the second switch unit, and the third switch unit is used to be electrically connected to the power supply end, and is turned on when the second switch unit is turned on; the fourth switch unit is electrically connected to the third switch unit and the switch module respectively, and the fourth switch unit is used to be turned on when the third switch unit is turned on, so that the switch module is disconnected.

[0012] Optionally, the first control submodule includes a fifth switch unit and a sixth switch unit; the fifth switch unit is used to be electrically connected to the power supply end, and is disconnected when the power supply end is powered on and the voltage at the power supply end is less than or equal to the voltage threshold; the sixth switch unit is electrically connected to the fifth switch unit, and the sixth switch unit is used to be turned on when the fifth switch unit is disconnected, so that the switch module is disconnected.

[0013] Optionally, the first control module also includes a second diode; the first end of the first control submodule is electrically connected to the first electrode of the power supply end and the positive electrode of the second diode respectively; the negative electrode of the second diode is electrically connected to the first electrode of the bus capacitor.

[0014] Optionally, the second control submodule includes a voltage acquisition unit and a controllable precision voltage-stabilizing power supply device; the first end of the voltage acquisition unit is electrically connected to the first electrode of the power supply end, the second end of the voltage acquisition unit is electrically connected to the second electrode of the power supply end, the output end of the voltage acquisition unit is electrically connected to the reference end of the controllable precision voltage-stabilizing power supply device, and the voltage acquisition unit is used to acquire the voltage of the power supply end; the cathode of the controllable precision voltage-stabilizing power supply device is electrically connected to the control end of the switch module, and the anode of the controllable precision voltage-stabilizing power supply device is electrically connected to the second electrode of the power supply end, and the controllable precision voltage-stabilizing power supply device is used to turn on when the voltage of the power supply end is greater than the voltage threshold, so as to control the switch module to disconnect.

[0015] Optionally, the discharge control circuit also includes a second control module; the second control module is electrically connected to the switch module, and the second control module is used to be electrically connected to the switching power supply of the inverter, and to control the switch module to be disconnected when the switching power supply is working, and to control the switch module to be turned on when the switching power supply stops working.

[0016] Optionally, the second control module includes a fifteenth resistor and an optocoupler; the first end of the fifteenth resistor is electrically connected to the first electrode of the switching power supply, and the second end of the fifteenth resistor is electrically connected to the anode of the optocoupler; the cathode of the optocoupler is electrically connected to the second electrode of the switching power supply, the collector of the optocoupler is electrically connected to the control end of the switching module, and the emitter of the optocoupler is electrically connected to the second electrode of the power supply end.

[0017] Optionally, the switching power supply of the inverter is electrically connected to the electrical devices of the inverter; the bus capacitor is electrically connected to the switching power supply, and when the switching power supply is working, the electrical devices are powered by the switching power supply.

[0018] In a second aspect, an embodiment of the present application provides an inverter, comprising the discharge control circuit as described in the first aspect.

[0019] In an embodiment of the present application, since the discharge resistor, the switch module and the bus capacitor of the inverter form a loop, and the first control module is electrically connected to the switch module, and the first control module is electrically connected to the power supply end of the inverter, when the power supply end is powered on, the first control module controls the switch module to disconnect, so that the loop is disconnected, so as to avoid the discharge resistor of the bus capacitor consuming power when the inverter is powered on but the switching power supply in the inverter stops working, thereby saving energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments.

[0021] Figure 1 1 is a structural diagram of a discharge control circuit provided in an embodiment of the present application;

[0022] Figure 2 This is a schematic diagram of the specific structure of a discharge control circuit provided in an embodiment of the present application;

[0023] Figure 3 is a schematic diagram of the specific structure of another discharge control circuit provided in an embodiment of the present application;

[0024] Figure 4 This is a schematic diagram of the specific structure of another discharge control circuit provided in an embodiment of the present application;

[0025] Figure 5 This is a specific structural diagram of yet another discharge control circuit provided in an embodiment of the present application.

[0026] Reference numerals:

[0027] 10-first control module; 11-first control submodule; 111-first switch unit; 112-second switch unit; 113-third switch unit; 114-fourth switch unit; 115-fifth switch unit; 116-sixth switch unit; 12-second control submodule; 121-voltage acquisition unit; 20-switch module; 30-bleeder resistor; 40-bus capacitor; 50-power supply terminal; 60-second control module; 70-switching power supply; 80-electrical device; U1-controllable precision voltage stabilizing source device; U2-optocoupler device; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor; R6-sixth resistor; R7-seventh resistor; R8-eighth resistor; R9-ninth resistor; R10-tenth resistor; R11-eleventh resistor; R12- The twelfth resistor; R13-the thirteenth resistor; R14-the fourteenth resistor; R15-the fifteenth resistor; R16-the sixteenth resistor; R17-the seventeenth resistor; R18-the eighteenth resistor; R19-the nineteenth resistor; R20-the twentieth resistor; R20-the twenty-first resistor; R20-the twenty-second resistor; R23-the twenty-third resistor; Q1-the first switching device; Q2-the second switching device; Q3-the third switching device; Q4-the fourth switching device; Q5-the fifth switching device; Q6-the sixth switching device; Q7-the seventh switching device; Q8-the eighth switching device; C1-the first capacitor; C2-the second capacitor; C3-the third capacitor; D1-the first diode; D2-the second diode; D3-the third diode; D4-the fourth diode; D5-the fifth diode; D6-the sixth diode; L1-the inductor. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0030] Reference Figure 1 An embodiment of the present application provides a discharge control circuit, including: a bleeder resistor 30, a switch module 20, and a first control module 10; the bleeder resistor 30, the switch module 20, and the bus capacitor 40 of the inverter form a loop; the first control module 10 is electrically connected to the switch module 20, and the first control module 10 is used to electrically connect to the power supply terminal 50 of the inverter, and when the power supply terminal 50 is energized, control the switch module 20 to disconnect, thereby disconnecting the loop.

[0031] In some embodiments, when the switch module 20 is turned on, the loop composed of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 is discharged through the bleeder resistor 30, that is, the electric energy of the bus capacitor 40 is consumed by the bleeder resistor 30; when the switch module 20 is turned off, the loop composed of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned off, and the bus capacitor 40 stops discharging through the bleeder resistor 30.

[0032] In some embodiments, when the inverter is powered off, the switch module 20 is turned on, the loop consisting of the bleeder resistor 30 , the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 is discharged through the bleeder resistor 30 .

[0033] In some embodiments, the bus capacitor 40 is electrically connected to the power supply terminal 50 , and the bus capacitor 40 is connected in parallel to the first control module 10 .

[0034] In some embodiments, the switch module 20 is connected in series with the bleeder resistor 30 , the branch of the switch module 20 and the bleeder resistor 30 is electrically connected to the power supply terminal 50 , and the branch of the switch module 20 and the bleeder resistor 30 is connected in series with the bus capacitor 40 in parallel.

[0035] In some embodiments, the power terminal 50 of the inverter is used to electrically connect to an external power source.

[0036] In some embodiments, the external power source is a photovoltaic panel.

[0037] In some embodiments, the switching power supply 70 of the inverter is electrically connected to the power terminal 50 .

[0038] In some embodiments, when the power terminal 50 of the inverter is powered on, the switching power supply 70 of the inverter is powered on; when the power terminal 50 of the inverter is powered off, the switching power supply 70 of the inverter is powered off.

[0039] In some embodiments, when the power-on voltage of the inverter, that is, the voltage at the power supply terminal 50 of the inverter is less than the starting voltage of the switching power supply 70, the switching power supply 70 is in the off state; when the power-on voltage of the inverter is greater than or equal to the starting voltage of the switching power supply 70, the switching power supply 70 is in the starting state.

[0040] In some embodiments, when the switching power supply 70 is switched from the off state to the on state, the inverter starts to work after a preset time period, that is, it switches from the off state to the working state.

