CN221227385U - Motor circuit and vehicle - Google Patents

Abstract

The application provides a motor circuit and a vehicle. The motor circuit includes a motor and a switching circuit. The motor comprises multiphase windings, at least two of which are connected to form a neutral point, and at least two neutral points are provided. The switching circuit is connected between at least two neutral points and used for controlling the on-off of a circuit between the neutral points; when the motor is in a first rotating speed state, the switching circuit is in a first state, and the switching circuit breaks a line between neutral points; when the motor is in the second rotating speed state, the switching circuit is in the second state, and the switching circuit is communicated with a line between neutral points. The motor circuit provided by the application controls the state of the motor by adding the switching circuit connected between neutral points, and can control the number of motor phases and the magnitude of motor flux linkage at different rotating speeds so as to improve the efficiency and torque density of the motor.

Description

Motor circuit and vehicle

Technical Field

The present application relates to the field of motor control technologies, and in particular, to a motor circuit and a vehicle.

Background

The current driving motor of the electric automobile requires high efficiency, high power density, high reliability, low noise and low cost. A multiphase motor achieves one of the technical means of this requirement. The six-phase motor can offset specific order harmonic waves, reduce torque pulsation and improve NVH (Noise, vibration, harshness, noise, vibration and harshness) performance of the motor relative to the three-phase motor.

However, for a permanent magnet synchronous motor, the rotor magnetic field is constant, the flux linkage of the motor cannot be changed, and the counter electromotive force of the motor is increased along with the increase of the motor rotating speed. When the counter electromotive force of the motor approaches to the externally applied voltage, the rotating speed of the motor cannot be continuously increased, and the D-axis current needs to be increased to perform weak magnetic expansion, so that the efficiency of the motor is reduced.

Disclosure of utility model

The application provides a motor circuit and a vehicle, which can improve motor efficiency.

One aspect of the present application provides a motor circuit comprising:

the motor comprises a multi-phase winding, wherein at least two phase windings in the multi-phase winding are connected to form a neutral point, and the number of the neutral points is at least two; and

The switching circuit is connected between at least two neutral points and used for controlling the on-off of a circuit between the neutral points; when the motor is in a first rotating speed state, the switch circuit is in a first state, and the switch circuit breaks a line between the neutral points; when the motor is in a second rotating speed state, the switch circuit is in a second state, and the switch circuit is communicated with a line between neutral points.

The motor circuit controls the state of the motor by adding the switching circuit connected between neutral points, and can control the phase number of the motor and the size of the motor flux linkage at different rotating speeds so as to improve the efficiency and the torque density of the motor.

Further, the switching circuit comprises at least one control switch, and the control switch is connected between two adjacent neutral points; the motor circuit comprises a controller, wherein the controller is connected with the control switch and is used for controlling the on-off of the control switch according to the state of the motor.

Further, the motor circuit comprises a driving circuit connected with the winding and used for driving the motor to work; the driving circuit comprises a plurality of inverter circuits, and each inverter circuit is connected with one phase of winding.

Further, the motor comprises a six-phase motor, the windings comprise six-phase windings, each two phases of windings are connected to form a first neutral point, a second neutral point and a third neutral point, and the first neutral point, the second neutral point and the third neutral point are all connected with the switch circuit; when the switching circuit is in the first state, the switching circuit breaks a line between the first neutral point, the second neutral point and the third neutral point; when the switch circuit is in the second state, the switch circuit is communicated with a line among the first neutral point, the second neutral point and the third neutral point.

Further, the switching circuit comprises a first control switch and a second control switch, the first control switch is connected between the first neutral point and the second neutral point, the second control switch is connected between the second neutral point and the third neutral point, and when the switching circuit is in the first state, the first control switch and the second control switch are both disconnected; when the switch circuit is in the second state, the first control switch and the second control switch are both closed.

