Overcurrent protection circuit and procedure

Abstract

The present invention relates to an overcurrent protection circuit 10 and an overcurrent protection method, wherein the overcurrent protection circuit 10 and the method are implemented by the following steps: sampling a current flowing through the compressor controller 11 and converting the current into a sampling voltage; comparing the sampling voltage with an overcurrent protection threshold and generating an overcurrent detection signal if the sampling voltage is greater than the overcurrent protection threshold; generating a first trigger signal based on the overcurrent detection signal; generating an overcurrent shutdown signal based on the first trigger signal; and switching off the compressor controller 11 based on the overcurrent shutdown signal.and generating an initial setting signal and blocking the overcurrent shutdown signal based on the initial setting signal and the initial trigger signal, so that the compressor controller 11 can remain switched off to implement overcurrent protection of the component.;

Description

[0001] The present invention relates to the field of overcurrent protection technologies and in particular to an overcurrent protection circuit and an overcurrent protection method for a compressor controller of a refrigerator.

[0002] A refrigerator is a commonly used appliance in everyday life that keeps food fresh at low temperatures (for example, by cooling). The low temperature inside the refrigerator is primarily achieved by controlling the operation of a compressor using a compressor controller.

[0003] However, during operation, the compressor may seize, experience a phase failure, or overpower, which can lead to excessive output current, overheating of the compressor controller, and burnout of components.

[0004] To prevent the aforementioned overheating and damage to the compressor controller, a fuse system is typically used in existing refrigerators. In other words, if an overcurrent occurs, a fuse blows, interrupting the power supply to the compressor controller and thus stopping its operation. However, refrigerators using this fuse mechanism are complex and cumbersome to maintain, resulting in high costs. For example, after a power outage, maintenance work such as replacing a fuse inside the refrigerator is required. Furthermore, the power supply cannot be restored until a new fuse is installed to restart the component and complete the process.

[0005] The technical problem solved by the present invention is to provide a protection mechanism for a refrigerator compressor controller that allows for easy maintenance. To this end, the present invention provides a novel overcurrent protection circuit for a compressor controller and an overcurrent protection method.

[0006] According to a first aspect of the present invention, an overcurrent protection circuit is provided in which a power supply is connected to a compressor controller of a refrigerator via the overcurrent protection circuit. The overcurrent protection circuit includes a switching module configured to disconnect the power supply from the compressor controller and to connect the power supply to the compressor controller. Furthermore, the overcurrent protection circuit includes a sampling module that samples a current flowing through the compressor controller and converts the current into a sampling voltage. The overcurrent protection circuit also includes a reference module that provides a reference voltage to establish an overcurrent protection threshold.Furthermore, the overcurrent protection circuit includes a detection module that compares the sampling voltage with the reference voltage. A detection signal output by the detection module transitions into an overcurrent detection signal when the sampling voltage is found to be greater than the reference voltage. The overcurrent protection circuit also includes a detection signal control module comprising a trigger element and a switching element. The trigger element receives the overcurrent detection signal and generates an initial trigger signal based on the overcurrent detection signal, while the switching element receives the initial trigger signal and generates an overcurrent shutdown signal based on the initial trigger signal. The detection signal control module further includes a signal control element.Furthermore, the overcurrent protection circuit includes a switching control module that, based on the overcurrent shutdown signal, controls the switching module to disconnect the power supply from the compressor controller. Finally, the overcurrent protection circuit includes a setting module that provides an initial setting signal. The signal control element blocks the overcurrent shutdown signal based on this initial setting signal and the initial trigger signal, thus keeping the power supply disconnected from the compressor controller and shutting it down.

[0007] According to the overcurrent protection circuit for a compressor controller as described in the first aspect of the present invention, a fuse structure in an existing refrigerator is replaced, information from the compressor controller is collected and compared with reference information, and the energy supplied to the compressor controller by the power supply can be switched off by the switching module in the circuit based on a comparison of overcurrent information to protect components (to protect the components from overheating and burning out). Therefore, overcurrent information is detected by the circuit and the electrical connection is interrupted, thus avoiding the need for corresponding maintenance work (such as replacing a fuse) after the fuse has blown, thereby simplifying and reducing the complexity and cost of maintenance.reduced (and even the need for maintenance is eliminated).

[0008] Furthermore, the overcurrent protection circuit according to the first aspect of the present invention can have the following additional technical features. According to one aspect of the present invention: when the compressor controller needs to be restarted, the refrigerator is completely switched off and then switched back on; the setting module provides a second setting signal;The determination module is able to determine, when the compressor controller is in a shutdown state, that the reference voltage is greater than the sampling voltage, and the determination module outputs an operating determination signal, wherein the signal control element, based on the second setting signal, cooperates with the trigger element, which receives the operating determination signal, so that the trigger element generates a second trigger signal, the switching element receives the second trigger signal and, on the basis of the second trigger signal, unlocks the output of the overcurrent shutdown signal to output an operating line signal, and the switching control module, on the basis of the operating line signal, controls the switching module to connect the power supply to the compressor controller in order to restore the operation of the compressor controller;and switches the setting module to providing an initial setting signal after the compressor controller restarts.

[0009] If a restart is required, the connection between the power supply and the compressor controller via the overcurrent protection circuit according to this aspect of the present invention can be easily restored by completely switching off the refrigerator and then switching it back on, thereby restoring the operation of the compressor controller and, consequently, the normal operation of the refrigerator. Therefore, it is simpler to restart the refrigerator by directly restoring the electrical connection through the circuit.

[0010] According to one aspect of the present invention, the overcurrent protection circuit further includes an automatic restart control module, wherein the automatic restart control module includes a first terminal and a second terminal, and the first terminal detects an output from the switching element, wherein, when the first terminal detects an overcurrent shutdown signal output by the switching element and the signal has been output for a period of time, the second terminal of the automatic restart control module is able to provide a restart control signal;The determination module is able to determine, when the compressor controller is in a shutdown state, that the reference voltage is greater than the sampling voltage, and the determination module outputs an operating determination signal, wherein the signal control element, based on the restart control signal, cooperates with the trigger element, which receives the operating determination signal, so that the trigger element generates a second trigger signal, the switching element receives the second trigger signal and, on the basis of the second trigger signal, unlocks the output of the overcurrent shutdown signal to output an operating line signal, and the switching control module, on the basis of the operating line signal, controls the switching module to connect the power supply to the compressor controller in order to restore the operation of the compressor controller;and after the compressor controller restarts, the second connection of the control module for automatic restart causes the setting module to continue providing an initial setting signal.

