Power supply circuit of vacuum pump, control circuit of vacuum pump and vacuum pump

Abstract

The utility model relates to the field of vacuum pumps, and provides a vacuum pump power supply circuit, a vacuum pump control circuit and a vacuum pump. The power supply circuit of the vacuum pump comprises a frequency conversion unit and a voltage conversion unit. Wherein the frequency conversion unit comprises a direct current bus, an energy storage circuit and an inverter circuit which are connected in sequence. The inverter circuit is connected with a motor unit of the vacuum pump. The motor unit is used for outputting charging electric energy to the inverter circuit when the actual rotating speed is smaller than the driving rotating speed. The inverter circuit charges the energy storage circuit according to the charging electric energy. The voltage conversion unit is connected with the DC bus. The energy storage circuit can maintain the voltage of the direct-current bus within a period of time after instantaneous power failure or voltage fluctuation occurs, so that the voltage conversion unit can continuously output working power to the control unit of the vacuum pump within the period of time, and it is ensured that the control unit of the vacuum pump cannot be powered down when the instantaneous power failure or the voltage fluctuation occurs. The power supply stability of the vacuum pump is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vacuum pumps, and particularly relates to a power supply circuit of a vacuum pump, a control circuit of the vacuum pump and the vacuum pump. BACKGROUND

[0002] The vacuum pump is used for vacuumizing and / or maintaining a vacuum environment of a closed space or a closed container, such as a closed warehouse, a gas tank and the like. At present, when a vacuum environment of a closed space is manufactured or maintained by using a vacuum pump, a related power supply scheme of the vacuum pump can provide alternating current for a motor unit of the vacuum pump and provide direct current for a control unit of the vacuum pump.

[0003] However, when instantaneous power failure or voltage fluctuation occurs, the power supply of the control unit will be affected, and even after the power supply is restored, the control unit will be restarted or the vacuum pump will be stopped, thereby affecting the normal work of the vacuum pump. Therefore, a new scheme capable of improving the stability of the vacuum pump is urgently needed. INNOVATION CONTENT

[0004] The application aims to provide a power supply circuit of a vacuum pump, a control circuit of the vacuum pump and the vacuum pump, and provide a new scheme capable of improving the power supply stability of the vacuum pump.

[0005] The first aspect of the application provides a power supply circuit of a vacuum pump, comprising:

[0006] A frequency conversion unit comprising a direct current bus, an energy storage circuit and an inverter circuit connected in sequence, the inverter circuit is connected with a motor unit of the vacuum pump, the motor unit is used for outputting charging electric energy to the inverter circuit when an actual rotating speed is less than a driving rotating speed, and the direct current bus is used for connecting with an external power supply;

[0007] A voltage conversion unit connected with the direct current bus, the voltage conversion unit is used for converting the voltage of the direct current bus to output working electricity to a control unit of the vacuum pump;

[0008] The inverter circuit is used for charging the energy storage circuit by using the charging electric energy.

[0009] The embodiment of the present application provides a power supply circuit of a vacuum pump, which comprises a frequency conversion unit and a voltage conversion unit. The frequency conversion unit comprises a DC bus, an energy storage circuit and an inverter circuit connected in sequence. The inverter circuit is connected with a motor unit of the vacuum pump. The motor unit is used for outputting charging electric energy to the inverter circuit when the actual rotating speed is less than the driving rotating speed. Since the DC bus is used for being connected with an external power supply, the voltage conversion unit is connected with the DC bus, so that the inverter circuit and the voltage conversion unit can take electric energy from the DC bus, the inverter circuit outputs alternating current to the motor unit of the vacuum pump, and the voltage conversion unit outputs working electric energy to a control unit of the vacuum pump. When the external power supply is instantaneously powered off or voltage fluctuates, the actual rotating speed of the motor unit is less than the driving rotating speed after the motor unit is instantaneously powered off, at this moment, the motor unit generates an induced electromotive force under the action of rotating inertia and rotating speed sudden drop, and then generates electric energy output to the inverter circuit with gradually decreasing current. The inverter circuit can use the electric energy as the charging electric energy to charge the energy storage circuit. In this way, the energy storage circuit can maintain the voltage of the DC bus for a period of time after the instant power-off or voltage fluctuation, so that the voltage conversion unit can continuously output working electric energy to the control unit of the vacuum pump in the period of time, and ensures that the control unit of the vacuum pump is not powered off when the instant power-off or voltage fluctuation occurs, thereby avoiding that the control unit is restarted or the vacuum pump is stopped after the power supply is restored, and the stability of the power supply of the vacuum pump is improved.

