IPM module protection circuit

Abstract

The utility model discloses an IPM module protection circuit. The circuit comprises an IPM module, a voltage detection module and a master control module. The voltage input end of the IPM module is used for being connected with a power supply voltage, the control end of the IPM module is connected with the signal output end of the main control module, and the voltage output end of the IPM module is used for outputting a driving voltage; the voltage detection module and the voltage output end of the IPM module form a current loop, and voltage detection is carried out on the voltage output end of the IPM module. The master control module is used for carrying out voltage sampling on the voltage detection module. Before the IPM module is started, the main control module does not output a control signal to the IPM module, the voltage output by the IPM module should be low level, when high level occurs, a current loop is formed through the voltage detection module, voltage sampling is carried out, when short-circuit voltage is detected, it is judged that the IPM module has a short-circuit fault, and IPM module short-circuit fault detection before starting is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic products, in particular to an IPM module protection circuit. Background Art

[0002] In an air-conditioning system, an IPM module (Intelligent Power Module) plays an important role. It integrates power switch devices and a drive circuit. The IPM module also includes an inverter circuit that can convert a DC power supply into an AC power supply to drive an AC motor in the air conditioner. The IPM module can control the flow of current by turning on and off, thereby controlling the speed of the motor and adjusting the cooling or heating effect of the air conditioner.

[0003] The existing technical solutions cannot identify the short-circuit fault of the IPM module before the IPM module starts. If the IPM module is directly turned on when a short circuit occurs in the IPM module, it will directly cause a fault in the controller and affect the safe operation of the air conditioner. Summary of the Utility Model

[0004] The purpose of the embodiments of the utility model is to provide an IPM module protection circuit that can detect short-circuit faults before the IPM module starts.

[0005] The embodiments of the utility model provide an IPM module protection circuit, which includes an IPM module, a voltage detection module, and a main control module;

[0006] The voltage input end of the IPM module is used to connect to a supply voltage. The control end of the IPM module is connected to the signal output end of the main control module. The voltage output end of the IPM module is used to output a drive voltage;

[0007] The detection end of the voltage detection module is connected to the voltage output end of the IPM module and is used to detect the short-circuit current at the voltage output end of the IPM module;

[0008] The main control module is connected to the sampling end of the voltage detection module and receives the sampling value of the voltage detection module.

[0009] Preferably, the IPM module includes an upper-bridge-arm switch unit and a lower-bridge-arm switch unit;

[0010] The input end of the upper-bridge-arm switch unit serves as the voltage input end of the IPM module. The output end of the upper-bridge-arm switch unit is connected to the input end of the lower-bridge-arm switch unit. The output end of the lower-bridge-arm switch unit is grounded;

[0011] The output end of the upper-bridge-arm switch unit serves as the voltage output end of the IPM module;

[0012] The control terminals of the upper-bridge-arm switching unit and the lower-bridge-arm switching unit are connected to different signal output terminals of the main control module.

[0013] Further, the voltage detection module includes a first detection unit and a second detection unit;

[0014] The first detection unit is used to sample the short-circuit current of the lower-bridge-arm switching unit and output a sampled value;

[0015] The second detection unit is used to sample the short-circuit current of the upper-bridge-arm switching unit and output a sampled value.

[0016] Further, the input terminal of the first detection unit is used to connect to a DC voltage, the output terminal of the first detection unit serves as the detection terminal of the voltage detection module and is connected to the voltage output terminal of the IPM module. The first detection unit is configured with a first unidirectional component that conducts unidirectionally from the input terminal to the output terminal, and a first sampling terminal connected to the main control module is configured on the first detection unit.

[0017] Preferably, the input terminal of the second detection unit serves as the detection terminal of the voltage detection module and is connected to the voltage output terminal of the IPM module, the output terminal of the second detection unit is used to connect to ground, the second detection unit is configured with a second unidirectional component that conducts unidirectionally from the input terminal to the output terminal, and a second sampling terminal connected to the main control module is configured on the second detection unit.

[0018] As a preferred solution, the first detection unit further includes a first voltage-dividing component;

[0019] The first unidirectional component and the first voltage-dividing component are connected in series between the input terminal and the output terminal of the first detection unit;

[0020] The first voltage-dividing component includes a first resistor and a second resistor connected in series, and the connection point of the first resistor and the second resistor serves as the first sampling terminal of the first detection unit.