[0041] In the embodiment of the present application, since the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter form a loop, and the first control module 10 is electrically connected to the switch module 20, and the first control module 10 is electrically connected to the power supply terminal 50 of the inverter, the first control module 10 controls the switch module 20 to be disconnected when the power supply terminal 50 is powered on, so that the loop is disconnected, thereby avoiding the bleeder resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0042] Optional, see Figure 2 In some embodiments, the first control module 10 includes a first control submodule 11 and a second control submodule 12; the first control submodule 11 is electrically connected to the switch module 20, and the first control submodule 11 is used to electrically connect to the power supply terminal 50, and when the power supply terminal 50 is powered on and the voltage of the power supply terminal 50 is less than or equal to the voltage threshold, control the switch module 20 to be disconnected; the second control submodule 12 is electrically connected to the switch module 20, and the second control submodule 12 is used to electrically connect to the power supply terminal 50, and when the power supply terminal 50 is powered on and the voltage of the power supply terminal 50 is greater than the voltage threshold, control the switch module 20 to be disconnected; wherein, when the voltage of the power supply terminal 50 is less than or equal to the voltage threshold, the switching power supply 70 of the inverter is turned off; when the voltage of the power supply terminal 50 is greater than the voltage threshold, the switching power supply 70 is started.

[0043] In some embodiments, the voltage at the power supply terminal 50 is the voltage for supplying power to the bus capacitor 40 .

[0044] In some embodiments, the voltage threshold is a startup voltage of the switching power supply 70 .

[0045] In the embodiment of the present application, when the voltage at the power supply terminal 50 is less than or equal to the voltage threshold, the switching power supply 70 of the inverter is turned off and stops working. The switching power supply 70 cannot be used to control the bleeder resistor 30 to be disconnected from the bus capacitor 40. Therefore, when the first control submodule 11 is powered on at the power supply terminal 50 and the voltage at the power supply terminal 50 is less than or equal to the voltage threshold, the switch module 20 is controlled to be disconnected to prevent the bleeder resistor 30 from consuming energy from the bus capacitor 40 or the external power supply. When the voltage at the power supply terminal 50 is greater than the voltage threshold, the switching power supply 70 is started and remains in a started but stopped state for a preset time period. Since the switching power supply 70 stops working, the bleeder resistor 30 cannot be controlled to be disconnected from the bus capacitor 40. Therefore, when the second control submodule 12 is powered on at the power supply terminal 50 and the voltage at the power supply terminal 50 is greater than the voltage threshold, the switch module 20 is controlled to be disconnected to prevent the bleeder resistor 30 from consuming energy from the bus capacitor 40 or the external power supply.

[0046] Optional, see Figure 3 In some embodiments, the first control submodule 11 includes a first switch unit 111, a second switch unit 112, a third switch unit 113, and a fourth switch unit 114; the first switch unit 111 is used to be electrically connected to the power supply terminal 50, and is disconnected when the power supply terminal 50 is powered and the voltage of the power supply terminal 50 is less than or equal to the voltage threshold; the second switch unit 112 is electrically connected to the first switch unit 111, and the second switch unit 112 is used to be electrically connected to the power supply terminal 50, and is turned on when the first switch unit 111 is disconnected; the third switch unit 113 is electrically connected to the second switch unit 112, and the third switch unit 113 is used to be electrically connected to the power supply terminal 50, and is turned on when the second switch unit 112 is turned on; the fourth switch unit 114 is electrically connected to the third switch unit 113 and the switch module 20 respectively, and the fourth switch unit 114 is used to be turned on when the third switch unit 113 is turned on, so that the switch module 20 is disconnected.

[0047] In the embodiment of the present application, the first switch unit 111 is energized at the power supply end 50 and is disconnected when the voltage at the power supply end 50 is less than or equal to the voltage threshold, and then the second switch unit 112 is turned on when the first switch unit 111 is disconnected, and then the third switch unit 113 is turned on when the second switch unit 112 is turned on, and then the fourth switch unit 114 is turned on when the third switch unit 113 is turned on, so that the switch module 20 is disconnected, and then the loop consisting of the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is disconnected, so as to avoid the discharge resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0048] Optionally, in some embodiments, the first switching unit 111 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first switching device Q1; the first end of the first resistor R1 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the control end of the first switching device Q1 respectively; the first end of the second resistor R2 is electrically connected to the control end of the first switching device Q1, and the second end of the second resistor R2 is electrically connected to the second end of the first switching device Q1 and the second electrode of the power supply terminal 50 respectively; the first end of the third resistor R3 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the third resistor R3 is electrically connected to the first end of the first switching device Q1 and the control end of the second switching unit 112 respectively; the first end of the first switching device Q1 is electrically connected to the control end of the second switching unit 112, and the second end of the first switching device Q1 is electrically connected to the second electrode of the power supply terminal 50.

[0049] In some embodiments, the type of the first switching device Q1 includes a transistor, a MOS transistor (Met al-Oxide-Semiconductor Field-Effect Transistor), etc. For example, the first switching device Q1 is an NPN transistor or an NMOS transistor, wherein the NPN transistor is composed of three semiconductors, including two N (Negative Electricity) type semiconductors (electron type semiconductors) and one P (Positive Electricity) type semiconductor (hole type semiconductor), with the P-type semiconductor in the middle and two N-type semiconductors on both sides; the NMOS transistor is a negative channel metal-oxide semiconductor transistor (Negative channel-Metal-Oxide-Semiconductor).

[0050] In some embodiments, the first switching unit 111 further includes a sixteenth resistor R16, the first end of the sixteenth resistor R16 being electrically connected to the second end of the first resistor R1 and the control end of the first switching device Q1, respectively, and the second end of the sixteenth resistor R16 being electrically connected to the second electrode of the power supply end 50.

[0051] In an embodiment of the present application, the first resistor R1 and the second resistor R2 are voltage-dividing resistors, and the third resistor R3 is a current-limiting and pull-up resistor. The first switching device Q1 is disconnected when the voltage of the second resistor R2 is less than the first voltage-dividing threshold, so that the second switching device Q2 is turned on when the first switching device Q1 is disconnected, and is turned on when the voltage of the second resistor R2 is greater than the first voltage-dividing threshold, so that the second switching device Q2 is disconnected when the first switching device Q1 is turned on. Since the voltage of the power supply terminal 50 is equal to the total voltage of the first resistor R1 and the second resistor R2, the voltage of the second resistor R2 is less than the first voltage-dividing threshold, indicating that the voltage of the power supply terminal 50 is less than or equal to the voltage threshold, and the voltage of the second resistor R2 is greater than the first voltage-dividing threshold, indicating that the voltage of the power supply terminal 50 is greater than the voltage threshold.

[0052] In some embodiments, the power supply terminal 50 of the inverter includes an inductor L1 and a sixth switching device Q6, the first end of the inductor L1 is used to be electrically connected to the first electrode of the external power supply, the second end of the inductor L1 is electrically connected to the first end of the first control submodule 11 and the first end of the sixth switching device Q6, respectively; the second end of the sixth switching device Q6 is electrically connected to the second electrode of the external power supply.

[0053] In some embodiments, the first electrode of the external power source is a positive electrode, and the second electrode of the external power source is a negative electrode.

[0054] In some embodiments, a control terminal of the sixth switching device Q6 is electrically connected to a first terminal of an external controller, and the controller is used to control the on and off of the sixth switching device Q6.

[0055] In some embodiments, the sixth switching device Q6 is a transistor, a MOS transistor, or the like.

