Driving board over-voltage and under-voltage protection circuit, compressor and air conditioning unit

Abstract

The utility model discloses a drive board overvoltage and undervoltage protection circuit, a compressor and an air conditioning unit. The drive board overvoltage and undervoltage protection circuit comprises a rectification unit, an energy storage filtering unit, an inversion unit and a first brake unit. The rectifying unit is used for being connected with an alternating current power supply, the rectifying unit is further connected with the energy storage filtering unit, the energy storage filtering unit is connected with the inversion unit, and the inversion unit is used for being connected with a compressor; the first braking unit is connected with the energy storage filtering unit, and the first braking unit is used for releasing excess energy of the energy storage filtering unit at a low speed. When the energy storage filtering unit firstly has an undervoltage fault and is boosted to cause an overvoltage fault, excess energy in the energy storage filtering unit can be slowly released by starting the first braking unit, so that the voltage in the energy storage filtering unit can be recovered to a normal level, and the safety of the energy storage filtering unit is not influenced even if the energy storage filtering unit runs without shutdown; and the user experience is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electricity, in particular to an over-voltage and under-voltage protection circuit for a driving board, a compressor and an air-conditioning unit. Background Art

[0002] The compressor driving board is a key part of the operation of the air-conditioning unit. However, in daily use, affected by the power grid fluctuation, the power supply fluctuation of the air-conditioning unit is also unstable, thus resulting in over-voltage faults or under-voltage faults.

[0003] Among them, the power grid fluctuation is often relatively rapid. Therefore, for the sake of its own safety, the air-conditioning unit has a very sensitive fault response. It will make the air-conditioning unit stop running quickly after receiving the fault signal of over-voltage fault or under-voltage fault, resulting in unstable operation of the air-conditioning unit.

[0004] However, when an under-voltage fault occurs and an over-voltage fault occurs due to boosting the unit with an under-voltage fault, if the air-conditioning unit can adjust the voltage to recover by itself, the air-conditioning unit will not affect its own safety when it does not stop running. However, when the above faults occur in the existing air-conditioning unit, it still stops running quickly. Therefore, the air-conditioning unit needs to wait for the power supply to return to normal and then start again, which takes a period of time and affects the user experience. Summary of the Utility Model

[0005] In view of this, the utility model provides an over-voltage and under-voltage protection circuit for a driving board, a compressor and an air-conditioning unit, which is used to solve the problem that the fault response of the driving board is too sensitive due to power supply fluctuation and other reasons in the prior art, resulting in unstable operation and affecting the user experience.

[0006] The technical solution of the utility model is an over-voltage and under-voltage protection circuit for a driving board, which includes a rectifying unit, an energy storage and filtering unit, an inverting unit and a first braking unit;

[0007] The rectifying unit is used to connect to an AC power supply. The rectifying unit is also connected to the energy storage and filtering unit. The energy storage and filtering unit is connected to the inverting unit. The inverting unit is used to connect to a compressor;

[0008] The first braking unit is connected to the energy storage and filtering unit. The first braking unit is used to slowly discharge the excess energy of the energy storage and filtering unit.

[0009] Further, the over-voltage and under-voltage protection circuit for the driving board further includes a second braking unit. The second braking unit is connected to the energy storage and filtering unit. The second braking unit is used to quickly discharge the excess energy of the energy storage and filtering unit.

[0010] Further, the energy storage and filtering unit includes a capacitor C1;

[0011] The positive electrode of the capacitor C1 is respectively connected to one end of the output side of the rectifying unit, one end of the input side of the first braking unit, and one end of the input side of the second braking unit;

[0012] The negative electrode of the capacitor C1 is respectively connected to the other end of the output side of the rectifying unit, the other end of the input side of the first braking unit, and the other end of the input side of the second braking unit.

[0013] Further, the first braking unit includes a resistor R1 and a switching transistor Q1;

[0014] The positive electrode of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the switching transistor Q1, and the emitter of the switching transistor Q1 is connected to the negative electrode of the capacitor C1.

[0015] Further, the second braking unit includes a resistor R2 and a switching transistor Q2;

[0016] The positive electrode of the capacitor C1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the collector of the switching transistor Q2, and the emitter of the switching transistor Q2 is connected to the negative electrode of the capacitor C1.

[0017] Further, the resistance value of the resistor R1 is greater than the resistance value of the resistor R2.

