Contactor driving circuit and electrical equipment
By designing the contactor driving circuit, using the combination of the charging timing module, the driving module and the comparison module, the delay drives multiple parallel contactors to absorb, solving the problem of excessive driving current in the parallel high-power contactor and reducing the driving power supply Rated current.
Patent Information
- Application Number
- CN202411546059.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2024-12-13
AI Technical Summary
In high-power inverters and inverters, when multiple contactors are driven in parallel, the instantaneous pull-in current is too large, resulting in an increase in the rated current of the drive power supply, which cannot meet the current requirement of all contactors to pull-in at the same time.
A contactor driving circuit is designed, including a charging timing module, a driving module and a comparison module. By delay, multiple contactors connected in parallel are driven to absorb and reduce the instantaneous driving current and reduce the rated current of the driving power supply. In the specific implementation, the charging timing unit receives the drive control signal, the output branch is connected to the drive unit, the comparison unit determines the contactor's suction state, and delays the suction signal to control the contactor's suction.
It effectively reduces the instantaneous driving current of the contactor, reduces the rated current of the driving power supply, and solves the problem of large volume of the parallel driving power supply of the high-power contactor.
Smart Images
Figure CN119132888A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrical automation technology, and in particular to a contactor drive circuit and electrical equipment. Background Art
[0002] At present, in many applications, such as high-power frequency converters and inverters, multiple contactors need to be connected in parallel. The contactor parallel drive scheme is a common circuit design scheme, which is usually used to control the switch of large load current. For example, when it is necessary to control high-power motors or lighting equipment, the use of contactors in parallel can achieve reliable switch control.
[0003] However, as the number of contactors in parallel increases, the instantaneous pull-in current is relatively large due to the energy-saving design of the internal excitation coil of the contactor, but the holding current after pull-in is 5-8 times less than the pull-in current corresponding to the pull-in moment. This causes the rated current margin of the power supply to be large when selecting the contactor. When multiple contactors are connected in parallel, a single power supply cannot meet the current requirements of all contactors when they are pulled in at the same time. Summary of the invention
[0004] In view of this, the present invention aims to solve one of the problems in the related art at least to a certain extent. To this end, the object of the present invention is to provide a contactor drive circuit and an electrical device.
[0005] The present application provides a contactor drive circuit. The contactor drive circuit includes a charging timing module, a driving module, a comparison module and a contactor module; the charging timing module includes a first charging timing unit, the driving module includes a first driving unit and a second driving unit; the comparison module includes a first comparison unit; the contactor module includes a first contactor and a second contactor connected in parallel; the input end of the first charging timing unit receives the driving control signal; the first charging timing unit includes a first output branch and a second output branch connected in parallel, the first output branch includes a first output end, and the second output branch includes a second output end; the first output end is connected to the input end of the first driving unit, the output end of the first driving unit is connected to the first contactor, and the first driving unit is used to drive the first contactor to be attracted according to the driving control signal; the second output end is connected to the input end of the second driving unit through the first comparison unit, and the output end of the second driving unit is connected to the second contactor; the first comparison unit is used to determine that the first contactor is in an attracted state and output a first attraction signal to the second driving unit when it is determined that the voltage value of the second output end is greater than or equal to a preset threshold; the second driving unit is used to drive the second contactor to be attracted according to the first attraction signal.
[0006] In some embodiments, the contactor drive circuit also includes a control module and an optocoupler isolation module, the control module is used to issue an initial drive signal, the first end of the optocoupler isolation module is connected to the control module, and the second end of the optocoupler isolation module is connected to the input end of the first charging timing unit; the optocoupler isolation module is used to receive the initial drive signal and perform level conversion on the initial drive signal to output the drive control signal.
[0007] In some embodiments, the optocoupler isolation module includes a photocoupler and a first transistor, the base of the first transistor is connected to the control module, one end of the collector of the first transistor is connected to the cathode of the photocoupler, and the emitter of the first transistor is grounded; the anode of the photocoupler is connected to the input end of the first charging timing unit.
[0008] In some embodiments, the optocoupler isolation module also includes a first filtering unit, which includes a first voltage-dividing resistor and a first filtering capacitor connected in parallel; the first end of the first filtering unit is connected to the control module, and the second end of the first filtering unit is connected to the base of the first transistor; the first filtering unit is used to filter the drive control signal to obtain a first drive signal.
[0009] In some embodiments, the optocoupler isolation module also includes a second filtering unit, which includes a current limiting resistor, a bias resistor and a second filter capacitor connected in parallel; the first end of the second filtering unit is connected to the collector of the first transistor, the second end of the second filtering unit is connected to the cathode of the photocoupler, and the third end of the second filtering unit is connected to the first power supply; the second filtering unit is used to filter the second drive signal after the first drive signal is amplified by the first transistor to obtain the drive control signal.
[0010] In some embodiments, the first charging timing unit includes: a second voltage-dividing resistor, a second transistor connected in parallel with the second voltage-dividing resistor, a third voltage-dividing resistor and a third filter capacitor connected in parallel with the third voltage-dividing resistor; the first end of the second voltage-dividing resistor receives the drive control signal, the second end of the second voltage-dividing resistor is connected to the second power supply, the third end of the second voltage-dividing resistor is connected to the base of the second transistor, the emitter of the second transistor is connected to the second power supply, and the collector of the second transistor is respectively connected to the first drive unit and the first end of the third voltage-dividing resistor.