[0021] Preferably, the second detection unit further includes a second voltage-dividing component;

[0022] The second unidirectional component and the second voltage-dividing component are connected in series between the input terminal and the output terminal of the second detection unit;

[0023] The second voltage-dividing component includes a third resistor and a fourth resistor connected in series, and the connection point of the third resistor and the fourth resistor serves as the second sampling terminal of the second detection unit.

[0024] Preferably, the upper-bridge-arm switching unit and the lower-bridge-arm switching unit each include three switching components;

[0025] Each switching component in the upper-bridge switching unit is respectively connected in series with a corresponding switching component in the lower-bridge switching unit. The connection point between each switching component in the upper-bridge switching unit and the corresponding switching component in the lower-bridge switching unit serves as a voltage output terminal of the IPM module, forming a three-phase voltage output.

[0026] The control terminal of each switching component is connected to a different signal output terminal of the main control module.

[0027] Preferably, the first unidirectional component is composed of three diodes connected in parallel;

[0028] The input ends of the three diodes all serve as the input end of the first unidirectional component;

[0029] The output end of each diode is separately connected to a voltage output terminal of the IPM module.

[0030] Preferably, the second unidirectional component is composed of three diodes connected in parallel;

[0031] The output ends of the three diodes all serve as the output end of the second unidirectional component;

[0032] The input end of each diode is separately connected to a voltage output terminal of the IPM module.

[0033] Compared with the prior art, an IPM module protection circuit disclosed by the present utility model includes an IPM module, a voltage detection module, and a main control module. The voltage input terminal of the IPM module is used to connect to a supply voltage. The control terminal of the IPM module is connected to the signal output terminal of the main control module. The voltage output terminal of the IPM module is used to output a driving voltage. The detection terminal of the voltage detection module is connected to the voltage output terminal of the IPM module for short-circuit current detection of the voltage output terminal of the IPM module. The main control module is used to perform voltage sampling on the voltage detection module. Before the IPM module is started, the main control module does not output a control signal to the IPM module, and the voltage output by the IPM module should be at a low level. When a high level appears, a current loop is formed through the voltage detection module for voltage sampling. When a short-circuit voltage is detected, it is determined that the IPM module has a short-circuit fault, realizing the short-circuit fault detection of the IPM module before startup. Description of the Drawings

[0034] Figure 1 It is a partial structural schematic diagram of the refrigeration circuit of a household electrical appliance product provided by an embodiment of the present utility model;

[0035] Figure 2 It is a structural schematic diagram of an IPM module protection circuit provided by an embodiment of the present utility model;

[0036] Figure 3 is a schematic structural diagram of the IPM module provided by an embodiment of the present utility model;

[0037] Figure 4 is a schematic structural diagram of the voltage detection module provided by an embodiment of the present utility model;

[0038] Figure 5 is a schematic structural diagram of the first detection unit provided by an embodiment of the present utility model;

[0039] Figure 6 is a schematic structural diagram of the second detection unit provided by an embodiment of the present utility model;

[0040] Figure 7 is another schematic structural diagram of the first detection unit provided by an embodiment of the present utility model;

[0041] Figure 8 is another schematic structural diagram of the second detection unit provided by an embodiment of the present utility model;

[0042] Figure 9 is another schematic structural diagram of the protection circuit of the IPM module provided by an embodiment of the present utility model. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0044] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0045] The terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0046] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0047] An IPM module protection circuit provided by an embodiment of the present utility model can be specifically applied to household electrical appliances. When the motor or device of a household electrical appliance is in use, a drive circuit is often required to drive motors with different voltage working ranges. The IPM module (Intelligent Power Module) is commonly used in the drive circuit. The IPM module usually uses a power switch device IGBT (Insulated Gate Bipolar Transistor), which has the advantages of high current density, low saturation voltage, and high voltage resistance of GTR (High Power Transistor), as well as the advantages of high input impedance, high switching frequency, and low drive power of MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The IPM integrates logic, control, detection, and protection circuits inside, which is convenient to use. It not only reduces the volume of the system and the development time, but also greatly enhances the reliability of the system, adapts to the development direction of current power devices - modularization, compounding, and Power Integrated Circuit (PIC), and is more and more widely used in the field of power electronics. The drive circuit is the interface between the IPM main circuit and the control circuit. A good drive circuit design is of great significance to the operation efficiency, reliability, and safety of the device.

[0048] The applications of IPM modules in household electrical appliances commonly include refrigeration devices such as refrigerators and air conditioners. An air conditioner has a controller and a refrigeration circuit. By circulating the refrigerant in the refrigeration circuit, it can perform a vapor compression refrigeration cycle. It is connected to the indoor and outdoor units using connecting pipes to form a refrigeration circuit for the refrigerant to circulate and achieve refrigeration.

