Overcurrent protection device of three-phase driver, three-phase driver and air conditioner

Abstract

The utility model discloses an overcurrent protection device of a three-phase driver, the three-phase driver and an air conditioner. The overcurrent protection device of the three-phase driver comprises a first voltage sensor, a second voltage sensor, a third phase voltage acquisition circuit which is respectively connected with the first voltage sensor and the second voltage sensor, and an overcurrent protection circuit which is respectively connected with the first voltage sensor, the second voltage sensor and the third phase voltage acquisition circuit, the first voltage sensor is arranged on a first-phase input wire of the three-phase driver and used for detecting first-phase input voltage, and the second voltage sensor is arranged on a second-phase input wire of the three-phase driver and used for detecting second-phase input voltage. According to the overcurrent protection device of the three-phase driver, the number of the voltage sensors is two, the number of the required voltage sensors is reduced, the overall circuit structure is simple, and the hardware cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of drivers, and in particular to an overcurrent protection device for a three-phase driver, a three-phase driver and an air conditioner. Background Art

[0002] When the power supply voltage is too high, the three-phase driver is prone to overcurrent, which can damage the three-phase driver. Therefore, an overcurrent protection device is usually provided in the related art to protect the three-phase driver from overcurrent. The input overcurrent protection device of the three-phase driver in the related art has a relatively complex structure and a high hardware cost. Utility Model Content

[0003] The main purpose of the present application is to provide an overcurrent protection device for a three-phase drive, a three-phase drive and an air conditioner, aiming to at least partially solve the technical problems of the rectifier overcurrent protection device in the related art, which has a relatively complex structure and high hardware cost. In order to have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. This summary is not a general review, nor is it intended to identify key / important components or describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0004] According to one aspect of an embodiment of the present application, there is provided an overcurrent protection device for a three-phase driver, comprising a first voltage sensor, a second voltage sensor, a third phase voltage acquisition circuit respectively connected to the first voltage sensor and the second voltage sensor, and an overcurrent protection circuit respectively connected to the first voltage sensor, the second voltage sensor and the third phase voltage acquisition circuit;

[0005] The first voltage sensor is arranged on the first phase input wire of the three-phase driver, and is used to detect the first phase input voltage;

[0006] The second voltage sensor is arranged on the second phase input wire of the three-phase driver and is used for detecting the second phase input voltage.

[0007] In some embodiments of the present application, the third phase voltage acquisition circuit includes a first operational amplifier and a second operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to the first voltage sensor, and the output terminal of the first operational amplifier is respectively connected to the overcurrent protection circuit and the inverting input terminal of the first operational amplifier; the inverting input terminal of the second operational amplifier is respectively connected to the second voltage sensor and the non-inverting input terminal of the first operational amplifier; the inverting input terminal of the first operational amplifier is connected to the first power supply, and the non-inverting input terminal of the second operational amplifier is connected to the second power supply.

[0008] In some embodiments of the present application, the overcurrent protection circuit includes a third operational amplifier, a fourth operational amplifier, a fifth operational amplifier, a sixth operational amplifier, a seventh operational amplifier, an eighth operational amplifier, a ninth operational amplifier and a saturation conduction circuit;

[0009] The inverting input terminal of the third operational amplifier and the non-inverting input terminal of the fourth operational amplifier are both connected to the first voltage sensor;

[0010] The inverting input terminal of the fifth operational amplifier and the non-inverting input terminal of the sixth operational amplifier are both connected to the second voltage sensor;

[0011] The inverting input terminal of the seventh operational amplifier and the non-inverting input terminal of the eighth operational amplifier are both connected to the third phase voltage acquisition circuit;

[0012] The non-inverting input terminal of each of the third operational amplifier, the fifth operational amplifier and the seventh operational amplifier is connected to a third power supply;

[0013] An inverting input terminal of each of the fourth operational amplifier, the sixth operational amplifier and the eighth operational amplifier is connected to a fourth power supply;

[0014] The output end of each of the third operational amplifier, the fourth operational amplifier, the fifth operational amplifier, the sixth operational amplifier, the seventh operational amplifier and the eighth operational amplifier is connected to the non-inverting input end of the ninth operational amplifier;

[0015] The saturation conduction circuit is connected to the output end of the ninth operational amplifier.

