CN215120636U

CN215120636U - SPIM motor drive circuit

Info

Publication number: CN215120636U
Application number: CN202121245094.0U
Authority: CN
Inventors: 刘占军; 马少才
Original assignee: Shanghai Rujing Intelligent Control Technology Co ltd
Current assignee: Shanghai Rujing Intelligent Control Technology Co ltd
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2021-12-10
Anticipated expiration: 2031-06-04

Abstract

The utility model provides a SPIM motor driving circuit, which comprises a driver and an alternating current unit; the driver is connected with a first winding of the SPIM motor and comprises a rectifying unit, a direct current bus and an inverting unit; the rectification unit is connected with the direct current bus, the direct current bus is connected with the inversion unit, and the inversion unit is connected with the first winding; the alternating current unit is connected with a second winding of the SPIM motor. The utility model discloses a SPIM motor drive circuit can realize less start-up current and less energy loss, and only need provide the required partial energy of SPIM motor.

Description

SPIM motor drive circuit

Technical Field

The utility model relates to a Single Phase asynchronous machine (SPIM), especially relate to a SPIM Motor drive circuit.

Background

SPIM motors refer to asynchronous motors that use a single phase AC power supply. The SPIM motor has the advantages of convenient use, wide application, simple structure, low cost, low noise, small interference to a radio system and the like because only single-phase alternating current is needed, so the SPIM motor is commonly used in household appliances with low power and small power machines, such as electric fans, washing machines, refrigerators, air conditioners, range hoods, electric drills, medical instruments, small fans, household water pumps and the like.

In the prior art, a SPIM motor is generally composed of a stator, a rotor, a bearing, a casing, an end cover and the like. Because the output power is not large, the rotor of the SPIM motor usually adopts a squirrel-cage rotor, and the stator is provided with a set of working windings called as Main windings (M windings for short), which can only generate positive and negative alternating pulsating magnetic fields in the air gap of the motor, but can not generate a rotating magnetic field, so that the starting torque can not be generated. In order to generate a rotating magnetic field in the air gap of the motor, an auxiliary winding (Aux, abbreviated as a winding) is also required on the stator. Because the magnetic field generated by the auxiliary winding and the magnetic field of the main winding are combined in the air gap of the motor to generate a rotating magnetic field, the motor generates starting torque, so that the rotor can rotate by itself.

The prior art SPIM motor starts in the manner shown in FIG. 1. However, in this way, the starting current of the main winding is too large, which is 5-10 times of the rated current, so that the SPIM motor generates heat seriously, and energy waste is caused.

The SPIM motor starts to enter the running state after being started, and at this time, the capacitor can be connected in the way shown in FIG. 1, or in the way of partial connection shown in FIG. 2, or in the way of only main winding connection shown in FIG. 3. However, in the above mode of operation of the SPIM motor, since the design of the SPIM motor cannot guarantee that the start and operation meet the optimal operating point at the same time, and the flux linkage of the motor is generally elliptical, the torque and rotation speed fluctuation can be caused, and the energy consumption is large; meanwhile, the SPIM motor cannot be adjusted and controlled to be at the optimal working point according to the load condition, and the energy consumption is also high.

When the SPIM motor adopts power electronic devices, the SPIM motor can adopt various operation modes as shown in FIGS. 4-6, and has the advantages of small starting current, stable flux linkage control, small fluctuation of rotating speed and torque, small energy loss, stable rotating speed control and the like. However, all of the energy of the SPIM motor comes from the drive, resulting in the drive needing to withstand the full motor power.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcomings of the prior art, the present invention is directed to a SPIM motor driving circuit, which can realize smaller starting current and smaller energy loss, and only needs to provide part of the energy required by the SPIM motor.

To achieve the above and other related objects, the present invention provides a SPIM motor driving circuit, which includes a driver and an ac unit; the driver is connected with a first winding of the SPIM motor and comprises a rectifying unit, a direct current bus and an inverting unit; the rectification unit is connected with the direct current bus, the direct current bus is connected with the inversion unit, and the inversion unit is connected with the first winding; the alternating current unit is connected with a second winding of the SPIM motor.

In an embodiment of the present invention, the inverter unit employs a two-level inverter or a three-level inverter.

In an embodiment of the present invention, the dc bus is an electrolytic capacitor or a battery.

In an embodiment of the present invention, the rectification unit adopts a single-phase uncontrolled rectification circuit, a single-phase PWM rectifier, a single-phase boost rectification circuit, a totem-pole structure rectification circuit, a voltage-doubling rectification circuit, a three-phase uncontrolled rectification circuit or a three-phase controllable rectification circuit.

In an embodiment of the present invention, the ac unit includes an ac power source and a capacitor; and the alternating current power supply and the capacitor are connected in series and then connected to two ends of the second winding.