[0011] In some embodiments, the first comparison unit includes a comparator, the second end of the third voltage-dividing resistor is connected to the first input end of the comparator, the second input end of the comparator is connected to a reference power supply, the power supply end of the comparator is connected to a third power supply, the ground end of the comparator is grounded, and the output end of the comparator is connected to the second driving unit.
[0012] In some embodiments, the first driving unit includes a first driving resistor, a first discharge resistor, a first transistor and a first freewheeling diode, the first driving resistor is connected in parallel with the first discharge resistor, the first end of the first driving resistor is connected to the collector of the second transistor, the second end of the first driving resistor is connected to the first end of the first discharge resistor and the gate of the first transistor, and the second end of the first discharge resistor is grounded; the drain of the first transistor is connected to the first end of the first freewheeling diode, and the second end of the first freewheeling diode is connected to a fourth power supply; the source of the first transistor is grounded; the second driving unit includes a second driving resistor, a second discharge resistor, a second transistor and a second freewheeling diode, the second driving resistor is connected in parallel with the second discharge resistor, the first end of the second driving resistor is connected to the output end of the comparator and the gate of the second transistor and the first end of the second discharge resistor, the second end of the second driving resistor is connected to the fifth power supply, the second end of the second discharge resistor is grounded, the drain of the second transistor is connected to the first end of the second freewheeling diode, and the second end of the second freewheeling diode is connected to the sixth power supply; the source of the second transistor is grounded.
[0013] In some embodiments, the charging timing module includes a second charging timing unit, the driving module includes a third driving unit; the comparison module includes a second comparison unit; the contactor module includes a third contactor; the input end of the second charging timing unit is connected to the second driving unit, the input end of the second comparison unit is connected to the output end of the second charging timing unit, the input end of the third driving unit is connected to the output end of the second comparison unit, the third contactor is connected to the output end of the third driving unit, and the first contactor, the second contactor and the third contactor are connected in parallel; the second comparison unit is used to determine that the second contactor is in an energized state and output a second energization signal to the third driving unit when detecting that the voltage value corresponding to the output end of the second charging timing unit is greater than or equal to a preset threshold value, and the third driving unit is used to drive the third contactor to energize according to the second energization signal.
[0014] In some embodiments, the second driving unit includes a second transistor, the second charging timing unit includes a third triode, and the third driving unit includes a third transistor, the base of the third triode is connected to the source of the second transistor, the collector of the third triode is connected to the seventh power supply, the emitter of the third triode is grounded, the gate of the third transistor is connected to the output end of the second charging timing unit, the source of the third transistor is grounded, and the drain of the third transistor is connected to the third contactor; after the third triode of the second charging timing unit is turned on, the second charging unit starts to charge until the comparator threshold voltage of the second comparison unit is reached, the output level of the second comparator unit is flipped to a high level, and the third transistor of the third driving unit is turned on, so that the third contactor is attracted.
[0015] In some embodiments, the contactor drive circuit includes at least one second charging timing unit, at least one second comparison unit, at least one third drive unit, and at least one third contactor connected in parallel in sequence; wherein the input end of the second charging timing unit of the next stage is connected to the source of the switching transistor in the third drive unit of the previous stage to sequentially drive the at least one third contactor to be attracted.
[0016] The present application also provides an electrical device, which is used to implement the contactor drive circuit described in any of the above embodiments.
[0017] In this way, the contactor drive circuit of the present application can delay driving a plurality of contactors connected in parallel to close, reduce the instantaneous drive current of the contactors, and lower the rated current of the drive power supply.
[0018] 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
[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:
[0020] Figure 1 is a schematic diagram of the structure of a contactor drive circuit of certain embodiments of the present application;
[0021] Figure 2 It is a schematic diagram of the structure of a contactor drive circuit in certain embodiments of the present application.
[0022] Main component reference numbers:
[0023] Contactor drive circuit 100;
[0024] Charging timing module 10, first charging timing unit 11, second charging timing unit 12, first output branch 111, second output branch 112, driving module 20, first driving unit 21, second driving unit 22, third driving unit 23, comparing module 30, first comparing unit 31, comparator 311, second comparing unit 32, contactor module 40, first contactor 41, second contactor 42, third contactor 43, control module 50, optocoupler isolation module 60, first filtering unit 61, second filtering unit 62;
[0025] Photocoupler A, first transistor Q1, first resistor R1, second resistor R2, first filter capacitor C1, first power supply V1, third resistor R3, fourth resistor R4, second filter capacitor C2, second transistor Q2, second power supply V2, fifth resistor R5, sixth resistor R6, seventh resistor R7, eighth resistor R8, third filter capacitor C3, second transistor Q2, first drive resistor R9, first discharge resistor R10, first transistor Q3, first freewheeling diode D1, second drive resistor R11, second discharge resistor R12, second transistor Q4, second freewheeling diode D2, second transistor Q4, third transistor Q5, third transistor Q6, third power supply V3, fourth power supply Vdrive1, fifth power supply V5, sixth power supply Vdrive2, seventh power supply V7, eighth power supply V8. DETAILED DESCRIPTION
[0026] The 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 only used to explain the present invention, and cannot be understood as limiting the present invention.