[0011] After the refrigerator has been stopped for a period of time, the overcurrent protection circuit, according to this aspect of the present invention, can automatically restore the connection between the power supply and the compressor controller, thereby automatically restoring the operation of the compressor controller and the normal operation of the refrigerator. Therefore, the complexity and cost of maintenance can be further simplified / reduced by automatically restoring the electrical connection through the circuit.

[0012] According to one aspect of the present invention, the determining signal control module is a gate combination circuit, wherein the trigger element is a first NAND gate circuit, the signal control element is a second NAND gate circuit, and the switching element is a third NAND gate circuit, wherein a second input terminal of the first NAND gate circuit is connected to an output terminal of the determining module as an input terminal of the determining signal control module, and a first input terminal of the first NAND gate circuit is connected to an output terminal of the second NAND gate circuit; a second input terminal of the second NAND gate circuit is connected to an output terminal of the first NAND gate circuit, and a first input terminal of the second NAND gate circuit is connected to the setting module;and a first input terminal and a second input terminal of the third NAND gate circuit are both connected to the output terminal of the first NAND gate circuit, and an output terminal of the third NAND gate circuit is used as an output terminal of the destination signal control module.

[0013] According to one aspect of the present invention, the setting module includes a first voltage division resistor and a capacitor connected in series, wherein one terminal of the first voltage division resistor is connected to a positive electrode of the power supply, one terminal of the capacitor is connected to a negative electrode of the power supply, and a common connecting terminal of the first voltage division resistor and the capacitor is connected to the signal control element.

[0014] According to one aspect of the present invention, the switching module is an N-MOSFET and the sampling module is a current-sampling resistor, wherein a drain of the N-MOSFET is connected to an input terminal for the negative electrode of the power supply of the compressor controller, a source of the N-MOSFET is connected to a terminal of the current-sampling resistor, and a gate of the N-MOSFET is connected to the switching control module, the other terminal of the current-sampling resistor being connected to a negative electrode of the power supply; the reference module includes a second voltage-dividing resistor and a third voltage-dividing resistor connected in series, wherein a terminal of the first voltage-dividing resistor is connected to a positive electrode of the power supply and a terminal of the second voltage-dividing resistor is connected to the negative electrode of the power supply;and the determination module is a comparator circuit, wherein a positive input terminal of the comparator circuit is connected to a common connection terminal of the first voltage division resistor and the second voltage division resistor, and a negative input terminal of the comparator circuit is connected to a common connection terminal of the N-MOSFET and the current sampling resistor.

[0015] According to one aspect of the present invention, the switching control module comprises a first NPN transistor and a second NPN transistor, wherein a base of the first NPN transistor is connected to an output terminal of the determining signal control module, a collector of the first NPN transistor is connected to the positive electrode of the power supply via a pull-up resistor, and an emitter of the first NPN transistor is connected to the negative electrode of the power supply; and a base of the second NPN transistor is connected to the collector of the first NPN transistor, a collector of the second NPN transistor is connected to the positive electrode of the power supply via a pull-up resistor, and an emitter of the second NPN transistor is connected to the negative electrode of the power supply, the collector of the second NPN transistor being connected to a gate of the switching module.

[0016] According to one aspect of the present invention, the switching control module comprises a first NPN transistor and a second PNP transistor, wherein a base of the first NPN transistor is connected to an output terminal of the determining signal control module, a collector of the first NPN transistor is connected to the positive electrode of the power supply via a pull-up resistor, and an emitter of the first NPN transistor is connected to the negative electrode of the power supply; a base of the second PNP transistor is connected to the collector of the first NPN transistor, an emitter of the second PNP transistor is connected to the positive electrode of the power supply, and a collector of the second PNP transistor is connected to a gate of the switching module via a current-limiting resistor.

[0017] According to one aspect of the present invention, the switching module includes a P-MOSFET, wherein a source of the P-MOSFET is connected to a positive electrode of the power supply, a drain of the P-MOSFET is connected to an input terminal for the positive electrode of the power supply of the compressor controller, and a gate of the P-MOSFET is connected to the switching control module; the sampling module is a current sampling resistor connected between an input terminal for the negative electrode of the power supply of the compressor controller and a negative electrode of the power supply;The reference module comprises a second voltage-division resistor and a third voltage-division resistor connected in series, with one terminal of the second voltage-division resistor connected to a positive electrode of the power supply and one terminal of the third voltage-division resistor connected to the negative electrode of the power supply; and the determination module is a comparator circuit, with a positive input terminal of the comparator circuit connected to a common connection terminal of the second voltage-division resistor and the third voltage-division resistor, and a negative input terminal of the comparator circuit connected between the current-sensing resistor and the input terminal for the negative electrode of the power supply of the compressor controller.

[0018] According to one aspect of the present invention, the switching control module includes a first NPN transistor, a base of the first NPN transistor is connected to an output terminal of the determining signal control module, a collector of the first NPN transistor is connected to a gate of the switching module via a current limiting resistor, an emitter of the first NPN transistor is connected to a negative electrode of the power supply, and the gate of the switching module is connected to the positive electrode of the power supply via a current limiting circuit.

[0019] According to a second aspect of the present invention, an overcurrent protection method for protecting a refrigerator compressor controller is provided, comprising the following steps: sampling a current flowing through the compressor controller and converting the current into a sampling voltage; comparing the sampling voltage with an overcurrent protection threshold and generating an overcurrent detection signal if the sampling voltage is greater than the overcurrent protection threshold; generating a first trigger signal based on the overcurrent detection signal; generating an overcurrent shutdown signal based on the first trigger signal; shutting down the compressor controller based on the overcurrent shutdown signal; and generating a first setting signal and blocking the overcurrent shutdown signal based on the first setting signal and the first trigger signal, so that the compressor controller can remain shut down.

[0020] According to one aspect of the present invention, the method includes the following steps when the compressor controller needs to be restarted: completely switching off the refrigerator and then switching it back on; generating a second setting signal; if the compressor controller is in a shutdown state, generating an operating signal when it can be determined by comparison that the reference voltage is greater than the sampling voltage; generating a second trigger signal based on the second setting signal and the operating signal; unlocking the output of the overcurrent shutdown signal based on the second trigger signal to output an operating signal; restoring operation of the compressor controller based on the operating signal; and switching to generating a first setting signal after the compressor controller has restarted.

[0021] According to one aspect of the present invention, the method further comprises the following steps: detecting an overcurrent shutdown signal and that the signal has been output for a period of time; generating a restart control signal; when the compressor controller is in a shutdown state, outputting an operating line signal if it can be determined by comparison that the reference voltage is greater than the sampling voltage; generating a second trigger signal based on the restart control signal and the operating line signal; unlocking the output of the overcurrent shutdown signal based on the second trigger signal to output an operating line signal; restoring operation of the compressor controller based on the operating line signal; and switching to continued generation of a first setting signal after the compressor controller has restarted.

