Surge suppression circuit, motor driving device and electric equipment

Abstract

The invention provides a surge suppression circuit, a motor driving device and electric equipment, the surge suppression circuit comprises a capacitor, the first end of the capacitor is connected with a positive bus, and the second end of the capacitor is connected with a negative bus; the switch tube is located on the positive bus or the negative bus; the first end of the driving circuit is connected with the positive bus, the second end of the driving circuit is connected with the negative bus, and the output end of the driving circuit is connected with the control end of the switching tube; wherein the switching tube is used for switching from saturation region conduction to amplification region conduction along with the increase of surge current under the condition that surge exists on the positive bus and / or the negative bus.

Description

Technical Field

[0001] The present invention relates to the field of circuit control technology, and in particular to a surge suppression circuit, a motor drive device and an electrical device. Background Art

[0002] In the related technical solutions, a passive surge suppression circuit or an active surge suppression circuit is used to suppress surges, so as to protect the subsequent circuits of the surge suppression circuit.

[0003] Figure 1 The passive surge suppression circuit diagram in the related technical solution is shown as follows: Figure 1 As shown, it includes a thermistor 102', a varistor 104', a rectifier and filter circuit 106' and an electrolytic capacitor 108'.

[0004] Specifically, the thermistor 102' is used to increase the input impedance of the subsequent circuit, thereby suppressing the current flowing into the subsequent circuit; the varistor 104' is used to limit the subsequent voltage. According to different varistor specifications, the limiting voltage is tens to hundreds of volts. The electrolytic capacitor 108' is used to store surge energy to prevent the energy from flowing to the subsequent stage and damaging the subsequent devices. The above passive surge suppression circuit protects the subsequent circuit by limiting the voltage and current and storing energy.

[0005] Figure 2 The active surge suppression circuit diagram in the related technical solution is shown as follows: Figure 2 As shown, it includes a varistor 104', a rectifier and filter circuit 106' and an active surge suppression circuit 110'.

[0006] However, both the passive surge suppression circuit and the active surge suppression circuit have the problem of excessive surge current, and the above problem makes the surge suppression complex to control, low in reliability and high in cost. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0008] To this end, a first aspect of the present invention is to provide a surge suppression circuit.

[0009] A second aspect of the present invention provides a motor drive device.

[0010] A third aspect of the present invention provides an electrical device.

[0011] In view of this, according to a first aspect of the present invention, the present invention provides a surge suppression circuit, comprising: a capacitor, a first end of the capacitor is connected to the positive bus, and a second end of the capacitor is connected to the negative bus; a switch tube, located on the positive bus or the negative bus; a drive circuit, a first end of the drive circuit is connected to the positive bus, a second end of the drive circuit is connected to the negative bus, and an output end of the drive circuit is connected to a control end of the switch tube; wherein the switch tube is used to switch from being turned on in a saturation region to being turned on in an amplification region when a surge occurs on the positive bus and / or the negative bus, as the surge current increases.

[0012] The technical solution of the present application proposes a surge suppression circuit, which can suppress the surge current while achieving surge suppression, thereby providing protection for circuits or equipment that use surge suppression current, reducing the probability of damage due to excessive surge current, and improving the protective effect of surge suppression.

[0013] The technical solution of the present application is implemented based on the following principles. Specifically, the first end and the second end of the driving circuit are respectively connected to the positive bus and the negative bus. Therefore, when there is a surge on the positive bus and the negative bus, a corresponding voltage can be output through the output end of the driving circuit to adjust the conduction state of the switching tube.

[0014] Specifically, in the absence of a surge, the output terminal of the driving circuit outputs a voltage, causing the switch tube to be turned on and its operating state to be in the saturation region. When a surge occurs, the operating state of the switch tube gradually enters the amplification region from the saturation region. At this stage, the impedance presented by the switch tube increases, and the overall impedance of the surge suppression circuit increases, so that the surge current is reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit is located, thereby ensuring the surge suppression effect.

[0015] In the above technical solution, capacitors are provided so as to utilize the capacitors to store surge energy, thereby reducing voltage fluctuations when the positive bus and the negative bus supply power to the load or the subsequent circuit, thereby ensuring the stability of power supply.

[0016] In one of the technical solutions, the positive bus and the negative bus are two power supply lines arranged and existing in pairs. For example, the positive bus user provides a voltage of a certain voltage value, and the negative bus user provides a ground voltage.

[0017] In one of the technical solutions, the switch tube may be a single switch device, such as MOSFET, IGBT, triode, thyristor, or a switch circuit composed of multiple devices.

[0018] Among them, MOSFET is the abbreviation of Metal-Oxide-Semiconductor Field-Effect Transistor, and its full name is Metal-Oxide Semiconductor Field Effect Transistor, abbreviated as Metal-Oxide-Semiconductor Field-Effect Transistor.

[0019] In one of the technical solutions, IGBT is the abbreviation of Insulated Gate Bipolar Transistor, and its full name is insulated gate bipolar transistor.