[0018] Further, the inverter unit includes a switching transistor Q3, a switching transistor Q4, a switching transistor Q5, a switching transistor Q6, a switching transistor Q7, and a switching transistor Q8;

[0019] The switching transistor Q3 and the switching transistor Q4 are connected in series to form a first bridge arm, the switching transistor Q5 and the switching transistor Q6 are connected in series to form a second bridge arm, and the switching transistor Q7 and the switching transistor Q8 are connected in series to form a third bridge arm;

[0020] Both ends of the first bridge arm, both ends of the second bridge arm, and both ends of the third bridge arm are respectively connected to both ends of the input side of the energy storage and filtering unit;

[0021] The midpoints of the first bridge arm, the second bridge arm, and the third bridge arm are respectively connected to the three phases of the compressor.

[0022] Further, the AC power supply is a single-phase power supply or a three-phase power supply.

[0023] The present utility model also provides a compressor, which includes the above-mentioned driving board over-voltage and under-voltage protection circuit.

[0024] The present utility model also provides an air-conditioning unit, which includes the above-mentioned compressor.

[0025] Compared with the prior art, the utility model has at least the following beneficial effects:

[0026] When the energy storage and filtering unit first has an undervoltage fault, and boosting it causes an overvoltage fault, the utility model can start the first braking unit to slowly discharge the excess energy in the energy storage and filtering unit, so that the voltage in the energy storage and filtering unit returns to the normal level, and thus it can operate without shutting down and will not affect its own safety, thereby improving the user experience. Description of the Drawings

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the utility model belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit the utility model; the terms "including" and "having" and any variations thereof in the specification and claims of the utility model and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the utility model or the above drawings are used to distinguish different objects and are not used to describe a specific order.

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the utility model, and for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a module block diagram of the driving board over-voltage and under-voltage protection circuit of the utility model;

[0030] Figure 2 It is a circuit diagram of the driving board over-voltage and under-voltage protection circuit of the utility model;

[0031] Figure 3 It is a module block diagram of the air conditioner unit of the utility model;

[0032] Figure 4 It is a flow chart of the detection method of the air conditioner unit of the utility model.

[0033] Reference Numerals:

[0034] 10. AC power supply;

[0035] 20. Rectification unit;

[0036] 30. Energy storage and filtering unit;

[0037] 40. Inversion unit;

[0038] 50. First braking unit;

[0039] 60. Second braking unit;

[0040] 70. Main control MCU;

[0041] 80. Voltage detection unit;

[0042] 90. Current detection unit;

[0043] 100. Variable frequency speed regulation unit;

[0044] 110. Delay unit. Detailed implementation manners

[0045] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model. Thus, a feature pointed out in this specification will be used to illustrate one feature of one embodiment of the present utility model, rather than implying that each embodiment of the present utility model must have the feature described. In addition, it should be noted that this specification describes many features. Although some features may be combined together to show possible system designs, these features can also be used in other combinations not explicitly described. Thus, unless otherwise stated, the described combination is not intended to be limiting.

[0046] The principle and structure of the present utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0047] Embodiment 1

[0048] The compressor drive board is a key part of the operation of the air conditioner unit. However, in daily use, affected by the fluctuations of the power grid (equivalent to the AC power supply 10), the power supply of the air conditioner unit also fluctuates unstably, thus generating overvoltage faults or undervoltage faults.

[0049] Among them, the power grid fluctuations are often relatively rapid. Therefore, for the sake of its own safety, the air conditioner unit responds to faults very quickly. It will cause the air conditioner unit to stop running quickly after receiving the fault signal of overvoltage fault or undervoltage fault, resulting in unstable operation of the air conditioner unit.

[0050] However, when an undervoltage fault occurs and boosting the voltage of the unit with the undervoltage fault causes an overvoltage fault, if the air conditioner unit can adjust the voltage to recover by itself, the safety of the air conditioner unit will not be affected when it does not stop running. However, when the above-mentioned faults occur in the existing air conditioner units, they still stop running quickly. Therefore, the air conditioner unit needs to wait for the power supply to return to normal and then start again, which requires waiting for a period of time and affects the user experience.