[0056] In some embodiments, the sixth switching device Q6 is a MOS transistor, for example, the sixth switching device Q6 is an NMOS transistor. The sixth switching device Q6 is provided with a sixth diode D6 as a parasitic diode. The cathode of the sixth diode D6 is electrically connected to the first end of the sixth switching device Q6 and the second end of the inductor L1, respectively, and the anode of the sixth diode D6 is electrically connected to the second end of the sixth switching device Q6 and the second electrode of the external power supply, respectively.

[0057] In the embodiment of the present application, when the sixth switching device Q6 is turned on, the external power supply charges the inductor L1; when the sixth switching device Q6 is turned off, the external power supply and the inductor L1 jointly charge the bus capacitor 40, so as to increase the supply voltage of the bus capacitor 40 from the voltage of the external power supply to the total voltage of the external power supply and the inductor L1.

[0058] In some embodiments, the first electrode of the power terminal 50 is the second end of the inductor L1 , and the second electrode of the power terminal 50 is the second electrode of the external power source.

[0059] Optionally, in some embodiments, the second switch unit 112 includes a fourth resistor R4 and a second switch device Q2; the first end of the fourth resistor R4 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the fourth resistor R4 is electrically connected to the first end of the second switch device Q2; the control end of the second switch device Q2 is electrically connected to the first end of the first switch unit 111, and the second end of the second switch device Q2 is electrically connected to the first end of the third switch unit 113.

[0060] In some embodiments, the second switch device Q2 is a transistor, a MOS transistor, etc. For example, the second switch device Q2 is an NPN transistor or an NMOS transistor.

[0061] In some embodiments, the second switching unit 112 also includes a first capacitor C1 and a third diode D3, wherein the first end of the first capacitor C1 is electrically connected to the second end of the second switching device Q2, and the second end of the first capacitor C1 is electrically connected to the second electrode of the power supply terminal 50; the cathode of the third diode D3 is electrically connected to the second end of the second switching device Q2, and the anode of the third diode D3 is electrically connected to the second electrode of the power supply terminal 50, wherein the first capacitor C1 is a filter capacitor, and the third diode D3 is a voltage regulator diode used to protect the transistor.

[0062] In the embodiment of the present application, the fourth resistor R4 is a current-limiting resistor. When the first switching device Q1 is disconnected, the third resistor R3 pulls up the control end of the second switching device Q2, so that the second switching device Q2 is turned on, and then the third switching device Q3 is turned on when the second switching device Q2 is turned on; when the first switching device Q1 is turned on, the control end of the second switching device Q2 is pulled down by the first switching device Q1, so that the second switching device Q2 is disconnected, and then the third switching device Q3 is disconnected when the second switching device Q2 is disconnected.

[0063] Optionally, in some embodiments, the third switch unit 113 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first diode D1 and a third switch device Q3; the first end of the fifth resistor R5 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the fifth resistor R5 is electrically connected to the negative electrode of the first diode D1 and the first end of the sixth resistor R6, respectively; the first end of the sixth resistor R6 is electrically connected to the negative electrode of the first diode D1, and the second end of the sixth resistor R6 is electrically connected to the second electrode of the power supply terminal 50; the first end of the seventh resistor R7 is electrically connected to the second end of the second switch unit 112, and the second end of the seventh resistor R7 is electrically connected to the first end of the third switch device Q3; the control end of the third switch device Q3 is electrically connected to the positive electrode of the first diode D1, and the second end of the third switch device Q3 is electrically connected to the control end of the fourth switch unit 114.

[0064] In some embodiments, the type of the third switching device Q3 includes a transistor, a MOS transistor, etc. For example, the third switching device Q3 is a PNP transistor or a PMOS transistor, wherein the PNP transistor is composed of three semiconductors, including an N-type semiconductor and two P-type semiconductors, with the N-type semiconductor in the middle and the two P-type semiconductors on both sides; the PMOS transistor is a positive channel Metal Oxide Semiconductor transistor.

[0065] In an embodiment of the present application, the fifth resistor R5 and the sixth resistor R6 are voltage-dividing resistors, the first diode D1 is an anti-reverse diode, and the seventh resistor R7 is a current-limiting resistor. When the second switching device Q2 is turned on, the first end of the third switching device Q3 is connected to the first electrode of the power supply terminal 50. When the voltage of the sixth resistor R6 is less than the second voltage-dividing threshold, the third switching device Q3 is turned on, and when the voltage of the sixth resistor R6 is greater than the second voltage-dividing threshold, the third switching device Q3 is turned off. Since the voltage of the power supply terminal 50 is equal to the total voltage of the fifth resistor R5 and the sixth resistor R6, the voltage of the sixth resistor R6 is less than the second voltage-dividing threshold, indicating that the voltage of the power supply terminal 50 is less than or equal to the voltage threshold, and the voltage of the sixth resistor R6 is greater than the second voltage-dividing threshold, indicating that the voltage of the power supply terminal 50 is greater than the voltage threshold.

[0066] Optionally, in some embodiments, the fourth switch unit 114 includes an eighth resistor R8, a ninth resistor R9 and a fourth switch device Q4; the first end of the eighth resistor R8 is electrically connected to the second end of the third switch unit 113, and the second end of the eighth resistor R8 is electrically connected to the control end of the fourth switch device Q4 and the first end of the ninth resistor R9, respectively; the first end of the ninth resistor R9 is electrically connected to the control end of the fourth switch device Q4, and the second end of the ninth resistor R9 is electrically connected to the second electrode of the power supply terminal 50; the first end of the fourth switch device Q4 is electrically connected to the control end of the switch module 20, and the second end of the fourth switch device Q4 is electrically connected to the second electrode of the power supply terminal 50.

[0067] In some embodiments, the fourth switch device Q4 is a transistor, a MOS transistor, etc. For example, the fourth switch device Q4 is an NPN transistor or an NMOS transistor.

[0068] In the embodiment of the present application, the eighth resistor R8 is a current limiting and pull-up resistor, and the ninth resistor R9 is a pull-down resistor. When the first end of the third switching device Q3 is connected to the first electrode of the power supply terminal 50 and the third switching device Q3 is turned on, the fourth switching device Q4 is turned on, so that the control end of the fifth switching device Q5 in the switch module 20 is pulled down, and the fifth switching device Q5 is disconnected, that is, the switch module 20 is disconnected; when the first end of the third switching device Q3 is disconnected from the first electrode of the power supply terminal 50, or the third switching device Q3 is disconnected, the ninth resistor R9 pulls down the control end of the fourth switching device Q4, and the fourth switching device Q4 is disconnected, and the control end of the fifth switching device Q5 in the switch module 20 stops being pulled down.

[0069] Optional, see Figure 4 In some embodiments, the first control submodule 11 includes a fifth switch unit 115 and a sixth switch unit 116; the fifth switch unit 115 is used to be electrically connected to the power supply terminal 50, and is disconnected when the power supply terminal 50 is powered and the voltage of the power supply terminal 50 is less than or equal to the voltage threshold; the sixth switch unit 116 is electrically connected to the fifth switch unit 115, and the sixth switch unit 116 is used to be turned on when the fifth switch unit 115 is disconnected, so that the switch module 20 is disconnected.

[0070] In the embodiment of the present application, the fifth switch unit 115 is powered on at the power supply end 50 and is disconnected when the voltage at the power supply end 50 is less than or equal to the voltage threshold. Then, the sixth switch unit 116 is turned on when the fifth switch unit 115 is disconnected, so that the switch module 20 is disconnected, and the loop consisting of the bleeder resistor 30, the switch module 20, and the bus capacitor 40 of the inverter is disconnected, so as to avoid the bleeder resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0071] Reference Figure 5 In some embodiments, the fifth switch unit 115 includes an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, and a seventh switch device Q7; a first end of the eighteenth resistor R18 is electrically connected to the first electrode of the power supply terminal 50, and a second end of the eighteenth resistor R18 is electrically connected to the first end of the nineteenth resistor R19 and the control end of the seventh switch device Q7, respectively; a first end of the nineteenth resistor R19 is electrically connected to the control end of the seventh switch device Q7, and a second end of the nineteenth resistor R19 is electrically connected to the second end of the seventh switch device Q7 and the second electrode of the power supply terminal 50, respectively; a first end of the twentieth resistor R20 is electrically connected to the first electrode of the power supply terminal 50, and a second end of the twentieth resistor R20 is electrically connected to the first end of the seventh switch device Q7 and the control end of the sixth switch unit 116, respectively; a first end of the seventh switch device Q7 is electrically connected to the control end of the sixth switch unit 116, and a second end of the seventh switch device Q7 is electrically connected to the second electrode of the power supply terminal 50.

