DC fan high voltage protection circuit, air conditioning controller, outdoor unit and air conditioner

Abstract

The invention discloses a DC fan high-voltage protection circuit, an air-conditioning controller, an outdoor unit and an air-conditioner, wherein the high-voltage protection circuit comprises: a voltage detection module, which is used to detect the voltage of a DC fan bus circuit; a trigger module, which is connected to the voltage detection module and outputs a trigger signal according to the voltage of the DC fan bus circuit; and a control module, which is connected to the trigger module and protects the DC fan bus circuit by shutting off a switch tube in a DC fan inverter circuit when the control module determines that the voltage of the DC fan bus circuit is greater than a first preset voltage according to the trigger signal, thereby effectively preventing components such as an electrolytic capacitor in the DC fan bus circuit from being damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a DC fan high-voltage protection circuit, an air conditioning controller, an outdoor unit and an air conditioner. Background Art

[0002] Based on the installation environment of the air conditioner, it is found that if the outdoor unit of the air conditioner is installed at the air outlet, especially in coastal areas, due to the large air volume, after the air conditioner is turned on and running, the outdoor unit fan rotates under the external force generated by the outside wind (downwind), and the fan changes from a motor to a generator and enters regeneration. Since the regeneration action generates a certain amount of electrical energy, the electrical energy will eventually be loaded on the electrolytic capacitor of the DC bus, which can easily cause the electrolytic capacitor to withstand voltage damage (explosion). Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first object of the present invention is to provide a DC fan high voltage protection circuit, which can protect the DC fan bus circuit and prevent components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0004] A second objective of the present invention is to provide an air conditioning controller.

[0005] The third object of the present invention is to provide an outdoor unit.

[0006] A fourth object of the present invention is to provide an air conditioner.

[0007] To achieve the above-mentioned purpose, the first aspect of the present invention proposes a DC fan high-voltage protection circuit, including: a voltage detection module, the voltage detection module is used to detect the voltage of the DC fan bus circuit; a trigger module, the trigger module is connected to the voltage detection module, and the trigger module outputs a trigger signal according to the voltage of the DC fan bus circuit; a control module, the control module is connected to the trigger module, and the control module determines that the voltage of the DC fan bus circuit is greater than a first preset voltage according to the trigger signal, and the switch tube in the DC fan inverter circuit is turned off to protect the DC fan bus circuit.

[0008] According to the DC fan high-voltage protection circuit of the embodiment of the present invention, the voltage of the DC fan bus circuit is detected by a voltage detection module, and a trigger signal is output according to the voltage of the DC fan bus circuit by a trigger module, and when the control module determines that the voltage of the DC fan bus circuit is greater than a first preset voltage according to the trigger signal, the DC fan bus circuit is protected by shutting down the switch tube in the DC fan inverter circuit, thereby effectively preventing components in the DC fan bus circuit such as electrolytic capacitors from being damaged.

[0009] According to one embodiment of the present invention, the trigger module includes: a comparator unit, the comparator unit is connected to the voltage detection module, and the comparator unit outputs a comparison signal according to the voltage of the DC fan bus circuit and the first preset voltage; a first trigger control unit, the control end of the first trigger control unit is connected to the output end of the comparator unit, the input end of the first trigger control unit is connected to the preset power supply, and the first trigger control unit is turned on or off under the control of the comparison signal to output a trigger control signal; at least one second trigger control unit, the control end of each second trigger control unit is connected to the output end of the first trigger control unit, the output end of each second trigger control unit is connected to the DC fan control signal end of the control module, and each second trigger control unit is turned on or off under the control of the trigger control signal to output a trigger signal to the control module respectively.

[0010] According to one embodiment of the present invention, the above-mentioned DC fan high-voltage protection circuit also includes: a voltage hysteresis module, the voltage hysteresis module is connected to the comparator unit, the voltage hysteresis module is used to provide a hysteresis voltage to the comparator unit, so that the comparator unit controls the first trigger control unit to shut down when the voltage of the DC fan bus loop is less than or equal to the difference between the first preset voltage and the hysteresis voltage, and each second trigger control unit is shut down, and the control module controls the conduction or shutdown of the switch tube in the DC fan inverter circuit to enable the DC fan to operate normally.

