Inverter AC output short circuit protection circuit and inverter

By designing an inverter AC output short-circuit protection circuit including voltage divider current limiting module, switch diode, optocoupler and switch module, the problem of difficult to achieve short-circuit protection of the inverter AC output is solved, and the effectiveness of the inverter is achieved Short circuit protection reduces equipment damage.

CN119448143APending Publication Date: 2025-02-14XIAMEN COSTCO ELECTRONIC IND CO LTD
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Patent Information

Application Number
CN202411563052.X
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-11-05
Publication Date
2025-02-14

AI Technical Summary

Technical Problem

The short circuit protection of the AC output of the inverter is difficult to effectively implement, resulting in the short circuit damage of the inverter and electrical equipment.

Method used

Design an inverter AC output short circuit protection circuit, including a first voltage divider current limiting module, a second voltage divider current limiting module, a switch diode, an optocoupler and a switching module, and control the opening of the switch module through the switch switch switch and shutdown, realize the AC output short circuit protection of the inverter.

Benefits of technology

It realizes timely protection of the inverter AC output short circuit, and reduces damage caused by short circuits in inverters and electrical equipment. The circuit is simple, low-cost and has a wide practical range.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention discloses an inverter AC output short-circuit protection circuit and an inverter. The inverter AC output short-circuit protection circuit comprises a first voltage-dividing current-limiting module, a second voltage-dividing current-limiting module, a switching diode, an optocoupler and a switching module. When the alternating current output of the inverter is normal, the optocoupler is periodically conducted, the switch module outputs a low level to a controller of the inverter, and the controller controls the inverter to normally work and the alternating current of the inverter to normally output; and when the AC output of the inverter is short-circuited, the optocoupler is disconnected, the switch module outputs a high level to a controller of the inverter, and the controller controls the inverter to stop inversion work and the AC output of the inverter to stop. Therefore, the circuit provided by the invention has the advantages of few used elements and simple structure, can realize the alternating current output short circuit protection of the inverter, and can reduce the damage of the inverter and the electric equipment caused by the short circuit of the electric equipment.
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Description

Technical Field

[0001] The present invention relates to the technical field of inverters, and in particular to an inverter AC output short-circuit protection circuit and an inverter. Background Art

[0002] An inverter is an electrical device that converts a DC power source such as a battery into an AC output. Its AC output can be used in various electrical devices in life. For example, various electrical appliances are used in cars, and the DC power of the car battery is converted into AC output through an inverter.

[0003] With the continuous use of electrical equipment, both the internal circuit boards and the external power cords will age to varying degrees, which can easily cause a short circuit. If it is not discovered in time and is still connected to the inverter for use, it can easily cause damage to the inverter and the inverter. Summary of the invention

[0004] In view of this, an embodiment of the present application provides an inverter AC output short-circuit protection circuit and an inverter using the inverter AC output short-circuit protection circuit to achieve inverter AC output short-circuit protection.

[0005] On the one hand, an embodiment of the present application provides an inverter AC output short-circuit protection circuit, comprising:

[0006] A first voltage-dividing and current-limiting module, a second voltage-dividing and current-limiting module, a switching diode, an optocoupler and a switching module;

[0007] One end of the first voltage-dividing and current-limiting module is connected to the AC neutral line output end of the inverter, and the other end of the first voltage-dividing and current-limiting module is connected to the anode of the switching diode;

[0008] One end of the second voltage-dividing and current-limiting module is connected to the AC live wire output end of the inverter, and the other end of the second voltage-dividing and current-limiting module is connected to the cathode of the switching diode;

[0009] The two ends of the switch diode are also connected to the light emitting diode side of the optical coupler and are connected in reverse direction thereto;

[0010] The output side of the optical coupler is connected to the control end of the switch module;

[0011] The output end of the switch module is connected to the controller of the inverter, the first input end of the switch module is connected to a high level, and the second input end of the switch module is connected to a low level;

[0012] When the inverter AC output is normal, the optical coupler is periodically turned on, and the switch module outputs a low level to the inverter controller. The controller controls the inverter to work normally, and the inverter AC output is normal;

[0013] When the inverter AC output is short-circuited, the optical coupler is disconnected, and the switch module outputs a high level to the inverter controller. The controller controls the inverter to stop the inversion work, and the inverter stops outputting AC.