[0072] In some embodiments, the fifth switch device Q5 is a transistor, a MOS transistor, etc. For example, the fifth switch device Q5 is an NPN transistor or an NMOS transistor.

[0073] In some embodiments, the fifth switching unit 115 also includes a twenty-first resistor R21, the first end of the twenty-first resistor R21 is electrically connected to the second end of the eighteenth resistor R18 and the control end of the seventh switching device Q7, respectively, and the second end of the twenty-first resistor R21 is electrically connected to the second electrode of the power supply terminal 50.

[0074] In the embodiment of the present application, the eighteenth resistor R18 and the nineteenth resistor R19 are voltage-dividing resistors, and the twentieth resistor R20 is a current-limiting and pull-up resistor. The seventh switching device Q7 is disconnected when the voltage of the nineteenth resistor R19 is less than the third voltage-dividing threshold, so that the eighth switching device Q8 is turned on by the pull-up action of the second resistor when the seventh switch unit is disconnected, and is turned on when the voltage of the nineteenth resistor R19 is greater than the third voltage-dividing threshold, so that the eighth switching device Q8 is disconnected by the pull-down action of the seventh switching device Q7 when the seventh switching device Q7 is turned on. Since the voltage at the power supply terminal 50 is equal to the total voltage of the eighteenth resistor R18 and the nineteenth resistor R19, the voltage of the nineteenth resistor R19 is less than the third voltage-dividing threshold, indicating that the voltage at the power supply terminal 50 is less than or equal to the voltage threshold, and the voltage of the nineteenth resistor R19 is greater than the third voltage-dividing threshold, indicating that the voltage at the power supply terminal 50 is greater than the voltage threshold.

[0075] In some embodiments, the sixth switch unit 116 includes a twenty-second resistor R22, a twenty-third resistor R23 and an eighth switch device Q8; the first end of the twenty-second resistor R22 is electrically connected to the second end of the twentieth resistor R20 and the first end of the seventh switch device Q7, respectively, and the second end of the twenty-second resistor R22 is electrically connected to the control end of the eighth switch device Q8 and the first end of the twenty-third resistor R23, respectively; the first end of the twenty-third resistor R23 is electrically connected to the control end of the eighth switch device Q8, and the second end of the twenty-third resistor R23 is electrically connected to the second electrode of the power supply terminal 50; the first end of the eighth switch device Q8 is electrically connected to the control end of the switch module 20, and the second end of the eighth switch device Q8 is electrically connected to the second electrode of the power supply terminal 50.

[0076] In some embodiments, the eighth switch device Q8 is a transistor, a MOS transistor, etc. For example, the eighth switch device Q8 is an NPN transistor or an NMOS transistor.

[0077] In the embodiment of the present application, the twenty-second resistor R22 is a current limiting and pull-up resistor, and the twenty-third resistor R23 is a pull-down resistor. When the seventh switch device Q7 is disconnected, the control end of the eighth switch device Q8 is pulled up through the twenty-second resistor R22 and the twenty-second resistor R20, and the eighth switch device Q8 is turned on, so that the control end of the fifth switch device Q5 in the switch module 20 is pulled down, and the fifth switch device Q5 is disconnected, that is, the switch module 20 is disconnected; when the seventh switch device Q7 is turned on, the twenty-third resistor R23 pulls down the control end of the eighth switch device Q8, and the eighth switch device Q8 is disconnected, and the control end of the fifth switch device Q5 in the switch module 20 stops being pulled down.

[0078] Optionally, in some embodiments, the first control module 10 further includes a second diode D2; the first end of the first control submodule 11 is electrically connected to the first electrode of the power supply end 50 and the positive electrode of the second diode D2, respectively; and the negative electrode of the second diode D2 is electrically connected to the first electrode of the bus capacitor 40.

[0079] In an embodiment of the present application, the second diode D2 is an anti-reverse diode, which is used to block the current of the bus capacitor 40 discharging, so as to prevent the current of the bus capacitor 40 discharging from causing the first switch unit 111 to be disconnected, the second switch unit 112 to be turned on, the third switch unit 113 to be turned on, and the fourth switch unit 114 to be turned on when the power supply end 50 is powered off, thereby preventing the switch module 20 from being disconnected and the bus capacitor 40 from being able to discharge through the discharge resistor 30.

[0080] Optionally, in some embodiments, the second control submodule 12 includes a voltage acquisition unit 121 and a controllable precision voltage-stabilizing power supply device U1; the first end of the voltage acquisition unit 121 is electrically connected to the first electrode of the power supply terminal 50, the second end of the voltage acquisition unit 121 is electrically connected to the second electrode of the power supply terminal 50, the output end of the voltage acquisition unit 121 is electrically connected to the reference end of the controllable precision voltage-stabilizing power supply device U1, and the voltage acquisition unit 121 is used to acquire the voltage of the power supply terminal 50; the cathode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the control end of the switch module 20, the anode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the second electrode of the power supply terminal 50, and the controllable precision voltage-stabilizing power supply device U1 is used to turn on when the voltage of the power supply terminal 50 is greater than the voltage threshold, so as to control the switch module 20 to disconnect.

[0081] In the embodiment of the present application, the voltage of the power supply terminal 50 is collected by the voltage collection unit 121, and then the controllable precision voltage stabilizing source device U1 is turned on when the voltage of the power supply terminal 50 is greater than the voltage threshold to control the switch module 20 to be disconnected, thereby disconnecting the loop consisting of the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter, so as to avoid the discharge resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0082] In some embodiments, the second control submodule 12 includes a tenth resistor R10, an eleventh resistor R11 and a controllable precision voltage-stabilizing power supply device U1; the first end of the tenth resistor R10 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the tenth resistor R10 is electrically connected to the first end of the eleventh resistor R11 and the reference end of the controllable precision voltage-stabilizing power supply device U1 respectively; the first end of the eleventh resistor R11 is electrically connected to the reference end of the controllable precision voltage-stabilizing power supply device U1, and the second end of the eleventh resistor R11 is electrically connected to the second electrode of the power supply terminal 50; the cathode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the control end of the switch module 20, and the anode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the second electrode of the power supply terminal 50, and the controllable precision voltage-stabilizing power supply device U1 is used to control the switch module 20 to be disconnected when it is turned on; wherein, when the voltage of the power supply terminal 50 is greater than the voltage threshold, the controllable precision voltage-stabilizing power supply device U1 is turned on.

[0083] In some embodiments, the controllable precision voltage regulator device U1 may be a controllable precision voltage regulator chip.

[0084] In the embodiment of the present application, the tenth resistor R10 and the eleventh resistor R11 are voltage-dividing resistors. When the voltage at the power supply terminal 50 is greater than the voltage threshold, the controllable precision voltage-stabilizing source device U1 is turned on. When the controllable precision voltage-stabilizing source device U1 is turned on, the switch module 20 is controlled to be disconnected, thereby disconnecting the loop consisting of the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter, so as to avoid the discharge resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption. Among them, since the voltage of the power supply terminal 50 is equal to the total voltage of the tenth resistor R10 and the eleventh resistor R11, the voltage of the eleventh resistor R11 is less than the fourth voltage dividing threshold, indicating that the voltage of the power supply terminal 50 is less than or equal to the voltage threshold, and the voltage of the eleventh resistor R11 is greater than the fourth voltage dividing threshold, indicating that the voltage of the power supply terminal 50 is greater than the voltage threshold, and the precision voltage stabilizing source device is disconnected when the voltage of the eleventh resistor R11 is less than the fourth voltage dividing threshold, and is turned on when the voltage of the eleventh resistor R11 is greater than the fourth voltage dividing threshold.