[0016] In some embodiments of the present application, the saturated conduction circuit includes a PNP transistor; the base of the PNP transistor is connected to the output end of the ninth operational amplifier, and the collector of the PNP transistor is connected to the switch drive circuit of the three-phase driver.

[0017] In some embodiments of the present application, a first capacitor is connected between the output terminal of the ninth operational amplifier and the non-inverting input terminal of the ninth operational amplifier.

[0018] In some embodiments of the present application, the saturated conduction circuit also includes a second capacitor, a first end of the second capacitor is connected to the base of the PNP transistor, a second end of the second capacitor is connected to a second power supply, and an emitter of the PNP transistor is connected to the second power supply.

[0019] In some embodiments of the present application, the saturated conduction circuit further includes a first resistor, a first end of the first resistor is connected to the base of the PNP transistor, and a second end of the first resistor is connected to the second end of the second capacitor.

[0020] In some embodiments of the present application, the saturated conduction circuit further includes a second resistor, and the collector of the PNP transistor is connected to the switch driving circuit of the three-phase driver through the second resistor.

[0021] In some embodiments of the present application, the overcurrent protection circuit also includes a first diode and a second diode connected in series, the cathode of the first diode is connected to the second power supply, the anode of the second diode is grounded, and the anode of the first diode is connected to the non-inverting input terminal of the ninth operational amplifier.

[0022] According to another aspect of the embodiments of the present application, a three-phase driver is provided, comprising the overcurrent protection device described in any embodiment, a controller, a switch drive circuit, a filter inductor circuit, a rectifier circuit, a switch circuit and an output capacitor circuit connected in sequence, the controller, the overcurrent protection circuit and the switch drive circuit are interconnected in pairs, and the switch drive circuit is connected to the switch circuit.

[0023] According to another aspect of the embodiments of the present application, an air conditioner is provided, comprising the overcurrent protection device of the three-phase driver described in any embodiment of the present application.

[0024] The technical solution provided by one aspect of the embodiments of the present application may have the following beneficial effects:

[0025] An overcurrent protection device for a three-phase driver provided in an embodiment of the present application includes a first voltage sensor, a second voltage sensor, a third-phase voltage acquisition circuit respectively connected to the first voltage sensor and the second voltage sensor, and an overcurrent protection circuit respectively connected to the first voltage sensor, the second voltage sensor and the third-phase voltage acquisition circuit. The first voltage sensor is arranged on the first phase input wire of the three-phase driver for detecting the first phase input voltage, and the second voltage sensor is arranged on the second phase input wire of the three-phase driver for detecting the second phase input voltage. The number of voltage sensors included in the overcurrent protection device is two, which reduces the number of required voltage sensors, simplifies the overall circuit structure, and reduces the hardware cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 This is the circuit diagram of the Vienna rectifier.

[0028] Figure 2 FIG. 1 is a structural diagram of an overcurrent protection device for a three-phase driver according to an embodiment.

[0029] Figure 3 It is a structural diagram of an embodiment in which a three-phase driver and an overcurrent protection device are arranged together.

[0030] Figure 4 FIG. 4 is a circuit diagram of a third phase voltage acquisition circuit according to an embodiment.

[0031] Figure 5 FIG. 4 is a structural diagram of an overcurrent protection circuit according to an embodiment of the present invention.

[0032] Figure 6 FIG. 4 is a structural diagram of a three-phase driver according to an embodiment of the present invention.

[0033] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0039] In the related art, the overcurrent protection device of a three-phase driver usually needs to detect the value of each phase current, and a voltage sensor is set on each phase input current wire. A total of at least three voltage sensors need to be set, so the structure is relatively complex and the hardware cost is high.

[0040] In response to the technical problems existing in the related art, an embodiment of the present application proposes an overcurrent protection device for a three-phase driver, comprising a first voltage sensor, a second voltage sensor, a third phase voltage acquisition circuit respectively connected to the first voltage sensor and the second voltage sensor, and an overcurrent protection circuit respectively connected to the first voltage sensor, the second voltage sensor and the third phase voltage acquisition circuit. The first voltage sensor is arranged on the first phase input wire of the three-phase driver for detecting the first phase input voltage, and the second voltage sensor is arranged on the second phase input wire of the three-phase driver for detecting the second phase input voltage. The number of voltage sensors included in the overcurrent protection device is two, which reduces the number of required voltage sensors compared with the related art, simplifies the overall circuit structure, and reduces the hardware cost.