[0010] The second aspect of the embodiment of the present application provides a control circuit of a vacuum pump, which further comprises the power supply circuit of the vacuum pump provided in the first aspect.

[0011] The third aspect of the embodiment of the present application provides a vacuum pump, which further comprises the control circuit of the vacuum pump provided in the second aspect.

[0012] It can be understood that the beneficial effects of the control circuit of the vacuum pump provided in the second aspect and the vacuum pump provided in the third aspect can be referred to the related description in the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A structural schematic diagram of the power supply circuit of the vacuum pump provided in the embodiment of the present application;

[0014] Figure 2 A structural schematic diagram of the power supply circuit of the vacuum pump provided in another embodiment of the present application;

[0015] Figure 3 A structural schematic diagram of the power supply circuit of the vacuum pump provided in another embodiment of the present application;

[0016] Figure 4 A whole scheme schematic diagram of the power supply circuit of the vacuum pump provided in the embodiment of the present application;

[0017] Figure 5 A structural schematic diagram of a control circuit of a vacuum pump is provided for an embodiment of the present application.

[0018] Figure 6 A structural schematic diagram of a vacuum pump is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0020] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0021] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0022] Reference Figure 1 , Figure 1 A structural schematic diagram of a power supply circuit of a vacuum pump is shown according to an embodiment of the present application. For ease of illustration, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0023] In Figure 1 , a power supply circuit 100 of a vacuum pump includes a frequency conversion unit 10 and a voltage conversion unit 20. Specifically:

[0024] The frequency conversion unit 10 includes a direct current bus 11, an energy storage circuit 12 and an inverter circuit 13 connected in sequence. The inverter circuit 13 is connected to a motor unit 110 of the vacuum pump, and the motor unit 110 is configured to output charging electric energy to the inverter circuit 13 when the actual rotation speed is less than the drive rotation speed. The direct current bus 11 is configured to be connected to an external power supply. The voltage conversion unit 20 is connected to the direct current bus 11. The voltage conversion unit 20 is configured to convert the voltage of the direct current bus 11 to output working electric energy to a control unit 120 of the vacuum pump. The inverter circuit 13 is configured to charge the energy storage circuit 12 with the charging electric energy.

[0025] In the embodiment, the DC bus 11, the energy storage circuit 12 and the inverter circuit 13 in the frequency conversion unit 10 are connected in sequence, so that when the inverter circuit 13 is used to output AC power to the motor unit 110, the energy storage circuit 12 can obtain the power on the DC bus 11, and after the energy storage circuit 12 is charged with the charging power, the energy storage circuit 12 can maintain the voltage on the DC bus 11, thereby continuously supplying power to the voltage conversion unit 20.

[0026] For example, in the specific implementation, one end of the DC bus 11 is connected with the energy storage circuit 12, and the other end is used to connect an external power supply. Here, the external power supply can be a power supply providing DC power, such as a storage battery, a battery pack, etc. Of course, the external power supply can also be a power supply providing AC power, such as a mains power supply, etc., which is not limited here.

[0027] It is easy to understand that when the external power supply is a power supply providing AC power, the AC power provided by the external power supply can be converted by an AC-DC conversion circuit, and then output as DC power through the DC bus 11.

[0028] In the embodiment, when the vacuum pump is powered, the inverter circuit 13 and the voltage conversion unit 20 can both obtain power from the DC bus 11. The inverter circuit 13 outputs AC power to the motor unit 110 of the vacuum pump, and the voltage conversion unit 20 converts the voltage of the DC bus 11 to output working power to the control unit 120 of the vacuum pump.

[0029] For example, the DC bus 11 can output DC power to the inverter circuit 13 through the energy storage circuit 12, and the DC power can specifically be DC power with a voltage greater than or equal to a preset voltage value. For example, the DC bus 11 can provide DC power with a converted voltage, or DC power with a constant voltage equal to the preset voltage value.

[0030] As an example, when the DC bus 11 can provide DC power with a converted voltage to the energy storage circuit 12, the energy storage circuit 12 is charged to the preset voltage value under the action of the DC power. The inverter circuit 13 can output AC power to the motor unit 110 under the action of the voltage of the energy storage circuit 12.

