Driving control circuit and intelligent device

Abstract

The utility model discloses a drive control circuit and an intelligent device. The drive control circuit comprises a rectification unit and a bus capacitor connected with the rectification unit. The sampling unit is connected with the rectifying unit, and the sampling unit is used for collecting an output signal of the rectifying unit and generating a sampling signal; the main control unit is used for outputting a low-level signal; and the soft start unit is respectively connected with the sampling unit, the main control unit and the bus capacitor, and the soft start unit is used for switching on and off according to the sampling signal and the low level signal. When the drive control circuit is temporarily interrupted, the sampling unit outputs a low-level sampling signal to the soft start unit, and the main control unit outputs a low-level signal to the soft start unit, so that the soft start unit cannot be immediately conducted when being electrified again, the charging current in the drive control circuit is reduced, and the service life of the drive control circuit is prolonged. Therefore, the condition that components in the driving control circuit are damaged due to overlarge charging current is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, and in particular to a drive control circuit and an intelligent device. Background Art

[0002] Existing drive control circuits such as Figure 1 As shown, the AC voltage is rectified into DC power by the rectifier unit and stored in the bus capacitor. The DC power is then inverted into three-phase AC power by the three-phase inverter unit and applied to the three-phase winding of the motor, thereby realizing variable frequency control of the motor.

[0003] In order to prevent excessive charging current from damaging devices during power-on, a charging resistor R1′ is usually provided between the bus capacitor and the rectifier unit. The two ends of the charging resistor R1′ are respectively connected to the two contact pins of the charging relay KA′. One of the coil pins of the charging relay KA′ is respectively connected to the first end of the pull-up resistor R2′ and the collector of the switch tube G1′. The gate of the switch tube G1′ is connected to the main control chip, and the emitter of the switch tube G1′ is grounded. The second end of the pull-up resistor R2′ and the other coil pin of the charging relay KA′ are respectively connected to the VCC pin.

[0004] In this way, when the bus voltage is greater than the first set value, the main control chip will input a high-level signal to the base of the switch tube G1′. At this time, the switch tube G1′ is turned on, the voltage of the collector of the switch tube G1′ is low, the coil of the charging relay KA′ is energized, the normally open contact is closed, and the charging resistor R1′ is bypassed, thereby reducing power loss during operation.

[0005] When the bus voltage is lower than the second set value, the main control chip will input a low-level signal to the base of the switch tube G1′. At this time, the switch tube G1′ is disconnected, the collector of the switch tube G1′ is high, the coil of the charging relay KA′ is de-energized, and the contacts are disconnected, thereby preventing the charging current from being too large when the voltage recovers.

[0006] However, in most cases, in order to reduce false alarm protection, the second set value is set to a small value. If the voltage flash is not long enough, the charging relay KA' will not be disconnected in time before the power is restored, which will also cause excessive charging current to damage components. Utility Model Content

[0007] The utility model provides a drive control circuit and an intelligent device, which are used to solve the problem in the prior art that the drive control circuit is immediately turned on when it is powered on again after a short interruption, resulting in excessive current and damage to components.

[0008] The technical solution of the utility model is a drive control circuit, comprising a rectifier unit and a bus capacitor connected to the rectifier unit; and further comprising:

[0009] a sampling unit connected to the rectifier unit, the sampling unit being configured to collect an output signal of the rectifier unit and generate a sampling signal;

[0010] The main control unit is used to output a low-level signal;

[0011] A soft start unit is connected to the sampling unit, the main control unit and the bus capacitor respectively, and the soft start unit is used to switch on and off according to the sampling signal and the low-level signal.