Further, the first control switch comprises an IGBT tube, a collector electrode of the first control switch is connected with the first neutral point, and an emitter electrode of the first control switch is connected with the second neutral point; and/or

The second control switch comprises an IGBT tube, the collector electrode of the second control switch is connected with the second neutral point, and the emitter electrode of the second control switch is connected with the third neutral point.

Further, the motor circuit comprises a driving circuit connected with the winding and used for driving the motor to work; the driving circuit comprises six inverter circuits, each inverter circuit comprises a first switch tube, a second switch tube, a first diode and a second diode, the first switch tube and the second switch tube which are connected in series are connected in parallel between the positive electrode and the negative electrode of a power supply, the first diode and the first switch tube are connected in parallel, the second diode and the second switch tube are connected in parallel, and the input end of each phase of winding is connected between the first switch tube and the second switch tube.

Further, the first switching tube and the second switching tube both comprise IGBT tubes, the collector electrode of the first switching tube is connected with the positive electrode of the power supply, the emitter electrode of the first switching tube is connected with the collector electrode of the second switching tube, and the emitter electrode of the second switching tube is connected with the negative electrode of the power supply; the cathode of the first diode is connected with the collector of the first switching tube, and the anode of the first diode is connected with the emitter of the first switching tube; the cathode of the second diode is connected with the collector of the second switching tube, and the anode of the second diode is connected with the emitter of the second switching tube;

When the switching circuit is in the first state, a first switching tube in the inverter circuit connected with one of the two phase windings forming the neutral point is opened, and a second switching tube in the inverter circuit is closed; when the switching circuit is in the second state, a first switching tube in the inverter circuit connected to one of the two phase windings forming the neutral point is closed, and a second switching tube in the inverter circuit is opened.

Further, the power supply also comprises a voltage stabilizing capacitor connected with the power supply in parallel.

Another aspect of the application provides a vehicle comprising:

A power supply; and

A motor circuit as claimed in any preceding claim, the motor circuit being connected to the power supply.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a schematic diagram of an embodiment of a motor circuit according to the present application;

Fig. 2 is a schematic diagram showing motor winding connections in the motor circuit shown in fig. 1.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the application. Rather, they are merely examples of apparatus and methods consistent with aspects of the application as detailed in the accompanying claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "several" means at least two. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. The word "comprising" or "comprises", and the like, means that elements or items appearing before "comprising" or "comprising" are encompassed by the element or item recited after "comprising" or "comprising" and equivalents thereof, and that other elements or items are not excluded. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

The motor circuit includes a motor and a switching circuit. The motor comprises multiphase windings, at least two of which are connected to form a neutral point, and at least two neutral points are provided. The switching circuit is connected between at least two neutral points and used for controlling the on-off of a circuit between the neutral points; when the motor is in a first rotating speed state, the switching circuit is in a first state, and the switching circuit breaks a line between neutral points; when the motor is in the second rotating speed state, the switching circuit is in the second state, and the switching circuit is communicated with a line between neutral points.

The motor circuit controls the state of the motor by adding the switching circuit connected between neutral points, and can control the phase number of the motor and the size of the motor flux linkage at different rotating speeds so as to improve the efficiency and the torque density of the motor.

The vehicle provided by the application comprises a power supply and a motor circuit, wherein the motor circuit is connected with the power supply.

The motor circuit and the vehicle of the present application will be described in detail with reference to the accompanying drawings. The features of the examples and embodiments described below may be combined with each other without conflict.

The motor circuit of the embodiment of the application can be applied to vehicles, and is mainly applied to new energy vehicles, including pure electric vehicles, hybrid vehicles, plug-in hybrid vehicles and other vehicles taking vehicle-mounted power batteries as main power sources or one of power sources. The vehicle may include a power source and a motor circuit coupled to the power source. The motor circuit may include a motor, a power source coupled to the motor to provide a source of power for operation of the motor.