[0022] The present invention is explained in more detail below in conjunction with the accompanying drawings and exemplary embodiments. The accompanying drawings show: Fig. Figure 1 is a schematic block diagram of functional modules of an overcurrent protection circuit according to the first aspect of the present invention, in which a functional relationship between the circuit, a power supply and a compressor controller is generally shown; Fig. 2A to 2C are circuit diagrams of a first implementation up to a third implementation of an overcurrent protection circuit according to the first aspect of the present invention, in which a connection relationship between the circuit, a power supply and a compressor controller is generally shown; Fig. Figure 3 is a schematic block diagram of functional modules of an overcurrent protection circuit with a control module for automatic restart according to the first aspect of the present invention, in which a functional relationship between the circuit, a power supply and a compressor controller is generally shown; Fig. Figures 4A to 4C are circuit diagrams of a first to third implementation of an overcurrent protection circuit with a control module for automatic restart according to the first aspect of the present invention, wherein a connection relationship between the circuit, a power supply and a compressor controller is generally shown; and Fig. Figures 5 to 7 are flowcharts of an overcurrent protection method according to the second aspect of the present invention.

[0023] Embodiments of the present invention are described in detail below, and examples of the embodiments are illustrated in the drawings, where identical or similar reference numerals denote identical or similar elements or elements with identical or similar functions. The embodiments described below with reference to the drawings are exemplary and serve to illustrate the present invention, but are not to be understood as limiting the present invention.

[0024] In order to make the tasks, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described in more detail below with reference to the accompanying drawings.

[0025] Referring to Fig. 1 and Fig. 2A, in an overcurrent protection circuit 10 of the first implementation, a switching module is, for example, an N-MOSFET Q1, a sampling module is a current sampling resistor R1, a reference module includes a second voltage division resistor R2 and a third voltage division resistor R3, a determining module is a comparator circuit C1, a determining signal control module is a gate combination circuit with three NAND gate circuits N1 to N3, an adjustment module includes a first voltage division resistor R5 and a capacitor C, and a switching control module includes a first NPN transistor Q2 and a second NPN transistor Q3.

[0026] The structures and the interconnection between related main modules in the overcurrent protection circuit according to the first implementation of the present invention are described below with reference to the Fig. 1 and Fig. Section 2A describes in more detail. A power supply V is connected via the overcurrent protection circuit 10 to a compressor controller 11 of a refrigerator, wherein a P+ terminal and a P- terminal of the overcurrent protection circuit 10 are connected to an input terminal for the positive electrode of the power supply and an input terminal for the negative electrode of the power supply of the compressor controller, respectively. A drain of the N-MOSFET Q1, which is used as a switching module, is connected to the input terminal for the negative electrode of the power supply of the compressor controller 11, a source of the N-MOSFET Q1 is connected to one terminal of the current-sensing resistor R1, while the other terminal of the current-sensing resistor R1 is connected to a negative electrode of the power supply V.The two voltage-dividing resistors R2 and R3, which form the reference module, are connected in series between the positive and negative electrodes of the power supply V. A positive input terminal of the comparator circuit C1 is connected to a common terminal of the voltage-dividing resistors R2 and R3, a negative input terminal of the comparator circuit C1 is connected to a common terminal of the N-MOSFET Q1 and the current-sensing resistor R1, and an output terminal of the comparator circuit C1 is connected to a second input terminal B of the first NAND gate circuit N1. A first input terminal A of the first NAND gate circuit is connected to an output terminal Y of the second NAND gate circuit N2.A second input terminal B of the second NAND gate circuit N2 is connected to an output terminal of the first NAND gate circuit N1, and a first input terminal A of the second NAND gate circuit N2 is connected to a common connection terminal of the first voltage division resistor R5 and the capacitor C (which are connected in series between the positive electrode and the negative electrode of the power supply V).A first input terminal A and a second input terminal B of the third NAND gate circuit N3 are both connected to the output terminal Y of the first NAND gate circuit N1, an output terminal Y of the third NAND gate circuit N3 is connected to a base of the first NPN transistor Q2, a collector of the first NPN transistor Q2 is connected via a pull-up resistor R7 to the positive electrode of the power supply V, and an emitter of the first NPN transistor Q2 is connected to the negative electrode of the power supply V.One base of the second NPN transistor Q3 is connected to the collector of the first NPN transistor Q2, one collector of the second NPN transistor Q3 is connected via a pull-up resistor R8 to the positive electrode of the power supply V, one emitter of the second NPN transistor Q3 is connected to the negative electrode of the power supply V (for example, the emitters of Q2 and Q3 are connected together and then to the negative electrode of the power supply), and the collector of the second NPN transistor Q3 is also connected to a gate of the N-MOSFET Q1.

[0027] With reference to Fig. 5 and Fig. 6 is a specific operating principle of the first implementation of the in Fig. The overcurrent protection circuit shown in 2A is as follows.

[0028] The current sampling resistor R1 samples a current I flowing through the compressor controller 11 and converts it into a sampling voltage V via I×R1.Abtast to, where the sampling voltage V Abtast It is used as the input of the negative input terminal of the comparator circuit C1. Resistors R2 and R3, which form the reference module, provide a reference voltage V via a voltage division function. Referenz =(R3 / R2+R3)V (that is, an overcurrent protection threshold) is used as the input to the positive input terminal of the comparator circuit C1. However, if the compressor experiences a seizure, a phase failure, or overload operation, resulting in excessive current (i.e., overcurrent), the sampling voltage V Abtast be greater than the reference voltage V Referenz , and the comparator circuit C1 outputs a low-level signal (for example, a digital signal "0"), that is, an overcurrent detection signal based on a comparison result of V Abtast > V ReferenzThe second input B of the first NAND gate circuit N1 receives the overcurrent detection signal (i.e., the low-level signal) output by the comparator circuit, and the output Y of the first NAND gate circuit generates / outputs a high-level signal (for example, a digital signal "1"), which is the first trigger signal. The first input A and the second input B of the third NAND gate circuit N3 both receive the first trigger signal (i.e., the high-level signal), and the output Y of the third NAND gate circuit generates / outputs a low-level signal (i.e., an overcurrent shutdown signal).The first NPN transistor Q2 is not turned on because its base receives the low-level signal generated / output by the output terminal Y of the third NAND gate circuit N3. This signal turns on the second NPN transistor Q3, which in turn pulls the gate of the N-MOSFET Q1 low, preventing it from turning on. Because Q1 is not turned on, the connection between the power supply V and the compressor controller 11 is broken. The second input terminal B of the second NAND gate circuit N2 receives the high-level signal output by the first NAND gate circuit N1. The first input terminal of the second NAND gate circuit receives a high-level signal (i.e., a first tuning signal) provided by resistor R5 and capacitor C through their voltage division function, which together form the tuning module.The second NAND gate circuit N2 therefore outputs a low-level signal to the first input terminal A of the first NAND gate circuit N1 in order to block the output of the third NAND gate circuit N3 as a low-level signal (i.e., an overcurrent shutdown signal) in order to maintain the isolation between the power supply V and the compressor controller 11 (to avoid the case where the overcurrent shutdown signal cannot be output continuously because there is an immediate transition from a determining signal back to a high-level signal because the reference voltage after isolation is greater than the sampling voltage), thereby achieving the purpose of protecting the compressor controller.