[0020] In the above technical solution, the switch circuit composed of multiple devices can be configured according to actual use requirements, which will not be described in detail here.

[0021] In the above technical solution, surge is a transient high voltage or high current. Usually, when an electronic circuit is struck by lightning or when an inductive load is connected or disconnected, a surge voltage and surge current several to dozens of times the rated voltage and current will be generated. This high voltage and high current endangers the safe operation of the equipment, affects the stability of the equipment output, and in most cases will damage the equipment or internal components. Therefore, surge suppression is a key issue to ensure the safe and reliable operation of the equipment.

[0022] In addition, the surge suppression circuit proposed in this application also has the following additional technical features.

[0023] In the above technical solution, when the switch tube is located at the negative bus, the drive circuit includes: a first resistor, a first end of the first resistor is connected to the positive bus; a first voltage regulator diode, a cathode of the first voltage regulator diode is connected to the second end of the first resistor and the control end of the switch tube, and a cathode of the first voltage regulator diode is connected to the negative bus; a second resistor, the second resistor is located between the anode of the first voltage regulator diode and the first end of the switch tube.

[0024] In this technical solution, the topological structure of the driving circuit is refined. In this topological structure, the first resistor and the first voltage zener diode are connected in series between the positive bus and the negative bus. In this case, a loop is formed between the first resistor, the first voltage zener diode, the positive bus and the negative bus. In the absence of a surge, the driving circuit can output a certain voltage value. Since the second resistor is connected to the first end of the switch tube, a voltage value is formed between the control end and the first end of the switch tube. If the voltage value is greater than the on-voltage of the switch tube, the switch tube is in the on state and adjusts its own on-state according to the voltage value.

[0025] In the presence of a surge, as the surge current increases, the current flowing through the second resistor will increase, and correspondingly, the voltage on the second resistor will increase, and the voltage value formed between the control end and the first end of the switch tube will decrease. As the current flowing through the second resistor continues to increase, the voltage value formed between the control end and the first end of the switch tube will continue to decrease. Finally, when the voltage value is less than the on-voltage of the switch tube, the switch tube is in the cut-off state, and the switch tube cuts off the negative bus.

[0026] In this technical solution, when a surge occurs, the working state of the switching tube gradually enters the amplification zone from the saturation zone. At this stage, the impedance presented by the switching tube becomes larger, and the overall impedance of the surge suppression circuit becomes larger, so that the surge current can be reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit is located, thereby ensuring the surge suppression effect.

[0027] In this technical solution, in the absence of a surge, the switch tube is in the on state. At this time, the surge suppression circuit is in a low-resistance state, and its loss is low or negligible, and it can be regarded as a thermistor; in the presence of a surge, the surge suppression circuit automatically adjusts its impedance according to the size of the surge current. When the surge current reaches a certain value, the surge suppression circuit is in a high-resistance state, and the surge energy is completely suppressed, so that the subsequent circuit is protected and operates normally; when the surge disappears, the surge suppression circuit automatically returns to the initial low-resistance state, and the circuit or equipment where the surge suppression circuit is located operates normally and is not affected at all.

[0028] In addition, the voltage on the switching tube will also increase with the increase of surge current, taking on part of the surge voltage, so that the voltage of the capacitor's subsequent circuit does not increase much, thus playing a role in suppressing the surge voltage.

[0029] In any of the above technical solutions, the second resistor can be understood as a current limiting resistor.

[0030] In any of the above technical solutions, the driving circuit further includes: a third resistor, located between the positive electrode of the first voltage stabilizing diode and the negative bus.

[0031] In this technical solution, the third resistor is provided so as to utilize the third resistor to limit the current flowing through the first voltage zener diode, thereby achieving the effect of protecting the first voltage zener diode.

[0032] In any of the above technical solutions, when the switch tube is located at the positive bus, the drive circuit includes: a second voltage zener diode, the cathode of the second voltage zener diode is connected to the positive bus; a fourth resistor, the first end of the fourth resistor is connected to the anode of the second voltage zener diode and the control end of the switch tube, and the second end of the fourth resistor is connected to the negative bus; a fifth resistor, located between the cathode of the second voltage zener diode and the first end of the switch tube.

[0033] In this technical solution, the topological structure of the driving circuit is refined. In this topological structure, the fourth resistor and the second voltage-stabilizing diode are connected in series between the positive bus and the negative bus. In this case, the fourth resistor, the second voltage-stabilizing diode, the positive bus and the negative bus form a loop. In the absence of a surge, the driving circuit can output a certain voltage value. Since the fifth resistor is connected to the first end of the switch tube, a voltage value is formed between the control end and the first end of the switch tube. If the voltage value is greater than the conduction voltage of the switch tube, the switch tube is in the conduction state and adjusts its own conduction state according to the voltage value.