[0051] Therefore, to solve the above problems, referring to the attached Figure 1-2 , the present utility model provides an over-undervoltage protection circuit for a drive board, which includes a rectification unit 20, an energy storage and filtering unit 30, an inversion unit 40, and a first braking unit 50;

[0052] The rectification unit 20 is used to connect to an AC power supply 10. The rectification unit 20 is also connected to the energy storage and filtering unit 30. The energy storage and filtering unit 30 is connected to the inversion unit 40. The inversion unit 40 is used to connect to a compressor;

[0053] The first braking unit 50 is connected to the energy storage and filtering unit 30. The first braking unit 50 is used to slowly discharge the excess energy of the energy storage and filtering unit 30.

[0054] It should be noted that a main control MCU 70 is also provided on the drive board in this embodiment to control the first braking unit 50 and the inversion unit 40 to execute corresponding instructions or actions.

[0055] In this way, when an undervoltage fault occurs in the drive board, it will cause the voltage in the energy storage and filtering unit 30 to be undervoltage. At this time, the main control MCU 70 will control the inversion unit 40 to boost the voltage of the energy storage and filtering unit 30. If the overvoltage of the energy storage and filtering unit 30 is caused during the boosting process, the main control MCU 70 will start the first braking unit 50 to slowly discharge the excess energy in the energy storage and filtering unit 30. It is equivalent to that the first braking unit 50 can bear the excess energy for the energy storage and filtering unit 30 to prevent the energy storage and filtering unit 30 from being damaged due to overvoltage, and will not quickly discharge the energy to cause the voltage to be undervoltage again. In this way, the voltage in the energy storage and filtering unit 30 can be restored to the normal level, so that the drive board can run without stopping and will not affect its own safety.

[0056] Therefore, when the energy storage and filtering unit 30 first has an undervoltage fault and boosting its voltage causes an overvoltage fault, the present utility model can start the first braking unit 50 to slowly discharge the excess energy in the energy storage and filtering unit 30, so that the voltage in the energy storage and filtering unit 30 can be restored to the normal level, and then the drive board can run without stopping and will not affect its own safety, thereby improving the user experience.

[0057] Among them, referring to the attached Figure 1, the over-voltage and under-voltage protection circuit of the drive board further includes a second braking unit 60 connected to the main control MCU 70. The second braking unit 60 is connected to the energy storage and filtering unit 30, and the second braking unit 60 is used to quickly discharge the excess energy of the energy storage and filtering unit 30.

[0058] In this way, when an over-voltage fault occurs in the drive board, it will cause the voltage in the energy storage and filtering unit 30 to be over-voltage. At this time, the main control MCU 70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the over-voltage and under-voltage protection circuit of the drive board can stop quickly, enabling the over-voltage and under-voltage protection circuit of the drive board to start quickly and reliably the next time it starts.

[0059] Specifically, an AC power supply 10 is connected to the input side of the rectifying unit 20. The output side of the rectifying unit 20 is connected to the input side of the energy storage and filtering unit 30. The output side of the energy storage and filtering unit 30 is connected to the input side of the inverter unit 40. The output side of the inverter unit 40 is connected to the three phases of the compressor;

[0060] The output side of the energy storage and filtering unit 30 is also respectively connected to the input side of the first braking unit 50 and the input side of the second braking unit 60.

[0061] Among them, referring to the appendix Figure 2 , the energy storage and filtering unit 30 includes a capacitor C1;

[0062] The positive electrode of the capacitor C1 is respectively connected to one end of the output side of the rectifying unit 20, one end of the input side of the first braking unit 50, and one end of the input side of the second braking unit 60;

[0063] The negative electrode of the capacitor C1 is respectively connected to the other end of the output side of the rectifying unit 20, the other end of the input side of the first braking unit 50, and the other end of the input side of the second braking unit 60.

[0064] In this way, when an over-voltage fault occurs in the capacitor C1, the main control MCU 70 will activate the second braking unit 60 to quickly discharge the excess energy in the capacitor C1, so that the drive board can stop quickly, enabling the drive board to start quickly and reliably the next time it starts; when an under-voltage fault occurs in the capacitor C1, the main control MCU 70 controls the inverter unit 40 to boost the voltage of the capacitor C1. If the over-voltage occurs in the capacitor C1 during the boosting process, the main control MCU 70 will activate the first braking unit 50 to slowly discharge the excess energy in the capacitor C1. It is equivalent that the first braking unit 50 can withstand the excess energy of the capacitor C1 to prevent the capacitor C1 from being damaged due to over-voltage, and will not quickly discharge the energy to cause the voltage to be under-voltage again. In this way, the voltage in the capacitor C1 is restored to the normal level, enabling the drive board to operate without stopping and not affecting its own safety.