[0029] According to the overcurrent protection circuit for a compressor controller in this implementation, the presence of an overcurrent is determined by comparing the sampling voltage with the reference voltage; and if it is determined that the sampling voltage is greater than the reference voltage (i.e., an overcurrent is present), an overcurrent detection signal is generated / output, an overcurrent shutdown signal is generated / output based on the overcurrent detection signal, and the overcurrent shutdown signal is blocked to continuously shut down the compressor controller, thus achieving the purpose of protecting the compressor controller.Therefore, a safety mechanism in an existing refrigerator is replaced by the detection of an overcurrent and the interruption of the electrical connection by the circuit of the present invention, thereby avoiding the need for maintenance work (such as replacing a new fuse) after the fuse has blown, thus simplifying / reducing the complexity and cost of maintenance (and even eliminating the need for maintenance altogether).

[0030] The compressor controller can be restarted after the fault has been rectified (for example, after operation has been suspended for a period of time). Specifically, the refrigerator is completely switched off and then switched back on, and resistor R5 and capacitor C, which form the adjustment module, are reactivated. Capacitor C is initially charged, and during charging, it can be considered a low-level signal (i.e., a second adjustment signal) at the first input A of the second NAND gate circuit N2. This causes the output Y of the second NAND gate circuit N2 to output a high-level signal at the first input A of the first NAND gate circuit N1 (which can disable the overcurrent shutdown signal). If the compressor controller is in a shutdown state, the comparator circuit C1 can determine by comparison whether the compressor controller is in a shutdown state.The reference voltage is greater than the sampling voltage, and the comparator circuit therefore outputs a high-level signal (i.e., a power-on signal). Since the first input terminal A of the first NAND gate circuit N1 receives the high-level signal output by the second NAND gate circuit N2, and the second input terminal B of the first NAND gate circuit receives the high-level signal output by the comparator circuit, the output terminal Y of the first NAND gate circuit N1 thus outputs a low-level signal (i.e., a second trigger signal). The first input terminal A and the second input terminal B of the third NAND gate circuit N3 both receive the second trigger signal, and the output terminal Y of the third NAND gate circuit thus generates / outputs a power-on signal (i.e., a high-level signal). The first NPN transistor Q2 is switched on.Because the base of the first NPN transistor receives the high-level signal generated / output by the output terminal Y of the third NAND gate circuit N3, which prevents the second NPN transistor Q3 from turning on, the gate of the N-MOSFET Q1 is pulled high, thus turning the N-MOSFET on, and because Q1 is on, the power supply V is reconnected to the compressor controller 11, restoring operation of the compressor controller and the refrigerator. The charging process of capacitor C may take approximately 100 milliseconds, for example, to ensure that the second NAND gate circuit N2 can receive the low-level signal (i.e., the second setting signal) to release the overcurrent shutdown signal output by the third NAND gate circuit N3.so that the output of the third NAND gate circuit N3 can follow a change in the output of the comparator circuit C1 to transition to a period of operating line signal, but after restarting and completing the capacitor charging process due to a voltage division function of resistor R5 and capacitor C of the setting module, the third NAND gate circuit transitions to providing the high-level signal (i.e., the first setting signal) to the first input terminal A of the second NAND gate circuit N2, thus ensuring that the third NAND gate circuit can continuously output an operating line signal when the comparator circuit continuously outputs an operating determination signal during normal operation, and that the output of the third NAND gate circuit can transition to an overcurrent shutdown signal and be blocked.when the output of the comparator circuit transitions into an overcurrent detection signal when an overcurrent occurs.

[0031] If a refrigerator with overcurrent protection needs to be restarted according to this implementation, the connection between the power supply and the compressor controller via the overcurrent protection circuit can be easily restored by completely switching the refrigerator off and then on again. This restores the operation of the compressor controller and the normal operation of the refrigerator. Therefore, the electrical connection is restored directly via the overcurrent protection circuit according to this implementation, eliminating the need to replace a fuse before restarting and simplifying the refrigerator restart process.

[0032] Additionally or alternatively, in the first implementation, a diode D1 can optionally be connected between the emitter of the first NPN transistor Q2, the emitter of the second NPN transistor Q3, and the negative electrode of the power supply V. Diode D1 can protect the circuit in case of accidental reverse polarity of the input connection. Additionally or alternatively, in the first implementation, a voltage-stabilizing diode D2 can be connected to the gate of the N-MOSFET Q1 to stabilize the gate voltage.

[0033] With reference to Fig. 1 and Fig. 2B. A difference between the overcurrent protection circuit 10 in the second implementation and that in the first implementation lies in the specific structure of a switching control module, where the switching control module includes, for example, a first NPN transistor Q2 and a second PNP transistor Q4. The structures and the specific interconnection relationships of the other modules in this implementation are essentially the same as those of the other modules in the first implementation and are not repeated here. Only the structure of the different switching control modules and the interconnection relationship between the switching control module and the other components are described in detail.Specifically, the switching control module comprises a first NPN transistor Q2 and a second PNP transistor Q4. The base of the first NPN transistor Q2 is connected to the output terminal Y of the third NAND gate circuit N3. A collector of the first NPN transistor is connected to the positive electrode of the power supply V via a pull-up resistor R7, and an emitter of the first NPN transistor is connected to the negative electrode of the power supply V. A base of the second PNP transistor Q4 is connected to the collector of the first NPN transistor Q2, an emitter of the second PNP transistor Q4 is connected to the positive electrode of the power supply V, and a collector of the second PNP transistor Q4 is connected to the gate of the switching module N-MOSFET Q1 via a current-limiting resistor R8.