[0012] Furthermore, the soft start unit includes a first charging resistor, a charging relay, a first switch tube, a second switch tube, a second resistor and a third resistor;

[0013] The first end of the first charging resistor and the common contact of the charging relay are both connected to the first input end of the sampling unit, and the second end of the first charging resistor and the normally closed contact of the charging relay are both connected to the positive electrode of the bus capacitor; the first coil pin of the charging relay is respectively connected to the collector of the first switching tube and the first end of the third resistor, the gate of the first switching tube is connected to the output end of the main control unit, the emitter of the first switching tube is respectively connected to the first end of the second resistor and the collector of the second switching tube, and the gate of the second switching tube is connected to the second input end of the sampling unit;

[0014] The second end of the second resistor and the second end of the third resistor are both used to connect to the VCC pin, and the first coil pin of the charging relay is used to connect to the VCC pin; the emitter of the second switch tube is grounded.

[0015] Furthermore, the sampling unit includes a fourth resistor and a fifth resistor;

[0016] The first end of the fourth resistor is connected to the first end of the first charging resistor, the second end of the fourth resistor and the first end of the fifth resistor are both connected to the gate of the second switch tube, and the second end of the fifth resistor is grounded.

[0017] Furthermore, the fourth resistor and the fifth resistor are both provided in plurality, and the plurality of the fourth resistors and the plurality of the fifth resistors are respectively connected in series.

[0018] Furthermore, when the sampling unit continuously outputs the sampling signal to the soft start unit, the first switch tube and the second switch tube are turned on, and the charging relay is closed;

[0019] When the sampling signal is briefly interrupted, the first switch tube and the second switch tube are disconnected, and the charging relay is disconnected.

[0020] Furthermore, the first switching tube and the second switching tube are both any one of an insulated gate bipolar transistor, a field effect transistor, a bipolar transistor and a thyristor.

[0021] Furthermore, there are multiple first charging resistors, and the multiple first charging resistors are connected in series.

[0022] Furthermore, the rectifier unit includes a first bridge arm and a second bridge arm each consisting of two rectifier diodes;

[0023] The midpoint of the first bridge arm and the midpoint of the second bridge arm are both used to connect to the AC power grid; one end of the first bridge arm and one end of the second bridge arm are both connected to the input end of the soft start unit, and the other end of the first bridge arm and the other end of the second bridge arm are both connected to the negative electrode of the bus capacitor.

[0024] Furthermore, the drive control circuit further includes an inverter unit, and the inverter unit includes a third bridge arm, a fourth bridge arm, and a fifth bridge arm each consisting of two switch tubes;

[0025] The midpoint of the third bridge arm, the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm are respectively used to connect to the motor; the two ends of the third bridge arm, the two ends of the fourth bridge arm and the two ends of the fifth bridge arm are respectively connected to the two ends of the bus capacitor.

[0026] The present utility model also provides an intelligent device, comprising a frequency converter, wherein the frequency converter comprises the drive control circuit described above.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] When a short interruption occurs in the drive control circuit of the present invention, the sampling unit outputs a low-level sampling signal to the soft start unit, and the main control unit outputs a low-level signal to the soft start unit, so that the soft start unit cannot be turned on immediately when it is powered on again, thereby reducing the charging current in the drive control circuit to prevent the charging current from being too large and damaging the components in the drive control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains; the terms used in the specification of the application are intended only to describe specific embodiments and are not intended to limit this invention; the terms "including" and "having," as well as any variations thereof, in the specification and claims of this invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the specification and claims of this invention and the accompanying drawings are used to distinguish between different objects, not to describe a specific order.

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A circuit diagram of an existing drive control circuit in the background art;

[0032] Figure 2 This is a module block diagram of the drive control circuit proposed in the present utility model;

[0033] Figure 3 This is a circuit diagram of a drive control circuit proposed by the utility model;

[0034] Figure 4 This is a circuit diagram of another drive control circuit proposed by the utility model.

[0035] Reference numerals:

[0036] 10. Rectifier unit;

[0037] 20. Sampling unit;

[0038] 30. Main control unit;

[0039] 40. Soft start unit;

[0040] 50. Inverter unit;

[0041] 60. Motor. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly stated. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0043] The principle and structure of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0044] Example 1

[0045] Existing drive control circuits such as Figure 1 As shown, the AC voltage is rectified into DC power by the rectifier unit and stored in the bus capacitor. The DC power is then inverted into three-phase AC power by the three-phase inverter unit and applied to the three-phase winding of the motor, thereby realizing variable frequency control of the motor.

