Inverter topological structure, motor and electric vehicle

Abstract

The invention provides an inverter topological structure, a motor and an electric vehicle. The inverter topology is applied to an electric machine comprising a first phase winding, a second phase winding and a third phase winding, where the first phase winding comprises a first winding and a second winding connected via a first node, the second phase winding comprises a third winding and a fourth winding connected via a second node, the third phase winding comprises a fifth winding and a sixth winding which are connected through a third node, and the inverter topological structure comprises an inverter used for converting direct current into alternating current so as to drive the motor; and the switching circuit is used for controlling the connection of the inverter with the first phase winding, the second phase winding and the third phase winding, and the switching circuit is connected with the first node, the second node and the third node. Therefore, the cost and the volume of the driving unit can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to an inverter topology structure, a motor and an electric vehicle. Background Art

[0002] In the related art, electric vehicles are driven by permanent magnet synchronous motors (PMSM). The motor includes windings and an inverter topology. Under given current conditions, in order to meet the peak torque requirements, the no-load back electromotive force (BEMF) of the motor cannot be designed too low, but when the motor speed reaches the peak, the back electromotive force cannot be too high for the electric drive system without a disconnect device. Due to the wide speed range, it is very difficult to take these two requirements into account.

[0003] In addition, in order to meet the peak power operating range, the motor has to apply a large weak magnetic current in the high-speed stage to suppress the back electromotive force. However, this weak magnetic current will bring additional copper loss and may increase the risk of permanent magnet demagnetization. In addition, the common operating conditions of electric vehicles are mainly concentrated in medium and low speeds and light loads, and the voltage utilization rate is low, resulting in a large PWM harmonic content of voltage and current, which may generate additional harmonic losses and reduce the average efficiency.

[0004] Therefore, the related technology is difficult to meet the motor's requirements for high-speed drive windings and low-speed drive windings. Summary of the invention

[0005] The object of the present invention is to overcome or at least alleviate the deficiencies of the above-mentioned prior art and to provide an inverter topology structure, a motor and an electric vehicle, so as to reduce the number of required switches while meeting the motor's requirements for high-speed drive windings and low-speed drive windings.

[0006] According to one aspect of the present invention, an inverter topology is proposed, which is applied to a motor, wherein the motor includes a first phase winding, a second phase winding and a third phase winding, wherein the first phase winding includes a first winding and a second winding connected via a first node, the second phase winding includes a third winding and a fourth winding connected via a second node, and the third phase winding includes a fifth winding and a sixth winding connected via a third node, and the inverter topology includes: an inverter for converting direct current into alternating current to drive the motor; a switching circuit for controlling the connection between the inverter and the first phase winding, the second phase winding and the third phase winding, wherein the switching circuit is connected to the first node, the second node and the third node.

[0007] For the above inverter topology, in a possible implementation, the switch circuit includes a first switch device, one end of which is connected to the first node and the other end of which is connected to the second node and the third node.

[0008] For the above-mentioned inverter topology, in a possible implementation, the switching circuit includes a first switching device and a second switching device, one end of the first switching device is connected to the first node and the other end is connected to the third node, and one end of the second switching device is connected to the second node and the other end is connected to the third node.

[0009] For the above-mentioned inverter topology, the switching circuit includes a first switching device, a second switching device and a third switching device, one end of the first switching device is connected to the first node, one end of the second switching device is connected to the second node, one end of the third switching device is connected to the third node, and the other end of the first switching device, the other end of the second switching device and the other end of the third switching device are connected to each other.

[0010] For the above-mentioned inverter topology, the inverter includes a first bridge arm, a second bridge arm and a third bridge arm connected in parallel, the first bridge arm includes a first transistor and a second transistor connected in series, the second bridge arm includes a third transistor and a fourth transistor connected in series; the third bridge arm includes a fifth transistor and a sixth transistor connected in series, a node shared by the first transistor and the second transistor is connected to one end of the first winding, a node shared by the third transistor and the fourth transistor is connected to one end of the third winding, a node shared by the fifth transistor and the sixth transistor is connected to one end of the fifth winding, the other end of the first winding is connected to the first node, the other end of the third winding is connected to the second node, the other end of the fifth winding is connected to the third node, one end of the second winding is connected to the first node, one end of the fourth winding is connected to the second node, one end of the sixth winding is connected to the third node, and the other end of the second winding, the other end of the fourth winding and the other end of the sixth winding are connected to each other.

[0011] For the above inverter topology, the switching device included in the switching circuit includes one of a power tube, a relay and a contactor.

[0012] According to another aspect of the present invention, a motor is provided for use in an electric vehicle, comprising: the first phase winding, the second phase winding and the third phase winding; and the inverter topology structure.