[0085] In some embodiments, the fourth voltage division threshold is 2.5 volts, the on-state voltage drop of the precision voltage regulator device is 1.2 volts, and the on-state voltage drop of the precision voltage regulator device is less than the on-state threshold of the fifth switching device Q5.

[0086] Optionally, in some embodiments, the switch module 20 includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14 and a fifth switch device Q5; the first end of the twelfth resistor R12 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the twelfth resistor R12 is respectively electrically connected to the first end of the thirteenth resistor R13 and the second end of the first control module 10; the first end of the thirteenth resistor R13 is electrically connected to the second end of the first control module 10, and the second end of the thirteenth resistor R13 is respectively electrically connected to the first end of the fourteenth resistor R14 and the control end of the fifth switch device Q5; the first end of the fourteenth resistor R14 is electrically connected to the control end of the fifth switch device Q5, and the second end of the fourteenth resistor R14 is electrically connected to the second electrode of the power supply terminal 50; the first end of the fifth switch device Q5 is electrically connected to the second end of the discharge resistor 30, and the second end of the fifth switch device Q5 is electrically connected to the second electrode of the power supply terminal 50; the first end of the discharge resistor 30 is electrically connected to the first electrode of the power supply terminal 50.

[0087] In some embodiments, the switch module 20 further includes a fourth diode D4, the anode of the fourth diode D4 is electrically connected to the second electrode of the power supply terminal 50, and the cathode of the fourth diode D4 is electrically connected to the second end of the twelfth resistor R12 and the first end of the thirteenth resistor R13 respectively.

[0088] In some embodiments, the switch module 20 also includes a fourteenth resistor R14 and a second capacitor C2, the first end of the fourteenth resistor R14 is electrically connected to the second end of the thirteenth resistor R13 and the control end of the fifth switch device Q5, respectively, and the second end of the fourteenth resistor R14 is electrically connected to the second electrode of the power supply terminal 50; the first end of the second capacitor C2 is electrically connected to the second end of the thirteenth resistor R13 and the control end of the fifth switch device Q5, respectively, and the second end of the second capacitor C2 is electrically connected to the second electrode of the power supply terminal 50.

[0089] In some embodiments, the fifth switching device Q5 is a transistor, a MOS transistor, or the like.

[0090] In some embodiments, the fifth switching device Q5 is a MOS transistor, for example, the fifth switching device Q5 is an NMOS transistor. The fifth switching device Q5 is provided with a fifth diode D5 as a parasitic diode. The cathode of the fifth diode D5 is electrically connected to the first end of the fifth switching device Q5 and the second end of the bleeder resistor 30, respectively, and the anode of the fifth diode D5 is electrically connected to the second end of the sixth switching device Q6 and the second electrode of the power supply terminal 50, respectively.

[0091] In the embodiment of the present application, the twelfth resistor R12 is a pull-up resistor, the thirteenth resistor R13 is a current limiting and pull-up resistor, the fourth diode D4 is a voltage-stabilizing diode, which is used to protect the control end of the fifth switch device Q5, and the fourteenth resistor R14 and the second capacitor C2 form an RC (resistance-capacitance) parallel circuit, which is used to protect the control end of the fifth switch device Q5. When the fourth switch device Q4 in the first control submodule 11 is turned on, or the controllable precision voltage-stabilizing source device U1 in the second control submodule 12 is turned on, or the optocoupler device U2 in the second control module 60 is turned on, the control end of the fifth switch device Q5 is pulled down, and the fifth switch device Q5 is disconnected, and then The loop consisting of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is disconnected to avoid power consumption of the bleeder resistor 30 of the bus capacitor 40; when the fourth switch device Q4 in the first control submodule 11 is disconnected, the controllable precision voltage regulator device U1 in the second control submodule 12 is disconnected, and the optocoupler device U2 in the second control module 60 is disconnected, the control end of the fifth switch device Q5 is pulled up through the twelfth resistor R12 and the thirteenth resistor R13, and the fifth switch device Q5 is turned on, so that the loop consisting of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 is discharged through the bleeder resistor 30.

[0092] Optionally, in some embodiments, the discharge control circuit further includes a second control module 60; the second control module 60 is electrically connected to the switch module 20, and the second control module 60 is used to be electrically connected to the switching power supply 70 of the inverter, and to control the switch module 20 to be disconnected when the switching power supply 70 is working, and to control the switch module 20 to be turned on when the switching power supply 70 stops working.

[0093] In an embodiment of the present application, the second control module 60 controls the switch module 20 to be disconnected when the switching power supply 70 is working, thereby disconnecting the loop consisting of the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter, so as to avoid the discharge resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on, thereby saving energy consumption, and the second control module 60 controls the switch module 20 to be turned on when the switching power supply 70 stops working, so that when the inverter is powered off and the switching power supply 70 stops working, the bus capacitor 40 in the inverter is discharged through the discharge resistor 30 to discharge the electrical energy of the bus capacitor 40.

[0094] When the power supply terminal 50 is powered on, the voltage of the power supply terminal 50 is greater than the voltage threshold, and the switching power supply 70 starts working, the second control submodule 12 and the second control module 60 are redundant structures for controlling the switch module 20 to be disconnected.

[0095] Optionally, in some embodiments, the second control module 60 includes a fifteenth resistor R15 and an optocoupler device U2; the first end of the fifteenth resistor R15 is electrically connected to the first electrode of the switching power supply 70, and the second end of the fifteenth resistor R15 is electrically connected to the anode of the optocoupler device U2; the cathode of the optocoupler device U2 is electrically connected to the second electrode of the switching power supply 70, the collector of the optocoupler device U2 is electrically connected to the control end of the switching module 20, and the emitter of the optocoupler device U2 is electrically connected to the second electrode of the power supply end 50.

[0096] In some embodiments, the second control module 60 also includes a seventeenth resistor R17, the first end of the seventeenth resistor R17 is electrically connected to the fifteenth resistor R15 and the anode of the optocoupler device U2, respectively, and the second end of the seventeenth resistor R17 is electrically connected to the cathode of the optocoupler device U2, wherein the seventeenth resistor R17 is a voltage divider resistor.

[0097] In some embodiments, the second control module 60 also includes a third capacitor C3, a first end of the third capacitor C3 is electrically connected to the collector of the optocoupler device U2, and a second end of the third capacitor C3 is electrically connected to the emitter of the optocoupler device U2 and the second electrode of the power supply terminal 50, respectively, wherein the third capacitor C3 is a filter capacitor.

[0098] In the embodiment of the present application, the fifteenth resistor R15 is a current limiting resistor. When the switching power supply 70 is working, the switching power supply 70 outputs current to the anode of the optocoupler device U2, the optocoupler device U2 is turned on, the control end of the fifth switching device Q5 is pulled down, and the fifth switching device Q5 is turned off, thereby disconnecting the loop composed of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter, thereby preventing the bleeder resistor 30 of the bus capacitor 40 from consuming power; when the switching power supply 70 stops working, the switching power supply 70 stops outputting current to the anode of the optocoupler device U2, and the optocoupler device U2 is turned off, so that when the inverter is powered off and the switching power supply 70 stops working, the control end of the fifth switching device Q5 is pulled up through the twelfth resistor R12 and the thirteenth resistor R13, and the fifth switching device Q5 is turned on, so that the loop composed of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 is discharged through the bleeder resistor 30.