The motor circuit of the embodiment of the application comprises a motor and a switch circuit. The motor comprises multiphase windings, at least two of which are connected to form a neutral point, and at least two neutral points are provided. The switching circuit is connected between at least two neutral points and used for controlling the on-off of a circuit between the neutral points; when the motor is in a first rotating speed state, the switching circuit is in a first state, and the switching circuit breaks a line between neutral points; when the motor is in the second rotating speed state, the switching circuit is in the second state, and the switching circuit is communicated with a line between neutral points.

The motor circuit controls the state of the motor by adding the switching circuit connected between neutral points, and can control the phase number of the motor and the size of the motor flux linkage at different rotating speeds so as to improve the efficiency and the torque density of the motor.

It should be noted that the first rotational speed state of the motor is a low-speed operation state of the motor, and the second rotational speed state of the motor is a high-speed operation state of the motor. The application does not specifically define the low speed and the high speed, and can be adjusted according to the actual working condition of the motor. The motor in embodiments of the present application may be a multi-phase motor including, but not limited to, a six-phase motor and a twelve-phase motor. It will be appreciated that a six-phase motor includes six-phase windings and a twelve-phase motor includes twelve-phase windings. Of course, motors with other phases are also within the protection scope of the present application, and will not be described again.

In some embodiments, the motor circuit may further include a controller coupled to the motor, the controller may monitor the rotational speed and rotor position of the motor in real time via a resolver of the motor, and calculate a flux linkage magnitude of the motor.

In some embodiments, the switching circuit includes at least one control switch connected between adjacent neutral points. The controller is connected with the control switch and is used for controlling the on-off of the control switch according to the state of the motor. The controller obtains the rotating speed and the rotor position of the motor, calculates the flux linkage of the motor, and then judges the running state of the motor. When the motor works at a low speed, the phase number of the motor is reduced by controlling the state of the control switch. At the moment, the motor flux linkage is strong, the back electromotive force is improved, and the peak torque is higher under the same current. When the motor rises to a certain value at high speed, the number of phases of the motor is increased by adjusting the conducting state of the control switch. At the moment, the flux linkage of the motor is reduced, the counter electromotive force of the motor is reduced, the motor does not need to be subjected to weak magnetism to increase the rotating speed, reactive current is reduced, the efficiency of the motor is improved, and meanwhile, the torque of the motor can still keep higher output due to the improvement of the phase number of the motor.

In some embodiments, the motor circuit includes a drive circuit coupled to the windings for driving the motor into operation. Specifically, the driving circuit may include a plurality of inverter circuits, each inverter circuit being connected to one phase winding. The inverter circuit, i.e. the inverter bridge, the inverter, can convert the dc voltage provided by the power supply into an ac voltage. Specifically, in embodiments in which the motor is a six-phase motor, the drive circuit includes six inverter circuits, i.e., six-phase inverter bridges; in embodiments where the motor is a twelve-phase motor, the drive circuit includes twelve inverter circuits, i.e., twelve-phase inverter bridges.

Specifically, the inverter circuit may include a first switching tube, a second switching tube, a first diode, and a second diode, the first and second switching tubes connected in series are connected in parallel between the positive and negative poles of the power supply, the first diode and the first switching tube are connected in parallel, the second diode and the second switching tube are connected in parallel, and the input terminal of each phase winding is connected between the first and second switching tubes. Further, the first switching tube and the second switching tube respectively comprise IGBT tubes, the collector electrode of the first switching tube is connected with the positive electrode of the power supply, the emitter electrode of the first switching tube is connected with the collector electrode of the second switching tube, and the emitter electrode of the second switching tube is connected with the negative electrode of the power supply; the cathode of the first diode is connected with the collector of the first switch tube, and the anode of the first diode is connected with the emitter of the first switch tube; the cathode of the second diode is connected with the collector of the second switching tube, and the anode of the second diode is connected with the emitter of the second switching tube.