[0046] In order to prevent excessive charging current from damaging devices during power-on, a charging resistor R1′ is usually provided between the bus capacitor and the rectifier unit. The two ends of the charging resistor R1′ are respectively connected to the two contact pins of the charging relay KA′. One of the coil pins of the charging relay KA′ is respectively connected to the first end of the pull-up resistor R2′ and the collector of the switch tube G1′. The gate of the switch tube G1′ is connected to the main control chip, and the emitter of the switch tube G1′ is grounded. The second end of the pull-up resistor R2′ and the other coil pin of the charging relay KA′ are respectively connected to the VCC pin.

[0047] In this way, when the bus voltage is greater than the first set value, the main control chip will input a high-level signal to the base of the switch tube G1′. At this time, the switch tube G1′ is turned on, the voltage of the collector of the switch tube G1′ is low, the charging relay KA′ is energized, and the charging resistor R1′ is bypassed, thereby reducing power loss during operation.

[0048] When the bus voltage is lower than the second set value, the main control chip will input a low-level signal to the base of the switch tube G1′. At this time, the switch tube G1′ is disconnected, the collector of the switch tube G1′ is high, and the charging relay KA′ is disconnected, thereby preventing the charging current from being too large when the voltage recovers.

[0049] However, in most cases, in order to reduce false alarm protection, the second set value is set to a small value. If the voltage interruption is not long enough, the charging relay KA' will not be disconnected before the power is restored, which will also cause excessive charging current to damage components.

[0050] Therefore, in order to solve the above problems, refer to the attached Figure 2 The present invention provides a drive control circuit, comprising a rectifier unit 10 and a bus capacitor C connected to the rectifier unit 10; and further comprising:

[0051] a sampling unit 20 connected to the rectifier unit 10, the sampling unit 20 being configured to collect an output signal of the rectifier unit 10 and generate a sampling signal;

[0052] The main control unit 30 is used to output a low-level signal;

[0053] The soft start unit 40 is connected to the sampling unit 20 , the main control unit 30 and the bus capacitor C respectively. The soft start unit 40 is used to switch on and off according to the sampling signal and the low-level signal.

[0054] It should be noted that the output signal of the rectifier unit 10 in this embodiment is preferably an output voltage; the sampling unit 20 is used to monitor the output voltage of the rectifier unit 10 and generate a corresponding sampling signal. Preferably, the sampling signal generated by the sampling unit 20 is a high-level signal, which is used to control the on-off state of the subsequent circuit.

[0055] Among them, when the output voltage of the rectifier unit 10 is output normally, the sampling unit 20 will generate a high-level sampling signal according to the output voltage and output it to the soft start unit 40. At this time, the main control unit 30 will output a high-level signal to the soft start unit 40 after the bus voltage of the bus capacitor C reaches the first preset voltage, and the soft start unit 40 will be turned on after receiving the sampling signal and the high-level signal, thereby reducing the power loss during the operation of the drive control circuit; if the output voltage of the rectifier unit 10 is briefly interrupted, the sampling unit 20 will generate a low-level sampling signal and output it to the soft start unit 40. The main control unit 30 outputs a low-level signal to the soft start unit 40, so that the soft start unit 40 cannot be turned on immediately when it is powered on again, reducing the charging current in the drive control circuit to prevent the charging current from being too large to damage the components in the drive control circuit.