[0031] As another example, when the DC bus 11 can provide DC power with a constant voltage equal to the preset voltage value, the energy storage circuit 12 is not charged under the action of the DC power. The inverter circuit 13 can output AC power to the motor unit 110 under the action of the DC power provided by the DC bus 11.

[0032] In all embodiments of the present application, the control unit 120 of the vacuum pump at least includes a controller for controlling the operation of the motor unit 110 of the vacuum pump, and an external circuit of the controller.

[0033] Based on this, the voltage conversion unit 20 outputs working electricity for the control unit 120 of the vacuum pump, which can be low-voltage direct current suitable for the control unit 120. The direct current bus 11 provides direct current, and the voltage conversion unit 20 converts the direct current voltage provided by the direct current bus 11 to obtain low-voltage direct current suitable for the control unit 120 when taking electricity from the direct current bus 11.

[0034] In a specific implementation, the voltage conversion unit 20 can be implemented by using an existing DC-DC conversion circuit. For example, the voltage conversion unit 20 can include a DC-DC voltage conversion chip, and a corresponding DC-DC conversion circuit can be built based on the DC-DC voltage conversion chip. By converting the direct current voltage of the direct current bus 11, the control unit 120 is provided with suitable low-voltage direct current.

[0035] As an embodiment, the voltage conversion unit 20 can include a voltage reduction circuit (not shown in the figure). The voltage reduction circuit is connected between the direct current bus 11 and the control unit 120 of the vacuum pump. The voltage reduction circuit is used to reduce the voltage of the direct current bus 11 to obtain working electricity, and the voltage range of the working electricity is between 10V and 38V. Here, the working electricity refers to the working electricity of the control unit 120.

[0036] Taking the voltage range of the direct current bus 11 as an example, the voltage conversion unit 20 can reduce the voltage of the direct current bus 11 to obtain working electricity with a voltage range of 10V to 38V.

[0037] It is easy to understand that the actual speed of the motor unit 110 is less than the drive speed, which means that the speed of the motor unit 110 at a certain moment is lower than the drive speed or the indicated speed. For example, when a transient power failure or voltage fluctuation occurs, the power supply that provides power to the power supply circuit is disconnected for a short time / instant and then restored. During this process, it is easy to have the phenomenon that the actual speed of the motor unit 110 is less than the drive speed. In actual application, taking the power supply that provides power to the power supply circuit as an example, it is easy to have the phenomenon of transient power failure or voltage fluctuation due to line switching or partial power grid failure of the power supply, and the time of transient power failure or voltage fluctuation is very short, about a few milliseconds to a few milliseconds.

[0038] In the embodiment, when the instantaneous power failure or voltage fluctuation occurs, the actual rotating speed of the motor unit 110 is less than the driving rotating speed after the instantaneous power failure of the motor unit 110, and the induced electromotive force is generated under the action of the rotating inertia and the rotating speed sudden drop. That is, when the instantaneous power failure or voltage fluctuation occurs, the working state of the motor unit 110 is equivalent to that of a generator, and the gradually decreasing current electric energy can be output to the inverter circuit 13. Based on this, the inverter circuit 13 can use the electric energy as the charging electric energy to charge the energy storage circuit 12.

[0039] Exemplarily, in the specific implementation, the alternating current output by the inverter circuit 13 to the motor unit 110 can be three-phase alternating current. Correspondingly, the inverter circuit 13 can be a three-phase inverter circuit, such as a three-phase voltage type inverter circuit.

[0040] As an example, the inverter circuit 13 is a three-phase inverter circuit, which can specifically include three groups of switching tube branches. When the instantaneous power failure or voltage fluctuation occurs, the working state of the motor unit 110 is equivalent to that of a generator, and the gradually decreasing current electric energy is output to the inverter circuit 13. That is, the electric energy is transmitted to the energy storage circuit 12 through the parasitic diode of each switching tube in the three groups of switching tube branches, and then the electric energy output by the motor unit 110 during the instantaneous power failure can be used as the charging electric energy by the inverter circuit 13 to charge the energy storage circuit 12.