Fig. 1 is a schematic circuit diagram of an embodiment of a motor circuit according to the present application. In an embodiment in which the motor is a six-phase motor, each two-phase winding is connected to form a first neutral point N1, a second neutral point N2 and a third neutral point N3. The first neutral point N1, the second neutral point N2 and the third neutral point N3 are all connected to the switching circuit. When the switching circuit is in the first state, the switching circuit breaks the line between the first neutral point N1, the second neutral point N2 and the third neutral point N3. When the switch circuit is in the second state, the switch circuit is communicated with a line among the first neutral point N1, the second neutral point N2 and the third neutral point N3. Specifically, in the present embodiment, the six-phase winding of the motor includes a first winding, a second winding, a third winding, a fourth winding, a fifth winding, and a sixth winding. The output ends of the first winding and the second winding are connected to form a first neutral point N1; the output ends of the third winding and the fourth winding are connected to form a second neutral point N2, and the output ends of the fifth winding and the sixth winding are connected to form a third neutral point N3.

Fig. 2 is a schematic diagram showing motor winding connections in the motor circuit shown in fig. 1. Figure 2 shows a 24 slot 6 phase motor. As shown in fig. 2, the motor according to the embodiment of the present application is a motor with a variable phase number and windings Y connected. The outgoing line of the cable needs 9 cables which are respectively denoted by A, a, B, b, C, c, N, N2 and N3. A. a, B, b, C, c denotes the six phases of the motor, and N1, N2, N3 denote motor neutral point outlets.

Specifically, the number of stator slots (Z) of the motor needs to be selected so as to satisfy the following relation:

Z÷3＝2*N

wherein n=1, 2,3.

With continued reference to fig. 2, the stator phase windings in the motor circuit of the present embodiment need to be connected in a particular manner. In the related art, the output ends of the windings of each phase are connected to form a neutral point inside the motor. In the motor circuit of the embodiment of the application, the output ends of the windings of each phase are led out in a lead-out wire mode after being connected in the motor. Specifically, after the output ends of the phase A and the phase a are connected in the motor, a first neutral point is led out in a lead-out line mode, and the first neutral point is represented by N1; similarly, the output ends of the phase B and the phase B lead out a second neutral point, which is represented by N2; the output ends of the C phase and the C phase lead out a third neutral point, which is denoted by N3.

On the basis of the above embodiment, the switching circuit includes the first control switch Q13 and the second control switch Q14, the first control switch Q13 is connected between the first neutral point N1 and the second neutral point N2, the second control switch Q14 is connected between the second neutral point N2 and the third neutral point N3, and when the switching circuit is in the first state, both the first control switch Q13 and the second control switch Q14 are turned off; when the switching circuit is in the second state, both the first control switch Q13 and the second control switch Q14 are closed. It is understood that the windings of the motor are divided into three groups based on a six-phase motor, the adjacent two-phase windings are divided into one group, which is called a large phase, two windings in the large phase are connected to form a neutral point, and the neutral point is connected with the neutral point by using a control switch.

The first control switch Q13 may include an IGBT tube. Specifically, the collector of the first control switch Q13 is connected to the first neutral point N1, and the emitter of the first control switch Q13 is connected to the second neutral point N2. The second control switch Q14 may also include an IGBT tube. Specifically, the collector of the second control switch Q14 is connected to the second neutral point N2, and the emitter of the second control switch Q14 is connected to the third neutral point N3. The IGBT is an insulated gate bipolar transistor and has the characteristics of high power density, high efficiency, reliability, convenience in control and the like.

In some embodiments, the motor circuit includes a drive circuit coupled to the windings for driving the motor into operation. The driving circuit includes six inverter circuits. As described above, each inverter circuit includes a first switching tube, a second switching tube, a first diode and a second diode, the first switching tube and the second switching tube connected in series are connected in parallel between the positive pole and the negative pole of the power BT1, the first diode and the first switching tube are connected in parallel, the second diode and the second switching tube are connected in parallel, and the input end of each phase winding is connected between the first switching tube and the second switching tube. Alternatively, the first diode and the second diode may comprise freewheeling diodes.