[0034] In the case of a surge, as the surge current increases, the current flowing through the fifth resistor will increase, and correspondingly, the voltage on the fifth resistor will increase, and the voltage value formed between the control end and the first end of the switch tube will decrease. As the current flowing through the fifth resistor continues to increase, the voltage value formed between the control end and the first end of the switch tube will continue to decrease. Finally, when the voltage value is less than the on-voltage of the switch tube, the switch tube is in the cut-off state, and the switch tube cuts off the negative bus.

[0035] In this technical solution, when a surge occurs, the working state of the switching tube gradually enters the amplification region from the saturation region, the impedance presented by the switching tube increases, and the overall impedance of the surge suppression circuit increases, so that the surge current can be reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit is located, thereby ensuring the surge suppression effect.

[0036] In this technical solution, in the absence of a surge, the switch tube is in the on state. At this time, the surge suppression circuit is in a low-resistance state, and its loss is low or negligible, and it can be regarded as a thermistor; in the presence of a surge, the surge suppression circuit automatically adjusts its impedance according to the size of the surge current. When the surge current reaches a certain value, the surge suppression circuit is in a high-resistance state, and the surge energy is completely suppressed, so that the subsequent circuit is protected and operates normally; when the surge disappears, the surge suppression circuit automatically returns to the initial low-resistance state, and the circuit or equipment where the surge suppression circuit is located operates normally and is not affected at all.

[0037] In any of the above technical solutions, the driving circuit includes: a sixth resistor, located between the anode of the second voltage stabilizing diode and the first end of the fourth resistor.

[0038] In this technical solution, the sixth resistor is provided so as to utilize the sixth resistor to limit the current flowing through the second voltage zener diode, thereby achieving the effect of protecting the second voltage zener diode.

[0039] In any of the above technical solutions, the control end of the switch tube is the G pole, and the first end of the switch tube is the S pole. In any of the above technical solutions, the sixth resistor can be understood as a current limiting resistor.

[0040] In any of the above technical solutions, the driving circuit also includes: a transistor, a first end of the transistor is connected to the control end of the switch tube, the control end of the transistor is connected to the first end of the switch tube, when the switch tube is located at the negative bus, the second end of the transistor is connected to the negative bus; when the switch tube is located at the positive bus, the second end of the transistor is connected to the positive bus.

[0041] In this technical solution, a transistor is provided so as to limit the surge current to a certain range by using the transistor, so as to reduce the probability of damage to the circuit where the surge suppression circuit is located or the subsequent circuit due to excessive surge current, thereby ensuring the protection effect.

[0042] Specifically, as the surge current increases, the conduction condition of the transistor is met, the transistor is turned on, and correspondingly, the first end and the second end of the transistor are connected, the voltage difference between the control end and the first end of the switch tube decreases rapidly, and the switch tube is quickly turned off, cutting off the power supply output of the negative bus where it is located.

[0043] After the surge disappears, the transistor does not meet its conduction condition and the transistor is cut off until the transistor is turned on.

[0044] In one of the technical solutions, the transistor can be selected as a P-type transistor or an N-type transistor according to the setting requirements of the surge suppression circuit.

[0045] In any of the above technical solutions, the capacitor is a film capacitor or an electrolytic capacitor.

[0046] In this technical solution, the capacitor is limited to a film capacitor so as to avoid the disadvantage of large electrolytic capacitors having large volume.

[0047] In addition, compared with electrolytic capacitors, film capacitors have the characteristics of long service life and high reliability. They can be used in different DC and AC input scenarios, and are also suitable for different power scenarios ranging from a few watts to tens of kilowatts. They can be used in motor drives, household appliances, communication base stations, energy storage, charging piles and other equipment, broadening the use scenarios of surge suppression circuits.

[0048] In any of the above technical solutions, the surge suppression circuit also includes: a rectifier and filter circuit, the rectifier and filter circuit has a first input terminal and a second input terminal, the first input terminal and the second input terminal are used to connect to the power supply line; the rectifier and filter circuit also has a first output terminal and a second output terminal, the first output terminal is connected to the positive bus, and the second output terminal is connected to the negative bus.

[0049] In this technical solution, a rectifier and filter circuit is provided to filter and rectify the input side power supply signal, thereby supplying power to the positive bus and the negative bus.

[0050] In the above technical solution, when the power supply line is a DC power supply line, the rectifier and filter circuit is used to realize DC-to-DC voltage conversion and filter out voltage interference in the power supply output to the positive bus and the negative bus after conversion.

[0051] In the above technical solution, when the power supply line is an AC power supply line, the rectifier and filter circuit is used to realize the voltage conversion of AC to DC and filter the voltage interference in the power supply output to the positive bus and the negative bus after the conversion.

[0052] In the above technical solution, the rectifier and filter circuit can be selected according to actual use needs, and will not be described in detail here.