[0011] According to one embodiment of the present invention, the voltage detection module includes: a first resistor, one end of the first resistor is connected to the positive bus terminal of the DC fan bus loop; a second resistor, one end of the second resistor is connected to the other end of the first resistor; a third resistor, one end of the third resistor is connected to the other end of the second resistor and has a first node, the other end of the third resistor is connected to the negative bus terminal of the DC fan bus loop, and the first node serves as the output end of the voltage detection module; a first capacitor, and the first capacitor is connected in parallel with the third resistor.

[0012] According to one embodiment of the present invention, the comparator unit includes: a first preset voltage providing unit, which is used to provide a first preset voltage; a comparator, wherein the positive input terminal of the comparator is connected to the first preset voltage providing unit, and the negative input terminal of the comparator is connected to the voltage detection module, and the comparator jumps when the voltage of the DC fan bus circuit is greater than the first preset voltage to output a low-level comparison signal.

[0013] According to one embodiment of the present invention, the hysteresis voltage module is connected to the positive input terminal of the comparator, and provides a hysteresis voltage to the positive input terminal of the comparator after the comparator jumps, so that the comparator resumes outputting a high-level comparison signal when the voltage of the DC fan bus loop is less than or equal to the difference between the first preset voltage and the hysteresis voltage.

[0014] According to one embodiment of the present invention, the first preset voltage providing unit includes: a fourth resistor, one end of the fourth resistor is connected to a preset power supply; a fifth resistor and a sixth resistor connected in series, one end of the fifth resistor and the sixth resistor connected in series is connected to one end of the fourth resistor and has a second node, the other end of the fifth resistor and the sixth resistor connected in series is grounded, and the second node serves as the output end of the first preset voltage providing unit; a second capacitor, the second capacitor is connected in parallel with the fifth resistor and the sixth resistor connected in series.

[0015] According to one embodiment of the present invention, the first trigger control unit includes: a seventh resistor, one end of the seventh resistor serves as a control end of the first trigger control unit; a first transistor, the base of the first transistor is connected to the other end of the seventh resistor, the collector of the first transistor serves as the output end of the first trigger control unit, and the emitter of the first transistor is connected to a preset power supply; an eighth resistor, the eighth resistor is connected between the base and the emitter of the first transistor; and a third capacitor, the third capacitor is connected in parallel with the eighth resistor.

[0016] According to one embodiment of the present invention, the second trigger control unit includes: a ninth resistor, one end of the ninth resistor serving as a control end of the second trigger control unit; a second triode, the base of the second triode being connected to the other end of the ninth resistor, and the emitter of the second triode being grounded; a tenth resistor, the tenth resistor being connected between the base and the emitter of the second triode; a fourth capacitor, the fourth capacitor being connected to the tenth resistor in parallel; an eleventh resistor, one end of the eleventh resistor being connected to the collector of the second triode, and the other end of the eleventh resistor serving as an output end of the second trigger control unit.

[0017] To achieve the above object, a second embodiment of the present invention provides an air-conditioning controller, which includes the above-mentioned DC fan high-voltage protection circuit.

[0018] According to the air-conditioning controller of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high-voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0019] To achieve the above object, a third aspect of the present invention provides an outdoor unit, which includes the above-mentioned DC fan high-voltage protection circuit.

[0020] According to the outdoor unit of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0021] To achieve the above-mentioned object, a fourth aspect of the present invention provides an air conditioner, which includes the above-mentioned DC fan high-voltage protection circuit.

[0022] According to the air conditioner of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the external structure of a DC fan according to an embodiment of the present invention;

[0025] Figure 2 A circuit topology diagram of a DC fan inverter circuit according to an embodiment of the present invention;

[0026] Figure 3 for Figure 2 The current diagram corresponding to the DC fan inverter circuit in different situations is shown;

[0027] Figure 4 A block diagram of a DC fan high voltage protection circuit according to an embodiment of the present invention;

[0028] Figure 5 A block diagram of a DC fan high voltage protection circuit according to another embodiment of the present invention;

[0029] Figure 6 The figure is a circuit topology diagram of a DC fan high voltage protection circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] Based on the installation environment of the air conditioner, it is found that if the outdoor unit of the air conditioner is installed at the air outlet, especially in coastal areas, due to the large air volume, after the air conditioner is turned on and running, the outdoor unit fan rotates under the external force generated by the outside wind (downwind), and the fan changes from a motor to a generator and enters regeneration. Since the regeneration action generates a certain amount of electrical energy, the electrical energy will eventually be loaded on the electrolytic capacitor of the DC bus, which can easily cause the electrolytic capacitor to withstand voltage damage (explosion).