[0041] The three-phase driver involved in the embodiments of the present application may include, for example, a three-phase rectifier. A three-phase rectifier, such as a three-phase Vienna rectifier, may receive a three-phase AC power source and convert AC power into DC power. Figure 1As shown, the Vienna rectifier includes an inductor L1, an inductor L2, an inductor L3, a diode D1, a diode D2, a diode D3, a diode D4, a diode D5, a diode D6, a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a transistor Q5, a transistor Q6, a capacitor C10 and a capacitor C20. Among them, the transistor Q1, the transistor Q2, the transistor Q3, the transistor Q4, the transistor Q5 and the transistor Q6 constitute a switch circuit.

[0042] refer to Figure 2 As shown, an embodiment of the present application provides an overcurrent protection device for a three-phase driver, including a first voltage sensor IC1, a second voltage sensor IC2, a third phase voltage acquisition circuit connected to the first voltage sensor IC1 and the second voltage sensor IC2 respectively, and an overcurrent protection circuit connected to the first voltage sensor IC1, the second voltage sensor IC2 and the third phase voltage acquisition circuit respectively. Any voltage sensor in the embodiment of the present application may be, for example, a Hall sensor.

[0043] refer to Figure 3 As shown, the first voltage sensor IC1 is arranged on the first phase input wire of the three-phase driver, the positive electrode of the first voltage sensor IC1 is connected to the inductor L1, and the negative electrode of the first voltage sensor IC1 is connected to the positive electrode of the diode D1. The first voltage sensor IC1 is used to detect the first phase input voltage VL1. The second voltage sensor IC2 is arranged on the second phase input wire of the three-phase driver, the negative electrode of the second voltage sensor IC2 is connected to the inductor L2, the positive electrode of the second voltage sensor IC2 is connected to the positive electrode of the diode D2, and the second voltage sensor IC2 is used to detect the second phase input voltage VL2.

[0044] refer to Figure 4 As shown, the third phase voltage acquisition circuit includes a first operational amplifier A1 and a second operational amplifier A2, the non-inverting input terminal of the first operational amplifier A1 is connected to the first voltage sensor IC1, and the output terminal of the first operational amplifier A1 is respectively connected to the overcurrent protection circuit and the inverting input terminal of the first operational amplifier A1; the inverting input terminal of the second operational amplifier A2 is respectively connected to the second voltage sensor IC2 and the non-inverting input terminal of the first operational amplifier A1; the inverting input terminal of the first operational amplifier A1 is connected to the first power supply, and the non-inverting input terminal of the second operational amplifier is connected to the second power supply.

[0045] Specifically, the first power supply may be, for example, 2.5V, and the second power supply may be, for example, 5V. A resistor R406 is provided on the line connected between the first power supply and the first operational amplifier A1, and a resistor R407 is provided on the line connected between the inverting input terminal of the first operational amplifier A1 and the output terminal of the first operational amplifier A1. A resistor R404 is provided on the line connected between the non-inverting input terminal of the first operational amplifier A1 and the first voltage sensor IC1, a resistor R405 is provided on the line connected between the non-inverting input terminal of the first operational amplifier A1 and the second operational amplifier A2, a resistor R32 is provided on the line connected between the inverting input terminal of the second operational amplifier A2 and the second voltage sensor IC2, a resistor R34 is provided on the line connected between the inverting input terminal of the second operational amplifier A2 and the resistor R405, a resistor R33 is provided on the line connected between the non-inverting input terminal of the second operational amplifier A2 and the second power supply, and the non-inverting input terminal of the second operational amplifier A2 is connected to the first end of the resistor R419, and the second end of the resistor R419 is connected to the analog ground AGND. Resistors R404, R405, R406, R407 and the first operational amplifier A1 form an adding circuit and subtract the Hall DC bias; resistors R32, R33, R34, R419 and the second operational amplifier A2 form a differential circuit.