[0065] Among them, referring to the attached Figure 2 , to ensure that the first braking unit 50 can slowly discharge the excess energy in the capacitor C1, this embodiment proposes a circuit structure of the first braking unit 50:

[0066] The first braking unit 50 includes a resistor R1 and a switching transistor Q1;

[0067] The positive electrode of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the switching transistor Q1, and the emitter of the switching transistor Q1 is connected to the negative electrode of the capacitor C1.

[0068] In this way, when the driving board has an undervoltage fault, resulting in an undervoltage of the voltage in the energy storage and filtering unit 30, the main control MCU70 will turn on the switching transistor Q1, so that the resistor R1 bears the excess energy of the capacitor C1, realizing the slow discharge of the excess energy in the capacitor C1, so that the voltage in the capacitor C1 returns to the normal level, so that the driving board can operate without stopping and will not affect its own safety.

[0069] Among them, referring to the attached Figure 2 , to ensure that the second braking unit 60 can quickly discharge the excess energy in the capacitor C1, this embodiment proposes a circuit structure of the second braking unit 60:

[0070] The second braking unit 60 includes a resistor R2 and a switching transistor Q2;

[0071] The positive electrode of the capacitor C1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the collector of the switching transistor Q2, and the emitter of the switching transistor Q2 is connected to the negative electrode of the capacitor C1.

[0072] In this way, when the driving board has an overvoltage fault or the compressor has an overcurrent fault, the main control MCU70 will turn on the switching transistor Q2, so that the resistor R2 quickly discharges the excess energy in the capacitor C1, so that the driving board stops quickly, so that the driving board can start quickly and reliably the next time it starts

[0073] Among them, the first braking unit 50 is capable of slowly discharging the excess energy in the capacitor C1, and the resistance value of the resistor R1 of the first braking unit 50 is selected to be relatively large; while the second braking unit 60 is capable of quickly discharging the excess energy in the capacitor C1, and the resistance value of the resistor R2 of the second braking unit 60 is selected to be relatively small to bear the excess energy in the capacitor C1. Therefore, the resistance value of the resistor R1 is greater than the resistance value of the resistor R2.

[0074] Among them, referring to the attached Figure 2 , the inverter unit 40 includes a switching transistor Q3, a switching transistor Q4, a switching transistor Q5, a switching transistor Q6, a switching transistor Q7 and a switching transistor Q8;

[0075] The switching transistor Q3 and the switching transistor Q4 are connected in series to form a first bridge arm, the switching transistor Q5 and the switching transistor Q6 are connected in series to form a second bridge arm, and the switching transistor Q7 and the switching transistor Q8 are connected in series to form a third bridge arm;

[0076] The midpoints of the first bridge arm, the second bridge arm, and the third bridge arm are respectively connected to the three phases of the compressor;

[0077] Both ends of the first bridge arm, both ends of the second bridge arm, and both ends of the third bridge arm are respectively connected to both ends of the input side of the energy storage and filtering unit 30 (equivalent to one end of the first bridge arm, the second bridge arm, and the third bridge arm close to their upper tubes are all connected to the positive pole of the first capacitor C1, and the other ends of the first bridge arm, the second bridge arm, and the third bridge arm close to their lower tubes are all connected to the negative pole of the first capacitor C1).

[0078] In this way, when an undervoltage fault occurs in the energy storage and filtering unit 30, the main control MCU70 will turn on the corresponding switching transistor in the inverter unit 40, so that the inverter unit 40 reversely transmits the energy of the compressor to the energy storage and filtering unit 30 to solve the undervoltage fault of the energy storage and filtering unit 30.

[0079] It should be noted that the rectifier unit 20 contains a rectifier bridge.

[0080] Among them, the AC power supply 10 is a single-phase power supply or a three-phase power supply. This enables the present invention to be applied to different scenarios according to actual situations. For example: the single-phase power supply is applied to household electrical equipment such as lighting and household appliances; while the three-phase power supply is more applied to large motors and production equipment in industrial environments.