[0027] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, and may refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection, or mutual communication; direct connection, indirect connection through an intermediate medium, internal connection between two elements, or interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0029] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.
[0030] The 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 only used to explain the present invention, and cannot be understood as limiting the present invention.
[0031] See also Figure 1 The embodiment of the present application discloses a contactor drive circuit 100. The contactor drive circuit 100 includes a charging timing module 10, a driving module 20, a comparison module 30 and a contactor module 40. The charging timing module 10 includes a first charging timing unit 11, and the driving module 20 includes a first driving unit 21 and a second driving unit 22. The comparison module 30 includes a first comparison unit 31. The contactor module 40 includes a first contactor 41 and a second contactor 42 connected in parallel.
[0032] An input terminal of the first charging timing unit 11 receives a driving control signal.
[0033] The first charging timing unit 11 includes a first output branch 111 and a second output branch 112 connected in parallel, the first output branch 111 includes a first output end, and the second output branch 112 includes a second output end. The first output end is connected to the input end of the first driving unit 21, and the output end of the first driving unit 21 is connected to the first contactor 41. The first driving unit 21 is used to drive the first contactor 41 to attract according to the driving control signal. The second output end is connected to the input end of the second driving unit 22 through the first comparison unit 31, and the output end of the second driving unit 22 is connected to the second contactor 42.
[0034] The first comparison unit 31 is used to determine that the first contactor 41 is in the energized state and output a first energizing signal to the second drive unit 22 when the voltage value of the second output terminal of the first charging timing unit 11 is greater than or equal to a preset threshold value. The second drive unit 22 is used to drive the second contactor 42 to energize according to the first energizing signal.
[0035] Specifically, the driving control signal may be an electrical signal, for example, a high-level signal, or other signals, which are not limited here.
[0036] Taking the driving control signal as a high-level signal as an example, when the input end of the first charging timing unit 11 receives a high-level signal, since the first output end of the first charging timing unit 11 is directly connected to the first driving unit 21, and the output end of the first driving unit 21 is directly connected to the first contactor 41, the first driving unit 21 can directly drive the first contactor 41 to be attracted according to the driving control signal without delay.
[0037] In addition, the second output end of the first charging timing unit 11 is connected to the input end of the second driving unit 22 through the first comparison unit 31, and the output end of the second driving unit 22 is connected to the second contactor 42. The first comparison unit 31 is used to determine that the voltage value of the second output end of the first charging timing unit 11 is greater than or equal to a preset threshold, and then determine that the first contactor 41 is in the pull-in state and output the first pull-in signal to the second driving unit 22, that is, the first comparison unit 31 has a delay effect. Among them, the preset threshold can be a reference voltage threshold of the comparator in the first comparison unit 31.
[0038] Therefore, the second output end of the first charging timing unit 11 can send a first attraction signal to the second driving unit 22 to control the second contactor 42 to be attracted when the first contactor 41 is already in the attracted state through the delay effect of the first comparing unit 31, thereby realizing the process of sequentially controlling the attraction of the second contactor 42 and the first contactor 41 connected in parallel, thereby reducing the instantaneous driving current of the two contactors and reducing the rated current of the driving power supply.
[0039] In this way, the contactor drive circuit 100 of the present application can delay driving a plurality of contactors connected in parallel to close, thereby reducing the instantaneous drive current of the contactors and lowering the rated current of the drive power supply.
[0040] That is to say, the contactor drive circuit 100 of the present application can solve the problem that the instantaneous current of high-power contactors driven in parallel is too large, and the rated current of the driving power supply is large and the power supply volume is large.
[0041] See also Figure 1In some embodiments, the contactor drive circuit 100 further includes a control module 50 and an optocoupler isolation module 60. The control module 50 is used to send an initial drive signal, and a first end of the optocoupler isolation module 60 is connected to the control module 50. A second end of the optocoupler isolation module 60 is connected to an input end of the first charging timing unit 11. The optocoupler isolation module 60 is used to receive the initial drive signal and perform level conversion on the initial drive signal to output a drive control signal.
[0042] Specifically, the control module 50 may include a control power supply and a control switch connected in series, and may also include other control elements. The initial drive signal may be an electrical signal generated when the control switch is closed.
[0043] It is understandable that in the circuit system, different voltage or level standards may exist between different parts or different devices. The optocoupler isolation module 60, due to its good electrical isolation performance, can effectively realize the conversion between different voltages or levels, ensure the normal operation of the circuit system and the accuracy of data transmission, thereby ensuring the stability and reliability of the contactor control circuit 100. That is, the optocoupler isolation module 60 of the present application can perform level conversion on the initial drive signal sent by the control module 50 to obtain a drive control signal suitable for the first charging timing unit 11, thereby ensuring the stability and reliability of the contactor control circuit 100.
[0044] The optocoupler isolation module 60 also plays multiple roles in the contactor control circuit 100, such as signal isolation, enhancing anti-interference capability, and improving safety. The optocoupler isolation module 60 is one of the key components to ensure stable operation of the circuit system and accuracy of data transmission.