[0032] Specifically, assuming that the outside wind is zero, the fan rotates at the rated speed Nr (in rps), the fan wind speed is Vr (in m / s), and the wind volume per unit time generated by the fan is Qr (in m3 / s) and the dynamic pressure is Pdr (unit: Pa). The air volume per unit time Qr generated by the fan is determined by the effective area Bh (unit: m 2 ) is determined by the product of the height d (unit: m) of the fan blade, the number of blades nh, and the number of rotations Nr of the fan blade, that is, Qr = Bh × d × nh × Nr, and the effective area of ​​the fan blade Bh = (a 2 -b 2 ) / 4×π(e.g. Figure 1 Assume the cross-sectional area of ​​the air duct is A (unit: m 2 ), then the air volume per unit time Qr is the product of the fan wind speed Vr and the cross-sectional area A of the air duct, and assuming that the effective area Bh of the fan blade is basically the same as the cross-sectional area A of the air duct, then Qr=Vr×A≈Vr×Bh. The dynamic pressure Pdr is determined by the air density ρ (unit: kg / m 3 ) and the wind speed Vr of the fan are calculated using Bernoulli's theorem, that is, Pdr = 1 / 2 × ρ × Vr 2 Then, the power of the fan blade can be calculated based on the air volume per unit time Qr and the dynamic pressure Pdr generated by the fan: Wr = Pdr × Qr.

[0033] When the outside wind speed V3 (m / s) is greater than the fan speed Vr, the static pressure Ps3 corresponding to the outside wind speed V3 is greater than the static pressure Ps2 corresponding to the fan speed Vr, and the difference between the two is α, that is, Ps3 = Ps2 + α (α is a positive value). According to Bernoulli's theorem, Pdr = 1 / 2 × ρ × Vr 2 =Pd3+Ps3=Pd3+Ps2+α=Pd3+Pdr+α, therefore Pd3=-α, i.e. the dynamic pressure Pd3 corresponding to the external wind speed V3 is a negative value, and the corresponding power W3 of the wind blade is a negative value, i.e. W3=Pd3×Qr=-α×Qr.

[0034] Therefore, under the influence of external wind (tailwind), the torque of the fan becomes negative, and the fan enters regeneration action, that is, the fan blades rotate due to external force, causing the fan to change from a motor to a generator.

[0035] In the case of regenerative action, the electric energy generated by the regenerative action will cause the voltage of the DC fan bus circuit to rise. Figure 2 Take the inverter circuit of the DC fan shown in the figure as an example, refer to Figure 2-Figure 3As shown, when the inverter output voltage Vo> the regenerative power voltage E, assuming that the switch on time Ton is equal to the off time Toff, the inverter output voltage Vo is half of the voltage Vdc of the DC fan bus circuit. Since the regenerative power voltage E is less than the inverter output voltage Vo, the direction of the output current Im is the right direction in the figure, the current Iqn flowing through the switch tube Qn and the current Idp flowing through the diode Dp are both zero, the current Iqp flowing through the switch tube Qp and the current Idn flowing through the diode Dn are the same and complementary, the current Idc of the DC fan bus circuit and the current Iqp flowing through the switch tube Qp are the same, at this time the inverter output power is Vo×Im (unit W), and the power provided by the DC fan bus circuit is Vdc×(Im / 2).

[0036] When the inverter output voltage Vo = the regenerative electric energy voltage E, the current Idc of the DC fan bus circuit, the current Iqp flowing through the switch tube Qp, the current Idn flowing through the diode Dn, the current Iqn flowing through the switch tube Qn, the current Idp flowing through the diode Dp and the output current Im are all zero.

[0037] When the inverter output voltage Vo<regenerative electric energy voltage E, the direction of the output current Im is the left direction in the figure (indicated by the right arrow in the figure, the corresponding currents are all negative), the current Iqn flowing through the switch tube Qn and the current Idp flowing through the diode Dp are the same and complementary, the current Iqp flowing through the switch tube Qp and the current Idn flowing through the diode Dn are both zero, the current Idc of the DC fan bus loop and the current Idp flowing through the diode Dp are the same in magnitude and opposite in direction, at this time the inverter output power is Vo×(-Im) (unit W), the power provided by the DC fan bus loop is Vdc×(-Im / 2), this power is called regenerative power, indicating that a certain amount of electric energy is converted to the DC fan bus loop, causing the voltage of the DC fan bus loop to rise, and then causing the voltage at both ends of the electrolytic capacitor in the bus loop to rise, when it exceeds the withstand voltage limit of the electrolytic capacitor, the electrolytic capacitor will be damaged (burst).