[0056] Among them, refer to the attached Figure 3 , the utility model proposes a circuit structure of a soft start unit 40:

[0057] The soft start unit 40 includes a first charging resistor R1, a charging relay KA, a first switch tube G1, a second switch tube G2, a second resistor R2 and a third resistor R3;

[0058] The first end of the first charging resistor R1 and the common contact of the charging relay KA are both connected to the first input end of the sampling unit 20, and the second end of the first charging resistor R1 and the normally closed contact of the charging relay KA are both connected to the positive electrode of the bus capacitor C; the first coil pin of the charging relay KA is respectively connected to the collector of the first switching transistor G1 and the first end of the third resistor R3, the gate of the first switching transistor G1 is connected to the output end of the main control unit 30, the emitter of the first switching transistor G1 is respectively connected to the first end of the second resistor R2 and the collector of the second switching transistor G2, and the gate of the second switching transistor G2 is connected to the second input end of the sampling unit 20;

[0059] The second end of the second resistor R2 and the second end of the third resistor R3 are both used to connect to the VCC1 pin, and the first coil pin of the charging relay KA is used to connect to the VCC pin; the emitter of the second switch tube G2 is grounded.

[0060] It should be noted that the VCC1 pin and the VCC pin in this embodiment are both power supply pins, and are both used to provide operating voltage for the drive control circuit.

[0061] The second resistor R2 and the third resistor R3 are both pull-up resistors. The second resistor R2 can ensure that when the second switch tube G2 is turned on, the emitter and collector of the second switch tube G2 are at the same voltage level. Similarly, the third resistor R3 can ensure that when the first switch tube G1 is turned on, the emitter and collector of the first switch tube G1 are at the same voltage level.

[0062] In this way, when the output voltage of the rectifier unit 10 is output normally, the sampling unit 20 will generate a high-level sampling signal according to the output voltage and output it to the base of the second switch tube G2, resulting in a voltage difference between the emitter and the gate of the second switch tube G2, so that the second switch tube G2 is turned on, and at this time, the emitter and the collector of the second switch tube G2 are both low-level. At the same time, the main control unit 30 will output a high-level to the gate of the first switch tube G1 after the bus voltage of the bus capacitor C reaches the first preset voltage, so as to turn on the first switch tube G1 and close the charging relay KA (the coil of the charging relay KA is energized and the contacts of the charging relay KA are closed), so that the charging relay KA bypasses the first charging resistor R1, thereby reducing the power loss during the operation of the drive control circuit.

[0063] When the drive control circuit is briefly interrupted, the sampling unit 20 generates a low-level sampling signal and outputs it to the base of the second switch G2, resulting in no voltage difference between the emitter and gate of the second switch G2, turning off the second switch G2. At this time, the emitter of the second switch G2 is at a high level. Therefore, no matter what signal is input to the gate of the first switch G1, the charging relay KA is disconnected (the coil of the charging relay KA is not energized, and the contacts of the charging relay KA are open). The first charging resistor R1 is connected in series with the bus capacitor C. When the drive control circuit is powered on again, the sampling unit 20 generates a high-level sampling signal based on the output voltage and outputs it to the base of the second switch G2, resulting in a voltage difference between the emitter and gate of the second switch G2 (equivalent to the gate of the second switch G2 being at a high level), turning on the second switch G2. At this time, the emitter and collector of the second switch G2 are both at low levels. Since the emitter of the first switch G1 is connected to the collector of the second switch G2, During the short interruption, the emitter of the first switch G1 is also at a low level. Before the short interruption occurs, the gate of the first switch G1 remains at a high level. A voltage difference exists between the gate and emitter of the first switch G1, causing the first switch G1 to turn on instantaneously. Both the emitter and collector of the first switch G1 are at a low level, and the charging relay KA is energized. At this time, to prevent the first charging resistor R1 from being bypassed and failing to limit the current, the output end of the main control unit 30 inputs a low-level signal to the gate of the first switch G1. As a result, when the drive control circuit is powered on again, the first switch G1 cannot turn on immediately, and the charging relay KA is quickly disconnected (i.e., the coil of the charging relay KA is not energized, and the contacts of the charging relay KA are disconnected and remain open). The first charging resistor R1 is connected in series with the bus capacitor C to reduce the charging current in the drive control circuit and prevent excessive charging current from damaging components within the drive control circuit. The charging relay KA is not closed until the main control unit 30 detects that the bus voltage of the bus capacitor C has reached a first preset voltage.