[0045] In this way, the contactor drive circuit 100 of the present application can ensure the stable operation of the circuit system and the accuracy of data transmission by providing the optical coupling isolation module 60, thereby ensuring the stability and reliability of the contactor control circuit 100.
[0046] See also Figure 1 In some embodiments, the optical coupling isolation module 60 includes a photocoupler A and a first transistor Q1, the base of the first transistor Q1 is connected to the control module 50, one end of the collector of the first transistor Q1 is connected to the cathode of the photocoupler A, and the emitter of the first transistor Q1 is grounded. The anode of the photocoupler A is connected to the input end of the first charging timing unit 11.
[0047] It can be understood that the working principle of the transistor is based on the conductive principle of the PN junction. When the base voltage is positive, the transistor is in the on state, allowing current to pass; when the base voltage is zero or negative, the transistor is in the off state, preventing current from passing. This characteristic enables the transistor to be used as a switch in the circuit.
[0048] In the optocoupler circuit, the transistor can amplify the weak input signal to a level sufficient to drive the load. This amplification is achieved through the current amplification characteristics of the transistor, that is, when the base current changes slightly, the collector current will change significantly. This amplification characteristic makes the photocoupler
[0049] The coupled circuit can handle a wider range of input signals and improve the reliability and stability of the circuit. This feature allows the triode to be used as an amplifier in the circuit.
[0050] Specifically, since the base of the first transistor Q1 is connected to the control module 50, the high-level initial driving signal sent by the control module 50 will make the first transistor Q1 in a conducting state. When the control module 50 does not send an electrical signal, the first transistor Q1 is in a cut-off state, preventing current from passing. Therefore, the first transistor Q1 can be used as a switch and amplifier in the optical coupling isolation module 60.
[0051] That is, the first transistor Q1 inside the optocoupler isolation module 60 of the present application plays important roles in the circuit, such as amplification, control and protection, etc. These roles together enable the optocoupler isolation module 60 to work stably and reliably in various application scenarios.
[0052] Photocoupler A generally consists of three parts: light emission, light reception and signal amplification. Specifically, photocoupler A is mainly composed of a light emitting diode and a photosensitive element. The light emitting diode can be, for example, an LED light emitting diode, and the photosensitive element can be, for example, a phototransistor and a photosensitive diode. The light emitting diode serves as a light source, and the photosensitive element is responsible for receiving the light signal and converting it into an electrical signal.
[0053] Optocoupler A realizes the conversion and transmission of electrical signals through the photoelectric effect, and has the characteristics and advantages of electrical isolation, strong anti-interference ability, and fast transmission speed.
[0054] In this way, the optocoupler isolation module 60 of the present application is internally provided with a first transistor Q1 used as a switch and amplifier in the circuit, and the photoelectric coupler A realizes the conversion and transmission of electrical signals through the photoelectric effect, thereby ensuring the stable operation of the circuit system and the accuracy of data transmission, and ensuring the stability and reliability of the contactor control circuit 100.
[0055] See also Figure 1 In some embodiments, the optocoupler isolation module 60 further includes a first filter unit 61. The first filter unit 61 includes a first voltage-dividing resistor and a first filter capacitor C1 connected in parallel. The first end of the first filter unit 61 is connected to the control module 50, and the second end of the first filter unit 61 is connected to the base of the first transistor Q1. The first filter unit 61 is used to filter the drive control signal to obtain a first drive signal.
[0056] Specifically, the first voltage dividing resistor may include Figure 1 The first resistor R1 and the second resistor R2 are shown. The voltage divider resistor plays many roles in the circuit, such as reducing voltage, stabilizing voltage, measuring voltage, protecting circuit and changing circuit performance. It is one of the indispensable components in electrical equipment and circuits, providing important guarantee for the normal operation and performance optimization of the circuit.
[0057] The optical coupling isolation module 60 of the present application can obtain the output voltage required by the contactor control circuit 100 by adjusting the resistance value of the first voltage-dividing resistor. That is, the present application can obtain the output voltage required by the contactor control circuit 100 by adjusting the resistance values of the first resistor R1 and the second resistor R2.
[0058] In addition, the first filter capacitor C1 can eliminate high-frequency noise and ripples in the signal, making the DC signal in the circuit more stable.
[0059] Thus, the contactor drive circuit 100 of the present application can set a first filter unit 61 composed of a first voltage-dividing resistor and a first filter capacitor C1 between the control module 50 and the first transistor Q1 to filter the drive control signal to obtain a more stable denoised first drive signal.
[0060] In some embodiments, the optical coupling isolation module 60 may further include a second filtering unit 62. The second filtering unit 62 includes a current limiting resistor, a bias resistor, and a second filtering capacitor C2 connected in parallel. The first end of the second filtering unit 62 is connected to the collector of the first transistor Q1, the second end of the second filtering unit 62 is connected to the cathode of the photocoupler A, and the third end of the second filtering unit 62 is connected to the first power supply V1. The second filtering unit 62 is used to filter the second drive signal after the first drive signal is amplified by the first transistor Q1 to obtain a drive control signal.
[0061] Specifically, the current limiting resistor can be Figure 1 The third resistor R3 shown in FIG. 1 and the bias resistor may be as follows: Figure 1 The fourth resistor R4 is shown.