[0038] Based on this, the present application provides a DC fan high voltage protection circuit, referring to Figure 4 As shown, the DC fan high voltage protection circuit 100 includes: a voltage detection module 110, a trigger module 120 and a control module 130. Among them, the voltage detection module 110 is used to detect the voltage of the DC fan bus circuit; the trigger module 120 is connected to the voltage detection module 110, and the trigger module 120 outputs a trigger signal according to the voltage of the DC fan bus circuit; the control module 130 is connected to the trigger module 120, and the control module 130 determines that the voltage of the DC fan bus circuit is greater than the first preset voltage according to the trigger signal, and protects the DC fan bus circuit by shutting down the switch tube in the DC fan inverter circuit.

[0039] That is to say, the voltage detection module 110 detects the voltage of the DC fan bus circuit in real time (such as Figure 2 The Vdc in the DC fan is sent to the trigger module 120, and the trigger module 120 generates a trigger signal when the voltage of the DC fan bus circuit is greater than the first preset voltage and outputs it to the control module 130. Then the control module 130 turns off the switch tube in the DC fan inverter circuit according to the trigger signal (such as Figure 2 The switch tubes Qp and Qn in the DC fan are turned off, that is, the DC fan inverter circuit is controlled to stop working, so that the voltage of the DC fan bus circuit stops rising. Due to the effect of inertia, the fan will continue to run, but because there are other loads in the DC fan bus circuit (such as discharge resistors or controlled switching power supplies), the load will consume the power of the DC fan bus circuit, and the voltage of the DC fan bus circuit will drop accordingly. At the same time, since the DC fan has no continuous energy supply, the fan speed will drop. The voltage of the regenerated electric energy generated by the speed drop is lower than the voltage of the DC fan bus circuit, and will not charge the electrolytic capacitor in the DC fan bus circuit, so that the voltage of the electrolytic capacitor will not rise above its withstand voltage limit, effectively avoiding withstand voltage damage (explosion) of the electrolytic capacitor.

[0040] In this embodiment, the voltage of the DC fan bus loop is detected by the voltage detection module, and the trigger module outputs a trigger signal according to the voltage of the DC fan bus loop, and when the control module determines that the voltage of the DC fan bus loop is greater than the first preset voltage according to the trigger signal, the switch tube in the DC fan inverter circuit is turned off to protect the DC fan bus loop, thereby effectively preventing components in the DC fan bus loop such as electrolytic capacitors from being damaged.

[0041] According to one embodiment of the present invention, referring to Figure 5 As shown, the trigger module 120 includes: a comparator unit 121, a first trigger control unit 122 and at least one second trigger control unit 123. Among them, the comparator unit 121 is connected to the voltage detection module 110, and the comparator unit 121 outputs a comparison signal according to the voltage of the DC fan bus circuit and the first preset voltage; the control end of the first trigger control unit 122 is connected to the output end of the comparator unit 121, the input end of the first trigger control unit 122 is connected to the preset power supply VCC, and the first trigger control unit 122 is turned on or off under the control of the comparison signal to output a trigger control signal; the control end of each second trigger control unit 123 is connected to the output end of the first trigger control unit 122, and the output end of each second trigger control unit 133 is connected to the DC fan control signal end of the control module 130, and each second trigger control unit 122 is turned on or off under the control of the trigger control signal to output a trigger signal to the control module 130 respectively.

[0042] Specifically, the comparator unit 121 is mainly used to determine whether the voltage of the DC fan bus circuit exceeds the first preset voltage. If it exceeds, a comparison signal (such as a high level or a low level signal) is output. The first trigger control unit 122 is mainly used to turn on or off under the action of the comparison signal to generate a trigger control signal (such as a high level or a low level signal). The second trigger control unit 123 is mainly used to generate a trigger signal (such as a high level or a low level signal) according to the trigger control signal and output it to the control module 130, and the control module 130 controls the switch tube in the DC fan inverter circuit to turn off according to the trigger signal. The second trigger control unit 123 may include one or more, which can be specifically determined according to the number of DC fans.