[0046] The first voltage sensor IC1 inputs the detected first phase input voltage VL1 into the non-inverting input terminal of the first operational amplifier A1. The second voltage sensor IC2 inputs the detected second phase input voltage VL2 into the inverting input terminal of the second operational amplifier A2. The output signal of the second operational amplifier A2 is input to the non-inverting input terminal of the first operational amplifier A1. The first phase input voltage VL1 and the output signal of the second operational amplifier A2 are input to the first operational amplifier A1. After being processed by the first operational amplifier A1, the first operational amplifier A1 outputs the third phase input voltage VL3.

[0047] For example, the direction of AC power flowing into the rectifier bridge is the positive direction of current, VL1, VL2 and VL3 are all voltage signals based on Hall DC bias, and the Hall DC bias can be 2.5 V. The first power supply is a power supply that provides Hall DC bias.

[0048] VL1=Hall DC bias+Av*I1, VL2=Hall DC bias-Av*I2, where Av represents the Hall gain, I1 is the first phase input current, and I2 is the second phase input current.

[0049] The output signal of the second operational amplifier A2 is V7=the second power supply voltage-VL2, wherein the second power supply voltage may be 5V, for example;

[0050] The third phase input voltage output by the first operational amplifier A1

[0051] VL3 = VL1 + V7 - Hall DC bias = VL1 - VL2 + Hall DC bias = Hall DC bias + Av (I1 + I2);

[0052] Because the sum of the three-phase currents is 0, that is, I1+I2+I3=0, VL3=Hall DC bias-Av*I3, and the third-phase current I3=(Hall DC bias-VL3) / Av.

[0053] refer to Figure 5 As shown, the overcurrent protection circuit may include a third operational amplifier A3, a fourth operational amplifier A4, a fifth operational amplifier A5, a sixth operational amplifier A6, a seventh operational amplifier A7, an eighth operational amplifier A8, a ninth operational amplifier A9 and a saturation conduction circuit.

[0054] The inverting input terminal of the third operational amplifier A3 and the non-inverting input terminal of the fourth operational amplifier A4 are both connected to the first voltage sensor IC1; the inverting input terminal of the fifth operational amplifier A5 and the non-inverting input terminal of the sixth operational amplifier A6 are both connected to the second voltage sensor IC2; the inverting input terminal of the seventh operational amplifier A7 and the non-inverting input terminal of the eighth operational amplifier A8 are both connected to the third phase voltage acquisition circuit; the non-inverting input terminal of each operational amplifier in the third operational amplifier A3, the fifth operational amplifier A5 and the seventh operational amplifier A7 is connected to the third power supply Vref_H; the inverting input terminal of each operational amplifier in the fourth operational amplifier A4, the sixth operational amplifier A6 and the eighth operational amplifier A8 is connected to the fourth power supply Vref_L; the output terminal of each operational amplifier in the third operational amplifier A3, the fourth operational amplifier A4, the fifth operational amplifier A5, the sixth operational amplifier A6, the seventh operational amplifier A7 and the eighth operational amplifier A8 is connected to the non-inverting input terminal of the ninth operational amplifier A9; the saturation conduction circuit is connected to the output terminal of the ninth operational amplifier A9.

[0055] The output terminal of the first operational amplifier A1 is connected to the inverting input terminal of the seventh operational amplifier A7, and the third phase input voltage VL3 output by the first operational amplifier A1 is input to the inverting input terminal of the seventh operational amplifier A7 and the non-inverting input terminal of the eighth operational amplifier A8.

[0056] The first voltage sensor IC1 inputs the detected first phase input voltage VL1 to the non-inverting input terminal of the first operational amplifier A1, the inverting input terminal of the third operational amplifier A3, and the non-inverting input terminal of the fourth operational amplifier. The second voltage sensor IC2 inputs the detected second phase input voltage VL2 to the inverting input terminal of the second operational amplifier A2, the inverting input terminal of the fifth operational amplifier A5, and the non-inverting input terminal of the sixth operational amplifier A6.

[0057] Exemplarily, the overcurrent protection circuit may further include a first diode D10 and a second diode D20 connected in series, wherein the cathode of the first diode D10 is connected to the second power supply, the anode of the second diode D20 is connected to the analog ground, and the anode of the first diode D10 is connected to the non-inverting input terminal of the ninth operational amplifier A9.