[0062] Understandably, in order to protect the light-emitting diode in the photocoupler A from being burned due to excessive current, it is necessary to add the third resistor R3 as a current-limiting resistor to mainly play a current-limiting role, and the role of the fourth resistor R4 is to provide a bias current, increase the threshold of the photocoupler conduction current, and prevent the photocoupler from mis-conducting. In actual circuits, signals are often interfered by field noise, resulting in a signal waveform that is not smooth enough and has many small glitches. Therefore, by connecting the second filter capacitor C2 in parallel in the circuit, these noise interferences can be effectively absorbed, so that the waveform of the final drive control signal is smoother.
[0063] That is, the optocoupler isolation module 60 of the present application can be used as an RC filter circuit through the combination of the second filter capacitor C2 and the third resistor R3 in the second filter unit 62 and the combination of the second filter capacitor C2 and the fourth resistor R4 to filter out high-frequency noise and interference in the second drive signal, so that the waveform of the final drive control signal is smoother, thereby ensuring the accuracy of the transmission of the drive control signal.
[0064] See also Figure 1 In some embodiments, the first charging timing unit 11 includes a second voltage-dividing resistor, a second transistor Q2 connected in parallel with the second voltage-dividing resistor, a third voltage-dividing resistor, and a third filter capacitor C3 connected in parallel with the third voltage-dividing resistor. The first end of the second voltage-dividing resistor receives a driving control signal, the second end of the second voltage-dividing resistor is connected to the second power supply V2, the third end of the second voltage-dividing resistor is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is connected to the second power supply V2, and the collector of the second transistor Q2 is connected to the first driving unit 21 and the first end of the third voltage-dividing resistor, respectively.
[0065] Specifically, Figure 1 As shown, the second voltage-dividing resistor includes a fifth resistor R5 and a sixth resistor R6 connected in parallel. The third voltage-dividing resistor includes a seventh resistor R7 and an eighth resistor R8 connected in parallel. The voltage-dividing resistor plays a variety of roles in the circuit, such as reducing voltage, stabilizing voltage, measuring voltage, protecting circuits, and changing circuit performance, providing important guarantees for the normal operation and performance optimization of the circuit.
[0066] Since the collector of the second transistor Q2 is respectively connected to the first drive unit 21 and the first end of the third voltage-dividing resistor, the seventh resistor R7, the eighth resistor R8 and the third filter capacitor C3 are connected in parallel to form an RC filter circuit, thereby filtering out high-frequency noise and interference in the first pull-in signal emitted by the first drive unit 21.
[0067] That is, in the first charging timing unit 11 of the present application, the collector of the second transistor Q2 can be directly connected to the first driving unit 21, so that the driving control signal emitted by the collector of the second transistor Q2 can be directly sent to the first driving unit 21 to make the first contactor 41 energized.
[0068] In detail, when the secondary anode of the photocoupler A is turned on, the second transistor Q2 is turned on to start charging the first charging timing unit 11, and the voltage on the third filter capacitor C3 gradually increases. At the same time, the switch transistor in the first drive unit 21 is turned on, so that the first drive unit 21 can drive the first contactor 41 to close.
[0069] In addition, the collector of the second transistor Q2 can also be connected to the third voltage-dividing resistor and the third filter capacitor C3 connected in parallel with the third voltage-dividing resistor, so as to filter out high-frequency noise and interference in the first pull-in signal emitted by the first driving unit 21 and ensure the accuracy of the first pull-in signal.
[0070] In some embodiments, the first comparison unit 31 includes a comparator 311. The second end of the third voltage-dividing resistor is connected to the first input end of the comparator 311, and the second input end of the comparator 311 is connected to the reference power supply V REF The power supply end of the comparator 311 is connected to the third power supply V3 , the ground end of the comparator 311 is grounded, and the output end of the comparator 311 is connected to the second driving unit 22 .
[0071] Specifically, Figure 1 As shown, the eighth resistor R8 is connected to the first input terminal of the comparator 311. Therefore, the first input terminal of the comparator 311 can detect in real time the first voltage value U1 corresponding to the output terminal of the second transistor Q2. Since the second input terminal of the comparator 311 is connected to the reference power supply V REF Therefore, the voltage value input to the second input terminal of the comparator 311 is the first reference voltage U REF Therefore, the comparator 311 can compare the first voltage value U1 detected by the first input terminal with the first reference voltage U REF and outputs a second pull-in signal to the second driving unit 22 according to the comparison result.
[0072] In one embodiment, the comparison result may be that the first voltage value U1 of the first input terminal obtained by the comparator 311 is greater than or equal to the first reference voltage U REF , then at this time the comparator 311 can output a first pull-in signal to the second drive unit 22, and the second drive unit 22 drives the second contactor 42 to pull in according to the first pull-in signal.
[0073] In this way, the first contactor 41 and the second contactor 42 can be closed in sequence, which avoids the simultaneous closing of multiple contactors connected in parallel, reduces the instantaneous drive current of the contactor, and lowers the rated current of the drive power supply.