[0081] Embodiment 2

[0082] The present invention also proposes a compressor, and the compressor includes the above-mentioned driving board over-voltage and under-voltage protection circuit.

[0083] Among them, referring to the attached Figure 3 , the compressor further includes a voltage detection unit 80, a current detection unit 90, a variable frequency speed regulation unit 100, and a delay unit 110.

[0084] The main control MCU70 is also respectively connected to the voltage detection unit 80, the current detection unit 90, the variable frequency speed regulation unit 100, and the delay unit 110; the energy storage and filtering unit 30 is connected to the voltage detection unit 80, and the voltage detection unit 80 is also connected to the delay unit 110; the current detection unit 90 is connected to the compressor, and the variable frequency speed regulation unit 100 is connected to the inverter unit 40.

[0085] Among them, the voltage detection unit 80 is used to detect the voltage of the energy storage and filtering unit 30 to determine whether the energy storage and filtering unit 30 has an undervoltage fault or an overvoltage fault.

[0086] The current detection unit 90 is used to detect the current passing through the compressor to determine whether the compressor has an overcurrent.

[0087] It should be noted that the voltage detection unit 80, the current detection unit 90, the variable frequency speed regulation unit 100, and the delay unit 110 are all prior arts, and their circuit structures will not be elaborated here.

[0088] In this way, when the compressor has an undervoltage fault, it will cause the voltage in the energy storage and filtering unit 30 to be undervoltaged. At this time, the main control MCU 70 will control the inverter unit 40 through the variable frequency speed regulation unit 100, so that the inverter unit 40 boosts the voltage of the energy storage and filtering unit 30. If the voltage in the energy storage and filtering unit 30 becomes overvoltage during the boosting process, the main control MCU 70 will start the first braking unit 50 to slowly discharge the excess energy in the energy storage and filtering unit 30. It is equivalent that the first braking unit 50 can bear the excess energy for the energy storage and filtering unit 30 to prevent the energy storage and filtering unit 30 from being damaged due to overvoltage, and will not quickly discharge the energy to cause the voltage to be undervoltaged again. In this way, the voltage in the energy storage and filtering unit 30 is restored to the normal level, so that the compressor can operate without stopping and will not affect its own safety.

[0089] When the compressor has an overvoltage fault, it will cause the voltage in the energy storage and filtering unit 30 to be overvoltage. At this time, the main control MCU 70 will start the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the compressor can stop quickly, enabling the compressor to start quickly and reliably the next time it starts.

[0090] Therefore, when the compressor first has an undervoltage fault and then an overvoltage fault, the present utility model can start the first braking unit 50 to restore the voltage of the compressor to the normal level, thereby enabling the compressor to operate without stopping and not affecting its own safety, and further improving the user experience.

[0091] Embodiment 3

[0092] The present utility model also proposes an air-conditioning unit, and the air-conditioning unit includes the compressor described above.

[0093] In this way, when an under-voltage fault occurs in the air-conditioning unit, it will cause the voltage in the energy storage and filtering unit 30 to be under-voltage. At this time, the main control MCU70 will control the inverter unit 40 through the variable-frequency speed regulation unit 100, so that the inverter unit 40 boosts the voltage of the energy storage and filtering unit 30. If the voltage in the energy storage and filtering unit 30 becomes over-voltage during the boosting process, the main control MCU70 will activate the first braking unit 50 to slowly discharge the excess energy in the energy storage and filtering unit 30. This is equivalent to the first braking unit 50 being able to bear the excess energy for the energy storage and filtering unit 30 to prevent the energy storage and filtering unit 30 from being damaged due to over-voltage, and the energy will not be quickly discharged to cause the voltage to be under-voltage again. In this way, the voltage in the energy storage and filtering unit 30 is restored to the normal level, so that the air-conditioning unit can operate without shutting down and will not affect its own safety.

[0094] When an over-voltage fault occurs in the air-conditioning unit, it will cause the voltage in the energy storage and filtering unit 30 to be over-voltage. At this time, the main control MCU70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air-conditioning unit can quickly shut down, enabling the air-conditioning unit to start quickly and reliably the next time it starts.

[0095] Therefore, when the air-conditioning unit first experiences an under-voltage fault and then an over-voltage fault, the present utility model can activate the first braking unit 50 to restore the voltage of the air-conditioning unit to the normal level, thereby enabling the air-conditioning unit to operate without shutting down and not affecting its own safety, and further improving the user experience.