[0049] See Figure 1, which is a partial structural schematic diagram of the refrigeration circuit of the household appliance product provided by the embodiment of the present utility model. In this application, the refrigeration circuit 130 performs the refrigeration cycle of the air conditioner by using a compressor 131, an indoor heat exchanger 132, a throttling component 133, and an outdoor heat exchanger 134. The refrigeration cycle includes a series of processes, involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the conditioned and heat-exchanged air. Among them, the indoor heat exchanger 132 is usually arranged in the indoor unit 110, the compressor 131 and the outdoor heat exchanger 134 are usually arranged in the outdoor unit 120, the throttling component 133 can be arranged in the indoor unit 110 or the outdoor unit 120, and the indoor heat exchanger 132 and the outdoor heat exchanger 134 are used as condensers or evaporators. When the indoor heat exchanger 132 is used as a condenser, the air conditioner serves as a heater in the heating mode. When the indoor heat exchanger 132 is used as an evaporator, the air conditioner serves as a cooler in the cooling mode.

[0050] The compressor 131 compresses the refrigerant gas in a high-temperature and high-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process. The throttling component 133 expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the throttling component 133 and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor 131. The evaporator can achieve a refrigeration effect by using the latent heat of evaporation of the refrigerant to perform heat exchange with the material to be cooled. During the entire cycle, the air conditioner can adjust the temperature of the indoor space.

[0051] In an air conditioner, an IPM module is usually required to drive the compressor and / or the fan to ensure the normal operation of the compressor and the fan within the rated voltage range.

[0052] When the IPM module is driven, if the IPM module has short-circuited before startup, it will cause a failure or even burnout of the controller. The existing technical solutions mainly judge whether an IPM failure occurs by the current value when the IPM module is working. However, the existing solutions cannot identify the short-circuit fault of the IPM module before starting the compressor. And directly starting the IPM module when the IPM module has a short circuit will directly cause a failure of the controller, affecting the safe operation of the air conditioner.

[0053] To solve this problem, the present utility model proposes an IPM module protection circuit, which is characterized in that the circuit includes an IPM module, a voltage detection module, and a main control module;

[0054] The voltage input end of the IPM module is used to connect the power supply voltage, the control end of the IPM module is connected to the signal output end of the main control module, and the voltage output end of the IPM module is used to output the driving voltage;

[0055] The detection terminal of the voltage detection module is connected to the voltage output terminal of the IPM module, and is used to detect the short - circuit current of the voltage output terminal of the IPM module;

[0056] The main control module is connected to the sampling terminal of the voltage detection module and receives the sampling value of the voltage detection module.

[0057] When specifically implementing this embodiment, refer to Figure 2 , which is a schematic structural diagram of an IPM module protection circuit provided by an embodiment of the present utility model. The circuit includes an IPM module, a voltage detection module, and a main control module;

[0058] Specifically, the IPM module is controlled by the signal output terminal of the main control module to perform drive voltage control and output a drive voltage to an external power device, specifically including a compressor or a fan, etc.

[0059] Specifically, the voltage input terminal of the IPM module is used to connect to the supply voltage VDC, generally connecting to an external DC drive voltage. The control terminal of the IPM module is connected to the signal output terminal of the main control module. The voltage output terminal of the IPM module is connected to an external power component and is used to output the supply voltage. The main control module controls the conduction or cut - off during the switching period in the IPM module by outputting a control signal to control the drive voltage output to the power device.

[0060] The acquisition terminal of the voltage detection module provided in this case is connected to the voltage output terminal of the IPM module. The acquisition terminal and the IPM module form a current loop to perform short - circuit voltage sampling on the voltage output terminal of the IPM module;

[0061] The main control module is connected to the sampling terminal of the voltage detection module and receives the sampling value of the voltage detection module. The main control module is used to perform voltage sampling on the voltage detection module.

[0062] The main control module identifies the voltage sampling value of the voltage detection terminal of the voltage detection module to achieve short - circuit detection.

[0063] The main control module determines whether there is a sampling current according to the received sampling value to achieve the judgment of the IPM module short - circuit.

[0064] In the present utility model, by setting a current sampling module at the voltage output terminal of the IPM module to form a current loop of the IPM module. Before the IPM module starts, the main control module does not output a control signal to the IPM module, and the voltage output by the IPM module should be low - level. When a high - level appears, a current loop is formed through the voltage detection module to perform voltage sampling. When a short - circuit voltage is detected, it is determined that the IPM module has a short - circuit fault, realizing the short - circuit fault detection of the IPM module before startup.