On the basis of the embodiment, the first switching tube and the second switching tube comprise IGBT tubes, the collector electrode of the first switching tube is connected with the positive electrode of the power supply BT1, the emitter electrode of the first switching tube is connected with the collector electrode of the second switching tube, and the emitter electrode of the second switching tube is connected with the negative electrode of the power supply BT 1; the cathode of the first diode is connected with the collector of the first switch tube, and the anode of the first diode is connected with the emitter of the first switch tube; the cathode of the second diode is connected with the collector of the second switching tube, and the anode of the second diode is connected with the emitter of the second switching tube.

Specifically, the driving circuit includes a first inverter circuit, a second inverter circuit, a third inverter circuit, a fourth inverter circuit, a fifth inverter circuit, and a sixth inverter circuit. As shown in fig. 1, the first inverter circuit includes a first switching tube Q1, a second switching tube Q2, a first diode D1, and a second diode D2. The second inverter circuit includes a first switching tube Q3, a second switching tube Q4, a first diode D3, and a second diode D4. The third inverter circuit includes a first switching tube Q5, a second switching tube Q6, a first diode D5, and a second diode D6. The fourth inverter circuit includes a first switching tube Q7, a second switching tube Q8, a first diode D7, and a second diode D8. The fifth inverter circuit includes a first switching tube Q9, a second switching tube Q10, a first diode D9, and a second diode D10. The sixth inverter circuit includes a first switching tube Q11, a second switching tube Q12, a first diode D11, and a second diode D12. The specific connection relationship is shown in fig. 1, and will not be described again.

In some embodiments, the motor circuit further includes a voltage stabilizing capacitor C1 connected in parallel with the power BT1, and connected between the positive electrode and the negative electrode of the power BT1, which can play a role of filtering, and eliminate high-frequency noise and interference, so as to improve the anti-interference capability of the motor circuit.

The specific control flow of the motor circuit in the embodiment of the application is as follows:

When the motor runs at a low speed, the switching circuit is in a first state, and the controller respectively controls the first switching tube Q3, the first switching tube Q7, the first switching tube Q11, the first control switch Q13 and the second control switch Q14 to be opened, and simultaneously controls the second switching tube Q4, the second switching tube Q8 and the second switching tube Q12 to be closed. At the moment, the motor is a three-phase motor, the magnetic linkage of the motor is large, the counter electromotive force of the motor is high, and the high torque output of the motor can be supported.

As the rotational speed of the motor increases, the back electromotive force of the motor increases continuously, and when the back electromotive force of the motor is equal to the battery voltage, the flux linkage of the motor needs to be reduced in order to continue increasing the rotational speed of the motor. In the related art, the magnetic field generated by the rotor permanent magnet can be counteracted by increasing the current of the D shaft of the motor and utilizing the stator of the motor to generate a reverse magnetic field; but the increase of the reactive current leads to an increase of copper loss of the motor, which leads to a decrease of efficiency of the motor. The motor circuit of the embodiment of the application can control the switching circuit to be in the second state at this time, namely, the first control switch Q13 and the second control switch Q14 are closed by the controller, and meanwhile, the switching states of the first switching tube Q3, the first switching tube Q7, the first switching tube Q11, the second switching tube Q4, the second switching tube Q8 and the second switching tube Q12 are adjusted, so that the motor is changed into a six-phase motor from a three-phase motor. At this time, the number of windings of each phase of windings is halved, the flux linkage is reduced to halved, the counter electromotive force of the motor is reduced, the motor does not need weak magnetism to expand the speed, and the efficiency of the motor is improved. Under normal conditions, the sine degree of SVPWM waves generated by the power supply BT1 is reduced due to the improvement of frequency in the high-speed stage, the air gap harmonic wave of the motor is increased, and the NVH effect of the motor is deteriorated; after the motor is regulated to be a six-phase motor, the frequency of space harmonic magnetomotive force generated by fundamental wave current of the motor is increased, the input torque pulsation of the motor is reduced, and the NVH performance of the motor is optimized.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather to enable any modification, equivalent replacement, improvement or the like to be made within the spirit and principles of the application.