[0096] Among them, referring to the attached Figure 4 , this embodiment also proposes a detection method for an air-conditioning unit:

[0097] If the main control MCU70 detects that the energy storage and filtering unit 30 is over-voltage through the voltage detection unit 80 or detects that the compressor is over-current through the current detection unit 90, the main control MCU70 will generate an over-voltage protection signal or an over-current protection signal, and the main control MCU70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air-conditioning unit can quickly shut down, enabling the air-conditioning unit to start quickly and reliably the next time it starts; at the same time, when the air-conditioning unit shuts down, the main control MCU70 will send an over-voltage protection signal or an over-current protection signal to the host computer to report the over-voltage fault or over-current fault.

[0098] When the main control MCU 70 detects undervoltage of the energy storage and filtering unit 30 through the voltage detection unit 80, the main control MCU 70 will generate an undervoltage protection signal; since the compressor is in a power generation state during the deceleration process of the variable frequency speed regulation unit 100, the main control MCU 70 can control the deceleration rate of the compressor through the variable frequency speed regulation unit 100 for undervoltage compensation (or reverse the energy of the compressor to the energy storage and filtering unit 30 through the inverter unit 40 for boosting). Therefore, when the main control MCU 70 detects undervoltage of the energy storage and filtering unit 30, the main control MCU 70 will send the undervoltage protection signal to the delay unit 110, so that the delay unit 110 delays the undervoltage protection signal for a predetermined time and then sends it to the host computer.

[0099] After delaying for the predetermined time, when the main control MCU 70 detects undervoltage of the energy storage and filtering unit 30 again through the voltage detection unit 80 or detects overcurrent of the compressor through the current detection unit 90, the main control MCU 70 will generate an undervoltage protection signal or an overcurrent protection signal again, and the main control MCU 70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air conditioner unit can stop quickly, enabling the air conditioner unit to start quickly and reliably the next time it starts; at the same time, when the air conditioner unit stops, the main control MCU 70 will send the undervoltage protection signal or the overcurrent protection signal to the host computer to report the undervoltage fault or the overcurrent fault.

[0100] After delaying for the predetermined time, when the main control MCU 70 detects overvoltage of the energy storage and filtering unit 30 through the voltage detection unit 80, the main control MCU 70 will activate the first braking unit 50 to bear the overvoltage. At this time, the main control MCU 70 will continuously monitor the voltage abnormality (that is, judge whether it is overvoltage or undervoltage). If no voltage abnormality is detected, the main control MCU 70 will turn off the first braking unit 50 and clear the fault signal, and the air conditioner unit will operate normally. At this time, the air conditioner unit will re-detect whether there is a fault; if the main control MCU 70 detects undervoltage of the energy storage and filtering unit 30 through the voltage detection unit 80, the main control MCU 70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air conditioner unit can stop quickly. At the same time, when the air conditioner unit stops, the main control MCU 70 will send the undervoltage protection signal to the host computer to report the undervoltage fault; if the main control MCU 70 detects overvoltage of the energy storage and filtering unit 30 through the voltage detection unit 80, the main control MCU 70 will activate the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air conditioner unit can stop quickly. At the same time, when the air conditioner unit stops, the main control MCU 70 will send a power abnormality signal to the host computer to report the power abnormality fault.

[0101] Among them, the air-conditioning unit delays and starts the first braking unit 50. After the air-conditioning unit boosts the voltage, at this time, the AC power supply 10 has not returned to normal yet, and the power generation state of the air-conditioning unit cannot be maintained stably. Therefore, it is still necessary to detect whether the energy storage and filtering unit 30 will be overvoltage or undervoltage.

[0102] It should be noted that when the voltage detection unit 80 detects that the voltage of the energy storage and filtering unit 30 is above the preset overvoltage protection value, it determines that the energy storage and filtering unit 30 has an overvoltage fault; when the voltage detection unit 80 detects that the voltage of the energy storage and filtering unit 30 is below the preset undervoltage protection value, it determines that the energy storage and filtering unit 30 has an undervoltage fault; when the current detection unit 90 detects that the current of the compressor is above the preset overcurrent protection value, it determines that the compressor has an overcurrent fault.