[0041] From a microscopic point of view, when the instantaneous power failure or voltage fluctuation occurs, the direct current bus 11 also has an instantaneous power failure, or the electric energy of the energy storage circuit 12 is exhausted due to the large electric energy required by the motor unit 110. At this time, since the voltage conversion unit 20 provides low-voltage direct current for the working electric energy of the control unit 120, the voltage conversion unit 20 will not immediately lose power when the direct current bus 11 also has an instantaneous power failure or the electric energy of the energy storage circuit 12 is exhausted. Within a few milliseconds to tens of milliseconds of the recovery of the power supply, the induced electric energy generated by the motor unit 110 can be transmitted to the energy storage circuit 12 through the inverter circuit 13, that is, the energy storage circuit 12 is charged, so that the electric energy on the direct current bus 11 can be maintained. Based on this, the voltage conversion unit 20 can continuously take electric energy from the direct current bus 11 to provide working electric energy for the control unit 120 within a few milliseconds to tens of milliseconds of the recovery of the power supply.

[0042] The scheme provides a power supply circuit 100 of a vacuum pump, including a frequency conversion unit 10 and a voltage conversion unit 20. The frequency conversion unit 10 includes a DC bus 11, an energy storage circuit 12 and an inverter circuit 13 connected in sequence. The inverter circuit 13 is connected with a motor unit 110 of the vacuum pump. The motor unit 110 is used to output charging electric energy to the inverter circuit 13 when the actual rotating speed is less than the driving rotating speed. Since the DC bus 11 is used to be connected with an external power supply, the voltage conversion unit 20 is connected with the DC bus 11, so that the inverter circuit 13 and the voltage conversion unit 20 can take electric energy from the DC bus 11. The inverter circuit 13 outputs alternating current to the motor unit 110 of the vacuum pump, and the voltage conversion unit 20 outputs working electric energy to a control unit 120 of the vacuum pump. When the external power supply is instantaneously powered off or voltage fluctuates, the motor unit 110 is instantaneously powered off, and the actual rotating speed is less than the driving rotating speed. At this time, the motor unit 110 generates an induced electromotive force under the action of rotating inertia and rotating speed sudden drop, and then generates electric energy output to the inverter circuit 13 with gradually decreasing current. The inverter circuit 13 can use the electric energy as charging electric energy to charge the energy storage circuit 12. In this way, the energy storage circuit 12 can maintain the voltage of the DC bus 11 for a period of time after the instant power-off or voltage fluctuation, so that the voltage conversion unit 20 can continuously output working electric energy to the control unit 120 of the vacuum pump for the period of time, ensuring that the control unit 120 of the vacuum pump is not powered off when the instant power-off or voltage fluctuation occurs, thereby avoiding the restart of the control unit 120 or the shutdown of the vacuum pump after the power supply is restored, and improving the stability of the power supply of the vacuum pump.

[0043] Figure 2 A structure diagram of a power supply circuit of a vacuum pump provided by another embodiment of the application is shown. As shown in Figure 2 , as an embodiment, different from the embodiment shown in Figure 1 , the frequency conversion unit 10 further includes a rectifier circuit 14.

[0044] In Figure 2 , one end of the rectifier circuit 14 is connected with the DC bus 11. The other end of the one end of the rectifier circuit 14 is connected with an alternating current power supply. The rectifier circuit 14 is used to rectify the alternating current of the alternating current power supply and output direct current.

[0045] In the embodiment, the external power supply is an alternating current power supply. The rectifier circuit 14 rectifies the alternating current provided by the alternating current power supply, and can directly output the rectified direct current through the DC bus 11, or can set a voltage conversion circuit to perform voltage conversion on the rectified direct current, obtain direct current with higher voltage, and then output the direct current through the DC bus 11.

[0046] In practice, the rectifier circuit 14 can be implemented using an existing full-bridge rectifier circuit or a half-bridge rectifier circuit; no restrictions are imposed here.

[0047] The above solution, by setting a rectifier circuit 14 in the frequency converter unit 10, allows the power supply circuit 100 of the vacuum pump to be directly connected to AC power, thus broadening the application range of the power supply circuit 100 of the vacuum pump.

[0048] Figure 3 A schematic diagram of the power supply circuit for a vacuum pump according to another embodiment of this application is shown. Figure 3 As shown, as an example, with Figure 2 The illustrated embodiment differs in that the frequency converter 10 further includes a unidirectional voltage conversion circuit 15. Figure 2 In the circuit, one end of the unidirectional voltage conversion circuit 15 is connected to the rectifier circuit 14, and the other end of the unidirectional voltage conversion circuit 15 is connected to the DC bus 11.

[0049] In this embodiment, the unidirectional voltage conversion circuit 15 can perform voltage conversion based on the DC power output from the rectifier circuit 14, and then output DC power with a constant voltage to the DC bus 11.