[0043] According to one embodiment of the present invention, continue to refer to Figure 5 As shown, the above-mentioned DC fan high-voltage protection circuit also includes: a voltage hysteresis module 140, the voltage hysteresis module 140 is connected to the comparator unit 121, and the voltage hysteresis module 140 is used to provide a hysteresis voltage to the comparator unit 121, so that the comparator unit 121 controls the first trigger control unit 122 to shut down when the voltage of the DC fan bus circuit is less than or equal to the difference between the first preset voltage and the hysteresis voltage, and each second trigger control unit 123 is shut down, and the control module 130 controls the conduction or shutdown of the switch tube in the DC fan inverter circuit to enable the DC fan to operate normally.

[0044] That is, when the voltage of the DC fan bus circuit is greater than the first preset voltage, the comparator unit 121 outputs a comparison signal (such as a low-level signal) to the first trigger control unit 122, and the first trigger control unit 122 is turned on under the action of the comparison signal to output a trigger control signal (such as a high-level signal) to the second trigger control unit 123, and the second trigger control unit 123 generates a trigger signal (such as a low-level signal) according to the trigger control signal, and the control module 130 turns off the switch tube in the DC fan inverter circuit according to the trigger signal to stop the inverter circuit from working, thereby stopping the voltage of the DC fan bus circuit from rising. Then, under the action of other loads, the voltage of the DC fan bus circuit decreases, and when it decreases to the difference between the first preset voltage and the hysteresis voltage, the comparator unit 121 outputs a jump (such as a jump from a low-level signal to a high-level signal), and the first trigger control unit 122 and the second trigger control unit 123 are both turned off. At this time, the control module 130 controls the switch tube in the DC fan inverter circuit to turn on or off according to the normal control timing control, so that the DC fan can operate normally. Therefore, under the action of external wind (tailwind), when the voltage of the DC fan bus circuit rises to exceed the first preset voltage, the switch tube in the DC fan inverter circuit is controlled to be turned off to protect the DC fan bus circuit and avoid damage to components in the circuit. At the same time, when the voltage drops back to a certain value below the first preset voltage, the DC fan inverter circuit is automatically controlled to continue working, so that the DC fan can continue to work, thereby ensuring the safe and reliable operation of the DC fan.

[0045] In one embodiment of the present invention, reference Figure 6 As shown, the voltage detection module 110 includes: a first resistor R1, a second resistor R2, a third resistor R3 and a first capacitor C1. One end of the first resistor R1 is connected to the positive end of the busbar of the DC fan bus circuit; one end of the second resistor R2 is connected to the other end of the first resistor R1; one end of the third resistor R3 is connected to the other end of the second resistor R2 and has a first node J1, and the other end of the third resistor R3 is connected to the negative end of the busbar of the DC fan bus circuit. The first node J1 serves as the output end of the voltage detection module 110; the first capacitor C1 is connected in parallel with the third resistor R3. That is, the voltage of the DC fan bus circuit is detected in real time by the voltage divider circuit composed of the first resistor R1, the second resistor R2 and the third resistor R3, and the first capacitor C1 is connected in series between the detection point, that is, the first node J1 and the negative end of the busbar of the DC fan bus circuit, and the first capacitor C1 is used to filter the voltage at the detection point to ensure the stability of the voltage, so as to avoid frequent start and stop of the DC fan inverter circuit due to voltage fluctuation.

[0046] Further, refer to Figure 6As shown, the comparator unit 121 includes: a first preset voltage providing unit 1211 and a comparator U1, the first preset voltage providing unit 1211 is used to provide a first preset voltage VCC1; the positive input terminal of the comparator U1 is connected to the first preset voltage providing unit 1211, and the negative input terminal of the comparator U1 is connected to the voltage detection module 110, and the comparator U1 jumps when the voltage of the DC fan bus circuit is greater than the first preset voltage VCC1 to output a low-level comparison signal. Further, the hysteresis voltage module 140 is connected to the positive input terminal of the comparator U1, and provides a hysteresis voltage to the positive input terminal of the comparator U1 after the comparator U1 jumps, so that the comparator U1 restores the output of the high-level comparison signal when the voltage of the DC fan bus circuit is less than or equal to the difference between the first preset voltage and the hysteresis voltage.