Claims (10)

1.A motor circuit, comprising:

the motor comprises a multi-phase winding, wherein at least two phase windings in the multi-phase winding are connected to form a neutral point, and the number of the neutral points is at least two; and

The switching circuit is connected between at least two neutral points and used for controlling the on-off of a circuit between the neutral points; when the motor is in a first rotating speed state, the switch circuit is in a first state, and the switch circuit breaks a line between the neutral points; when the motor is in a second rotating speed state, the switch circuit is in a second state, and the switch circuit is communicated with a line between neutral points.

2. The motor circuit of claim 1, wherein the switching circuit comprises at least one control switch connected between adjacent two of the neutral points; the motor circuit comprises a controller, wherein the controller is connected with the control switch and is used for controlling the on-off of the control switch according to the state of the motor.

3. The motor circuit of claim 1, wherein the motor circuit includes a drive circuit coupled to the windings for driving the motor in operation; the driving circuit comprises a plurality of inverter circuits, and each inverter circuit is connected with one phase of winding.

4. The motor circuit of claim 1, wherein the motor comprises a six-phase motor, the windings comprise six-phase windings, each two phases of the windings being connected to form a first neutral point, a second neutral point, and a third neutral point, the first neutral point, the second neutral point, and the third neutral point being connected to the switching circuit; when the switching circuit is in the first state, the switching circuit breaks a line between the first neutral point, the second neutral point and the third neutral point; when the switch circuit is in the second state, the switch circuit is communicated with a line among the first neutral point, the second neutral point and the third neutral point.

5. The motor circuit of claim 4, wherein the switching circuit includes a first control switch and a second control switch, the first control switch being connected between the first neutral point and the second neutral point, the second control switch being connected between the second neutral point and the third neutral point, the first control switch and the second control switch both being open when the switching circuit is in the first state; when the switch circuit is in the second state, the first control switch and the second control switch are both closed.

6. The motor circuit of claim 5, wherein the first control switch comprises an IGBT tube, a collector of the first control switch is connected to the first neutral point, and an emitter of the first control switch is connected to the second neutral point; and/or

The second control switch comprises an IGBT tube, the collector electrode of the second control switch is connected with the second neutral point, and the emitter electrode of the second control switch is connected with the third neutral point.

7. The motor circuit of claim 5, wherein the motor circuit includes a drive circuit coupled to the windings for driving the motor in operation; the driving circuit comprises six inverter circuits, each inverter circuit comprises a first switch tube, a second switch tube, a first diode and a second diode, the first switch tube and the second switch tube which are connected in series are connected in parallel between the positive electrode and the negative electrode of a power supply, the first diode and the first switch tube are connected in parallel, the second diode and the second switch tube are connected in parallel, and the input end of each phase of winding is connected between the first switch tube and the second switch tube.

8. The motor circuit of claim 7, wherein the first switching tube and the second switching tube each comprise an IGBT tube, a collector of the first switching tube is connected to a positive pole of the power supply, an emitter of the first switching tube is connected to a collector of the second switching tube, and an emitter of the second switching tube is connected to a negative pole of the power supply; the cathode of the first diode is connected with the collector of the first switching tube, and the anode of the first diode is connected with the emitter of the first switching tube; the cathode of the second diode is connected with the collector of the second switching tube, and the anode of the second diode is connected with the emitter of the second switching tube;

When the switching circuit is in the first state, a first switching tube in the inverter circuit connected with one of the two phase windings forming the neutral point is opened, and a second switching tube in the inverter circuit is closed; when the switching circuit is in the second state, a first switching tube in the inverter circuit connected to one of the two phase windings forming the neutral point is closed, and a second switching tube in the inverter circuit is opened.

9. The motor circuit of claim 1, further comprising a voltage stabilizing capacitor connected in parallel with the power supply.

10. A vehicle, characterized by comprising:

A power supply; and

The motor circuit of any one of claims 1-9, connected to the power supply.