[0064] Wherein, the first switch tube G1 and the second switch tube G2 are both any one of an insulated gate bipolar transistor, a field effect transistor, a bipolar transistor and a thyristor.

[0065] It should be noted that in this embodiment, the first switching transistor G1 and the second switching transistor G2 are preferably insulated gate bipolar transistors (IGBTs). This is because IGBTs have fast switching speeds, which improve the response time and dynamic performance of the drive control circuit; IGBTs have low on-resistance, which reduces power loss during conduction and improves the operating efficiency of the drive control circuit; and IGBTs have high voltage resistance, which improves the safety and reliability of the drive control circuit.

[0066] In order to ensure that the sampling unit 20 can divide the output voltage of the rectifier unit 10 by resistors and generate a sampling signal, refer to the attached Figure 3 , this embodiment proposes a circuit structure of the sampling unit 20:

[0067] The sampling unit 20 includes a fourth resistor R4 and a fifth resistor R5;

[0068] A first end of the fourth resistor R4 is connected to a first end of the first charging resistor R1 , a second end of the fourth resistor R4 and a first end of the fifth resistor R5 are both connected to the gate of the second switch tube G2 , and a second end of the fifth resistor R5 is grounded.

[0069] When the sampling unit 20 continuously outputs the sampling signal to the soft start unit 40 , the first switch tube G1 and the second switch tube G2 are turned on, and the charging relay KA is closed;

[0070] When the sampling signal is briefly interrupted, the first switch tube G1 and the second switch tube G2 are disconnected, and the charging relay KA is disconnected.

[0071] In this way, when sampling unit 20 continuously outputs sampling signals to soft-start unit 40, the continuity and stability of the drive control circuit are ensured during normal operation. The conduction of first and second switching transistors G1 and G2, and the engagement of charging relay KA, ensure the normal operation of the drive control circuit. In the event of a brief interruption in the drive control circuit, the drive control circuit can respond quickly, disconnecting first and second switching transistors G1 and G2, and disengaging charging relay KA. This prevents malfunction or damage caused by signal interruption, thereby improving the reliability and safety of the drive control circuit.

[0072] In order to ensure that the drive control circuit can rectify AC power into DC power, refer to the attached Figure 3 , the drive control circuit further includes a rectifier unit 10, the rectifier unit 10 includes a first bridge arm and a second bridge arm respectively composed of two rectifier diodes;

[0073] The midpoint of the first bridge arm and the midpoint of the second bridge arm are both used to connect to the AC power grid; one end of the first bridge arm and one end of the second bridge arm are both connected to the first end of the first charging resistor R1, and the other end of the first bridge arm and the other end of the second bridge arm are both connected to the negative electrode of the bus capacitor C.

[0074] In order to ensure that the charging current of the drive control circuit can stably supply power to the motor 60 and realize the variable frequency control of the motor 60, refer to the attached Figure 3, the drive control circuit further includes an inverter unit 50, and the inverter unit 50 includes a third bridge arm, a fourth bridge arm and a fifth bridge arm each consisting of two switch tubes;

[0075] The midpoint of the third bridge arm, the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm are respectively used to connect to the three phases of the motor 60; the two ends of the third bridge arm, the two ends of the fourth bridge arm and the two ends of the fifth bridge arm are respectively connected to the two ends of the bus capacitor C.

[0076] Example 2

[0077] In order to make the first charging resistor R1 better limit the charging current of the drive control circuit when the charging relay KA is closed, refer to the attached Figure 4 , the utility model also proposes another circuit diagram of the drive control circuit:

[0078] There are preferably two first charging resistors, namely a first charging resistor R1 and a first charging resistor R1 ″, and the first charging resistor R1 and the first charging resistor R1 ″ are connected in series.