[0047] Further, refer to Figure 6 As shown, the first preset voltage providing unit 1211 includes: a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6 connected in series, and a second capacitor C2. One end of the fourth resistor R4 is connected to the preset power supply VCC; one end of the fifth resistor R5 and the sixth resistor R6 connected in series is connected to one end of the fourth resistor R4 and has a second node J2, the other end of the fifth resistor R5 and the sixth resistor R6 connected in series is grounded GND, and the second node J2 serves as the output end of the first preset voltage providing unit 1211; the second capacitor C2 is connected in parallel with the fifth resistor R5 and the sixth resistor R6 connected in series. That is, the voltage of the preset power supply VCC is divided by the voltage divider circuit formed by the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 to obtain the first preset voltage VCC1 input to the positive input end of the comparator U1, and the voltage dividing point, that is, the second node J2, is connected in series with the ground. The second capacitor C2 is used to filter the voltage at the dividing point to ensure the stability of the voltage.

[0048] Further, refer to Figure 6 As shown, the hysteresis voltage module 140 includes: a first diode D1, a second diode D2 and a twelfth resistor R12. The anode of the first diode D1 is connected to the preset power supply VCC; the anode of the second diode D2 is connected to the cathode of the first diode D1, and the cathode of the second diode D2 is connected to the output end of the comparator U1; one end of the twelfth resistor R12 is connected to the anode of the second diode D2 and the cathode of the first diode D1 respectively, and the other end of the twelfth resistor R12 is connected to the positive input end of the comparator U1. That is, the voltage hysteresis feedback is performed through the hysteresis circuit composed of the first diode, the second diode and the twelfth resistor, so that after the voltage of the DC fan bus circuit drops, the comparator U1 resumes outputting a high-level comparison signal, thereby allowing the DC fan to continue to work.

[0049] Further, refer to Figure 6As shown, the first trigger control unit 122 includes: a seventh resistor R7, a first transistor Q1, an eighth resistor R8 and a third capacitor C3. One end of the seventh resistor R7 serves as the control end of the first trigger control unit 122; the base of the first transistor Q1 is connected to the other end of the seventh resistor R7, the collector of the first transistor Q1 serves as the output end of the first trigger control unit 122, and the emitter of the first transistor Q1 is connected to the preset power supply VCC; the eighth resistor R8 is connected between the base and the emitter of the first transistor Q1; the third capacitor C3 is connected in parallel with the eighth resistor R8. That is, the circuit formed by the switch tube converts the comparison signal output by the comparator unit 121 into a trigger control signal and provides it to the subsequent circuit.

[0050] Further, refer to Figure 6 As shown, the second trigger control unit 123 includes: a ninth resistor R9, a second triode Q2, a tenth resistor R10, a fourth capacitor C4 and an eleventh resistor R11. One end of the ninth resistor R9 serves as the control end of the second trigger control unit 123; the base of the second triode Q2 is connected to the other end of the ninth resistor R9, and the emitter of the second triode Q2 is grounded GND; the tenth resistor R10 is connected between the base and the emitter of the second triode Q2; the fourth capacitor C4 is connected in parallel with the tenth resistor R10; one end of the eleventh resistor R11 is connected to the collector of the second triode Q2, and the other end of the eleventh resistor R11 serves as the output end of the second trigger control unit 123. That is, the circuit formed by the switch tube converts the trigger control signal into a trigger signal and provides it to the control module 130, so that the control module 130 controls the switch tube in the DC fan inverter circuit according to the trigger signal to protect the DC fan bus circuit.

[0051] Specifically, under normal circumstances, the voltage of the DC fan bus circuit is less than the first preset voltage. At this time, the comparator U1 outputs a high-level signal, the first diode D1 and the second diode D2 are in a disconnected state, the first trigger control unit 122 and the second trigger control unit 123 are both turned off, and the control module 130 controls the switch tube in the DC fan inverter circuit to be turned on or off according to the normal control timing (such as Figure 2The switch tubes Qp and Qn in the DC fan are turned on or off). Under the action of the external wind (tailwind), the voltage of the DC fan bus circuit will rise. When it rises to exceed the first preset voltage, the comparator U1 outputs a low-level signal, the first trigger control unit 122 is turned on and outputs a high-level signal under the action of the low-level signal, and the second trigger control unit 123 is turned on and outputs a low-level signal under the action of the high-level signal (that is, Vsp_fan1 and Vsp_fan1 are low-level signals). The control module 130 controls the switch tubes of the DC fan inverter circuit to turn off according to the low-level signal, so that the DC fan stops working, and the voltage of the DC fan bus circuit no longer rises. At this time, under the action of other loads (such as discharge resistors) in the DC fan bus circuit, the voltage of the DC fan bus circuit gradually decreases, and at the same time, the first diode D1 and the second diode D2 in the hysteresis voltage module 140 are both turned on, and the hysteresis voltage provided by the preset power supply VCC is fed back to the positive input terminal of the comparator U1. When the voltage of the DC fan bus circuit drops to the difference between the first preset voltage and the hysteresis voltage, the comparator U1 outputs a high-level signal, the first diode D1 and the second diode D2 are both in the off state, the first trigger control unit 122 and the second trigger control unit 123 are both turned off, and the control module 130 controls the switch tube in the DC fan inverter circuit to be turned on or off according to the normal control timing, and the DC fan continues to run.