[0013] According to another aspect of the present invention, there is provided an electric vehicle comprising the above motor.

[0014] According to the inverter topology structure, motor and electric vehicle of the present invention, the inverter topology structure includes a switch circuit connected to an output terminal drawn from the middle node of each phase winding in the first to third phase windings, and the motor's demand for high-speed drive windings and low-speed drive windings is realized by turning on and off the switch circuit, wherein the motor's demand for high-speed drive windings is realized when the switch circuit is turned on, and the motor's demand for low-speed drive windings is realized when the switch circuit is turned off. Thus, the inverter topology structure of this embodiment can meet the motor's demand for high-speed drive windings and low-speed drive windings. In addition, compared with the number of switches required in the related art, since the switch circuit in this embodiment is connected to an output terminal drawn from the middle node of each phase winding in the first to third phase windings, the switch circuit can be shared among multi-phase windings, thereby effectively reducing the number of switches, and thus suppressing the increase in the cost and volume of the drive unit due to the excessive number of required switches.

[0015] Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the invention and, together with the description, serve to explain the principles of the invention.

[0017] Figure 1 A three-phase double three-phase transformation diagram of the windings of a permanent magnet synchronous motor with dynamic winding transformation speed regulation in the related art is shown.

[0018] Figure 2 A schematic diagram of a segmented winding motor controller in the related art is shown.

[0019] Figure 3 A schematic diagram showing a motor winding switching device in the related art.

[0020] Figure 4 is a schematic diagram showing an inverter topology structure according to an exemplary embodiment.

[0021] Figure 5 is a detailed schematic diagram showing an inverter topology structure according to an exemplary embodiment.

[0022] Figure 6 is a schematic diagram showing the connection relationship of windings when a switch is disconnected according to an exemplary embodiment.

[0023] Figure 7is a schematic diagram showing the connection relationship of windings when a switch is turned on according to an exemplary embodiment.

[0024] Figure 8 is a detailed schematic diagram showing an inverter topology structure according to an exemplary embodiment.

[0025] Fig. 9 is a detailed schematic diagram showing an inverter topology structure according to an exemplary embodiment. DETAILED DESCRIPTION

[0026] Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0027] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0028] In addition, in order to better illustrate the present invention, numerous specific details are provided in the following specific embodiments. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0029] As mentioned above, due to the wide speed range, the back electromotive force must not be too low or too high, and the risk of permanent magnet demagnetization must be reduced. Therefore, it is necessary to be able to change the connection mode of the windings within a wide speed range. In other words, it is necessary to provide an inverter topology that can achieve different winding connections for different speeds.

[0030] In the related art, additional switches are usually added to change the winding connection in a wide speed range. The winding connection in series or parallel mode is realized by controlling the additional switches in different speed ranges. Figure 1-3 The aforementioned related technologies are described in detail.

[0031] See also Figure 1, the winding three-phase double three-phase transformation diagram includes a first three-phase winding and a second three-phase winding located in the stator slot, the first three-phase winding includes an A1 phase winding, a B1 phase winding and a C1 phase winding, and the second three-phase winding includes an A2 phase winding, a B2 phase winding and a C2 phase winding. Among them, the first end of the A1 phase winding, the first end of the B1 phase winding and the first end of the C1 phase winding are respectively connected to the first three-phase inverter. The second end of the A1 phase winding is connected to the first end of the second switch S2 and the first end of the third switch S3, the second end of the B1 phase winding is connected to the first end of the fifth switch S5 and the first end of the sixth switch S6, and the second end of the C1 phase winding is connected to the first end of the eighth switch S8 and the first end of the ninth switch S9.

[0032] The second end of the second switch S2 is connected to the first end of the A2 phase winding and the second end of the first switch S1. The second end of the third switch S3 is connected to the second end of the sixth switch S6 and the second end of the C2 phase winding. The second end of the fifth switch S5 is connected to the first end of the B2 phase winding and the second end of the fourth switch S4. The second end of the eighth switch S8 is connected to the first end of the C2 phase winding and the second end of the seventh switch S7. The second end of the A2 phase winding is connected to the second end of the B2 phase winding and the second end of the ninth switch S9. The first end of the first switch S1, the first end of the fourth switch S4 and the first end of the seventh switch S7 are connected to the second three-phase inverter.

[0033] When the motor speed is below the rated speed, the second switch S2, the fifth switch S5 and the eighth switch S8 are closed, and the first switch S1, the third switch S3, the fourth switch S4, the sixth switch S6, the seventh switch S7 and the ninth switch S9 are opened, so the A1 phase winding is connected in series with the A2 phase winding, the B1 phase winding is connected in series with the B2 phase winding, and the C1 phase winding is connected in series with the C2 phase winding, forming a three-phase connection.