[0034] The operating principle of the overcurrent protection circuit of the in Fig. The second implementation shown in 2B is essentially similar to the operating principle of the overcurrent protection circuit shown in Fig. The first implementation shown in Figure 2A differs in its operating principle, specifically in the switching control module. The operating principle of the switching control module is as follows: When an overcurrent is detected, the first NPN transistor Q2 is not turned on because its base receives the low-level signal (i.e., the overcurrent shutdown signal) generated / output by the third NAND gate circuit N3. This prevents the second PNP transistor Q4 from turning on, which in turn pulls the gate of the N-MOSFET Q1 to a low level, thus preventing the N-MOSFET from turning on. When Q1 is not turned on, the power supply V to the compressor controller 11 is disconnected.When a restart is required, the first NPN transistor Q2 is switched on because the base of the first NPN transistor receives the high-level signal (i.e., the operating line signal) generated / output by the output terminal Y of the third NAND gate circuit N3, which switches on the second PNP transistor Q4, causing the gate of the N-MOSFET Q1 to be pulled to a high level and thus switching on the N-MOSFET, and when Q1 is switched on, the power supply V is reconnected to the compressor controller 11.

[0035] Additionally or alternatively, in the second implementation, a diode D1 can optionally be connected between the emitter of the first NPN transistor Q2 and the negative electrode of the power supply V. Diode D1 can protect the circuit in case of accidental reverse polarity of the input connection. Additionally or alternatively, in the second implementation, a voltage-stabilizing diode D2 can be connected to the gate of the N-MOSFET Q1 to stabilize a voltage at the gate.

[0036] Referring to Fig. 1 and Fig. 2C. A difference between the overcurrent protection circuit 10 in the third implementation and that in the first implementation lies in the specific structures of a switching control module and a switching module, where, for example, the switching control module includes a first NPN transistor Q2 and the switching module includes a P-MOSFET Q5. The structures and specific interconnection relationships of the other modules in this implementation are essentially the same as those of the other modules in the first implementation and are not repeated here. Only the structures of the different switching control modules and switching modules, and the interconnection relationships between the switching control module, the switching module, and the other components, are described in detail.Specifically, the switching control module includes a first NPN transistor Q2, a base of the first NPN transistor Q2 is connected to the output terminal Y of the third NAND gate circuit N3, a collector of the first NPN transistor is connected via a current limiting resistor R8 to a gate of the P-MOSFET Q5, an emitter of the first NPN transistor is connected to the negative electrode of the power supply V, a source of the P-MOSFET Q5 is connected to the positive electrode of the power supply V, a drain of the P-MOSFET is connected to the positive input terminal of the power supply of the compressor controller, and the gate of the P-MOSFET is also connected to the positive electrode of the power supply V via a current limiting resistor R7.

[0037] The operating principle of the overcurrent protection circuit of the third implementation, which is in Fig. The operating principle of the overcurrent protection circuit of the first implementation, as shown in 2C, is essentially similar to the operating principle of the overcurrent protection circuit of the first implementation, which is shown in Fig. 2A is shown, and one difference lies in the operating principle of the different switching control module and switching module. The operating principle of the switching control module and the switching module is as follows: When an overcurrent is detected, the first NPN transistor Q2 is not switched on because the base of the first NPN transistor receives the low-level signal (i.e., the overcurrent shutdown signal) generated / output by the third NAND gate circuit N3, which causes the gate of the P-MOSFET Q5 to be pulled to a high level and the P-MOSFET is therefore not switched on, and if Q5 is not switched on, the power supply V to the compressor controller 11 is disconnected.When a restart is required, the first NPN transistor Q2 is switched on because the base of the first NPN transistor receives the high-level signal (i.e., the operating line signal) generated / output by the output terminal Y of the third NAND gate circuit N3, which causes the gate of the P-MOSFET Q5 to be pulled to a low level and thus the P-MOSFET is switched on, and when Q5 is switched on, the power supply V is reconnected to the compressor controller 11.

[0038] Additionally or alternatively, in the second implementation, a diode D1 can optionally be connected between the emitter of the first NPN transistor Q2 and the negative electrode of the power supply V. The diode D1 can protect the circuit in case of accidental reverse polarity of the input connection.

[0039] The structures, interconnection, and operating principle of the associated main modules in an overcurrent protection circuit with an automatic restart control module C2 according to the present invention are described below with reference to Fig. 3, Fig. 4A to 4C and Fig. 7 described. The difference between the one described in the Fig. The overcurrent protection circuit shown in sections 4A to 4C and the one in the Fig. The overcurrent protection circuit shown in modules 2A to 2C differs in that the first module has a control module for automatic restart. Therefore, the structures, specific connection relationships, and overcurrent protection operating principle of the other modules are not part of the implementation. Fig. 4A to 4C are essentially the same as those of the other modules of the implementation of Fig. Sections 2A to 2C are not repeated here, and only the structure of the automatic restart control module C2, the connection between the automatic restart control module and the other modules, and the restart operating principle are described in detail. The automatic restart control module C2 includes a first terminal IO1 and a second terminal IO2. The first terminal IO1 is connected to the output terminal Y of the third NAND gate circuit N3, and the second terminal IO2 is connected to the first input terminal A of the second NAND gate circuit N2 (it can also be considered to be connected to the common terminal of resistor R5 and capacitor C). An automatic restart operates according to the following principle: The first terminal IO1 can be used to detect the output of the third NAND gate circuit N3.If the automatic restart control module detects a low-level signal (i.e., an overcurrent shutdown signal) output by the third NAND gate circuit N3 via the first terminal, and the signal has been output for a certain period of time, the automatic restart control module can, for example, connect the first input terminal A of the second NAND gate circuit N2 to the negative electrode of the power supply via the second terminal IO2 (similar to a switch) to provide a low-level signal (i.e., a restart control signal) to the first input terminal A, causing the output terminal Y of the second NAND gate circuit N2 to output a high-level signal to the first input terminal A of the first NAND gate circuit N1 (thus disabling the overcurrent shutdown signal).When the compressor controller is in a shutdown state, the comparator circuit C1 can determine by comparison that the reference voltage is higher than the sampling voltage, so the comparator circuit outputs a high-level signal (i.e., an operating signal). Since the first input terminal A of the first NAND gate circuit N1 receives a high-level signal output by the second NAND gate circuit N2, and the second input terminal B of the first NAND gate circuit receives the high-level signal output by the comparator circuit, the output terminal Y of the first NAND gate circuit N1 thus outputs a low-level signal (i.e., a second trigger signal).The first input terminal A and the second input terminal B of the third NAND gate circuit N3 both receive the second trigger signal, and the output terminal Y of the third NAND gate circuit thus generates / outputs a power line signal (that is, a high-level signal). The switching control module can be controlled based on the power line signal (in the same way as above with reference to the...). Fig. (described in sections 2A to 2C) control the switching module to connect the power supply to the compressor controller, thereby restoring operation of the compressor controller and the refrigerator. The time during which the automatic restart control module connects the first input terminal A of the second NAND gate circuit N2 to the negative electrode of the power supply via the second terminal IO2 can be, for example, approximately 100 milliseconds. This ensures that the second NAND gate circuit N2 can receive the low-level signal (i.e., the restart control signal) to release the overcurrent shutdown signal output by the third NAND gate circuit N3, allowing the output of the third NAND gate circuit N3 to respond to a change in the output of the comparator circuit C1.to switch to the entry point of an operating line signal. However, after the restart is complete (for example, after 100 milliseconds or a specific time interval after the operating line signal was detected by the first terminal), the automatic restart control module can connect the first input terminal A of the second NAND gate circuit N2 to the common connection terminal of resistor R5 and capacitor C via the second terminal IO2 to provide a high-level signal (i.e., an initial setting signal) to the first input terminal A of the second NAND gate circuit N2, thus ensuring that the third NAND gate circuit can continuously output an operating line signal if the comparator circuit continuously outputs an operating setting signal during normal operation.and that the output of the third NAND gate circuit can transition to an overcurrent shutdown signal and be blocked if the output of the comparator circuit transitions to an overcurrent detection signal upon the occurrence of an overcurrent.