[0014] In a possible implementation, the first voltage-dividing and current-limiting module includes: a first resistor and a second resistor, and the first resistor and the second resistor are connected in series.

[0015] In a possible implementation, the second voltage-dividing and current-limiting module includes: a third resistor and a fourth resistor, and the third resistor and the fourth resistor are connected in series.

[0016] In a possible implementation, the switch module includes: a switch tube, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, and a second capacitor;

[0017] One end of the seventh resistor is connected to the first end of the output side of the optical coupler, and the other end of the seventh resistor is connected to a high level;

[0018] The control end of the switch tube is connected to the second end of the output side of the optocoupler, the input end of the switch tube is connected to the output end of the switch module, and the input end of the switch tube is also connected to the output end of the switch module through the sixth resistor; the output end of the switch tube is connected to a low level;

[0019] The fifth resistor is connected in parallel to the control end and the output end of the switch tube;

[0020] The first capacitor is connected in parallel to the control end and the output end of the switch tube;

[0021] The second capacitor is connected in parallel to the input end and the output end of the switch tube.

[0022] In a possible implementation, the switch tube is a triode.

[0023] On the other hand, an embodiment of the present application provides an inverter, which includes the inverter AC output short-circuit protection circuit described in the first aspect above.

[0024] The inverter AC output short-circuit protection circuit of the present application includes: a first voltage-dividing current-limiting module, a second voltage-dividing current-limiting module, a switching diode, an optocoupler and a switch module. When the inverter AC output is normal, the optocoupler is periodically turned on, and the switch module outputs a low level to the inverter controller, and the controller controls the inverter to work normally, and the inverter AC outputs normally; when the inverter AC output is short-circuited, the optocoupler is disconnected, and the switch module outputs a high level to the inverter controller, and the controller controls the inverter to stop the inverter work, and the inverter AC stops outputting. It can be seen that the circuit of the present application uses fewer components and has a simple structure. It can realize the AC output short-circuit protection of the inverter, and can reduce the damage to the inverter and electrical equipment caused by the short circuit of the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0026] Attached Figure 1 A circuit diagram of an inverter AC output short-circuit protection circuit provided in an embodiment of the present application.

[0027] Attached Figure 2 This is a working flowchart of the inverter AC output short-circuit protection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0029] See also Figure 1 , is a circuit diagram of an inverter AC output short circuit protection circuit in an embodiment of the present application. The inverter AC output short circuit protection circuit 100 includes: a first voltage-dividing and current-limiting module 11, a second voltage-dividing and current-limiting module 12, a switching diode D1, an optical coupler PC1 and a switch module 20.

[0030] One end of the first voltage-dividing and current-limiting module 11 is connected to the AC neutral line output terminal AC-IN-N of the inverter, and the other end of the first voltage-dividing and current-limiting module 11 is connected to the anode of the switching diode D1;

[0031] Specifically, the first voltage-dividing and current-limiting module 11 includes: a first resistor R1 and a second resistor R2, and the first resistor R1 and the second resistor R2 are connected in series.

[0032] One end of the second voltage-dividing and current-limiting module 12 is connected to the AC live wire output terminal AC-IN-L of the inverter, and the other end of the second voltage-dividing and current-limiting module 12 is connected to the cathode of the switching diode D1;

[0033] Specifically, the second voltage-dividing and current-limiting module 12 includes: a third resistor R3 and a fourth resistor R4, and the third resistor R3 and the fourth resistor R4 are connected in series.