[0052] It should be noted that if the voltage of the DC fan bus circuit drops too slowly, when the drop speed meets the abnormal DC fan speed condition, the DC fan is controlled to stop and report a fault. For example, through experimental tests, it is found that the voltage of the DC fan bus circuit can usually be reduced to the difference between the first preset voltage and the hysteresis voltage in about 3 seconds. At this time, the DC fan continues to work, and the fan speed will not drop too much in a short time, so the fan speed abnormal alarm will not be triggered. If the voltage of the DC fan bus circuit drops too slowly, the fan speed will continue to drop during this process. When it drops too low, the fan speed abnormal alarm will be triggered. At this time, the DC fan is controlled to stop and report a fault, such as giving a corresponding fault code.

[0053] Therefore, by detecting the voltage of the DC fan bus circuit in real time, and when it exceeds the first preset voltage, controlling the switch tube of the DC fan inverter circuit to shut down, so as to prevent the voltage of the DC fan bus circuit from continuing to rise, causing the components in the circuit such as electrolytic capacitors to be damaged by the withstand voltage. At the same time, the consumption of the circuit voltage by other loads in the circuit is used to continuously reduce the voltage of the DC fan bus circuit, and when it is reduced to a safe value, the DC fan inverter circuit continues to be controlled to work normally to ensure the safe and reliable operation of the DC fan, and avoid the direct shutdown method resulting in the DC fan being unavailable even if the current environment is a safe environment. In particular, if the voltage of the DC fan bus circuit has not dropped to a safe value within a short period of time, the DC fan will be shut down and a fault will be reported to ensure the safety of the entire DC fan.

[0054] According to the DC fan high-voltage protection circuit of the embodiment of the present invention, the voltage of the DC fan bus circuit is detected by a voltage detection module, and a trigger signal is output according to the voltage of the DC fan bus circuit by a trigger module, and when the control module determines that the voltage of the DC fan bus circuit is greater than a first preset voltage according to the trigger signal, the DC fan bus circuit is protected by shutting down the switch tube in the DC fan inverter circuit, thereby effectively preventing components in the DC fan bus circuit such as electrolytic capacitors from being damaged.

[0055] In one embodiment of the present invention, an air-conditioning controller is also provided, which includes the above-mentioned DC fan high-voltage protection circuit.

[0056] According to the air-conditioning controller of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high-voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0057] In one embodiment of the present invention, an outdoor unit is also provided, which includes the above-mentioned DC fan high-voltage protection circuit.

[0058] According to the outdoor unit of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0059] In one embodiment of the present invention, an air conditioner is also provided, which includes the above-mentioned DC fan high-voltage protection circuit.

[0060] According to the air conditioner of the embodiment of the present invention, the DC fan bus circuit can be protected by the DC fan high voltage protection circuit, thereby preventing components such as electrolytic capacitors in the DC fan bus circuit from being damaged.