[0053] In any of the above technical solutions, the surge suppression circuit also includes: a first varistor, a first end of the first varistor is connected to the first input end, and a second end of the first varistor is connected to the second input end; and / or a second varistor, a first end of the second varistor is connected to the first output end, and a second end of the second varistor is connected to the second output end.

[0054] In this technical solution, a first varistor and / or a second varistor is provided so that the voltage amplitude of the power supply input to the rectifier and filter circuit and / or output from the rectifier and filter circuit can be limited by the first varistor and / or the second varistor, so as to reduce the probability of damage to the circuit located at the rear stage of the surge suppression circuit due to excessive voltage amplitude, thereby ensuring the effect of surge suppression.

[0055] In any of the above technical solutions, the surge suppression circuit further includes: a thermistor located at the first input end and / or the second input end.

[0056] In this technical solution, a thermistor is provided so as to utilize the thermistor to limit the magnitude of the current flowing into the rectifier and filter circuit, thereby achieving the effect of suppressing surges.

[0057] In one of the technical solutions, the thermistor is a resistor with a very large negative temperature coefficient.

[0058] According to a second aspect of the present invention, the present invention provides a motor drive device, comprising: a surge suppression circuit as described in any one of the above.

[0059] According to a third aspect of the present invention, the present invention provides an electrical device, comprising: a surge suppression circuit as described in any one of the above.

[0060] In the above technical solution, the electrical equipment includes one of the following: household electrical appliances, switching power supplies, energy storage equipment, and charging equipment.

[0061] In this technical solution, the household appliance may be a refrigerator, a washing machine, a water heater, an air conditioner, or a microwave oven.

[0062] In this technical solution, the energy storage device may be a power conversion system (PCS), which can control the charging and discharging process of the battery, perform AC / DC conversion, and directly supply power to AC loads when there is no power grid.

[0063] In the above technical solution, the charging device may be a charging pile or a charging vehicle.

[0064] 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

[0065] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0066] Figure 1 A passive surge suppression circuit diagram in a related technical solution is shown;

[0067] Figure 2 An active surge suppression circuit diagram in a related technical solution is shown;

[0068] Figure 3 A topological schematic diagram of a surge suppression circuit in an embodiment of the present invention is shown;

[0069] Figure 4 A topological schematic diagram of another surge suppression circuit in an embodiment of the present invention is shown;

[0070] Figure 5 A topological schematic diagram of another surge suppression circuit in an embodiment of the present invention is shown.

[0071] in, Figure 1 and Figure 2 The corresponding relationship between the reference numerals and the component names is as follows:

[0072] 102' thermistor, 104' varistor, 106' rectifier filter circuit, 108' electrolytic capacitor, 110' active surge suppression circuit.

[0073] in, Figures 3 to 5 The corresponding relationship between the reference numerals and the component names is as follows:

[0074] 100 surge suppression circuit, 200 positive bus, 300 negative bus, C capacitor, Q1 switch tube, 102 drive circuit, R1 first resistor, DZ1 first voltage-sensitive diode, R2 second resistor, R3 third resistor, DZ2 second voltage-sensitive diode, R4 fourth resistor, R5 fifth resistor, R6 sixth resistor, Q2 transistor, 104 rectifier and filter circuit, MOV1 first varistor, MOV2 second varistor, NTC thermistor. DETAILED DESCRIPTION

[0075] In order to more clearly understand the above aspects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0076] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0077] In one embodiment of the present application, Figure 3 , Figure 4 and Figure 5 As shown, a surge suppression circuit 100 is provided, including: a capacitor C, a first end of the capacitor C is connected to the positive bus 200, and a second end of the capacitor C is connected to the negative bus 300; a switch tube Q1, located on the positive bus 200 or the negative bus 300; a drive circuit 102, a first end of the drive circuit 102 is connected to the positive bus 200, a second end of the drive circuit 102 is connected to the negative bus 300, and an output end of the drive circuit 102 is connected to a control end of the switch tube Q1; wherein the switch tube Q1 is used to switch from being turned on in a saturation region to being turned on in an amplification region as the surge current increases when a surge exists on the positive bus 200 and / or the negative bus 300.

[0078] The embodiment of the present application proposes a surge suppression circuit 100, which can suppress the surge current while achieving surge suppression, thereby providing protection for circuits or devices that use surge suppression current, reducing the probability of damage due to excessive surge current, and improving the protective effect of surge suppression.

[0079] The embodiments of the present application are implemented based on the following principles. Specifically, the first end and the second end of the drive circuit 102 are respectively connected to the positive bus 200 and the negative bus 300. Therefore, when there is a surge on the positive bus 200 and the negative bus 300, a corresponding voltage can be output through the output end of the drive circuit 102 to adjust the conduction state of the switch tube Q1.

[0080] Specifically, in the absence of a surge, the output terminal of the driving circuit 102 outputs a voltage, so that the switch tube Q1 is turned on, and its working state is in the saturation region. When a surge occurs, the working state of the switch tube Q1 gradually enters the amplification region from the saturation region. In this stage, the impedance presented by the switch tube Q1 becomes larger, and the overall impedance of the surge suppression circuit becomes larger, so that the surge current can be reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit 100 is located, thereby ensuring the surge suppression effect.