[0103] And when the air-conditioning unit is running, the main control MCU70 will continuously perform fault detection through the voltage detection unit 80 and the current detection unit 90. When an overvoltage fault or an overcurrent fault is detected, the main control MCU70 will perform data interaction with the delay unit 110. If there is no undervoltage fault signal in the delay unit 110 at this time, the main control MCU70 will start the second braking unit 60 to quickly discharge the excess energy in the energy storage and filtering unit 30, so that the air-conditioning unit can stop quickly. At the same time, when the air-conditioning unit stops, the main control MCU70 will send an overvoltage protection signal or an overcurrent protection signal to the host computer to report the overvoltage fault or the overcurrent fault.

[0104] Obviously, the embodiments described above are only a part of the embodiments of the present invention, rather than all embodiments. The accompanying drawings show the preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements for some of the technical features. Any equivalent structure made directly or indirectly using the content of the specification and drawings of the present invention in other related technical fields shall be within the scope of the patent protection of the present invention by the same token.

Claims

1. The over-voltage and under-voltage protection circuit for the driving board, characterized in that It includes a rectifying unit (20), an energy storage and filtering unit (30), an inverter unit (40) and a first braking unit (50); The rectifying unit (20) is used to connect to an AC power supply (10), the rectifying unit (20) is also connected to the energy storage and filtering unit (30), the energy storage and filtering unit (30) is connected to the inverter unit (40), and the inverter unit (40) is used to connect to a compressor; The first braking unit (50) is connected to the energy storage and filtering unit (30), and the first braking unit (50) is used to slowly discharge the excess energy of the energy storage and filtering unit (30).

2. The over-voltage and under-voltage protection circuit for a driving board according to claim 1, wherein The over-voltage and under-voltage protection circuit of the drive board further includes a second braking unit (60), the second braking unit (60) is connected to the energy storage and filtering unit (30), and the second braking unit (60) is used to quickly discharge the excess energy of the energy storage and filtering unit (30).

3. The over-voltage and under-voltage protection circuit for the driving board according to claim 2, wherein The energy storage and filtering unit (30) includes a capacitor C1; The positive electrode of the capacitor C1 is respectively connected to one end of the output side of the rectifying unit (20), one end of the input side of the first braking unit (50) and one end of the input side of the second braking unit (60); The negative electrode of the capacitor C1 is respectively connected to the other end of the output side of the rectifying unit (20), the other end of the input side of the first braking unit (50) and the other end of the input side of the second braking unit (60).

4. The over-voltage and under-voltage protection circuit for the driving board according to claim 3, wherein The first braking unit (50) includes a resistor R1 and a switching tube Q1; The positive electrode of the capacitor C1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the switching tube Q1, and the emitter of the switching tube Q1 is connected to the negative electrode of the capacitor C1.

5. The over-voltage and under-voltage protection circuit for a driving board according to claim 4, wherein, The second braking unit (60) includes a resistor R2 and a switching tube Q2; The positive electrode of the capacitor C1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the collector of the switching tube Q2, and the emitter of the switching tube Q2 is connected to the negative electrode of the capacitor C1.

6. The over-voltage and under-voltage protection circuit for a driving board according to claim 5, wherein The resistance value of the resistor R1 is greater than the resistance value of the resistor R2.

7. The over-voltage and under-voltage protection circuit for a driving board according to claim 1, characterized in that, The inverter unit (40) includes a switching tube Q3, a switching tube Q4, a switching tube Q5, a switching tube Q6, a switching tube Q7 and a switching tube Q8; The switching tube Q3 and the switching tube Q4 are connected in series to form a first bridge arm, the switching tube Q5 and the switching tube Q6 are connected in series to form a second bridge arm, and the switching tube Q7 and the switching tube Q8 are connected in series to form a third bridge arm; Both ends of the first bridge arm, both ends of the second bridge arm and both ends of the third bridge arm are respectively connected to both ends of the input side of the energy storage and filtering unit (30); The midpoints of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected to the three phases of the compressor.

8. The over-voltage and under-voltage protection circuit for a driving board according to claim 1, wherein The AC power supply (10) is a single-phase power supply or a three-phase power supply.

9. Compressor, characterized in that, The compressor includes the over-voltage and under-voltage protection circuit of the drive board according to any one of claims 1-8.

10. An air-conditioning unit, characterized in that, The air-conditioning unit includes the compressor according to claim 9.

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