[0065] In another embodiment provided by the present utility model, the IPM module includes an upper-bridge-arm switching unit and a lower-bridge-arm switching unit;

[0066] The input end of the upper-bridge-arm switching unit serves as the voltage input end of the IPM module. The output end of the upper-bridge-arm switching unit is connected to the input end of the lower-bridge-arm switching unit, and the output end of the lower-bridge-arm switching unit is grounded;

[0067] The output end of the upper-bridge-arm switching unit serves as the voltage output end of the IPM module;

[0068] The control end of the upper-bridge-arm switching unit is connected to different signal output ends of the main control module with the control end of the lower-bridge-arm switching unit.

[0069] When this embodiment is specifically implemented, refer to Figure 3 , which is a schematic structural diagram of the IPM module provided by the embodiment of the present utility model. The IPM module includes an upper-bridge-arm switching unit and a lower-bridge-arm switching unit.

[0070] The upper-bridge-arm switching unit and the lower-bridge-arm switching unit are connected in series between the input voltage and the ground end to achieve control of different voltages.

[0071] The input end of the upper-bridge-arm switching unit serves as the voltage input end of the IPM module for connecting the power supply voltage; the output end of the upper-bridge-arm switching unit is connected to the input end of the lower-bridge-arm switching unit, and the output end of the lower-bridge-arm switching unit is grounded;

[0072] The output end of the upper-bridge-arm switching unit serves as the voltage output end of the IPM module for outputting the driving voltage.

[0073] The control end of the upper-bridge-arm switching unit is connected to different signal output ends of the main control module with the control end of the lower-bridge-arm switching unit.

[0074] By controlling the upper-bridge-arm switching unit and the lower-bridge-arm switching unit respectively through the main control module, the output control of the driving voltage is realized.

[0075] In another embodiment provided by the present utility model, the voltage detection module includes a first detection unit and a second detection unit;

[0076] The first detection unit is used to sample the short-circuit current of the lower-bridge-arm switching unit and output a sampled value;

[0077] The second detection unit is used to sample the short-circuit current of the upper-bridge-arm switching unit and output a sampled value.

[0078] When this embodiment is specifically implemented, refer to Figure 4, which is a schematic structural diagram of the voltage detection module provided by an embodiment of the present utility model. The voltage detection module includes a first detection unit and a second detection unit;

[0079] The first detection unit and the second detection unit respectively perform current sampling on the upper-bridge-arm switching unit;

[0080] The first detection unit is used to sample the short-circuit current of the lower-bridge-arm switching unit. The current direction is output from the first detection unit, grounded through the lower-bridge-arm switching unit. The first detection unit performs short-circuit current sampling and outputs the sampling value through the first sampling terminal connected to the main control module.

[0081] The second detection unit is used to sample the short-circuit current of the upper-bridge-arm switching unit. The current direction is output to the second detection unit through the lower-bridge-arm switching unit and then grounded. The second detection unit performs short-circuit current sampling and outputs the sampling value through the first sampling terminal connected to the main control module.

[0082] Through the first detection unit and the second detection unit, current sampling is respectively performed to achieve separate detection of the short circuits of the upper-bridge-arm switching unit and the lower-bridge-arm switching unit.

[0083] In another embodiment provided by the present utility model, the input end of the first detection unit is used to connect a DC voltage. The output end of the first detection unit serves as the detection end of the voltage detection module and is connected to the voltage output end of the IPM module. The first detection unit is configured with a first one-way component that conducts unidirectionally from the input end to the output end. A first sampling terminal connected to the main control module is configured on the first detection unit.

[0084] During the specific implementation of this embodiment, refer to Figure 5 , which is a schematic structural diagram of the first detection unit provided by an embodiment of the present utility model. The first detection unit includes a first one-way component with single-way conduction.

[0085] The input end of the first detection unit is used to connect the DC voltage VCC. The output end of the first detection unit serves as the detection end of the voltage detection module and is connected to the voltage output end of the IPM module. The DC voltage input through the input end of the first detection unit is grounded through the voltage output end of the IPM module and the lower-bridge-arm switching unit of the IPM module to form a current detection loop. When the lower-bridge-arm switching unit of the IPM module is short-circuited, a short-circuit current is formed in the first detection unit, and the detection of the short circuit of the lower-bridge-arm switching unit is achieved by detecting the circuit current.

[0086] During specific detection, the main control unit outputs a first voltage sampling value through the first sampling terminal on the first detection unit to achieve voltage detection.