[0081] In the above embodiment, the capacitor C is provided so as to utilize the capacitor C to store surge energy, thereby reducing voltage fluctuation when the positive bus 200 and the negative bus 300 supply power to the load or the subsequent circuit, thereby ensuring the stability of power supply.

[0082] In one embodiment, the positive bus 200 and the negative bus 300 are two power supply lines arranged and existing in pairs. For example, the positive bus 200 provides a voltage of a certain voltage value, and the negative bus 300 provides a ground voltage.

[0083] In one embodiment, the switch tube Q1 can be a single switch device, such as MOSFET, IGBT, transistor Q2, thyristor, or a switch circuit composed of multiple devices.

[0084] Among them, MOSFET is the abbreviation of Metal-Oxide-Semiconductor Field-Effect Transistor, and its full name is Metal-Oxide Semiconductor Field Effect Transistor, abbreviated as Metal-Oxide-Semiconductor Field-Effect Transistor.

[0085] In one embodiment, IGBT is the abbreviation of Insulated Gate Bipolar Transistor, which is the full name of Insulated Gate Bipolar Transistor.

[0086] In the above embodiments, the switch circuit composed of multiple devices can be configured according to actual use requirements, which will not be described in detail here.

[0087] In the above embodiments, surge is a transient high voltage or high current. Usually, when an electronic circuit is struck by lightning or when an inductive load is connected or disconnected, a surge voltage or current several to dozens of times the rated voltage or current will be generated. This high voltage and high current endangers the safe operation of the equipment, affects the stability of the equipment output, and in most cases damages the equipment or internal components. Therefore, surge suppression is a key issue to ensure the safe and reliable operation of the equipment.

[0088] In the above embodiment, when the switch tube Q1 is located at the negative bus 300, the drive circuit 102 includes: a first resistor R1, a first end of the first resistor R1 is connected to the positive bus 200; a first voltage regulator diode DZ1, a cathode of the first voltage regulator diode DZ1 is connected to the second end of the first resistor R1 and the control end of the switch tube Q1; an anode of the first voltage regulator diode DZ1 is connected to the negative bus 300; and a second resistor R2, the second resistor R2 is located between the anode of the first voltage regulator diode DZ1 and the first end of the switch tube Q1.

[0089] In this embodiment, the topological structure of the driving circuit 102 is refined. In this topological structure, the first resistor R1 and the first voltage zener diode DZ1 are connected in series between the positive bus 200 and the negative bus 300. In this case, a loop is formed between the first resistor R1, the first voltage zener diode DZ1, the positive bus 200, and the negative bus 300. In the absence of a surge, the driving circuit 102 can output a certain voltage value. Since the second resistor R2 is connected to the first end of the switch tube Q1, a voltage value is formed between the control end and the first end of the switch tube Q1. If the voltage value is greater than the conduction voltage of the switch tube Q1, the switch tube Q1 is in a conduction state and adjusts its own conduction state according to the voltage value.

[0090] In the presence of a surge, as the surge current increases, the current flowing through the second resistor R2 will increase, and correspondingly, the voltage on the second resistor R2 will increase, and the voltage value formed between the control end and the first end of the switch tube Q1 will decrease. As the current flowing through the second resistor R2 continues to increase, the voltage value formed between the control end and the first end of the switch tube Q1 will continue to decrease. Finally, when the voltage value is less than the turn-on voltage of the switch tube Q1, the switch tube Q1 is in the cut-off state, and the switch tube Q1 cuts off the negative bus 300.

[0091] In this embodiment, when a surge occurs, the working state of the switch tube Q1 gradually enters the amplification region from the saturation region. In this stage, the impedance presented by the switch tube Q1 becomes larger, and the overall impedance of the surge suppression circuit becomes larger, so that the surge current can be reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit 100 is located, thereby ensuring the surge suppression effect.

[0092] In this embodiment, in the absence of a surge, the switch tube Q1 is in an on state. At this time, the surge suppression circuit 100 is in a low-resistance state, and its loss is low or negligible, and it can be regarded as a thermistor; in the presence of a surge, the surge suppression circuit 100 automatically adjusts its impedance according to the size of the surge current. When the surge current reaches a certain value, the surge suppression circuit 100 is in a high-resistance state, and the surge energy is completely suppressed, so that the subsequent circuit is protected and operates normally; when the surge disappears, the surge suppression circuit 100 automatically restores to the initial low-resistance state, and the circuit or equipment where the surge suppression circuit 100 is located operates normally and is not affected at all.

[0093] In addition, the voltage on the switch tube Q1 will also increase with the increase of surge current, taking on part of the surge voltage, so that the voltage of the subsequent circuit of the capacitor C does not increase much, thus playing a role in suppressing the surge voltage.