[0074] In some embodiments, the first driving unit 21 includes a first driving resistor R9, a first discharge resistor R10, a first transistor Q3 and a first freewheeling diode D1. The first driving resistor R9 is connected in parallel with the first discharge resistor R10, the first end of the first driving resistor R9 is connected to the collector of the second transistor Q2, and the second end of the first driving resistor R9 is connected to the first end of the first discharge resistor R10 and the gate G of the first transistor Q3. The second end of the first discharge resistor R10 is grounded. The drain D of the first transistor Q3 is connected to the first end of the first freewheeling diode D1, and the second end of the first freewheeling diode D1 is connected to the fourth power supply Vdrive1. The source S of the first transistor Q3 is grounded.
[0075] The second driving unit 22 includes a second driving resistor R11, a second discharge resistor R12, a second transistor Q4 and a second freewheeling diode D2. The second driving resistor R11 is connected in parallel with the second discharge resistor R12, the first end of the second driving resistor R11 is connected to the output end of the comparator and the gate G of the second transistor Q4 and the first end of the second discharge resistor R12, and the second end of the second driving resistor R11 is connected to the fifth power supply V5. The second end of the second discharge resistor R12 is grounded. The drain D of the second transistor Q4 is connected to the first end of the second freewheeling diode D2, and the second end of the second freewheeling diode D2 is connected to the sixth power supply Vdrive2. The source S of the second transistor Q4 is grounded.
[0076] Among them, when the first transistor Q3 is turned on, the first driving resistor R9 can limit the current flowing through the gate G of the first transistor Q3, thereby protecting the first transistor Q3 from excessive current impact and preventing it from being damaged. Similarly, when the second transistor Q4 is turned on, the second driving resistor R11 can limit the current flowing through the gate G of the second transistor Q4, thereby protecting the second transistor Q4 from excessive current impact and preventing it from being damaged.
[0077] The drive resistor can also help stabilize the turn-on process of the switching transistor to prevent oscillation or instability caused by too fast current changes. The drive resistor can also reduce the electromagnetic interference and noise generated by the switching action by limiting the rate of change of current.
[0078] In addition, when the contactor coil is de-energized, a reverse electromotive force will be generated due to the inductance of the coil. If this reverse electromotive force is not discharged in time, it may cause damage to other components in the circuit. The discharge resistor provides a current path so that the energy in the coil can be safely released, thereby protecting other components in the circuit from damage.
[0079] In addition, the freewheeling diode plays a freewheeling role when the contactor coil is powered off, but if the current in the coil is not discharged in time through the discharge resistor, the freewheeling diode may be damaged by excessive reverse voltage. Therefore, the discharge resistor also helps to protect the freewheeling diode. That is, the first discharge resistor R10 and the second discharge resistor R12 of the present application each bear an important protection function in the first drive unit 21 and the second drive unit 22 to ensure the stable operation of the circuit and the safety of the components.
[0080] See also Figure 1 and Figure 2 In some embodiments, the charging timing module 10 includes a second charging timing unit 12, and the driving module 20 includes a third driving unit 23. The comparing module 30 includes a second comparing unit 32, and the contactor module 40 includes a third contactor 43. The input end of the second charging timing unit 12 is connected to the second driving unit 22, the input end of the second comparing unit 32 is connected to the output end of the second charging timing unit 12, the input end of the third driving unit 23 is connected to the output end of the second comparing unit 32, and the third contactor 43 is connected to the output end of the third driving unit 23. The first contactor 41, the second contactor 42, and the third contactor 43 are connected in parallel.
[0081] The second comparison unit 32 is used to determine that the second contactor 42 is in the energized state and output a second energizing signal to the third drive unit 23 when the voltage value corresponding to the output end of the second charging timing unit 12 is greater than or equal to a preset threshold value. The third drive unit 23 is used to drive the third contactor 43 to energize according to the second energizing signal.
[0082] Specifically, the second charging timing unit 12 has the same structure as the first charging timing unit 11, and the function of the second charging timing unit 12 is the same as the function of the first charging timing unit 11, both of which play a timing role, thereby playing a delay role in the next-level contactor being attracted. In addition, the second comparison unit 32 has the same structure and function as the first comparison unit 31, and the third drive unit 23 has the same structure and function as the second drive unit 22, which will not be repeated here.
[0083] In detail, when the voltage value at the output end of the second charging timing unit 12 reaches the voltage threshold of the reference power supply end of the second comparing unit 32, the second comparing unit 32 can send a second pull-in signal to the third driving unit 23, thereby driving the third contactor 43 to pull in.
[0084] In this way, the present application can sequentially connect the second charging timing unit 12, the second comparison unit 32, the third driving unit 23 and the third contactor 43 at the output end of the second driving unit 22, thereby sequentially driving the first contactor 41, the second contactor 42 and the third contactor 43 to close, thereby achieving delayed driving of multiple contactors connected in parallel to close, reducing the instantaneous driving current of the contactor, and reducing the rated current of the driving power supply.
[0085] See also Figure 2 In some embodiments, the second driving unit 22 includes a second transistor Q4, the second charging timing unit 12 includes a third triode Q5, and the third driving unit 23 includes a third transistor Q6, the base of the third triode Q5 is connected to the source S of the second transistor Q4, the collector of the third triode Q5 is connected to the seventh power supply V7, and the emitter of the third triode Q5 is grounded. The gate G of the third transistor Q6 is connected to the output end of the second charging timing unit 12, the source S of the third transistor Q6 is grounded, and the drain D of the third transistor Q6 is connected to the third contactor 43.