As described above, the SPIM motor driving circuit of the present invention has the following advantages:

(1) the second winding is connected to the power grid through the capacitor, so that small starting current is realized; the first winding is connected to the driving circuit, so that the starting current is controllable;

(2) the current of the first winding can be adjusted to enable the synthetic magnetic field of the first winding and the second winding to be circular, so that the loss of the motor is reduced, and the efficiency of the motor is improved; the torque and rotating speed fluctuation is smaller, so that the motor abrasion is reduced, and the service life of the motor is prolonged;

(3) the driver only needs to provide part of energy required by the motor, and the other part of energy is directly provided by the power grid;

(4) the use of a high-current switch device is effectively saved, and the circuit cost is reduced.

Drawings

FIG. 1 is a schematic diagram of a SPIM motor start circuit in an embodiment of the prior art;

FIG. 2 is a schematic structural diagram of a SPIM motor operating circuit in a first embodiment in the prior art;

FIG. 3 is a schematic diagram of a SPIM motor operating circuit in a second embodiment of the prior art;

FIG. 4 is a schematic structural diagram of a SPIM motor control circuit in a third embodiment in the prior art;

FIG. 5 is a schematic diagram of a prior art SPIM motor control circuit in a fourth embodiment;

FIG. 6 is a schematic diagram of a prior art SPIM motor control circuit in a fifth embodiment;

fig. 7 is a schematic structural diagram of an embodiment of the SPIM motor driving circuit of the present invention;

fig. 8 is a flowchart illustrating a SPIM motor driving method according to an embodiment of the present invention.

Description of the element reference numerals

1 driver

11 rectifying unit

12 DC bus

13 inverter unit

2 alternating current unit

21 AC power supply

22 capacitance

3 SPIM motor

31 first winding

32 second winding

Detailed Description

The following description is provided for illustrative purposes, and other advantages and features of the present invention will become apparent to those skilled in the art from the following detailed description.

It should be understood that the structure, ratio, size and the like shown in the drawings attached to the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limit conditions that the present invention can be implemented, so that the present invention has no technical essential meaning, and any structure modification, ratio relationship change or size adjustment should still fall within the scope that the technical content disclosed in the present invention can cover without affecting the function that the present invention can produce and the purpose that the present invention can achieve. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description, and are not intended to limit the scope of the present invention, and changes or adjustments of the relative relationship thereof may be made without substantial technical changes, and the present invention is also regarded as the scope of the present invention.

The utility model discloses a SPIM motor drive circuit connects in the driver through the first winding with the SPIM motor, and the second winding is connected in the electric wire netting to realize the supply of the required energy of SPIM motor by driver and electric wire netting in coordination, realized less start current and less energy loss simultaneously, have the practicality. Wherein the first winding and the second winding form a main winding and an auxiliary winding of the SPIM motor. Namely, the first winding is a main winding or an auxiliary winding, and the second winding is an auxiliary winding or a main winding.

As shown in fig. 7, in an embodiment, the SPIM motor driving circuit of the present invention includes a driver 1 and an ac unit 2. The driver 1 is used for driving a first winding of the SPIM motor, and the alternating current unit 2 is used for driving a second winding of the SPIM motor, so that a small starting current is realized, and the starting current is controllable.

The driver 1 is connected with a first winding 31 of the SPIM motor 3, and comprises a rectifying unit 11, a direct current bus 12 and an inverting unit 13.

The rectifying unit 11 is connected to the dc bus 12, and is configured to convert an input AC into a dc and input the dc into the dc bus 12. Specifically, the rectification unit 11 adopts a single-phase uncontrolled rectification circuit, a single-phase PWM rectifier, a single-phase boost rectification circuit, a totem-pole structure rectification circuit, a voltage doubling rectification circuit, a three-phase uncontrolled rectification circuit or a three-phase controllable rectification circuit. Preferably, the rectifying unit 11 may adopt a two-level rectifying circuit as shown in fig. 7, or may adopt a three-level rectifying circuit. The rectifier circuit that only needs to convert the input alternating current into the direct current is in the protection scope of the utility model. In this embodiment, the input AC and the inductor are connected in series between two input ends of the rectifying unit 11, and two output ends are respectively connected to two ends of the dc bus 12.

The dc bus 12 is connected to the inverter unit 13, and is configured to input the dc power to the inverter unit 13. Specifically, two ends of the dc bus 12 are respectively connected to two input ends of the inverter unit 13, and are configured to carry the dc power generated by the rectifier unit 11 and input the dc power to the inverter unit 13. In an embodiment of the present invention, the dc bus 12 is an electrolytic capacitor or a battery.