[0094] In any of the above embodiments, the second resistor R2 can be understood as a current limiting resistor.

[0095] In the above technical solution, the driving circuit 102 further includes: a third resistor R3 located between the positive electrode of the first voltage stabilizing diode DZ1 and the negative bus 300 .

[0096] In this technical solution, the third resistor R3 is provided so as to utilize the third resistor R3 to limit the current flowing through the first Zener diode DZ1 , thereby achieving the effect of protecting the first Zener diode DZ1 .

[0097] Specifically, the driving voltage VD of the switch tube Q1 is expressed as follows:

[0098] VD=(Vin×R3+Vz×R1) / (R1+R3)-VR3, wherein Vz is the voltage stabilization value of the first voltage stabilizing diode DZ1, VR3 is the voltage on the second resistor R2, and Vin is the voltage difference between the positive bus and the negative bus.

[0099] In normal operation, VD is around 10V-15V, and the switch tube Q1 is saturated and turned on.

[0100] When a surge occurs, VR3 increases, that is, VD decreases, and the switch tube Q1 gradually enters the amplification area from the saturation area, that is, the voltage on the switch tube Q1 gradually increases. When the surge current reaches a certain value and makes VD close to 0V, the switch tube Q1 is cut off, which plays a role in suppressing the surge current; at the same time, because the voltage on the switch tube Q1 will also increase with the increase of the surge current, it bears part of the surge voltage, so that the voltage of Vo (Vo+ and Vo-) does not increase much, which plays a role in suppressing the surge voltage.

[0101] In one of the technical solutions, when the driving circuit 102 does not include the third resistor R3, the above VD can be transformed into Vz-VR3.

[0102] In any of the above embodiments, when the switch tube Q1 is located at the positive bus 200, the drive circuit 102 includes: a second voltage zener diode DZ2, the cathode of the second voltage zener diode DZ2 is connected to the positive bus 200; a fourth resistor R4, the first end of the fourth resistor R4 is connected to the anode of the second voltage zener diode DZ2 and the control end of the switch tube Q1, and the second end of the fourth resistor R4 is connected to the negative bus 300; a fifth resistor R5, located between the cathode of the second voltage zener diode DZ2 and the first end of the switch tube Q1.

[0103] In this embodiment, the topological structure of the driving circuit 102 is refined. In this topological structure, the fourth resistor R4 and the second voltage zener diode DZ2 are connected in series between the positive bus 200 and the negative bus 300. In this case, the fourth resistor R4 and the second voltage zener diode DZ2 form a loop with the positive bus 200 and the negative bus 300. In the absence of a surge, the driving circuit 102 can output a certain voltage value. Since the sixth resistor R6 is connected to the first end of the switch tube Q1, a voltage value is formed between the control end and the first end of the switch tube Q1. If the voltage value is greater than the conduction voltage of the switch tube Q1, the switch tube Q1 is in a conduction state and adjusts its own conduction state according to the voltage value.

[0104] In the presence of a surge, as the surge current increases, the current flowing through the fifth resistor R5 will increase, and correspondingly, the voltage on the fifth resistor R5 will increase, and the voltage value formed between the control end and the first end of the switch tube Q1 will decrease. As the current flowing through the fifth resistor R5 continues to increase, the voltage value formed between the control end and the first end of the switch tube Q1 will continue to decrease. Finally, when the voltage value is less than the turn-on voltage of the switch tube Q1, the switch tube Q1 is in the cut-off state, and the switch tube Q1 cuts off the negative bus 300.

[0105] In this embodiment, when a surge occurs, the working state of the switch tube Q1 gradually enters the amplification region from the saturation region, the impedance presented by the switch tube Q1 increases, and the overall impedance of the surge suppression circuit increases, so that the surge current can be reduced, reducing the damage of the surge to the circuit or equipment where the surge suppression circuit 100 is located, thereby ensuring the surge suppression effect.

[0106] In this embodiment, in the absence of a surge, the switch tube Q1 is in an on state. At this time, the surge suppression circuit 100 is in a low-resistance state, and its loss is low or negligible, and it can be regarded as a thermistor; in the presence of a surge, the surge suppression circuit 100 automatically adjusts its impedance according to the size of the surge current. When the surge current reaches a certain value, the surge suppression circuit 100 is in a high-resistance state, and the surge energy is completely suppressed, so that the subsequent circuit is protected and operates normally; when the surge disappears, the surge suppression circuit 100 automatically restores to the initial low-resistance state, and the circuit or equipment where the surge suppression circuit 100 is located operates normally and is not affected at all.

[0107] In any of the above technical solutions, the driving circuit 102 includes: a sixth resistor R6 located between the anode of the second voltage zener diode DZ2 and the first end of the fourth resistor R4.

[0108] In this technical solution, the sixth resistor R6 is provided so as to utilize the sixth resistor R6 to limit the current flowing through the second voltage zener diode DZ2, thereby achieving the effect of protecting the second voltage zener diode DZ2.