[0050] For example, in a specific implementation, the unidirectional voltage conversion circuit 15 can specifically utilize a DC-DC boost circuit. After rectifying the AC power, the rectifier circuit 14 outputs DC power to the DC-DC boost circuit. The DC-DC boost circuit boosts the DC power and then provides the boosted DC power to the DC bus 11.

[0051] It is easy to understand that since the unidirectional voltage conversion circuit 15 is connected between the rectifier circuit 14 and the DC bus 11, when the external power supply, such as the AC power supply, experiences a momentary power outage or voltage fluctuation, the inverter circuit 13 uses the charging energy provided by the motor unit 110 to charge the energy storage circuit 12. Therefore, while the energy storage circuit 12 maintains the voltage of the DC bus 11, the voltage of the DC bus 11 will not flow back through the unidirectional voltage conversion circuit 15. That is, the unidirectional voltage conversion circuit 15 can also serve as an isolation mechanism.

[0052] Figure 4 A schematic diagram of the overall scheme of a power supply circuit for a vacuum pump provided in an embodiment of this application is shown. Figure 4 As shown in the illustration, as one embodiment, the DC bus includes a first DC bus DC+ and a second DC bus DC-. The frequency converter unit 10 also includes an inductor L.

[0053] The first end of the inductor L is connected to the first DC bus DC+, and the second end of the inductor L is connected to the energy storage circuit 12.

[0054] Combination Figures 1 to 4In the embodiment, the inductor L is connected between the first DC bus DC+ and the energy storage circuit 12, which can reduce the DC fluctuation of the output of the rectifier circuit 14 and ensure the stability of the DC on the DC bus 11.

[0055] As shown in Figure 4 , as an embodiment, the energy storage circuit 12 at least includes an energy storage capacitor C. The first end of the energy storage capacitor C is connected with the second end of the inductor L, and the second end of the energy storage capacitor C is connected with the second DC bus DC-.

[0056] In the embodiment, the first end of the energy storage capacitor C is connected with the second end of the inductor L, and the second end of the energy storage capacitor C is connected with the second DC bus DC-, which is equivalent to connecting the energy storage capacitor C between the first DC bus DC+ and the second DC bus DC-.

[0057] Based on this, when the instantaneous power failure or voltage fluctuation occurs, the inverter circuit 13 can charge the energy storage capacitor C by using the charging power provided by the motor unit 110. In this way, the energy storage capacitor C can maintain the voltage of the DC bus 11 for a period of time after the instantaneous power failure or voltage fluctuation occurs, that is, maintain the voltage difference between the first DC bus DC+ and the second DC bus DC-, so that the voltage conversion unit 20 can continuously output the working power for the control unit 120 of the vacuum pump in the period of time, ensuring that the control unit 120 of the vacuum pump will not be powered off when the instantaneous power failure or voltage fluctuation occurs, thereby avoiding the restart of the control unit 120 or the shutdown of the vacuum pump after the power is restored, and improving the stability of the vacuum pump power supply.

[0058] Figure 5 A structure diagram of a control circuit of a vacuum pump provided by an embodiment of the application is shown. As shown in Figure 5 , the control circuit 200 of the vacuum pump includes the control unit 120, and further includes the power supply circuit 100 of the vacuum pump provided by the above embodiment.

[0059] In the embodiment, the frequency conversion unit 10 and the voltage conversion unit 20 are respectively arranged on different circuit boards. In specific implementation, the voltage conversion unit 20 can be connected with the DC bus 11 through external wires.

[0060] It can be understood that the control circuit of the vacuum pump provided by the embodiment, the improvement points and specific implementation manners related to the application have been described in detail in the Figures 1 to 4 embodiment of the corresponding power supply circuit 100 of the vacuum pump, so for details, please refer to the related description in the Figures 1 to 4 and Figures 1 to 4 corresponding embodiments, which will not be repeated here.

[0061] Figure 6A structural schematic diagram of a vacuum pump is shown. As shown in Figure 6 The vacuum pump 300 includes the motor unit 110, and further includes the control circuit 200 of the vacuum pump provided in the above embodiments.

[0062] In all embodiments of the present application, the motor unit 110 can specifically include a synchronous motor and / or an asynchronous motor.

[0063] In a specific implementation, the frequency conversion unit 10 can specifically be a frequency converter. That is, the energy storage circuit 12, the inverter circuit 13, and the rectifier circuit 14 can be packaged in an inverter.