[0087] To ensure the current direction on the first detection unit, a first one-way component that conducts unidirectionally from the input end to the output end is also configured on the first detection unit to avoid interference from the current output by the upper-bridge-arm switching unit.

[0088] It should be noted that the first one-way component is specifically a device for controlling the current flow direction. In specific use, a diode is often used but not limited to being used.

[0089] In another embodiment provided by the present utility model, the input end of the second detection unit is connected to the voltage output end of the IPM module as the detection end of the voltage detection module. The output end of the second detection unit is used for grounding. The second detection unit is configured with a second one-way component that conducts unidirectionally from the input end to the output end, and a second sampling end connected to the main control module is configured on the second detection unit.

[0090] In the specific implementation of this embodiment, refer to Figure 6 which is a schematic structural diagram of the second detection unit provided by the embodiment of the present utility model. The second detection unit includes a second one-way component with single-way conduction.

[0091] The input end of the second detection unit serves as the detection end of the voltage detection module and is connected to the voltage output end of the IPM module. The output end of the second detection unit is grounded. The DC voltage input through the input end of the second detection unit forms a current detection loop with the voltage output end of the IPM module and the upper-bridge-arm switching unit of the IPM module grounded. When the upper-bridge-arm switching unit of the IPM module is short-circuited, a short-circuit current is formed in the second detection unit. Then, by detecting the circuit current, the detection of the short circuit of the upper-bridge-arm switching unit is realized.

[0092] During specific detection, the main control unit outputs a second voltage sampling value through the second sampling end on the second detection unit to realize voltage detection.

[0093] To ensure the current direction on the second detection unit, a second one-way component that conducts unidirectionally from the input end to the output end is also configured on the second detection unit to avoid interference from the current output by the lower-bridge-arm switching unit.

[0094] In another embodiment provided by the present utility model, the first detection unit further includes a first voltage-dividing component;

[0095] The first one-way component and the first voltage-dividing component are connected in series between the input end and the output end of the first detection unit;

[0096] The first voltage-dividing component includes a second resistor connected in series with a first resistor. The connection point of the first resistor and the second resistor serves as the first sampling end of the first detection unit.

[0097] In the specific implementation of this embodiment, refer toFigure 7 , which is another schematic structural diagram of the first detection unit provided by the embodiment of the present utility model.

[0098] The first detection unit further includes a first voltage-dividing component, and the first voltage-dividing component is composed of a first resistor R1 and a second resistor R2;

[0099] The first detection unit is composed of a first one-way component and the first voltage-dividing component connected in series between the input end and the output end of the first detection unit;

[0100] In the attached drawing provided by this embodiment, the first end of the first voltage-dividing component is connected to the input end of the first detection unit, the second end of the second voltage-dividing component is connected to the anode of the first one-way component, the cathode of the first one-way component is connected to the output end of the first detection unit, and the output end of the first detection unit serves as the detection end of the voltage detection module. In other embodiments, other connection relationships can be adopted.

[0101] In the first voltage-dividing component, the first end of the second resistor R2 serves as the first end of the first voltage-dividing component, the second end of the second resistor R2 is connected to the first end of the first resistor R1, the second end of the first resistor R1 serves as the second end of the first voltage-dividing resistor, and the second end of the second resistor R2 serves as the first sampling end of the first detection unit.

[0102] Voltage division is carried out through the two resistors of the voltage-dividing component. When the lower-bridge-arm switching unit of the IPM module is short-circuited, there is a short-circuit current in the first detection unit. Then, due to the voltage division of the voltage-dividing resistor, the first sampling end will output a voltage sampling value to realize the short-circuit detection of the lower-bridge-arm switching unit.

[0103] In another embodiment provided by the present utility model, the second detection unit further includes a second voltage-dividing component;

[0104] The second one-way component and the second voltage-dividing component are connected in series between the input end and the output end of the second detection unit;

[0105] The second voltage-dividing component includes a third resistor and a fourth resistor connected in series, and the connection point of the third resistor and the fourth resistor serves as the second sampling end of the second detection unit.

[0106] During the specific implementation of this embodiment, refer to Figure 8 , which is another schematic structural diagram of the second detection unit provided by the embodiment of the present utility model.

[0107] The second detection unit further includes a second voltage-dividing component, and the second voltage-dividing component is composed of a third resistor R3 and a fourth resistor R4;

[0108] The second detection unit is composed of a second one-way component and the second voltage-dividing component connected in series between the input end and the output end of the first detection unit;

[0109] In the attached drawings provided in this embodiment, the anode of the second one-way component is connected to the input end of the second detection unit. The input end of the first detection unit serves as the detection end of the voltage detection module. The first end of the second voltage-dividing component is connected to the cathode of the first one-way component, and the second end of the second voltage-dividing component is connected to the output end of the first detection unit. In other embodiments, other connection relationships can be adopted.