[0034] The two ends of the switch diode D1 are also connected to the light emitting diode side of the optocoupler PC1 and are connected in reverse to it; Figure 1 As shown, the switch diode D1 is reversely connected to the light emitting diode of the optocoupler PC1.

[0035] The output side of the optical coupler PC1 is connected to the control end of the switch module 40; the output end of the switch module 40 (the short end as shown in the figure) is connected to the controller MCU of the inverter, the first input end of the switch module 40 is connected to a high level (the +3.3V end as shown in the figure), and the second input end of the switch module 40 is connected to a low level (the P-GND2 ground end as shown in the figure).

[0036] Optocoupler PC1 is an isolation type optocoupler that isolates the AC output from the low voltage circuit and acts as a switch.

[0037] When the inverter AC output is normal, the optical coupler PC1 is periodically turned on, and the switch module 40 outputs a low level to the inverter controller. The controller controls the inverter to work normally, and the inverter AC output is normal;

[0038] When the inverter AC output is short-circuited, the optical coupler PC1 is disconnected, and the switch module 40 outputs a high level to the inverter controller. The controller controls the inverter to stop the inversion work, and the inverter stops outputting AC.

[0039] Specifically, the switch module 40 includes: a switch tube Q1, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first capacitor C1 and a second capacitor C2; specifically, the switch tube Q1 is a triode, specifically an NPN triode.

[0040] One end of the seventh resistor R7 is connected to the first end of the output side of the optical coupler PC1, and the other end of the seventh resistor R7 is connected to a high level;

[0041] The control end (the base of the transistor) of the switch tube Q1 is connected to the second end of the output side of the optical coupler PC1, the input end (the collector of the transistor) of the switch tube Q1 is connected to the output end of the switch module 40, and the input end of the switch tube Q1 is also connected to the output end (short end) of the switch module 40 through the sixth resistor R6; the output end (the emitter of the transistor) of the switch tube Q1 is connected to a low level;

[0042] The fifth resistor R5 is connected in parallel to the control end and the output end of the switch tube Q1; the first capacitor C1 is connected in parallel to the control end and the output end of the switch tube Q1; and the second capacitor C2 is connected in parallel to the input end and the output end of the switch tube Q1.

[0043] See also Figure 1 The specific implementation principle of this embodiment is as follows:

[0044] The main circuit of the inverter consists of three parts: boost, rectification, and inversion. The inverter AC output short-circuit protection circuit and the inverter MCU of the present application are connected to the rectifier circuit of the inverter through a series of auxiliary power supply circuits for power supply. Regardless of whether the inverter AC output is normal or not, it does not affect the normal operation of the inverter MCU and the inverter AC output short-circuit protection circuit of the present application.

[0045] The inverter AC output short-circuit protection circuit of the present application includes a diode D1, resistors R1, R2, R3, R4, R5, R6, and R7, capacitors C1 and C2, a transistor Q1, and an optical coupler PC1.

[0046] Resistors R1, R2, R3, and R4 divide and limit the AC output of the inverter to form a voltage-dividing and current-limiting circuit; diode D1 is reversely connected to the light-emitting diode pin of the optocoupler PC1 to achieve voltage stabilization, clamping, and protection functions. The on and off of the optocoupler PC1 controls the on and off of the transistor Q1 to achieve a switching function. R5 and C1 are connected in parallel to the base and emitter of the transistor, and C2 is connected in parallel to the collector and emitter of the transistor. When the optocoupler is not conducting, the base of the transistor is pulled to a low potential by R5 to act as a bias, and C1 and C2 act as a delay shutdown and filtering. Resistors R6 and R7 also play a role in current limiting and voltage dividing in the circuit.