[0058] The overcurrent protection circuit may also include a resistor R3, a resistor R5, a resistor R7, a resistor R8, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5 and a capacitor C6. The first end of the resistor R3 is connected to the second power supply, and the second end of the resistor R3 is connected to the output end of the ninth operational amplifier A9. The first end of the resistor R5 is connected to the second power supply, and the second end of the resistor R5 is connected to the inverting input end of the ninth operational amplifier A9. The first end of the resistor R7 is connected to the output end of the ninth operational amplifier A9, and the second end of the resistor R7 is used to connect the controller. The first end of the resistor R8 is connected to the inverting input end of the ninth operational amplifier A9, and the second end of the resistor R8 is connected to the analog ground AGND. The first end of the capacitor C2 is connected to the non-inverting input end of the ninth operational amplifier A9, and the second end of the capacitor C2 is connected to the output end of the ninth operational amplifier A9. The first end of the capacitor C3 is connected to the inverting input end of the ninth operational amplifier A9, and the second end of the capacitor C3 is connected to the analog ground AGND. The first end of the capacitor C4 is connected to the inverting input end of the ninth operational amplifier A9, and the second end of the capacitor C4 is connected to the analog ground AGND. The first end of the capacitor C5 is connected to the positive power supply interface of the ninth operational amplifier A9, and the second end of the capacitor C5 is connected to the analog ground. The first end of the capacitor C6 is connected to the second end of the resistor R7, and the second end of the capacitor C6 is grounded.

[0059] The upper limit values ​​corresponding to the third operational amplifier A3, the fifth operational amplifier A5 and the seventh operational amplifier A7, and the lower limit values ​​corresponding to the fourth operational amplifier A4, the sixth operational amplifier A6 and the eighth operational amplifier A8 are set according to the overcurrent point. The upper limit value is the voltage value of the third power supply Vref_H, and the lower limit value is the voltage value of the fourth power supply Vref_L.

[0060] The first phase voltage signal VL1 and the voltage signal of the third power supply Vref_H are input to the third operational amplifier A3. When the first phase voltage signal VL1 is higher than the upper limit value, the third operational amplifier A3 outputs a low level signal. The first phase voltage signal VL1 and the voltage signal of the fourth power supply Vref_L are input to the fourth operational amplifier A4. When the first phase voltage signal VL1 is lower than the lower limit value, the fourth operational amplifier A4 outputs a low level signal.

[0061] The second phase voltage signal VL2 and the voltage signal of the third power supply Vref_H are input to the fifth operational amplifier A5. When the second phase voltage signal VL2 is higher than the upper limit value, the fifth operational amplifier A5 outputs a low level signal. The second phase voltage signal VL2 and the voltage signal of the fourth power supply Vref_L are input to the sixth operational amplifier A6. When the second phase voltage signal VL2 is lower than the lower limit value, the sixth operational amplifier A6 outputs a low level signal.

[0062] The third phase voltage signal VL3 and the voltage signal of the third power supply Vref_H are input to the seventh operational amplifier A7. When the third phase voltage signal VL3 is higher than the upper limit value, the seventh operational amplifier A7 outputs a low level signal. The third phase voltage signal VL3 and the voltage signal of the fourth power supply Vref_L are input to the eighth operational amplifier A8. When the third phase voltage signal VL3 is lower than the lower limit value, the eighth operational amplifier A8 outputs a low level signal.

[0063] The output signals of the third operational amplifier A3, the fifth operational amplifier A5, the seventh operational amplifier A7, the fourth operational amplifier A4, the sixth operational amplifier A6 and the eighth operational amplifier A8 are in a line-and relationship. If there is at least one low-level signal among the output signals of the third operational amplifier A3, the fifth operational amplifier A5, the seventh operational amplifier A7, the fourth operational amplifier A4, the sixth operational amplifier A6 and the eighth operational amplifier A8, the signal PF1 input to the ninth operational amplifier A9 is a low-level signal.

[0064] If PF1 is a low level signal, the output signal of the ninth operational amplifier A9 is a low level signal.

[0065] The overcurrent protection circuit can accurately identify the overcurrent condition of each phase current, thereby improving the accuracy of identifying the overcurrent condition.

[0066] The low level signal output by the ninth operational amplifier A9 is output to the controller to prompt that an overcurrent condition has occurred. The low level signal output by the ninth operational amplifier A9 is also output to the saturation conduction circuit to output a high level signal OCP-244 to the switch drive circuit to stop the switch drive circuit from driving the switch circuit of the three-phase driver. In this way, in the event of an overcurrent condition, the overcurrent protection operation can be performed quickly and timely, and the overcurrent protection response is fast.