[0086] After the third transistor Q5 of the second charging timing unit 12 is turned on, the second charging timing unit 12 starts to charge until the comparator threshold voltage of the second comparison unit 32 is reached, the output level of the second comparator unit 32 is flipped to a high level, and the third transistor Q6 of the third driving unit 23 is turned on, so that the third contactor 43 is attracted.
[0087] That is, the premise for the third contactor 43 of the present application to be attracted is that the third transistor Q5 in the second charging timing unit 12 is turned on and the second charging timing unit 12 starts to charge until the comparator threshold voltage of the second comparison unit 32 is reached, so that the output level of the second comparator unit 32 is flipped to a high level, that is, the high level signal is the second attraction signal, which can make the third transistor Q6 of the third driving unit 23 turned on, so that after the second contactor 42 is attracted, the third contactor 43 is attracted again.
[0088] In this way, the contactor drive circuit 100 of the present application can delay driving the three contactors connected in parallel to close, thereby reducing the instantaneous drive current of the contactor and lowering the rated current of the drive power supply.
[0089] In some embodiments, the contactor driving circuit 100 includes at least one second charging timing unit 12, at least one second comparing unit 32, at least one third driving unit 23, and at least one third contactor 43 connected in parallel. The second charging timing unit 12 of the next stage is connected to the source of the switching transistor in the third driving unit 23 of the previous stage, and the source is Figure 1 and Figure 2The S pole shown in FIG. 1 is used to sequentially drive at least one third contactor 43 to be attracted.
[0090] It can be understood that when the previous contactor is closed, that is, the previous switch transistor is turned on, the potential of its source will change, usually decrease, thereby triggering the second charging timing unit 12 to start charging. The contactor drive circuit 100 of the present application uses the principle of triggering the subsequent circuit by the change of the source potential when the switch transistor is turned on, so as to realize the closing of N contactors one by one.
[0091] That is, the third driving unit 23 of the present application can be expanded infinitely, and a circuit is added in which the input end of the second charging timing unit 12 is connected to the source of the switching transistor of the previous driving unit to determine whether the previous contactor is energized. After the previous contactor is energized, the second charging timing unit 12 starts charging timing. When the output end voltage of the second charging timing unit 12 reaches the voltage reference threshold of the comparison unit, the comparator in the comparison unit outputs a state reversal signal, thereby driving the next driving unit to achieve the energization of N contactors one by one.
[0092] It should be noted that Figure 1 and Figure 2 The voltages of the second power supply V2, the third power supply V3, the seventh power supply V7 and the eighth power supply V8 are all the same, and the voltage value of the fourth power supply Vdrive1 is equal to the voltage value of the sixth power supply Vdrive2. Similarly, the voltages of the corresponding positions in the corresponding drive circuits of other contactors are also the same.
[0093] The present application also provides an electrical device, which includes the contactor drive circuit 100 described in the above embodiment.
[0094] Specifically, the electrical device may be, for example, a frequency converter, or other devices, which are not limited here. The structure and working principle of the contactor drive circuit 100 are as described above, and will not be repeated here.
[0095] In this way, the contactor drive circuit 100 of the electrical device of the present application can delay driving a plurality of contactors connected in parallel to close, reduce the instantaneous drive current of the contactors, and lower the rated current of the drive power supply.
[0096] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.
Claims
1. A contactor drive circuit, characterized in that: The contactor drive circuit includes a charging timing module, a driving module, a comparison module and a contactor module; the charging timing module includes a first charging timing unit, the driving module includes a first driving unit and a second driving unit; the comparison module includes a first comparison unit; the contactor module includes a first contactor and a second contactor connected in parallel; The input end of the first charging timing unit receives the driving control signal; The first charging timing unit includes a first output branch and a second output branch connected in parallel, the first output branch includes a first output end, and the second output branch includes a second output end; the first output end is connected to the input end of the first driving unit, the output end of the first driving unit is connected to the first contactor, and the first driving unit is used to drive the first contactor to be attracted according to the driving control signal; The second output end is connected to the input end of the second driving unit through the first comparing unit, and the output end of the second driving unit is connected to the second contactor; The first comparison unit is used to determine that the first contactor is in the pull-in state and output a first pull-in signal to the second drive unit when it is determined that the voltage value of the second output terminal is greater than or equal to a preset threshold value; The second driving unit is used for driving the second contactor to be attracted according to the first attraction signal.
2. The contactor drive circuit according to claim 1, characterized in that: The contactor drive circuit further includes a control module and an optocoupler isolation module, wherein the control module is used to send an initial drive signal, a first end of the optocoupler isolation module is connected to the control module, and a second end of the optocoupler isolation module is connected to an input end of the first charging timing unit; The optical coupling isolation module is used to receive the initial driving signal and perform level conversion on the initial driving signal to output the driving control signal.
3. The contactor drive circuit according to claim 2, characterized in that: The optical coupling isolation module includes a photoelectric coupler and a first transistor, the base of the first transistor is connected to the control module, one end of the collector of the first transistor is connected to the cathode of the photoelectric coupler, and the emitter of the first transistor is grounded; the anode of the photoelectric coupler is connected to the input end of the first charging timing unit.