[0099] Optionally, in some embodiments, the switching power supply 70 of the inverter is electrically connected to the electrical device 80 of the inverter; the bus capacitor 40 is electrically connected to the switching power supply 70, and when the switching power supply 70 is working, the electrical device 80 is powered by the switching power supply 70.

[0100] In some embodiments, the first electrode of the switching power supply 70 is electrically connected to the positive electrode of the electrical device 80, and the second electrode of the switching power supply 70 is electrically connected to the negative electrode of the electrical device 80; the positive input terminal of the switching power supply 70 is electrically connected to the first end of the bus capacitor 40, and the negative input terminal of the switching power supply 70 is electrically connected to the second end of the bus capacitor 40; the first end of the bus capacitor 40 is electrically connected to the first electrode of the power supply terminal 50, and the second end of the bus capacitor 40 is electrically connected to the second electrode of the power supply terminal 50.

[0101] In some embodiments, the electrical device 80 may be a heat dissipation device, such as a fan.

[0102] In the embodiment of the present application, when the inverter is powered off and the voltage of the bus capacitor 40 is greater than the starting voltage of the switching power supply 70, the switching power supply 70 works, and the bus capacitor 40 supplies power to the electrical device 80 through the switching power supply 70. Therefore, the power of the bus capacitor 40 can be quickly consumed by the switching power supply 70 and the electrical device 80 to shorten the discharge time of the power of the bus capacitor 40 when the inverter is powered off; when the inverter is powered off and the voltage of the bus capacitor 40 is less than or equal to the starting voltage of the switching power supply 70, the switching power supply 70 The switching power supply 70 stops working, and the switching power supply 70 stops outputting current to the anode of the optocoupler device U2. The optocoupler device U2 is disconnected, so that when the inverter is powered off and the switching power supply 70 stops working, the control end of the fifth switching device Q5 is pulled up through the twelfth resistor R12 and the thirteenth resistor R13, and the fifth switching device Q5 is turned on, so that the loop composed of the bleeder resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 continues to discharge through the bleeder resistor 30, that is, the electric energy of the bus capacitor 40 continues to be consumed by the bleeder resistor 30.

[0103] In some embodiments, the first control module 10 may be a control chip, for example, the first control module 10 may be a digital signal processing (DSP) chip. The output end of the first control module 10 is electrically connected to the first end of the thirteenth resistor R13 in the switch module 20, and the output end of the first control module 10 outputs a drive signal for controlling the on and off of the fifth switch device Q5. When the inverter is powered off, the first control module 10 outputs a drive signal of a first level (for example, a high level) to turn on the fifth switch device Q5, and the bus capacitor 40 is discharged through the discharge resistor 30. When the inverter is powered on, the first control module 10 outputs a drive signal of a second level (for example, a low level) to turn off the fifth switch device Q5, and disconnect the loop composed of the discharge resistor 30, the switch module 20, and the bus capacitor 40 of the inverter, so as to avoid power consumption of the discharge resistor 30 of the bus capacitor 40, thereby saving energy consumption.

[0104] In some embodiments, the discharge control circuit includes: a discharge resistor 30, a switch module 20, a first control module 10 and a second control module 60; the first control module 10 includes a second diode D2, a first control submodule 11 and a second control submodule 12; the first control submodule 11 includes a first switch unit 111, a second switch unit 112, a third switch unit 113 and a fourth switch unit 114; the first switch unit 111 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first switch device Q1; the second switch unit 112 includes a fourth resistor R4 and a second switch device Q2; the third switch unit 113 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first switch device Q1; the second switch unit 112 includes a fourth resistor R4 and a second switch device Q2; the third switch unit 114 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first switch device Q1; the second switch unit 112 includes a fourth resistor R4 and a second switch device Q2; the third switch unit 113 ... first switch unit 111 includes a first resistor R1, a second resistor R2, a third resistor The element 113 includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first diode D1, and a third switch device Q3; the fourth switch unit 114 includes an eighth resistor R8, a ninth resistor R9, and a fourth switch device Q4; the second control submodule 12 includes a tenth resistor R10, an eleventh resistor R11, and a controllable precision voltage regulator device U1; the switch module 20 includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, and a fifth switch device Q5; the second control module 60 includes a fifteenth resistor R15 and an optocoupler device U2; the power supply terminal 50 of the inverter includes an inductor L1 and a sixth switch device Q6;

[0105] A first end of the inductor L1 is electrically connected to a first electrode of an external power source, and a second end of the inductor L1 is electrically connected to a first end of a sixth switching device Q6, a first end of a first resistor R1, a first end of a third resistor R3, a first end of a fourth resistor R4, a first end of a fifth resistor R5, and an anode of the second diode, respectively; a second end of the sixth switching device Q6 is electrically connected to a second electrode of the external power source;

[0106] The second end of the first resistor R1 is electrically connected to the first end of the second resistor R2 and the control end of the first switching device Q1, respectively; the first end of the second resistor R2 is electrically connected to the control end of the first switching device Q1, and the second end of the second resistor R2 is electrically connected to the second end of the first switching device Q1 and the second electrode of the power supply terminal 50, respectively; the second end of the third resistor R3 is electrically connected to the first end of the first switching device Q1 and the control end of the second switching device Q2, respectively; the first end of the first switching device Q1 is electrically connected to the control end of the second switching device Q2, and the second end of the first switching device Q1 is electrically connected to the second electrode of the power supply terminal 50; the second end of the fourth resistor R4 is electrically connected to the first end of the second switching device Q2; the control end of the second switching device Q2 is electrically connected to the first end of the first switching device Q1, and the second end of the second switching device Q2 is electrically connected to the first end of the seventh resistor;

[0107] The second end of the fifth resistor R5 is electrically connected to the cathode of the first diode D1 and the first end of the sixth resistor R6, respectively. The first end of the sixth resistor R6 is electrically connected to the cathode of the first diode D1, and the second end of the sixth resistor R6 is electrically connected to the second electrode of the power supply terminal 50. The second end of the seventh resistor R7 is electrically connected to the first end of the third switching device Q3. The control end of the third switching device Q3 is electrically connected to the anode of the first diode D1, and the second end of the third switching device Q3 is electrically connected to the first end of the eighth resistor. The second end of the eighth resistor R8 is electrically connected to the control end of the fourth switching device Q4 and the first end of the ninth resistor R9, respectively. The first end of the ninth resistor R9 is electrically connected to the control end of the fourth switching device Q4, and the second end of the ninth resistor R9 is electrically connected to the second electrode of the power supply terminal 50. The first end of the fourth switching device Q4 is electrically connected to the first end of the thirteenth resistor R13, and the second end of the fourth switching device Q4 is electrically connected to the second electrode of the power supply terminal 50.