[0047] like Figure 2 As shown, when the inverter AC output is normal, the optocoupler is periodically turned on through the voltage-limiting current of resistors R1, R2, R3, and R4 and the voltage-stabilizing clamp of D1. After filtering by C1, the base of the NPN transistor is at a high level, the transistor is turned on, the short output pin is pulled to a low potential, the MCU controls the inverter to work normally, and the inverter AC output is normal.

[0048] When the inverter AC output is short-circuited, the optocoupler is disconnected, the base of the NPN transistor is pulled to a low potential by the ground, the transistor is in a disconnected state, the short output pin is pulled to a high potential by 3.3V, the MCU stops inverting, and the inverter AC stops outputting.

[0049] The present application controls the on and off of the switch module by turning on and off the optocoupler, and forms a variable high and low level at the collector of the triode, and then uses this high and low level signal to control the working state of the inverter MCU to achieve the function of inverter AC output short circuit protection. The present invention has many advantages such as simple circuit, low cost, and wide practical range. It can stop the inverter work and output AC through the inverter MCU in time and effectively after a short circuit occurs in the electrical equipment, thereby reducing the damage to the inverter and the electrical equipment caused by the short circuit of the electrical equipment.

[0050] The embodiment of the present application also provides an inverter using the inverter AC output short-circuit protection circuit. The inverter AC output short-circuit protection circuit provided by the embodiment of the present application can achieve AC output short-circuit protection of the inverter.

[0051] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An inverter AC output short-circuit protection circuit, characterized in that: include: A first voltage-dividing and current-limiting module, a second voltage-dividing and current-limiting module, a switching diode, an optocoupler and a switching module; One end of the first voltage-dividing and current-limiting module is connected to the AC neutral line output end of the inverter, and the other end of the first voltage-dividing and current-limiting module is connected to the anode of the switching diode; One end of the second voltage-dividing and current-limiting module is connected to the AC live wire output end of the inverter, and the other end of the second voltage-dividing and current-limiting module is connected to the cathode of the switching diode; The two ends of the switch diode are also connected to the light emitting diode side of the optical coupler and are connected in reverse direction thereto; The output side of the optical coupler is connected to the control end of the switch module; The output end of the switch module is connected to the controller of the inverter, the first input end of the switch module is connected to a high level, and the second input end of the switch module is connected to a low level; When the inverter AC output is normal, the optical coupler is periodically turned on, and the switch module outputs a low level to the inverter controller. The controller controls the inverter to work normally, and the inverter AC output is normal; When the inverter AC output is short-circuited, the optical coupler is disconnected, and the switch module outputs a high level to the inverter controller. The controller controls the inverter to stop the inversion work, and the inverter stops outputting AC.

2. The inverter AC output short-circuit protection circuit according to claim 1, characterized in that: The first voltage-dividing and current-limiting module includes: a first resistor and a second resistor, and the first resistor and the second resistor are connected in series.

3. The inverter AC output short-circuit protection circuit according to claim 1, characterized in that: The second voltage-dividing and current-limiting module includes: a third resistor and a fourth resistor, and the third resistor and the fourth resistor are connected in series.

4. The inverter AC output short-circuit protection circuit according to claim 3, characterized in that: The switch module includes: a switch tube, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor and a second capacitor; One end of the seventh resistor is connected to the first end of the output side of the optical coupler, and the other end of the seventh resistor is connected to a high level; The control end of the switch tube is connected to the second end of the output side of the optocoupler, the input end of the switch tube is connected to the output end of the switch module, and the input end of the switch tube is also connected to the output end of the switch module through the sixth resistor; the output end of the switch tube is connected to a low level; The fifth resistor is connected in parallel to the control end and the output end of the switch tube; The first capacitor is connected in parallel to the control end and the output end of the switch tube; The second capacitor is connected in parallel to the input end and the output end of the switch tube.

5. The inverter AC output short-circuit protection circuit according to claim 4, characterized in that: The switch tube is a triode.

6. An inverter, characterized in that: The invention comprises the inverter AC output short-circuit protection circuit according to any one of claims 1 to 5.