[0064] As an embodiment, the frequency conversion unit 10 is configured on a first circuit board (not shown in the figure). Here, in order to isolate the strong electricity from the weak electricity, the voltage conversion unit 20 and the frequency conversion unit 10 can be respectively arranged on different circuit boards. That is, the voltage conversion unit 20 is arranged on a circuit board other than the first circuit board.

[0065] In an embodiment, the frequency conversion unit 10 and the control unit 120 are respectively configured on different circuit boards. And / or the voltage conversion unit 20 and the control unit 120 are respectively configured on different circuit boards.

[0066] In combination with the above example, the frequency conversion unit 10 is configured on the first circuit board. In an example, the voltage conversion unit 20 and the control unit 120 are both configured on a second circuit board (not shown in the figure). In another embodiment, the voltage conversion unit 20 is configured on the second circuit board (not shown in the figure). The control unit 120 is configured on a third circuit board (not shown in the figure).

[0067] In all embodiments of the present application, the motor unit 110 can specifically include a synchronous motor and / or an asynchronous motor.

[0068] It can be understood that the vacuum pump 300 provided in the present embodiment, the improvement points and specific implementation manners related to the present application, have been described in detail in the Figures 1 to 5 The embodiments of the power supply circuit 100 of the corresponding vacuum pump and the control circuit 200 of the vacuum pump are described in detail, so for details, please refer to Figures 1 to 5 , and Figures 1 to 5 The related descriptions in the corresponding embodiments, which will not be repeated here.

[0069] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0070] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A power supply circuit for a vacuum pump, characterized in that, include: The frequency conversion unit includes a DC bus, an energy storage circuit, and an inverter circuit connected in sequence. The inverter circuit is connected to the motor unit of the vacuum pump. The motor unit is used to output charging energy to the inverter circuit when the actual speed is less than the driving speed. The DC bus is used to connect to an external power source. A voltage conversion unit is connected to the DC bus. The voltage conversion unit is used to convert the voltage of the DC bus to output working power to the control unit of the vacuum pump. The inverter circuit is used to charge the energy storage circuit using the charging energy.

2. The power supply circuit for the vacuum pump according to claim 1, characterized in that, The frequency conversion unit also includes: a rectifier circuit; One end of the rectifier circuit is connected to the DC bus, and the other end of the rectifier circuit is connected to the AC power supply. The rectifier circuit is used to rectify the AC power supply and output DC power.

3. The power supply circuit for the vacuum pump according to claim 2, characterized in that, The frequency conversion unit also includes: A unidirectional voltage conversion circuit, one end of which is connected to the rectifier circuit, and the other end of which is connected to the DC bus.

4. The power supply circuit for the vacuum pump according to claim 2, characterized in that, The DC bus includes a first DC bus and a second DC bus; The frequency conversion unit also includes: an inductor; The first end of the inductor is connected to the first DC bus, and the second end of the inductor is connected to the energy storage circuit.

5. The power supply circuit for the vacuum pump according to claim 4, characterized in that, The energy storage circuit includes at least an energy storage capacitor; The first end of the energy storage capacitor is connected to the second end of the inductor, and the second end of the energy storage capacitor is connected to the second DC bus.

6. The power supply circuit for the vacuum pump according to claim 1, characterized in that, The voltage conversion unit includes a step-down circuit, which is connected between the DC bus and the control unit of the vacuum pump. The step-down circuit is used to step down the voltage of the DC bus to obtain the working power, and the voltage range of the working power is between 10V and 38V.

7. A control circuit for a vacuum pump, comprising a control unit, characterized in that, The control circuit of the vacuum pump also includes the power supply circuit of the vacuum pump as described in any one of claims 1 to 6; The frequency conversion unit and the voltage conversion unit are respectively configured on different circuit boards; The voltage conversion unit is connected to the DC bus via an external wire.

8. A vacuum pump, comprising a motor unit, characterized in that, The vacuum pump also includes the control circuit of the vacuum pump as described in claim 7.

9. The vacuum pump according to claim 8, characterized in that, The frequency converter and the control unit are respectively configured on different circuit boards; and / or The voltage conversion unit and the control unit are respectively configured on different circuit boards.

10. The vacuum pump according to any one of claims 7 to 9, characterized in that, The motor unit includes synchronous motors and / or asynchronous motors.

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