[0040] After the refrigerator has been stopped for a period of time, the overcurrent protection circuit with an automatic restart control module according to the present invention can automatically restore the connection between the power supply and the compressor controller, thereby automatically restarting the operation of the compressor controller and automatically restoring the normal operation of the refrigerator. Therefore, the complexity and cost of maintenance can be further simplified / reduced by automatically restoring the electrical connection via the circuit, and restarting the refrigerator is more convenient.

[0041] Additionally or alternatively, in an optional example of the overcurrent protection circuit according to the first aspect of the present invention, the output terminal Y of the comparator circuit C1 and the output terminal Y of the third NAND gate circuit N3 can optionally be connected to the positive electrode of the power supply via pull-up resistors R4 and R6, respectively.

[0042] According to a second aspect of the present invention, an overcurrent protection method is further provided, which includes, for example, the following overcurrent protection steps (see Fig. 5).

[0043] A current flowing through the compressor controller is sampled and converted into a sampling voltage. For example, the current I flowing through the compressor controller is sampled using a current sampling resistor R1 and converted into a sampling voltage V by I×R1. Abtast converted.

[0044] The sampling voltage is compared to an overcurrent protection threshold, and an overcurrent detection signal is generated if the sampling voltage is greater than the overcurrent protection threshold. The sampling voltage can be compared to the threshold voltage using a comparator circuit, for example. If the comparison determines that the sampling voltage is greater than the threshold voltage, a low-level signal is generated as the overcurrent detection signal.

[0045] A first trigger signal is generated based on the overcurrent detection signal. For example, one of the input terminals of a first NAND gate circuit in a gate combination circuit receives the overcurrent detection signal to generate a high-level signal as the first trigger signal.

[0046] An overcurrent shutdown signal is generated based on the first trigger signal. For example, both input terminals of a third NAND gate circuit in the gate combination circuit receive the first trigger signal to generate a low-level signal as the overcurrent shutdown signal.

[0047] The compressor controller is shut down based on the overcurrent shutdown signal. For example, a switching control module can receive the overcurrent shutdown signal, so that a switching module is not switched on to interrupt the power supply to the compressor controller.

[0048] An initial setting signal is generated, and the overcurrent shutdown signal is blocked based on this initial setting signal and the initial trigger signal, allowing the compressor controller to remain off. For example, one input of a second NAND gate circuit in the gate combination receives the initial setting signal as a high-level signal, and the other input receives the initial trigger signal, allowing it to output a low-level signal. This blocks the output of the third NAND gate as the overcurrent shutdown signal, ensuring continuous shutdown.

[0049] Additionally or alternatively, the overcurrent protection method according to the second aspect of the present invention includes, for example, the following restart steps (see Fig. 6).

[0050] The refrigerator is completely switched off and then switched back on. For example, the refrigerator can be unplugged and then plugged back in.

[0051] A second setting signal is generated. For example, when the refrigerator is switched on again, a capacitor in a setting module is first charged so that a low-level signal can be provided as a second setting signal at one of the input terminals of the second NAND gate circuit in the gate combination circuit.

[0052] When the compressor controller is in a shutdown state, an operating signal is generated if comparison reveals that the reference voltage is higher than the sampling voltage. For example, the sampling voltage in the shutdown state can be considered virtually zero, and the comparator circuit can determine by comparison that the reference voltage is higher than the sampling voltage in order to generate / output a high-level signal as an operating signal.

[0053] A second trigger signal is generated based on the second setting signal and the operating signal. For example, one of the input terminals of the first NAND gate circuit in the gate combination circuit receives the high-level signal output by the second NAND gate circuit based on the second setting signal, and the other input terminal receives the operating signal, so that a low-level signal is output as the second trigger signal.

[0054] The overcurrent shutdown signal is disabled based on the second trigger signal, allowing an operating signal to be output. For example, both input terminals of the third NAND gate in the gate combination circuit receive the second trigger signal to output a high-level signal as the operating signal.

[0055] The compressor controller's operation is restored based on the operating line signal. For example, the switching control module can receive the operating line signal, causing the switching module to turn on and restore the connection between the power supply and the compressor controller.

[0056] The adjustment module switches to generate an initial adjustment signal after the compressor controller restarts. For example, after restarting and completing the capacitor charging process, a high-level signal can be provided at one of the input terminals of the second NAND gate circuit as the initial adjustment signal.

[0057] Additionally or alternatively, the overcurrent protection method according to the second aspect of the present invention includes, for example, the following automatic restart steps (see Fig. 7).

[0058] An overcurrent shutdown signal is detected and the signal has been output for a certain period of time. This indicates that the compressor controller and the refrigerator have not been operating for a specific period.

[0059] A restart control signal is generated. For example, the automatic restart control module in the circuit can provide a low-level signal to one of the input terminals of the second NAND gate circuit in the gate combination circuit as a restart control signal.

[0060] When the compressor controller is in a shutdown state, an operating status signal is output if a comparison determines that the reference voltage is higher than the sampling voltage. For example, the sampling voltage in the shutdown state can be considered virtually zero, and the comparator circuit can determine by comparison that the reference voltage is higher than the sampling voltage, thus generating / outputting a high-level signal as an operating status signal.

[0061] A second trigger signal is generated based on the restart control signal and the operating status signal. For example, one of the input terminals of the first NAND gate circuit in the gate combination circuit receives the high-level signal output by the second NAND gate circuit based on the restart control signal, and the other terminal receives the operating status signal to output a low-level signal as the second trigger signal.