[0061] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0062] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0065] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A DC fan high voltage protection circuit, characterized in that: include: A voltage detection module, which is used to detect the voltage of the DC fan bus circuit; A trigger module, the trigger module is connected to the voltage detection module, and the trigger module outputs a trigger signal according to the voltage of the DC fan bus circuit; A control module, wherein the control module is connected to the trigger module, and when the control module determines according to the trigger signal that the voltage of the DC fan bus circuit is greater than a first preset voltage, the control module protects the DC fan bus circuit by shutting down a switch tube in a DC fan inverter circuit; The trigger module comprises: A comparator unit, the comparator unit is connected to the voltage detection module, and the comparator unit outputs a comparison signal according to the voltage of the DC fan bus loop and the first preset voltage; the comparator unit includes: a first preset voltage providing unit, the first preset voltage providing unit is used to provide the first preset voltage; a comparator, the positive input end of the comparator is connected to the first preset voltage providing unit, the negative input end of the comparator is connected to the voltage detection module, and the comparator jumps when the voltage of the DC fan bus loop is greater than the first preset voltage to output a low-level comparison signal; a first trigger control unit, wherein a control end of the first trigger control unit is connected to an output end of the comparator unit, an input end of the first trigger control unit is connected to a preset power supply, and the first trigger control unit is turned on or off under the control of the comparison signal to output a trigger control signal; At least one second trigger control unit, the control end of each second trigger control unit is connected to the output end of the first trigger control unit, the output end of each second trigger control unit is connected to the DC fan control signal end of the control module, and each second trigger control unit is turned on or off under the control of the trigger control signal to output the trigger signal to the control module respectively; A voltage hysteresis module, the voltage hysteresis module is connected to the comparator unit, and the hysteresis voltage module includes: a first diode, a second diode and a twelfth resistor; the anode of the first diode is connected to the preset power supply; the anode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode is connected to the output end of the comparator; one end of the twelfth resistor is respectively connected to the anode of the second diode and the cathode of the first diode, and the other end of the twelfth resistor is connected to the positive input end of the comparator; the hysteresis voltage module provides the hysteresis voltage to the positive input end of the comparator after the comparator jumps, so that the comparator controls the first trigger control unit to shut down when the voltage of the DC fan bus circuit is less than or equal to the difference between the first preset voltage and the hysteresis voltage, and each of the second trigger control units is shut down, and the control module controls the conduction or shutdown of the switch tube in the DC fan inverter circuit to enable the DC fan to operate normally.

2. The DC fan high voltage protection circuit according to claim 1, characterized in that: The voltage detection module comprises: A first resistor, one end of which is connected to the positive end of the busbar of the DC fan busbar loop; a second resistor, one end of the second resistor being connected to the other end of the first resistor; A third resistor, one end of the third resistor is connected to the other end of the second resistor and has a first node, the other end of the third resistor is connected to the negative end of the busbar of the DC fan busbar loop, and the first node serves as the output end of the voltage detection module; A first capacitor is connected in parallel with the third resistor.

3. The DC fan high voltage protection circuit according to claim 1, characterized in that: The first preset voltage providing unit comprises: a fourth resistor, one end of which is connected to a preset power supply; a fifth resistor and a sixth resistor connected in series, wherein one end of the fifth resistor and the sixth resistor connected in series is connected to one end of the fourth resistor and has a second node, the other end of the fifth resistor and the sixth resistor connected in series is grounded, and the second node serves as an output end of the first preset voltage providing unit; A second capacitor is connected in parallel with the fifth resistor and the sixth resistor connected in series.

4. The DC fan high voltage protection circuit according to claim 1, characterized in that: The first trigger control unit comprises: a seventh resistor, one end of which serves as a control end of the first trigger control unit; a first triode, wherein the base of the first triode is connected to the other end of the seventh resistor, the collector of the first triode serves as the output end of the first trigger control unit, and the emitter of the first triode is connected to a preset power supply; an eighth resistor connected between the base and the emitter of the first transistor; A third capacitor is connected in parallel with the eighth resistor.

5. The DC fan high voltage protection circuit according to claim 4, characterized in that: The second trigger control unit comprises: a ninth resistor, one end of which serves as a control end of the second trigger control unit; a second triode, wherein the base of the second triode is connected to the other end of the ninth resistor, and the emitter of the second triode is grounded; a tenth resistor connected between the base and the emitter of the second transistor; a fourth capacitor, the fourth capacitor being connected in parallel with the tenth resistor; An eleventh resistor, one end of the eleventh resistor is connected to the collector of the second transistor, and the other end of the eleventh resistor serves as the output end of the second trigger control unit.

6. An air conditioning controller, characterized in that: It comprises a DC fan high voltage protection circuit as claimed in any one of claims 1 to 5.

7. An outdoor unit, characterized in that: It comprises a DC fan high voltage protection circuit as claimed in any one of claims 1 to 5.

8. An air conditioner, characterized in that: It comprises a DC fan high voltage protection circuit as claimed in any one of claims 1 to 5.

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