[0110] In the second voltage-dividing component, the first end of the third resistor R3 serves as the first end of the first voltage-dividing component. The second end of the third resistor R3 is connected to the first end of the fourth resistor R4. The second end of the fourth resistor R4 serves as the second end of the second voltage-dividing resistor. The second end of the third resistor R3 serves as the second sampling end of the second detection unit.

[0111] Voltage division is performed by two resistors of the voltage-dividing component. When the upper-bridge-arm switching unit of the IPM module is short-circuited, there is a short-circuit current in the second detection unit. Then, due to the voltage division of the voltage-dividing resistor, the second sampling end will output a voltage sampling value to achieve the short-circuit detection of the upper-bridge-arm switching unit.

[0112] In another embodiment provided by the present utility model, the upper-bridge-arm switching unit and the lower-bridge-arm switching unit each include three switching components;

[0113] Each switching component in the upper-bridge-arm switching unit is respectively connected in series with a corresponding switching component in the lower-bridge-arm switching unit. The connection point of each switching component in the upper-bridge-arm switching unit and the corresponding switching component in the lower-bridge-arm switching unit serves as a voltage output end of the IPM module to form a three-phase voltage output;

[0114] The control end of each switching component is connected to different signal output ends of the main control module.

[0115] When specifically implementing this embodiment, refer to Figure 9 , which is another structural schematic diagram of the IPM module protection circuit provided by the embodiment of the present utility model.

[0116] The IPM module of the IPM module protection circuit includes that the upper-bridge-arm switching unit and the lower-bridge-arm switching unit each include three switching components;

[0117] The upper-bridge-arm switching unit includes a first switching component Q1, a third switching component Q3, and a fifth switching component Q5. The lower-bridge-arm switching unit includes a second switching component Q2, a fourth switching component Q4, and a sixth switching component Q6.

[0118] In Figure 9Among them, the provided switching component is 6 MOSFET tubes. The voltage input terminal of the IPM module is connected to 310V high-voltage direct current, the output terminal of the IPM module is grounded, and the IPM module receives the control signal from the main control board to control the on and off of the six MOSFET tubes to obtain an accurate control voltage, and the U / V / W three-phase outputs the control voltage to the compressor. The IPM module is internally divided into U / V / W three-phase control circuits, and each phase has 2 MOSFET tubes, which are respectively called the upper bridge arm circuit and the lower bridge arm circuit.

[0119] The input terminals of the first switching component Q1, the third switching component Q3, and the fifth switching component Q5 are all used as the input terminals of the IPM upper bridge arm switching unit, that is, as the voltage input terminal of the IPM module, and are connected to the power supply VDC. The output terminal of the first switching component Q1 is connected to the input terminal of the second switching component Q2, the output terminal of the third switching component Q3 is connected to the input terminal of the fourth switching component Q4, and the output terminal of the fifth switching component Q5 is connected to the input terminal of the sixth switching component Q6.

[0120] The control terminals of the first switching component Q1, the third switching component Q3, the fifth switching component Q5, the second switching component Q2, the fourth switching component Q4, and the sixth switching component Q6 are all controlled by one signal output terminal of the main control module to respectively control the upper and lower bridge arms of the three phases.

[0121] In another embodiment provided by the present invention, the first one-way component is composed of three diodes connected in parallel;

[0122] The output terminals of the three diodes are all used as the output terminal of the first one-way component;

[0123] The input terminal of each diode is separately connected to a voltage output terminal of the IPM module.

[0124] When the present invention is specifically implemented, refer to Figure 9 , the first one-way component is composed of three diodes connected in parallel, namely the first diode D1, the second diode D2, and the third diode D3.

[0125] The three diodes are respectively connected in parallel, and the output terminals of the three diodes are all used as the output terminal of the first one-way component;

[0126] The input terminal of each diode is separately connected to a voltage output terminal of the IPM module, that is, the first diode D1 is connected to the W-phase voltage output terminal, the second diode D2 is connected to the V-phase voltage output terminal, and the third diode D3 is connected to the U-phase voltage output terminal.

[0127] In another embodiment provided by the present invention, the second one-way component is composed of three diodes connected in parallel;

[0128] The output terminals of the three diodes all serve as the input terminals of the second unidirectional component;

[0129] The input terminal of each diode is separately connected to a voltage output terminal of the IPM module.