[0062] The overcurrent shutdown signal is disabled based on the second trigger signal, allowing an operating signal to be output. For example, both input terminals of the third NAND gate in the gate combination circuit receive the second trigger signal to output a high-level signal as the operating signal.

[0063] The compressor controller's operation is restored based on the operating line signal. For example, the switching control module can receive the operating line signal, causing the switching module to turn on and restore the connection between the power supply and the compressor controller.

[0064] After the compressor controller restarts, the adjustment module switches to continuously generating an initial adjustment signal. For example, after a restart, a high-level signal can be provided as the initial adjustment signal at one of the input terminals of the second NAND gate circuit.

[0065] In describing the present invention, it should be clear that the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying any relative meaning. Therefore, the features defined by "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0066] Although the embodiments of the present invention have been shown and described above, these embodiments are merely exemplary and should not be understood as limiting the present invention. Those skilled in the art can make combinations, changes, modifications, substitutions, and variations of the above embodiments within the scope of the present invention. REFERENCE MARK 10 Overcurrent protection circuit 11 Compressor controllers A first input connection B second input port C capacitor C1 comparator circuit C2 control module for automatic restart D1 Diode D2 voltage stabilizing diode IO1 first connection IO2 second port N1 first NAND gate circuit N2 second NAND gate circuit N3 third NAND gate circuit Q1 N-MOSFET Q2 first NPN transistor Q3 second NPN transistor Q4 second PNP transistor Q5 P-MOSFET R1 Current sampling resistor R2 second voltage division resistor R3 third voltage division resistor R4 Pull-Up Resistor R5 first voltage division resistor R6 Pull-Up Resistor R7 Pull-Up Resistor / Current Limiting Resistor R8 Pull-Up Resistor / Current Limiting Resistor V Energy supply Y output connector