4. The contactor drive circuit according to claim 3, characterized in that: The optocoupler isolation module also includes a first filtering unit, which includes a first voltage-dividing resistor and a first filtering capacitor connected in parallel; the first end of the first filtering unit is connected to the control module, and the second end of the first filtering unit is connected to the base of the first transistor; the first filtering unit is used to filter the drive control signal to obtain a first drive signal.
5. The contactor drive circuit according to claim 4, characterized in that: The optical coupling isolation module also includes a second filtering unit, which includes a current limiting resistor, a bias resistor and a second filtering capacitor connected in parallel; a first end of the second filtering unit is connected to the collector of the first transistor, a second end of the second filtering unit is connected to the cathode of the photoelectric coupler, and a third end of the second filtering unit is connected to the first power supply; The second filtering unit is used to filter the second driving signal after the first driving signal is amplified by the first transistor to obtain the driving control signal.
6. The contactor drive circuit according to claim 1, characterized in that: The first charging timing unit includes: a second voltage-dividing resistor, a second transistor connected in parallel with the second voltage-dividing resistor, a third voltage-dividing resistor, and a third filter capacitor connected in parallel with the third voltage-dividing resistor; The first end of the second voltage-dividing resistor receives the driving control signal, the second end of the second voltage-dividing resistor is connected to the second power supply, the third end of the second voltage-dividing resistor is connected to the base of the second transistor, the emitter of the second transistor is connected to the second power supply, and the collector of the second transistor is respectively connected to the first driving unit and the first end of the third voltage-dividing resistor.
7. The contactor drive circuit according to claim 6, characterized in that: The first comparison unit includes a comparator, the second end of the third voltage-dividing resistor is connected to the first input end of the comparator, the second input end of the comparator is connected to a reference power supply, the power supply end of the comparator is connected to a third power supply, the ground end of the comparator is grounded, and the output end of the comparator is connected to the second driving unit.
8. The contactor drive circuit according to claim 6, characterized in that: The first driving unit includes a first driving resistor, a first discharge resistor, a first transistor and a first freewheeling diode, the first driving resistor is connected in parallel with the first discharge resistor, a first end of the first driving resistor is connected to the collector of the second transistor, a second end of the first driving resistor is connected to the first end of the first discharge resistor and the gate of the first transistor, and a second end of the first discharge resistor is grounded; a drain of the first transistor is connected to a first end of the first freewheeling diode, and a second end of the first freewheeling diode is connected to a fourth power supply; and a source of the first transistor is grounded; The second driving unit includes a second driving resistor, a second discharge resistor, a second transistor and a second freewheeling diode, the second driving resistor is connected in parallel with the second discharge resistor, a first end of the second driving resistor is connected to the output end of the comparator, a gate of the second transistor and a first end of the second discharge resistor, a second end of the second driving resistor is connected to a fifth power supply, a second end of the second discharge resistor is grounded, a drain of the second transistor is connected to a first end of the second freewheeling diode, a second end of the second freewheeling diode is connected to a sixth power supply; and a source of the second transistor is grounded.
9. The contactor drive circuit according to claim 1, characterized in that: The charging timing module includes a second charging timing unit, the driving module includes a third driving unit; the comparing module includes a second comparing unit; the contactor module includes a third contactor; The input end of the second charging timing unit is connected to the second driving unit, the input end of the second comparing unit is connected to the output end of the second charging timing unit, the input end of the third driving unit is connected to the output end of the second comparing unit, the third contactor is connected to the output end of the third driving unit, and the first contactor, the second contactor and the third contactor are connected in parallel; The second comparison unit is used to determine that the second contactor is in the energized state and output a second energization signal to the third drive unit when detecting that the voltage value corresponding to the output end of the second charging timing unit is greater than or equal to a preset threshold value. The third drive unit is used to drive the third contactor to energize according to the second energization signal.
10. The contactor drive circuit according to claim 9, characterized in that: The second driving unit includes a second transistor, the second charging timing unit includes a third triode, the third driving unit includes a third transistor, the base of the third triode is connected to the source of the second transistor, the collector of the third triode is connected to the seventh power supply, the emitter of the third triode is grounded, the gate of the third transistor is connected to the output end of the second charging timing unit, the source of the third transistor is grounded, and the drain of the third transistor is connected to the third contactor; After the third transistor of the second charging timing unit is turned on, the second charging unit starts to charge until the comparator threshold voltage of the second comparison unit is reached, the output level of the second comparator unit is flipped to a high level, and the third transistor of the third driving unit is turned on, so that the third contactor is energized.
11. The contactor drive circuit according to claim 9, characterized in that: The contactor driving circuit comprises at least one second charging timing unit, at least one second comparing unit, at least one third driving unit and at least one third contactor connected in parallel in sequence; Wherein, the input end of the second charging timing unit of the next stage is connected to the source of the switching transistor in the third driving unit of the previous stage, so as to sequentially drive the at least one third contactor to be attracted.
12. An electrical device, characterized in that: The electrical device comprises the contactor drive circuit according to any one of claims 1 to 11.