[0109] In any of the above embodiments, the control end of the switch tube Q1 is the G pole, and the first end of the switch tube Q1 is the S pole. In any of the above embodiments, the sixth resistor R6 can be understood as a current limiting resistor.

[0110] In any of the above embodiments, the driving circuit 102 also includes: a transistor Q2, a first end of the transistor Q2 is connected to the control end of the switch tube Q1, the control end of the transistor Q2 is connected to the first end of the switch tube Q1, and when the switch tube Q1 is located at the negative bus 300, the second end of the transistor Q2 is connected to the negative bus; when the switch tube Q1 is located at the positive bus 200, the second end of the transistor Q2 is connected to the positive bus.

[0111] In this embodiment, transistor Q2 is provided so as to limit the surge current to a certain range by using transistor Q2, so as to reduce the probability of damage to the circuit where the surge suppression circuit 100 is located or the subsequent circuit due to excessive surge current, thereby ensuring the protection effect.

[0112] Specifically, as the surge current increases, the conduction condition of the transistor Q2 is met, and the transistor Q2 is turned on. Correspondingly, the first end and the second end of the transistor Q2 are connected, and the voltage difference between the control end and the first end of the switch tube Q1 decreases rapidly, and the switch tube Q1 is quickly turned off, cutting off the power supply output of the negative bus 300 where it is located.

[0113] After the surge disappears, the transistor Q2 does not meet its conduction condition, and the transistor Q2 is cut off until the transistor Q2 is turned on.

[0114] In one embodiment, the transistor Q2 can be selected as a P-type transistor or an N-type transistor according to the configuration requirements of the surge suppression circuit 100 .

[0115] Specifically, transistor Q2 keeps the surge suppression current at U2 / R3, where U2 is the PN junction voltage of transistor Q2.

[0116] In any of the above embodiments, the capacitor C is a film capacitor or an electrolytic capacitor.

[0117] In this embodiment, the capacitor C is limited to a film capacitor in order to avoid the disadvantage of large electrolytic capacitors having a large volume.

[0118] In addition, compared with electrolytic capacitors, film capacitors have the characteristics of long service life and high reliability. They can be applied to different DC and AC input scenarios, and are also suitable for different power scenarios ranging from a few watts to tens of kilowatts. They can be used in motor drives, household appliances, communication base stations, energy storage, charging piles and other equipment, broadening the use scenarios of surge suppression circuit 100.

[0119] In any of the above embodiments, the surge suppression circuit 100 also includes: a rectifier and filter circuit 104, the rectifier and filter circuit 104 has a first input terminal Vin+ and a second input terminal Vin-, the first input terminal and the second input terminal are used to connect to the power supply line; the rectifier and filter circuit 104 also has a first output terminal and a second output terminal, the first output terminal is connected to the positive bus 200, and the second output terminal is connected to the negative bus 300.

[0120] In this embodiment, a rectifier and filter circuit 104 is provided to filter and rectify the input-side power supply signal, thereby supplying power to the positive bus 200 and the negative bus 300 .

[0121] In the above embodiment, when the power supply line is a DC power supply line, the rectifier filter circuit 104 is used to realize DC-to-DC voltage conversion and filter the voltage interference in the power supply output to the positive bus 200 and the negative bus 300 after the conversion.

[0122] In the above embodiment, when the power supply line is an AC power supply line, the rectifier filter circuit 104 is used to realize the voltage conversion of AC to DC and filter the voltage interference in the power supply output to the positive bus 200 and the negative bus 300 after the conversion.

[0123] In the above embodiment, the rectifier and filter circuit 104 can be selected according to actual use requirements, and will not be described in detail here.

[0124] In any of the above embodiments, the surge suppression circuit 100 also includes: a first varistor MOV1, a first end of the first varistor MOV1 is connected to the first input end, and a second end of the first varistor MOV1 is connected to the second input end; and / or a second varistor MOV2, a first end of the second varistor MOV2 is connected to the first output end, and a second end of the second varistor MOV2 is connected to the second output end.

[0125] In this embodiment, the first varistor MOV1 and / or the second varistor MOV2 are provided so that the voltage amplitude of the power supply input to the rectifier and filter circuit 104 and / or output from the rectifier and filter circuit 104 can be limited by the first varistor MOV1 and / or the second varistor MOV2, so as to reduce the probability of damage to the circuit at the rear stage of the surge suppression circuit 100 due to excessive voltage amplitude, thereby ensuring the effect of surge suppression.

[0126] In any of the above embodiments, the surge suppression circuit 100 further includes: a temperature-sensitive resistor NTC, located at the first input end and / or the second input end.

[0127] In this embodiment, a temperature-sensitive resistor NTC is provided so as to utilize the temperature-sensitive resistor NTC to limit the magnitude of the current flowing into the rectifier filter circuit 104 , thereby achieving the effect of suppressing surge.