[0034] When the motor speed exceeds the rated speed, the second switch S2, the fifth switch S5 and the eighth switch S8 are disconnected, and the first switch S1, the third switch S3, the fourth switch S4, the sixth switch S6, the seventh switch S7 and the ninth switch S9 are closed, so the A1 phase winding is connected in parallel with the A2 phase winding, the B1 phase winding is connected in parallel with the B2 phase winding, and the C1 phase winding is connected in parallel with the C2 phase winding, forming a dual three-phase connection.

[0035] Therefore, the desired topology can be flexibly constructed by connecting the nine switches from the first switch S1 to the ninth switch S9 in series or in parallel, thereby meeting the motor's requirements for high-speed drive windings and low-speed drive windings. However, the large number of switches required may lead to an increase in the cost and size of the drive unit.

[0036] See also Figure 2The segmented winding motor controller includes a motor stator winding 3, and the three phases of the motor stator winding 3 are divided into two sections. One section is a high-speed and low-speed driving winding, the number of turns is W1, and the three-phase windings are respectively recorded as A, B and C, and the whole is an ABC winding; the other section is a low-speed driving winding, which is only connected to the circuit at low speed, the number of turns is W2, and the three-phase windings are respectively recorded as a, b and c, and the whole is an abc winding. The ABC winding and the abc winding are directly connected in series, and the rear end neutral point of the abc winding is directly connected. One end of the ABC winding is connected to the output end of the first inverter unit 1, and the middle of the ABC winding and the abc winding is connected to the output end of the second inverter unit 2. The first inverter unit 1 and the second inverter unit 2 are connected in parallel at both ends of the capacitor, and the first inverter unit 1 and the second inverter unit 2 together constitute a motor controller 4. The switch S1 is arranged between the first inverter unit 1 and the DC bus, and is used to prevent the coil induction energy from flowing back to the DC bus when the second inverter unit 2 is working.

[0037] When the motor runs at a low speed, the first inverter unit 1 works and the second inverter unit 2 does not work. At this time, all windings are working, and the number of turns of each phase is W1+W2 in series, which produces more ampere-turns and thus can generate large torque.

[0038] When the motor speed increases and reaches the rated speed, the first inverter unit 1 stops working and the second inverter unit 2 starts working. At this time, the motor enters a single winding working mode in which only the ABC winding works and the abc winding does not work, and the number of turns per phase is W1. Due to the small number of series turns, the back electromotive force is relatively small, which reduces the depth of weak magnetic field.

[0039] When the motor is decelerated from high speed and runs at low speed again, the first inverter unit 1 is operated again, the second inverter unit 2 stops working, and the winding series connection mode is entered again.

[0040] Therefore, the motor's needs for high-speed drive windings and low-speed drive windings can be met by replicating a typical bridge inverter with six transistors, but the large number of switches required may lead to a larger drive unit cost and size.

[0041] See also Figure 3The three-phase motor winding switching device includes a motor stator winding 1 and a winding switching device 4. Among them, the three phases of the motor stator winding 1 are divided into two sections, one section is a high-speed drive winding connected to the external terminal, the number of turns is W1, the three-phase windings are respectively recorded as A, B and C, and the whole is an ABC winding; the other section is a low-speed drive winding connected to the external terminal, which is only connected to the circuit at low speed, the number of turns is W2, the three-phase windings are respectively recorded as a, b and c, and the whole is an abc winding. The neutral points of the ABC winding and the abc winding are not directly connected, but are connected together through three controllable semiconductor switches. The controllable semiconductor switches connected to the ABC winding are the first to third controllable semiconductor switches S1 to S3, respectively, forming a high-speed switching circuit 2. The controllable semiconductor switches connected to the abc winding are the fourth to sixth controllable semiconductor switches S4 to S6, respectively, forming a low-speed switching circuit 3. The high-speed switching circuit 2 and the low-speed switching circuit 3 form a winding switching device 4 as a whole.

[0042] When the motor runs at low speed, the motor controller sends a PWM working signal to the main inverter circuit and at the same time sends a conduction signal to the fourth to sixth controllable semiconductor switches S4 to S6, so that the lower end point of the abc winding is short-circuited; thus, the ABC winding and the abc winding both participate in the work, and the number of turns of each phase is W1+W2 in series, generating a large torque.

[0043] When the motor speed increases and reaches high speed, the motor controller controls the motor current to decay to zero, and sends a shutdown signal to the fourth to sixth controllable semiconductor switches S4 to S6, so that the lower end of the abc winding is disconnected. Then, a conduction signal is sent to the first to third controllable semiconductor switches S1 to S3, and the motor enters a single winding working mode in which only the ABC winding works and the abc winding does not work, and the number of turns per phase is W1. Due to the small number of series turns, the back electromotive force is relatively small, which reduces the depth of weak magnetic field.