[0079] To ensure that the sampling unit 20 can further perform resistor division on the output voltage of the rectifier unit 10 and generate a sampling signal, the fourth resistor R4 and the fifth resistor R5 are preferably provided in pairs, namely, the fourth resistor R4, the fourth resistor R4″, the fifth resistor R5 and the fifth resistor R5″, respectively, and the fourth resistor R4 and the fourth resistor R4″ are arranged in series, and the fifth resistor R5 and the fifth resistor R5″ are arranged in series.

[0080] Specifically, the circuit structure of the drive control circuit in this embodiment is as follows:

[0081] The drive control circuit includes: a rectifier unit 10 including a first bridge arm and a second bridge arm each consisting of two rectifier diodes; a fourth resistor R4, a fourth resistor R4″, a fifth resistor R5 and a fifth resistor R5″ constituting the sampling unit 20; a first charging resistor R1, a first charging resistor R1″, a charging relay KA, a first switch tube G1, a second switch tube G2, a second resistor R2 and a third resistor R3 constituting the soft start unit 40; a bus capacitor C; and an inverter unit 50 including a third bridge arm, a fourth bridge arm and a fifth bridge arm each consisting of two switch tubes.

[0082] The midpoint of the first bridge arm and the midpoint of the second bridge arm are both used to connect to the AC power grid; one end of the first bridge arm and one end of the second bridge arm are both connected to a first wiring terminal, which is also connected to the first end of the first charging resistor R1, the first end of the fourth resistor R4, and the common contact of the charging relay KA; the second end of the fourth resistor R4 is connected to the first end of the fourth resistor R4", the second end of the fourth resistor R4" and the first end of the fifth resistor R5 are both connected to the gate of the second switching tube G2, the second end of the fifth resistor R5 is connected to the first end of the fifth resistor R5", and the second end of the fifth resistor R5" is grounded.

[0083] The second end of the first charging resistor R1 is connected to the first end of the first charging resistor R1″, and the second end of the first charging resistor R1″ and the normally closed contact of the charging relay KA are both connected to the positive electrode of the bus capacitor C; the first coil pin of the charging relay KA is respectively connected to the collector of the first switching tube G1 and the first end of the third resistor R3, the gate of the first switching tube G1 is connected to the output end of the main control unit 30, and the emitter of the first switching tube G1 is respectively connected to the first end of the second resistor R2 and the collector of the second switching tube G2; the second end of the second resistor R2 and the second end of the third resistor R3 are both used to connect to the VCC1 pin, and the first coil pin of the charging relay KA is used to connect to the VCC pin; the emitter of the second switching tube G2 is grounded.

[0084] The midpoint of the third bridge arm, the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm are respectively used to connect to the three phases of the motor 60; the two ends of the third bridge arm, the two ends of the fourth bridge arm and the two ends of the fifth bridge arm are respectively connected to the two ends of the bus capacitor C.

[0085] Example 3

[0086] The present utility model further provides an intelligent device, comprising a frequency converter, wherein the frequency converter comprises the drive control circuit described above.

[0087] In this way, when the output voltage of the rectifier unit 10 is output normally, the sampling unit 20 will generate a high-level sampling signal according to the output voltage and output it to the soft start unit 40. At this time, the main control unit 30 will output a high-level signal to the soft start unit 40 after the bus voltage of the bus capacitor C reaches the first preset voltage, and the soft start unit 40 will be turned on after receiving the sampling signal and the high level, thereby reducing the power loss during the operation of the drive control circuit; if the output voltage of the rectifier unit 10 is briefly interrupted, the sampling unit 20 will generate a low-level sampling signal and output it to the soft start unit 40. The main control unit 30 outputs a low-level signal to the soft start unit 40, so that the soft start unit 40 cannot be turned on immediately when it is powered on again, reducing the charging current in the drive control circuit to prevent the charging current from being too large and damaging the components in the drive control circuit.