[0130] During the specific implementation of the present utility model, refer to Figure 9 , the second unidirectional component consists of three diodes connected in parallel, namely the fourth diode D4, the fifth diode D5 and the sixth diode D6.

[0131] The three diodes are respectively connected in parallel, and the output terminals of the three diodes all serve as the output terminals of the second unidirectional component;

[0132] The input terminal of each diode is separately connected to a voltage output terminal of the IPM module, that is, the fourth diode D4 is connected to the W-phase voltage output terminal, the fifth diode D5 is connected to the V-phase voltage output terminal, and the sixth diode D6 is connected to the U-phase voltage output terminal.

[0133] The voltage detection module of the IPM module protection circuit provided by the present utility model is divided into a first detection unit and a second detection unit, which respectively perform upper-bridge-arm short-circuit detection protection and lower-bridge-arm short-circuit detection protection. The first detection unit is connected from the connection point of the upper and lower bridge arms of each phase (the E pole of the upper bridge arm and the C pole of the lower bridge arm), connected to the negative pole of the diode to prevent reverse, and then connected to the voltage-dividing resistors R1 / R2, and connected to VCC through the voltage-dividing resistors. It is composed of a current sampling device for the module circuit and a voltage-dividing device for dividing the collected current. The input terminal of the detection and protection unit is connected to the output terminal of the IPM module, and is used to detect whether a short-circuit fault occurs in the upper bridge arm of the IPM module, and output a signal indicating whether a short-circuit fault occurs in the IPM module.

[0134] The second detection unit is connected from the connection point of the upper and lower bridge arms of each phase (the E pole of the upper bridge arm and the C pole of the lower bridge arm), connected to the positive pole of the diode to prevent reverse, and then connected to the voltage-dividing resistors R3 / R4, and connected to GND through the voltage-dividing resistors. It is composed of a current sampling device for the module circuit and a voltage-dividing device for dividing the collected current. The input terminal of the detection and protection unit is connected to the output terminal of the IPM module, and is used to detect whether a short-circuit fault occurs in the lower bridge arm of the IPM module, and output a signal indicating whether a short-circuit fault occurs in the IPM module.

[0135] When detecting the lower bridge arm, after the indoor unit receives the start-up operation command, the outdoor main control receives the instruction to start the compressor, and the main control module MCU controls the IPM module to enter the self-check mode. The first detection unit of the lower bridge arm includes diodes D1, D2, D3 for preventing current reversal, and voltage-dividing resistors R1 = R2. One end of the voltage-dividing resistor R2 is connected to the power supply VCC of the main control module MCU, and the other end is connected to the sampling terminal of the main control module MCU. When any lower bridge arm of the three phases is short-circuited before the IPM module operates, the main circuit current flow of the IPM module is that VCC forms a current loop through R2, R1, D1 / D2 / D3, and the lower bridge arms of U / V / W phases. At this time, the chip port voltage at the first sampling terminal is less than the set voltage threshold VCC1 (for example: set R1 = R2 = 5.1V, VCC = 5V, then the VD1 port voltage VCC1 = (5 - 0.7) / 2 = 2.15V. Due to wiring device differences, VCC1 is set to 2.5V. When the VD1 voltage is less than 2.5V, it is considered that the lower bridge arm is short-circuited), then it is judged that any one phase or any two phases or all three phases of the lower bridge arms of U / V / W phases are short-circuited. When the voltage at the first sampling terminal is greater than the threshold VCC1, it is considered that the lower bridge arms are all normal.

[0136] When detecting the upper bridge arm: after the indoor unit receives the start-up operation command, the outdoor main control receives the instruction to start the compressor, and the main control module MCU controls the IPM module to enter the self-check mode. The first detection unit of the upper bridge arm includes diodes D4, D5, D6 for preventing current reversal, and voltage-dividing resistors R3 and R4. The ratio of R3 and R4 is generally set to a relatively large proportion. One end of the voltage-dividing resistor R4 is grounded, and the other end is connected to the ground terminal of the main control module MCU. When any upper bridge arm of a phase is short-circuited before the IPM operates, the main circuit current flow of the IPM module is that VDC forms a current loop through the upper bridge arms of U / V / W phases, R3, R4, and D4 / D5 / D6. At this time, the voltage at the second sampling port is equal to the set threshold VCC2 (for example, the VDC high voltage is equal to 310V, set R3:R4 = 100:1, then VD2 = (1 / 100)*310V = 3.1V. Due to wiring or device differences, VCC2 is set to 3V), then it is judged that any one phase or any two phases or all three phases of the upper bridge arms of U, V, W phases are short-circuited. When the voltage at the second sampling terminal is less than the set threshold VCC3 (because it may not be standard 0V due to device or wiring differences, so VCC3 = 0.5V), it is considered that the upper bridge arms are all normal.