[0128] In one embodiment, the NTC temperature sensitive resistor is a resistor with a large negative temperature coefficient.

[0129] In one embodiment, the present invention provides a motor drive device, comprising: a surge suppression circuit as described in any one of the above.

[0130] In one embodiment, the present invention provides an electrical device, including: a surge suppression circuit as described in any one of the above.

[0131] In the above embodiments, the electrical device includes one of the following: household electrical appliances, switching power supplies, energy storage devices, and charging devices.

[0132] In this embodiment, the household appliance may be a refrigerator, a washing machine, a water heater, an air conditioner, or a microwave oven.

[0133] In this embodiment, the energy storage device may be a power conversion system (PCS), wherein the energy storage converter can control the charging and discharging process of the battery, perform AC / DC conversion, and directly supply power to AC loads when there is no power grid.

[0134] In the above embodiments, the charging device may be a charging pile or a charging vehicle.

[0135] The term "first" or "second" in the specification and claims of the present application may include one or more of the features explicitly or implicitly. In the textual description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0136] In the claims, specification and drawings of the present invention, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings, which is only for the purpose of more conveniently describing the present invention and making the description process simpler, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation, so these descriptions cannot be understood as limiting the present invention; the terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood based on the specific circumstances of the above data.

[0137] In the claims, specification and drawings of the present invention, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like 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 the claims, specification and drawings of the present invention, the schematic representations of the above terms do 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.

[0138] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A surge suppression circuit, characterized in that: include: A capacitor, wherein a first end of the capacitor is connected to the positive bus, and a second end of the capacitor is connected to the negative bus; A switch tube is located on the positive bus or the negative bus; A drive circuit, wherein a first end of the drive circuit is connected to the positive bus, a second end of the drive circuit is connected to the negative bus, and an output end of the drive circuit is connected to a control end of the switch tube; Wherein, the switch tube is used for switching from being on in a saturation region to being on in an amplification region as the current of the surge increases when a surge exists on the positive bus and / or the negative bus.

2. The surge suppression circuit according to claim 1, characterized in that: When the switch tube is located at the negative bus, the drive circuit includes: a first resistor, wherein a first end of the first resistor is connected to the positive bus; a first voltage stabilizing diode, wherein a cathode of the first voltage stabilizing diode is connected to the second end of the first resistor and the control end of the switch tube, and an anode of the first voltage stabilizing diode is connected to the negative bus; A second resistor, wherein the second resistor is located between the anode of the first voltage regulator diode and the first end of the switch tube.

3. The surge suppression circuit according to claim 2, characterized in that: The driving circuit further includes: The third resistor is located between the positive electrode of the first voltage stabilizing diode and the negative bus.

4. The surge suppression circuit according to claim 1, characterized in that: When the switch tube is located at the positive bus, the drive circuit includes: A second voltage stabilizing diode, wherein a cathode of the second voltage stabilizing diode is connected to the positive bus; a fourth resistor, wherein a first end of the fourth resistor is connected to the anode of the second voltage stabilizing diode and the control end of the switch tube, and a second end of the fourth resistor is connected to the negative bus; The fifth resistor is located between the cathode of the second voltage stabilizing diode and the first end of the switch tube.

5. The surge suppression circuit according to claim 4, characterized in that: The driving circuit comprises: The sixth resistor is located between the anode of the second voltage stabilizing diode and the first end of the fourth resistor.

6. The surge suppression circuit according to claim 1, characterized in that: The driving circuit further includes: A triode, wherein the first end of the triode is connected to the control end of the switch tube, and the control end of the triode is connected to the first end of the switch tube; When the switch tube is located at the negative bus, the second end of the transistor is connected to the negative bus; When the switch tube is located at the positive bus, the second end of the transistor is connected to the positive bus.

7. The surge suppression circuit according to any one of claims 1 to 6, characterized in that: The surge suppression circuit further includes: A rectifier and filter circuit, wherein the rectifier and filter circuit has a first input end and a second input end, wherein the first input end and the second input end are used to connect to a power supply line; The rectifier and filter circuit also has a first output terminal and a second output terminal, wherein the first output terminal is connected to the positive bus, and the second output terminal is connected to the negative bus.

8. The surge suppression circuit according to claim 7, characterized in that: The surge suppression circuit further includes: a first varistor, wherein a first end of the first varistor is connected to the first input end, and a second end of the first varistor is connected to the second input end; and / or A second varistor, wherein a first end of the second varistor is connected to the first output end, and a second end of the second varistor is connected to the second output end.

9. The surge suppression circuit according to claim 7, characterized in that: The surge suppression circuit further includes: A temperature-sensitive resistor is located at the first input end and / or the second input end.

10. A motor drive device, characterized in that: include: A surge suppression circuit as claimed in any one of claims 1 to 9.

11. An electrical device, characterized in that: include: A surge suppression circuit as claimed in any one of claims 1 to 9.

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