[0108] A first end of the tenth resistor R10 is electrically connected to the cathode of the second diode D2, and a second end of the tenth resistor R10 is electrically connected to the first end of the eleventh resistor R11 and the reference end of the controllable precision voltage-stabilizing power supply device U1, respectively; a first end of the eleventh resistor R11 is electrically connected to the reference end of the controllable precision voltage-stabilizing power supply device U1, and a second end of the eleventh resistor R11 is electrically connected to the second electrode of the power supply terminal 50; a cathode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the first end of the thirteenth resistor R13, and an anode of the controllable precision voltage-stabilizing power supply device U1 is electrically connected to the second electrode of the power supply terminal 50;

[0109] A first end of the twelfth resistor R12 is electrically connected to the cathode of the second diode D2, and a second end of the twelfth resistor R12 is electrically connected to the first end of the thirteenth resistor R13 and the cathode of the controllable precision voltage-stabilizing power supply device U1, respectively; a first end of the thirteenth resistor R13 is electrically connected to the cathode of the controllable precision voltage-stabilizing power supply device U1, and a second end of the thirteenth resistor R13 is electrically connected to the first end of the fourteenth resistor R14 and the control end of the fifth switching device Q5, respectively; a first end of the fourteenth resistor R14 is electrically connected to the control end of the fifth switching device Q5, and a second end of the fourteenth resistor R14 is electrically connected to the second electrode of the power supply terminal 50; a first end of the fifth switching device Q5 is electrically connected to the second end of the bleeder resistor 30, and a second end of the fifth switching device Q5 is electrically connected to the second electrode of the power supply terminal 50; a first end of the bleeder resistor 30 is electrically connected to the cathode of the second diode D2;

[0110] The first end of the fifteenth resistor R15 is electrically connected to the first electrode of the switching power supply 70, and the second end of the fifteenth resistor R15 is electrically connected to the anode of the optocoupler U2; the cathode of the optocoupler U2 is electrically connected to the second electrode of the switching power supply 70, the collector of the optocoupler U2 is electrically connected to the first end of the thirteenth resistor R13, and the emitter of the optocoupler U2 is electrically connected to the second electrode of the power supply terminal 50; the positive input terminal of the switching power supply 70 is electrically connected to the first end of the bus capacitor 40, and the negative input terminal of the switching power supply 70 is electrically connected to the second end of the bus capacitor 40; the first end of the bus capacitor 40 is electrically connected to the negative electrode of the second diode D2, and the second end of the bus capacitor 40 is electrically connected to the second electrode of the power supply terminal 50.

[0111] In some embodiments, the first control submodule 11 includes a fifth switch unit 115 and a sixth switch unit 116; the fifth switch unit 115 includes an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, and a seventh switch device Q7; the sixth switch unit 116 includes a twenty-second resistor R22, a twenty-third resistor R23, and an eighth switch device Q8;

[0112] A first end of an eighteenth resistor R18 is electrically connected to the second end of the inductor L1, and a second end of the eighteenth resistor R18 is electrically connected to the first end of a nineteenth resistor R19 and the control end of the seventh switching device Q7, respectively. A first end of a nineteenth resistor R19 is electrically connected to the control end of the seventh switching device Q7, and a second end of the nineteenth resistor R19 is electrically connected to the second end of the seventh switching device Q7 and the second electrode of the power supply terminal 50, respectively. A first end of a twentieth resistor R20 is electrically connected to the second end of the inductor L1, and a second end of the twentieth resistor R20 is electrically connected to the first end of the seventh switching device Q7 and the first end of the twenty-second resistor R22, respectively. A first end of the seventh switching device Q7 is electrically connected to the first end of the twenty-second resistor R22, and a second end of the seventh switching device Q7 is electrically connected to the second electrode of the power supply terminal 50.

[0113] The first end of the twenty-second resistor R22 is electrically connected to the second end of the twentieth resistor R20 and the first end of the seventh switching device Q7, respectively. The second end of the twenty-second resistor R22 is electrically connected to the control end of the eighth switching device Q8 and the first end of the twenty-third resistor R23, respectively. The first end of the twenty-third resistor R23 is electrically connected to the control end of the eighth switching device Q8, and the second end of the twenty-third resistor R23 is electrically connected to the second electrode of the power supply terminal 50. The first end of the eighth switching device Q8 is electrically connected to the first end of the thirteenth resistor R13, and the second end of the eighth switching device Q8 is electrically connected to the second electrode of the power supply terminal 50.

[0114] An embodiment of the present application provides an inverter, comprising the aforementioned discharge control circuit.

[0115] The specific implementation of the discharge control circuit in the inverter is similar to the specific implementation of the discharge control circuit described above, and will not be repeated here.

[0116] In related technologies, after the inverter is powered off, the energy in the bus capacitor is naturally consumed through the inverter system circuit and the leakage current of the capacitor itself. However, natural discharge takes a long time. For example, in a high-power inverter, the natural discharge time can reach more than several hours, seriously affecting work efficiency.

[0117] In the embodiment of the present application, when the inverter is powered off and the voltage of the bus capacitor 40 is greater than the starting voltage of the switching power supply 70, the switching power supply 70 works, and the bus capacitor 40 supplies power to the electrical device 80 through the switching power supply 70. Therefore, the power of the bus capacitor 40 can be quickly consumed by the switching power supply 70 and the electrical device 80 to shorten the discharge time of the power of the bus capacitor 40 when the inverter is powered off. When the inverter is powered off and the voltage of the bus capacitor 40 is less than or equal to the starting voltage of the switching power supply 70, the switching power supply 70 stops working. The anode output current of the stop optocoupler device U2 is cut off, the optocoupler device U2 is disconnected, the control end of the fifth switch device Q5 is pulled up through the twelfth resistor R12 and the thirteenth resistor R13, and the fifth switch device Q5 is turned on, so that the loop composed of the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter is turned on, and the bus capacitor 40 continues to discharge through the discharge resistor 30, that is, the electric energy of the bus capacitor 40 continues to be consumed through the discharge resistor 30, so that when the inverter is powered off, the energy stored in the bus capacitor 40 can be quickly released, thereby ensuring personal safety and being more efficient, safe and reliable.

[0118] In related technologies, after the inverter is powered off, the bus capacitor is directly short-circuited to the ground, releasing energy instantaneously. However, a huge short-circuit current is generated at the moment of short-circuiting to the ground, endangering the safety of personnel and equipment.

[0119] In the embodiment of the present application, since the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter form a loop, when the inverter is powered off, the energy of the bus capacitor 40 is released through the switching power supply 70, the electrical device 80 and the discharge resistor 30, and there is no problem of generating a huge short-circuit current at the moment of short circuit to the ground, which endangers the safety of personnel and equipment.

[0120] In the related art, a high-impedance resistor is connected in parallel at both ends of the bus capacitor. After the inverter is powered off, the energy in the bus capacitor is discharged through the high-impedance resistor. However, the resistance of the high-impedance resistor is relatively large and the discharge time is long. The high-impedance resistor consumes the energy of the bus capacitor during the operation of the inverter, increasing energy consumption and reducing the efficiency of the inverter.

[0121] In an embodiment of the present application, when the inverter is powered off, the switching power supply 70 and the electrical device 80 quickly consume the electric energy of the bus capacitor 40 to shorten the discharge time of the electric energy of the bus capacitor 40 when the inverter is powered off, and then the energy of the bus capacitor 40 is continued to be consumed by the discharge resistor 30. When the inverter is powered off, the energy stored in the bus capacitor 40 can be quickly released, thereby improving the efficiency of the inverter. When the power supply end 50 is powered on, the first control module 10 controls the switch module 20 to be disconnected, so that the loop is disconnected, so as to avoid the discharge resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0122] In the related art, after the inverter is powered off, the switching tube in the main circuit of the inverter continues to work, and then the energy in the bus capacitor is consumed by the conduction loss and switching loss of the switching tube, thereby achieving rapid discharge. However, software is required to control the conduction and disconnection of the switching tube. The control logic is complex and the uncertainty factors are relatively high. When the voltage of the bus capacitor is lower than the starting voltage of the switching power supply, the entire inverter is powered off and the bus capacitor stops discharging.

[0123] In the embodiment of the present application, since the discharge resistor 30, the switch module 20 and the bus capacitor 40 of the inverter form a loop, when the inverter is powered off, the energy of the bus capacitor 40 is released through the switching power supply 70, the electrical device 80 and the discharge resistor 30. There is no need for software to control the conduction and disconnection of the switch tube. The control logic is complex and the uncertainty factors are relatively high. When the voltage of the bus capacitor 40 is lower than the starting voltage of the switching power supply 70, the entire inverter loses power and the bus capacitor 40 stops discharging.