[0067] The switch drive circuit may include a 244 chip and a drive unit connected to each other. The high-level signal OCP-244 may lock the 244 chip (the 244 enable signal is low valid), and stop sending the drive signal from the controller to the switch circuit of the three-phase driver via the drive unit, thereby disconnecting the switch circuit of the three-phase driver and stopping the three-phase driver from working, thereby avoiding the safety hazard caused by overcurrent.

[0068] The saturated conduction circuit includes a PNP transistor Q0; the base of the PNP transistor Q0 is connected to the output end of the ninth operational amplifier A9, and the collector of the PNP transistor Q0 is connected to the switch driving circuit of the three-phase driver.

[0069] A first capacitor C1 may be connected between the output terminal of the ninth operational amplifier A9 and the non-inverting input terminal of the ninth operational amplifier A9.

[0070] The saturated conduction circuit may further include a second capacitor C2, a first end of the second capacitor C2 is connected to the base of the PNP transistor Q0, a second end of the second capacitor C2 is connected to the second power supply, and an emitter of the PNP transistor Q0 is connected to the second power supply.

[0071] The saturation conduction circuit may further include a first resistor R1 , a first end of the first resistor R1 is connected to the base of the PNP transistor Q0 , and a second end of the first resistor R1 is connected to the second end of the second capacitor C2 .

[0072] The saturated conduction circuit may further include a second resistor R4, and the collector of the PNP transistor Q0 is connected to the switch driving circuit of the three-phase driver through the second resistor R4.

[0073] The input current overcurrent protection device of the three-phase driver in the related art has low overcurrent detection reliability and untimely response, which poses a hidden danger to the reliable operation of the power module. The overcurrent protection device of the embodiment of the present application improves the reliability of overcurrent detection and the timeliness of overcurrent protection response, and can be widely used in applications such as overcurrent detection and response of three-phase AC / DC rectifiers, greatly reducing the operating risks of the power module.

[0074] Another embodiment of the present application provides a three-phase driver, including an overcurrent protection device of the three-phase driver of any of the aforementioned embodiments, a controller, a switch drive circuit, a filter inductor circuit, a rectifier circuit, a switch circuit and an output capacitor circuit connected in sequence, the controller, the overcurrent protection circuit and the switch drive circuit are interconnected in pairs, and the switch drive circuit is connected to the switch circuit.

[0075] refer to Figure 6 As shown, the filter inductor circuit includes an inductor L1, an inductor L2 and an inductor L3, the rectifier circuit includes a diode D1, a diode D2, a diode D3, a diode D4, a diode D5 and a diode D6, the switch circuit includes a transistor Q1, a transistor Q2, a transistor Q3, a transistor Q4, a transistor Q5 and a transistor Q6, and the output capacitor circuit includes a capacitor C10 and a capacitor C20. The switch drive circuit includes a 244 chip and a drive unit connected to each other. The controller can be a single-chip microcomputer MCU or an ARM processor, etc.

[0076] The controller is used to send a drive signal to the switch drive circuit, and the switch drive circuit is used to send the drive signal from the controller to the switch drive circuit to turn on the switch drive circuit. When the overcurrent protection device detects that an overcurrent condition has occurred in the three-phase driver, the overcurrent protection device outputs a signal OCP-244 to the switch drive circuit to cause the switch drive circuit to stop driving the switch circuit of the three-phase driver, thereby stopping the three-phase driver from working and achieving overcurrent protection. When the overcurrent protection device detects that an overcurrent condition has occurred in the three-phase driver, the overcurrent protection device can also output a signal OCP-MCU to the controller to prompt that an overcurrent condition has occurred. After receiving the prompt signal that an overcurrent condition has occurred, the controller can send a notification signal to notify relevant staff that an overcurrent condition has occurred.

[0077] Another embodiment of the present application provides an air conditioner, which includes the overcurrent protection device of the three-phase driver described in any embodiment of the present application.