[0088] Obviously, the embodiments described above are only some of the embodiments of the present invention, rather than all of the embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and the accompanying drawings, directly or indirectly used in other related technical fields, is also within the scope of protection of the present invention patent.

Claims

1. A drive control circuit comprising a rectifier unit (10) and a bus capacitor connected to the rectifier unit (10); characterized in that: Also includes: A sampling unit (20) connected to the rectifier unit (10), the sampling unit (20) being used to collect an output signal of the rectifier unit (10) and generate a sampling signal; A main control unit (30) is used to output a low-level signal; A soft start unit (40) is connected to the sampling unit (20), the main control unit (30) and the bus capacitor respectively, and the soft start unit (40) is used for switching on and off according to the sampling signal and the low-level signal.

2. The drive control circuit according to claim 1, wherein: The soft start unit (40) comprises a first charging resistor, a charging relay, a first switch tube, a second switch tube, a second resistor and a third resistor; The first end of the first charging resistor and the common contact of the charging relay are both connected to the first input end of the sampling unit (20), and the second end of the first charging resistor and the normally closed contact of the charging relay are both connected to the positive electrode of the bus capacitor; the first coil pin of the charging relay is respectively connected to the collector of the first switching tube and the first end of the third resistor, the gate of the first switching tube is connected to the output end of the main control unit (30), the emitter of the first switching tube is respectively connected to the first end of the second resistor and the collector of the second switching tube, and the gate of the second switching tube is connected to the second input end of the sampling unit (20); The second end of the second resistor and the second end of the third resistor are both used to connect to the VCC1 pin, and the first coil pin of the charging relay is used to connect to the VCC pin; the emitter of the second switch tube is grounded.

3. The drive control circuit according to claim 2, wherein: The sampling unit (20) includes a fourth resistor and a fifth resistor; The first end of the fourth resistor is connected to the first end of the first charging resistor, the second end of the fourth resistor and the first end of the fifth resistor are both connected to the gate of the second switch tube, and the second end of the fifth resistor is grounded.

4. The drive control circuit according to claim 3, characterized in that: There are multiple fourth resistors and multiple fifth resistors, and the multiple fourth resistors and the multiple fifth resistors are respectively connected in series.

5. The drive control circuit according to claim 2, wherein: When the sampling unit (20) continuously outputs the sampling signal to the soft start unit (40), the first switch tube and the second switch tube are turned on, and the charging relay is closed; When the sampling signal is briefly interrupted, the first switch tube and the second switch tube are disconnected, and the charging relay is disconnected.

6. The drive control circuit according to claim 2, wherein: The first switching tube and the second switching tube are both any one of an insulated gate bipolar transistor, a field effect transistor, a bipolar transistor and a thyristor.

7. The drive control circuit according to claim 2, characterized in that: There are multiple first charging resistors, and the multiple first charging resistors are connected in series.

8. The drive control circuit according to claim 1, wherein: The rectifier unit (10) comprises a first bridge arm and a second bridge arm each consisting of two rectifier diodes; The midpoint of the first bridge arm and the midpoint of the second bridge arm are both used to connect to the AC power grid; one end of the first bridge arm and one end of the second bridge arm are both connected to the input end of the soft start unit (40), and the other end of the first bridge arm and the other end of the second bridge arm are both connected to the negative electrode of the bus capacitor.

9. The drive control circuit according to claim 1, wherein: The drive control circuit further comprises an inverter unit (50), wherein the inverter unit (50) comprises a third bridge arm, a fourth bridge arm and a fifth bridge arm, each consisting of two switch tubes; The midpoint of the third bridge arm, the midpoint of the fourth bridge arm, and the midpoint of the fifth bridge arm are respectively used to be connected to the motor (60); and the two ends of the third bridge arm, the two ends of the fourth bridge arm, and the two ends of the fifth bridge arm are respectively connected to the two ends of the bus capacitor.

10. An intelligent device, comprising a frequency converter, characterized in that: The frequency converter includes the drive control circuit according to any one of claims 1 to 9.

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