[0124] In the related art, the inverter has a problem that during the pre-charging process, when the voltage of the bus capacitor reaches the starting voltage of the switching power supply, but the switching power supply has not yet output normally, the discharge resistor consumes energy, affecting the efficiency of the energy storage inverter; the inverter also has a problem that when the inverter is powered on, the voltage of the bus capacitor cannot be pre-charged, or the voltage of the bus capacitor has not reached the starting voltage of the switching power supply, the discharge resistor consumes a lot of energy and generates serious heat, which seriously affects the efficiency, reliability and safety of the inverter.

[0125] In the embodiment of the present application, when the power supply terminal 50 is energized by the second control submodule 12 and the voltage at the power supply terminal 50 is greater than the voltage threshold, the switch module 20 is controlled to be disconnected to prevent the bleeder resistor 30 from consuming the power of the bus capacitor 40 or the external power supply. Therefore, the embodiment of the present application solves the problem of large energy consumption of the bleeder resistor 30 when the voltage of the bus capacitor 40 reaches the starting voltage of the switching power supply 70 but the switching power supply 70 has not yet output normally during the pre-charging (i.e., soft start) of the bus capacitor 40; when the power supply terminal 50 is energized by the first control submodule 11 and the voltage at the power supply terminal 50 is less than or equal to the voltage threshold, the switch module 20 is controlled to be disconnected to prevent the bleeder resistor 30 from consuming the power of the bus capacitor 40 or the external power supply. Therefore, the embodiment of the present application also solves the problem of large energy consumption and severe heat generation of the bleeder resistor 30 when the inverter is energized but the voltage of the bus capacitor 40 has not reached the starting voltage of the switching power supply 70, thereby making the entire inverter have higher efficiency, reliability and safety.

[0126] To summarize, in the embodiment of the present application, since the bleeder resistor 30, the switch module 20, and the bus capacitor 40 of the inverter form a loop, and the first control module 10 is electrically connected to the switch module 20, and the first control module 10 is electrically connected to the power supply terminal 50 of the inverter, the first control module 10 controls the switch module 20 to be disconnected when the power supply terminal 50 is energized, so that the loop is disconnected, thereby avoiding the bleeder resistor 30 of the bus capacitor 40 consuming power when the inverter is powered on but the switching power supply 70 in the inverter stops working, thereby saving energy consumption.

[0127] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0128] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A discharge control circuit, characterized in that: include: A discharge resistor (30), a switch module (20) and a first control module (10); The discharge resistor (30), the switch module (20) and the bus capacitor (40) of the inverter form a loop; The first control module (10) is electrically connected to the switch module (20), and the first control module (10) is used to be electrically connected to the power supply end (50) of the inverter, and when the power supply end (50) is powered on, control the switch module (20) to be disconnected, so that the circuit is disconnected.

2. The discharge control circuit according to claim 1, characterized in that , the first control module (10) includes a first control submodule (11) and a second control submodule (12); The first control submodule (11) is electrically connected to the switch module (20), and the first control submodule (11) is used to be electrically connected to the power supply terminal (50), and to control the switch module (20) to be disconnected when the power supply terminal (50) is powered on and the voltage of the power supply terminal (50) is less than or equal to a voltage threshold; The second control submodule (12) is electrically connected to the switch module (20), and the second control submodule (12) is used to be electrically connected to the power supply terminal (50), and to control the switch module (20) to be disconnected when the power supply terminal (50) is powered and the voltage of the power supply terminal (50) is greater than a voltage threshold; Wherein, when the voltage at the power supply end (50) is less than or equal to a voltage threshold, the switching power supply (70) of the inverter is turned off; when the voltage at the power supply end (50) is greater than the voltage threshold, the switching power supply (70) is started.

3. The discharge control circuit according to claim 2, characterized in that , the first control submodule (11) includes a first switch unit (111), a second switch unit (112), a third switch unit (113) and a fourth switch unit (114); The first switch unit (111) is used to be electrically connected to the power supply terminal (50), and is disconnected when the power supply terminal (50) is powered and the voltage of the power supply terminal (50) is less than or equal to the voltage threshold; The second switch unit (112) is electrically connected to the first switch unit (111), and the second switch unit (112) is used to be electrically connected to the power supply terminal (50), and is turned on when the first switch unit (111) is disconnected; The third switch unit (113) is electrically connected to the second switch unit (112), and the third switch unit (113) is used to be electrically connected to the power supply terminal (50) and is turned on when the second switch unit (112) is turned on; The fourth switch unit (114) is electrically connected to the third switch unit (113) and the switch module (20) respectively, and the fourth switch unit (114) is used to be turned on when the third switch unit (113) is turned on, so that the switch module (20) is turned off.

4. The discharge control circuit according to claim 2, characterized in that: The first control submodule (11) includes a fifth switch unit (115) and a sixth switch unit (116); The fifth switch unit (115) is used to be electrically connected to the power supply terminal (50), and is disconnected when the power supply terminal (50) is powered and the voltage of the power supply terminal (50) is less than or equal to the voltage threshold; The sixth switch unit (116) is electrically connected to the fifth switch unit (115), and the sixth switch unit (116) is used to be turned on when the fifth switch unit (115) is turned off, so that the switch module (20) is turned off.

5. The discharge control circuit according to claim 2, characterized in that: The first control module (10) further includes a second diode (D2); The first end of the first control submodule (11) is electrically connected to the first electrode of the power supply end (50) and the positive electrode of the second diode (D2) respectively; The cathode of the second diode (D2) is electrically connected to the first electrode of the bus capacitor (40).

6. The discharge control circuit according to claim 2, characterized in that: The second control submodule (12) includes a voltage acquisition unit (121) and a controllable precision voltage stabilizing source device (U1); The first end of the voltage acquisition unit (121) is electrically connected to the first electrode of the power supply terminal (50), the second end of the voltage acquisition unit (121) is electrically connected to the second electrode of the power supply terminal (50), the output end of the voltage acquisition unit (121) is electrically connected to the reference end of the controllable precision voltage-stabilizing source device (U1), and the voltage acquisition unit (121) is used to acquire the voltage of the power supply terminal (50); The cathode of the controllable precision voltage-stabilizing power supply device (U1) is electrically connected to the control end of the switch module (20), and the anode of the controllable precision voltage-stabilizing power supply device (U1) is electrically connected to the second electrode of the power supply end (50). The controllable precision voltage-stabilizing power supply device (U1) is used to be turned on when the voltage of the power supply end (50) is greater than the voltage threshold, so as to control the switch module (20) to be turned off.

7. The discharge control circuit according to claim 1, wherein: The discharge control circuit further includes a second control module (60); The second control module (60) is electrically connected to the switch module (20), and the second control module (60) is used to be electrically connected to the switching power supply (70) of the inverter, and to control the switch module (20) to be disconnected when the switching power supply (70) is working, and to control the switch module (20) to be turned on when the switching power supply (70) stops working.

8. The discharge control circuit according to claim 7, characterized in that: The second control module (60) includes a fifteenth resistor (R15) and an optocoupler device (U2); A first end of the fifteenth resistor (R15) is electrically connected to a first electrode of the switching power supply (70), and a second end of the fifteenth resistor (R15) is electrically connected to an anode of the optocoupler device (U2); The cathode of the optocoupler device (U2) is electrically connected to the second electrode of the switching power supply (70), the collector of the optocoupler device (U2) is electrically connected to the control end of the switch module (20), and the emitter of the optocoupler device (U2) is electrically connected to the second electrode of the power supply end (50).

9. The discharge control circuit according to claim 1, wherein: The switching power supply (70) of the inverter is electrically connected to the power-consuming device (80) of the inverter; The bus capacitor (40) is electrically connected to the switching power supply (70), and when the switching power supply (70) is in operation, the switching power supply (70) supplies power to the electrical device (80).

10. An inverter, characterized in that: The discharge control circuit comprises the discharge control circuit according to any one of claims 1 to 9.

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