[0078] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made based on the concept of the present application and the contents of the present application description and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An overcurrent protection device for a three-phase driver, characterized in that: It includes a first voltage sensor, a second voltage sensor, a third phase voltage acquisition circuit connected to the first voltage sensor and the second voltage sensor respectively, and an overcurrent protection circuit connected to the first voltage sensor, the second voltage sensor and the third phase voltage acquisition circuit respectively; The first voltage sensor is arranged on the first phase input wire of the three-phase driver, and is used to detect the first phase input voltage; The second voltage sensor is arranged on the second phase input wire of the three-phase driver and is used for detecting the second phase input voltage.

2. The device according to claim 1, characterized in that The third phase voltage acquisition circuit includes a first operational amplifier and a second operational amplifier, the non-inverting input terminal of the first operational amplifier is connected to the first voltage sensor, and the output terminal of the first operational amplifier is respectively connected to the overcurrent protection circuit and the inverting input terminal of the first operational amplifier; the inverting input terminal of the second operational amplifier is respectively connected to the second voltage sensor and the non-inverting input terminal of the first operational amplifier; the inverting input terminal of the first operational amplifier is connected to the first power supply, and the non-inverting input terminal of the second operational amplifier is connected to the second power supply.

3. The device according to claim 2, characterized in that The overcurrent protection circuit includes a third operational amplifier, a fourth operational amplifier, a fifth operational amplifier, a sixth operational amplifier, a seventh operational amplifier, an eighth operational amplifier, a ninth operational amplifier and a saturation conduction circuit; The inverting input terminal of the third operational amplifier and the non-inverting input terminal of the fourth operational amplifier are both connected to the first voltage sensor; The inverting input terminal of the fifth operational amplifier and the non-inverting input terminal of the sixth operational amplifier are both connected to the second voltage sensor; The inverting input terminal of the seventh operational amplifier and the non-inverting input terminal of the eighth operational amplifier are both connected to the third phase voltage acquisition circuit; The non-inverting input terminal of each of the third operational amplifier, the fifth operational amplifier and the seventh operational amplifier is connected to a third power supply; An inverting input terminal of each of the fourth operational amplifier, the sixth operational amplifier and the eighth operational amplifier is connected to a fourth power supply; The output end of each of the third operational amplifier, the fourth operational amplifier, the fifth operational amplifier, the sixth operational amplifier, the seventh operational amplifier and the eighth operational amplifier is connected to the non-inverting input end of the ninth operational amplifier; The saturation conduction circuit is connected to the output end of the ninth operational amplifier.

4. The device according to claim 3, characterized in that The saturated conduction circuit includes a PNP transistor; the base of the PNP transistor is connected to the output end of the ninth operational amplifier, and the collector of the PNP transistor is connected to the switch drive circuit of the three-phase driver.

5. The device according to claim 4, characterized in that A first capacitor is connected between the output terminal of the ninth operational amplifier and the non-inverting input terminal of the ninth operational amplifier.

6. The device according to claim 4 or 5, characterized in that The saturated conduction circuit also includes a second capacitor, a first end of the second capacitor is connected to the base of the PNP transistor, a second end of the second capacitor is connected to a second power supply, and an emitter of the PNP transistor is connected to the second power supply.

7. The device according to claim 6, characterized in that The saturation conduction circuit further includes a first resistor, a first end of the first resistor is connected to the base of the PNP transistor, and a second end of the first resistor is connected to the second end of the second capacitor.

8. The device according to claim 4, characterized in that The saturated conduction circuit further includes a second resistor, and the collector of the PNP transistor is connected to the switch driving circuit of the three-phase driver via the second resistor.

9. The device according to any one of claims 3 to 5, characterized in that The overcurrent protection circuit also includes a first diode and a second diode connected in series, wherein the cathode of the first diode is connected to the second power supply, the anode of the second diode is grounded, and the anode of the first diode is connected to the non-inverting input terminal of the ninth operational amplifier.

10. A three-phase driver, characterized in that: It comprises an overcurrent protection device as described in any one of claims 1 to 9, a controller, a switch drive circuit, a filter inductor circuit, a rectifier circuit, a switch circuit and an output capacitor circuit connected in sequence, the controller, the overcurrent protection circuit and the switch drive circuit are interconnected in pairs, and the switch drive circuit is connected to the switch circuit.

11. An air conditioner, characterized in that: An overcurrent protection device for a three-phase driver comprising any one of claims 1 to 9.

Images