[0137] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. An IPM module protection circuit, characterized in that, The circuit includes an IPM module, a voltage detection module, and a main control module; The voltage input terminal of the IPM module is used to connect to the supply voltage. The control terminal of the IPM module is connected to the signal output terminal of the main control module. The voltage output terminal of the IPM module is used to output a driving voltage; The detection terminal of the voltage detection module is connected to the voltage output terminal of the IPM module for short-circuit current detection of the voltage output terminal of the IPM module; The main control module is connected to the sampling terminal of the voltage detection module to receive the sampling value of the voltage detection module.

2. The IPM module protection circuit according to claim 1, characterized in that, The IPM module includes an upper bridge arm switch unit and a lower bridge arm switch unit; The input terminal of the upper bridge arm switch unit serves as the voltage input terminal of the IPM module. The output terminal of the upper bridge arm switch unit is connected to the input terminal of the lower bridge arm switch unit. The output terminal of the lower bridge arm switch unit is grounded; The output terminal of the upper bridge arm switch unit serves as the voltage output terminal of the IPM module; The control terminal of the upper bridge arm switch unit and the control terminal of the lower bridge arm switch unit are connected to different signal output terminals of the main control module.

3. The IPM module protection circuit according to claim 2, characterized in that, The voltage detection module includes a first detection unit and a second detection unit; The first detection unit is used to sample the short-circuit current of the lower bridge arm switch unit and output a sampling value; The second detection unit is used to sample the short-circuit current of the upper bridge arm switch unit and output a sampling value.

4. The IPM module protection circuit according to claim 3, characterized in that, The input terminal of the first detection unit is used to connect to a DC voltage. The output terminal of the first detection unit serves as the detection terminal of the voltage detection module and is connected to the voltage output terminal of the IPM module. The first detection unit is configured with a first one-way component that conducts unidirectionally from the input terminal to the output terminal. The first detection unit is configured with a first sampling terminal connected to the main control module.

5. The IPM module protection circuit according to claim 3, characterized in that, The input terminal of the second detection unit serves as the detection terminal of the voltage detection module and is connected to the voltage output terminal of the IPM module. The output terminal of the second detection unit is used to be grounded. The second detection unit is configured with a second one-way component that conducts unidirectionally from the input terminal to the output terminal. The second detection unit is configured with a second sampling terminal connected to the main control module.

6. The IPM module protection circuit according to claim 4, wherein, The first detection unit further includes a first voltage dividing component; The first one-way component and the first voltage dividing component are connected in series between the input terminal and the output terminal of the first detection unit; The first voltage dividing component includes a first resistor and a second resistor connected in series. The connection point of the first resistor and the second resistor serves as the first sampling terminal of the first detection unit.

7. The IPM module protection circuit according to claim 5, characterized in that The second detection unit further includes a second voltage dividing component; The second one-way component and the second voltage dividing component are connected in series between the input terminal and the output terminal of the second detection unit; The second voltage dividing component includes a third resistor and a fourth resistor connected in series. The connection point of the third resistor and the fourth resistor serves as the second sampling terminal of the second detection unit.

8. The IPM module protection circuit according to claim 2, characterized in that The upper bridge arm switch unit and the lower bridge arm switch unit each include three switch components; Each switch component in the upper bridge arm switch unit is respectively connected in series with a corresponding switch component in the lower bridge arm switch unit, and the connection point between each switch component in the upper bridge arm switch unit and the corresponding switch component in the lower bridge arm switch unit serves as a voltage output terminal of the IPM module, forming a three-phase voltage output; The control terminal of each switch component is connected to a different signal output terminal of the main control module.

9. The IPM module protection circuit according to claim 4, characterized in that, The first unidirectional component consists of three diodes connected in parallel; The input terminals of the three diodes all serve as the input terminal of the first unidirectional component; The output terminal of each diode is separately connected to a voltage output terminal of the IPM module.

10. The IPM module protection circuit according to claim 5, characterized in that, The second unidirectional component consists of three diodes connected in parallel; The output terminals of the three diodes all serve as the output terminal of the second unidirectional component; The input terminal of each diode is separately connected to a voltage output terminal of the IPM module.

Images