The inverter unit 13 is connected to the first winding 31, and is configured to convert the dc power into ac power, and input the ac power to the first winding 31 of the SPIM motor 3 to drive the first winding 31. Specifically, two output ends of the inverter unit 13 are respectively connected to two ends of the first winding 31, so that conversion from direct current to alternating current can be realized, and the alternating current obtained by the conversion is input to the first winding 31 to complete driving of the first winding 31. In an embodiment of the present invention, the inverter unit 13 may adopt a two-level inverter as shown in fig. 7, or may adopt a three-level inverter.

The ac unit 2 is connected to the second winding 32 of the SPIM motor 3, and the second winding 32 is driven by inputting ac power. In an embodiment of the present invention, the ac unit 2 includes an ac power source 21 and a capacitor 22. The alternating current power supply 21 and the capacitor 22 are connected in series and then connected to two ends of the second winding 32 to complete the driving of the second winding 32.

As shown in fig. 8, in an embodiment, the SPIM motor driving method of the present invention includes the following steps;

step S1, converting the input ac power into dc power based on the rectifying unit, and inputting the dc power into the dc bus.

Specifically, the rectification unit adopts a single-phase uncontrolled rectification circuit, a one-way boost rectification circuit, a totem-pole structure rectification circuit, a voltage doubling rectification circuit, a three-phase uncontrolled rectification circuit or a three-phase controllable rectification circuit. Preferably, the rectifying unit may adopt a two-level rectifying circuit as shown in fig. 7, or may adopt a three-level rectifying circuit. The rectifier circuit that only needs to convert the input alternating current into the direct current is in the protection scope of the utility model. In this embodiment, two neutral points of the rectifying unit are respectively connected to the input ac and the inductor, and two ends of the rectifying unit are respectively connected to two ends of the dc bus.

And step S2, inputting the direct current into an inversion unit based on the direct current bus.

Specifically, two ends of the dc bus are respectively connected to two ends of the inverter unit, and the dc bus can carry the dc power generated by the rectifier unit and input the dc power to the inverter unit. In an embodiment of the present invention, the dc bus is an electrolytic capacitor or a battery.

Step S3, converting the direct current into alternating current based on the inversion unit, and inputting the alternating current into a first winding of the SPIM motor to drive the first winding; driving a second winding of the SPIM motor based on an AC unit connected to the second winding.

Specifically, two output ends of the inverter unit are respectively connected to two ends of the first winding, so that conversion from direct current to alternating current can be realized, and the alternating current obtained through conversion is input to the first winding to complete driving of the first winding. In an embodiment of the present invention, the inverter unit may adopt a two-level inverter as shown in fig. 7, or may adopt a three-level inverter.

Specifically, the alternating current unit comprises an alternating current power supply and a capacitor. And the alternating current power supply and the capacitor are connected in series and then connected to two ends of the second winding to complete the driving of the second winding.

Preferably, the SPIM motor driving method of the present invention further includes adjusting the current of the first winding to make the resultant magnetic field of the first winding and the second winding form a circular shape, so as to reduce the damage and wear of the SPIM motor, and improve the energy efficiency and the life of the SPIM motor.

To sum up, the SPIM motor driving circuit of the utility model has a smaller current when starting because the second winding is connected to the power grid through the capacitor; the first winding is connected to the driving circuit, so that the starting current is controllable and is small; the current of the first winding can be adjusted to enable the synthetic magnetic field of the first winding and the second winding to be circular, so that the loss of the motor is reduced, and the efficiency of the motor is improved; the torque and rotating speed fluctuation is smaller, so that the motor abrasion is reduced, and the service life of the motor is prolonged; the driver only needs to provide part of energy required by the motor, and the other part of energy is directly provided by the power grid; the use of a high-current switch device is effectively saved, and the circuit cost is reduced. Therefore, the utility model effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A SPIM motor drive circuit characterized by: comprises a driver and an alternating current unit;

the driver is connected with a first winding of the SPIM motor and comprises a rectifying unit, a direct current bus and an inverting unit; the rectification unit is connected with the direct current bus, the direct current bus is connected with the inversion unit, and the inversion unit is connected with the first winding;

the alternating current unit is connected with a second winding of the SPIM motor.

2. The SPIM motor drive circuit of claim 1, wherein: the inversion unit adopts a two-level inverter or a three-level inverter.

3. The SPIM motor drive circuit of claim 1, wherein: the direct current bus adopts an electrolytic capacitor or a battery.

4. The SPIM motor drive circuit of claim 1, wherein: the rectification unit adopts a single-phase uncontrolled rectification circuit, a single-phase PWM rectifier, a single-phase boost rectification circuit, a totem-pole structure rectification circuit, a voltage doubling rectification circuit, a three-phase uncontrolled rectification circuit or a three-phase controllable rectification circuit.

5. The SPIM motor drive circuit of claim 1, wherein: the alternating current unit comprises an alternating current power supply and a capacitor; and the alternating current power supply and the capacitor are connected in series and then connected to two ends of the second winding.