Claims

[1] Overcurrent protection circuit (10), characterized by that a power supply (V) is connected to a compressor controller (11) of a refrigerator via the overcurrent protection circuit (10), wherein the overcurrent protection circuit (10) comprises: a switching module configured to disconnect the power supply (V) from the compressor controller (11) and to connect the power supply (V) to the compressor controller (11); a sampling module that samples a current flowing through the compressor controller (11) and converts the current into a sampling voltage; a reference module that provides a reference voltage to set an overcurrent protection threshold; a determination module that compares the sampling voltage with the reference voltage, wherein a determination signal output from the determination module changes to an overcurrent determination signal when it is determined that the sampling voltage is greater than the reference voltage; a determination signal control module including a trigger element (N1) and a switching element (N3), wherein the trigger element (N1) receives the overcurrent determination signal and generates a first trigger signal based on the overcurrent determination signal, and the switching element (N3) receives the first trigger signal and generates an overcurrent shutdown signal based on the first trigger signal, wherein the determination signal control module further comprises a signal control element (N2); a switching control module that controls the switching module based on the overcurrent shutdown signal to disconnect the power supply (V) from the compressor controller (11); and a setting module providing a first setting signal, wherein the signal control element (N2) blocks the overcurrent shutdown signal based on the first setting signal and the first trigger signal so that the power supply (V) can be kept separate from the compressor controller (11) to shut down the compressor controller (11). [2] Overcurrent protection circuit (10) according to claim 1, characterized by that when the compressor controller (11) needs to be restarted: the refrigerator is switched off completely and then switched on again; the setting module provides a second setting signal; the determination module is capable of determining, when the compressor controller (11) is in a shutdown state, that the reference voltage is greater than the sampling voltage, and the determination module outputs an operation determination signal, wherein the signal control element (N2) cooperates with the trigger element (N1) receiving the operation determination signal based on the second setting signal, so that the trigger element (N1) generates a second trigger signal, the switching element (N3) receives the second trigger signal and, based on the second trigger signal, releases the inhibition of outputting the overcurrent shutdown signal to output an operation line signal, and the switching control module controls the switching module based on the operation line signal to connect the power supply (V) to the compressor controller (11) to restore the operation of the compressor controller (11); and after restarting the compressor controller (11), the setting module switches to providing a first setting signal. [3] Overcurrent protection circuit (10) according to claim 1, characterized bythat the overcurrent protection circuit (10) further comprises an automatic restart control module (C2), wherein the automatic restart control module (C2) comprises a first terminal (IO1) and a second terminal (IO2), and the first terminal (IO1) detects an output of the switching element (N3), wherein when the first terminal (IO1) detects an overcurrent shutdown signal output by the switching element (N3) and the signal has been output for a period of time: the second terminal (IO2) of the automatic restart control module (C2) is capable of provide a restart control signal; the determination module is capable of determining, when the compressor controller (11) is in a shutdown state, that the reference voltage is greater than the sampling voltage, and the determination module outputs an operation determination signal, wherein the signal control element (N2) cooperates with the trigger element (N1) receiving the operation determination signal based on the restart control signal, so that the trigger element (N1) generates a second trigger signal, the switching element (N3) receives the second trigger signal and, based on the second trigger signal, releases the inhibition of outputting the overcurrent shutdown signal to output an operation line signal, and the switching control module controls the switching module based on the operation line signal to connect the power supply (V) to the compressor controller (11) to restore the operation of the compressor controller (11); and after the compressor controller (11) has restarted, the second terminal (IO2) of the automatic restart control module (C2) causes the setting module to continue to provide a first setting signal. [4] Overcurrent protection circuit (10) according to one of claims 1 to 3, characterized bythat the determination signal control module is a gate combination circuit, wherein the trigger element (N1) is a first NAND gate circuit (N1), the signal control element (N2) is a second NAND gate circuit (N2), and the switching element (N3) is a third NAND gate circuit (N3), wherein a second input terminal of the first NAND gate circuit (N1) is connected to an output terminal of the determination module as an input terminal of the determination signal control module, and a first input terminal of the first NAND gate circuit (N1) is connected to an output terminal of the second NAND gate circuit (N2); a second input terminal of the second NAND gate circuit (N2) is connected to an output terminal of the first NAND gate circuit (N1), and a first input terminal of the second NAND gate circuit (N2) is connected to the setting module;and a first input terminal and a second input terminal of the third NAND gate circuit (N3) are both connected to the output terminal of the first NAND gate circuit (N1), and an output terminal of the third NAND gate circuit (N3) is used as an output terminal of the determination signal control module; [5] Overcurrent protection circuit (10) according to one of claims 1 to 3, characterized by in that the setting module comprises a first voltage dividing resistor (R5) and a capacitor (C) connected in series, wherein a terminal of the first voltage dividing resistor (R5) is connected to a positive electrode of the power supply (V), a terminal of the capacitor (C) is connected to a negative electrode of the power supply (V), and a common connection terminal of the first voltage dividing resistor (R5) and the capacitor (C) is connected to the signal control element (N2). [6] Overcurrent protection circuit (10) according to one of claims 1 to 3, characterized by , that the switching module is an N-MOSFET (Q1) and the sensing module is a current sensing resistor (R1), wherein a drain of the N-MOSFET (Q1) is connected to an input terminal for the negative electrode of the power supply of the compressor controller (11), a source of the N-MOSFET (Q1) is connected to one terminal of the current sensing resistor (R1), and a gate of the N-MOSFET (Q1) is connected to the switching control module, the other terminal of the current sensing resistor (R1) being connected to a negative electrode of the power supply (V); the reference module comprises a second voltage dividing resistor (R2) and a third voltage dividing resistor (R3) connected in series, wherein one terminal of the first voltage dividing resistor (R5) is connected to a positive electrode of the power supply (V) and one terminal of the second voltage dividing resistor (R2) is connected to the negative electrode of the power supply (V); and the determination module is a comparator circuit (C1), wherein a positive input terminal of the comparator circuit (C1) is connected to a common connection terminal of the first voltage dividing resistor (R5) and the second voltage dividing resistor (R2) and a negative input terminal of the comparator circuit (C1) is connected to a common connection terminal of the N-MOSFET (Q1) and the current sensing resistor (R1). [7] Overcurrent protection circuit (10) according to claim 6, characterized bythat the switching control module comprises a first NPN transistor (Q2) and a second NPN transistor (Q3), wherein a base of the first NPN transistor (Q2) is connected to an output terminal of the determination signal control module, a collector of the first NPN transistor (Q2) is connected to the positive electrode of the power supply (V) via a pull-up resistor (R7), and an emitter of the first NPN transistor (Q2) is connected to the negative electrode of the power supply (V); and a base of the second NPN transistor (Q3) is connected to the collector of the first NPN transistor (Q2), a collector of the second NPN transistor (Q3) is connected to the positive electrode of the power supply (V) via a pull-up resistor (R8), and an emitter of the second NPN transistor (Q3) is connected to the negative electrode of the power supply (V), wherein the collector of the second NPN transistor (Q3) is connected to a gate of the switching module. [8] Overcurrent protection circuit (10) according to claim 6, characterized by in that the switching control module comprises a first NPN transistor (Q2) and a second PNP transistor (Q4), wherein a base of the first NPN transistor (Q2) is connected to an output terminal of the determination signal control module, a collector of the first NPN transistor (Q2) is connected to the positive electrode of the power supply (V) via a pull-up resistor (R7), and an emitter of the first NPN transistor (Q2) is connected to the negative electrode of the power supply (V); and a base of the second PNP transistor (Q4) is connected to the collector of the first NPN transistor (Q2), an emitter of the second PNP transistor (Q4) is connected to the positive electrode of the power supply (V), and a collector of the second PNP transistor (Q4) is connected to a gate of the switching module via a current limiting resistor (R8). [9] Overcurrent protection circuit (10) according to one of claims 1 to 3, characterized by , that the switching module comprises a P-MOSFET (Q5), wherein a source of the P-MOSFET (Q5) is connected to a positive electrode of the power supply (V), a drain of the P-MOSFET (Q5) is connected to an input terminal for the positive electrode of the power supply of the compressor controller (11), and a gate of the P-MOSFET (Q5) is connected to the switching control module; the sensing module is a current sensing resistor (R1) connected between an input terminal for the negative electrode of the power supply of the compressor controller (11) and a negative electrode of the power supply (V); the reference module comprises a second voltage dividing resistor (R2) and a third voltage dividing resistor (R3) connected in series, wherein one terminal of the second voltage dividing resistor (R2) is connected to a positive electrode of the power supply (V) and one terminal of the third voltage dividing resistor (R3) is connected to the negative electrode of the power supply (V); and the determination module is a comparator circuit (C1), wherein a positive input terminal of the comparator circuit (C1) is connected to a common connection terminal of the second voltage dividing resistor (R2) and the third voltage dividing resistor (R3), and a negative input terminal of the comparator circuit (C1) is connected between the current sensing resistor (R1) and the input terminal for the negative electrode of the power supply of the compressor controller (11). [10] Overcurrent protection circuit (10) according to claim 9, characterized by that the switching module comprises a first NPN transistor (Q2), a base of the first NPN transistor (Q2) is connected to an output terminal of the determination signal control module, a collector of the first NPN transistor (Q2) is connected to a gate of the switching module via a current limiting resistor, an emitter of the first NPN transistor (Q2) is connected to a negative electrode of the power supply (V), and the gate of the switching module is connected to the positive electrode of the power supply (V) via a current limiting resistor. [11] An overcurrent protection method for protecting a compressor controller (11) of a refrigerator, comprising the following steps: Sampling a current flowing through the compressor controller (11) and converting the current into a sampling voltage; Comparing the sensing voltage with an overcurrent protection threshold and generating an overcurrent determination signal when the sensing voltage is greater than the overcurrent protection threshold; Generating a first trigger signal based on the overcurrent determination signal; Generating an overcurrent shutdown signal based on the first trigger signal; Switching off the compressor controller (11) based on the overcurrent shutdown signal; and Generating a first setting signal and blocking the overcurrent shutdown signal based on the first setting signal and the first trigger signal so that the compressor controller (11) can remain switched off. [12] Overcurrent protection method according to claim 11, characterized by that when the compressor controller (11) needs to be restarted, the procedure includes the following steps: Turning the refrigerator off completely and then turning it back on; Generating a second setting signal; when the compressor controller (11) is in a shutdown state, generating an operation determination signal if it can be determined by comparison that the reference voltage is greater than the sampling voltage; Generating a second trigger signal based on the second setting signal and the operating determination signal; Canceling the inhibition of outputting the overcurrent shutdown signal based on the second trigger signal to output an operating line signal; Restoring the operation of the compressor controller (11) based on the operating line signal; and Switch to generating a first setting signal after restarting the compressor controller (11). [13] Overcurrent protection method according to claim 11, characterized by that it includes the following steps: Detecting an overcurrent shutdown signal and that the signal has been output for a period of time; Generating a restart control signal; when the compressor controller (11) is in a shutdown state, outputting an operation determination signal if it can be determined by comparison that the reference voltage is greater than the sampling voltage; Generating a second trigger signal based on the restart control signal and the operating determination signal; Canceling the inhibition of outputting the overcurrent shutdown signal based on the second trigger signal to output an operating line signal; Restoring the operation of the compressor controller (11) based on the operating line signal; and Switch to continued generation of a first setting signal after restarting the compressor controller (11).

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