[0044] When the motor is decelerated from high speed and runs at low speed again, the motor controller controls the motor current to decay to zero, and sends a turn-off signal to the first to third controllable semiconductor switches S1 to S3 to disconnect the lower end of the ABC winding. Then, a turn-on signal is sent to the fourth to sixth controllable semiconductor switches S4 to S6 to enter the winding series mode again.

[0045] Therefore, the motor's needs for high-speed drive windings and low-speed drive windings can be met by a bridge inverter and an additional six switches. However, the large number of switches required may lead to an increase in the cost and size of the drive unit.

[0046] That is to say, the above-mentioned related technologies all require at least six switches to meet the motor's requirements for high-speed drive windings and low-speed drive windings. Therefore, the large number of switches required may lead to an increase in the cost and size of the drive unit.

[0047] In view of this, considering that the number of switches can be reduced by sharing switches among the three-phase windings, a switch connected to an output terminal drawn from the intermediate node of the three-phase winding can be set. It should be understood that the switch should be able to be used to control the connection between multiple windings belonging to each phase winding. Therefore, the switch is shared by the multiple windings of each phase winding, thereby being able to meet the motor's requirements for high-speed drive windings and low-speed drive windings and reduce the number of required switches.

[0048] Therefore, the embodiments of the present invention provide an inverter topology structure, a motor and an electric vehicle that can reduce the number of switches required while meeting the motor's requirements for high-speed drive windings and low-speed drive windings. Figures 4 to 9 To describe an embodiment of the present invention.

[0049] Embodiment 1:

[0050] See also Figure 4 , the inverter topology 100 can be applied to a motor. The motor may include a first phase winding, i.e., a U phase winding, a second phase winding, i.e., a V phase winding, and a third phase winding, i.e., a W phase winding. The U phase winding may include a first winding UB1 and a second winding UB2, the first winding UB1 and the second winding UB2 being connected via a first node N1, the V phase winding may include a third winding VB1 and a fourth winding VB2, the third winding VB1 and the fourth winding VB2 being connected via a second node N2, and the W phase winding may include a fifth winding WB1 and a sixth winding WB2, the fifth winding WB1 and the sixth winding WB2 being connected via a third node N3. For ease of description, the first winding UB1, the third winding VB1, and the fifth winding WB1 are collectively referred to as UVW1 windings, and the second winding UB2, the fourth winding VB2, and the sixth winding WB2 are collectively referred to as UVW2 windings.

[0051] See also Figure 4 , the inverter topology 100 may include an inverter 110 and a switch circuit 120. The inverter 110 is used to convert direct current into alternating current to drive the motor; the switch circuit 120 is connected to the inverter 110 and is used to control the connection between the inverter 110 and the U-phase winding, the V-phase winding and the W-phase winding of the motor. The switch circuit 120 is connected to the first node N1, the second node N2 and the third node N3.

[0052] The inverter 110 is connected to a DC power supply (not shown) and is input with DC power. The inverter 110 is used to convert the DC power into three-phase AC power and output it to the motor. The motor is driven by the AC power output by the inverter 110. In one possible implementation, the inverter 100 is a bridge inverter and is composed of six switches. The switch may include but is not limited to bipolar transistors, IGBTs (Insulated Gate Bipolar Transistors), MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) or semiconductor thyristors, etc., but is not limited to these. Due to space limitations, the present invention will not be described in detail. The following will take transistors as switches as an example to illustrate the structure of the inverter. Each transistor of the inverter is controlled by a controller and is turned on and off in a certain order. For the specific structure of the inverter, please refer to the following about Figure 5 Detailed description.

[0053] When the motor runs at a low speed, the motor controller sends a shutdown signal to the switch circuit 120 for shutting down the switch circuit 120 to shut down the switch circuit 120. Since the switch circuit 120 is shut down, the phase windings corresponding to the nodes (N1-N3) connected to the switch circuit 120 are connected in series. At this time, the UVW1 winding and the UVW2 winding both participate in the work (all windings are connected in series), and the number of turns of each phase winding is the sum of the number of turns of the two windings included in the phase winding, so that a large torque can be generated, thereby meeting the torque requirement of the motor when running at a low speed.

[0054] Therefore, when the motor is running at a low speed, by means of the inverter topology of this embodiment, all windings are connected in series, and the motor can output a higher torque at the same supply current, or reduce the peak current at the same torque. Moreover, under conditions of medium and low speed and light load, such as urban working conditions, due to the higher number of series turns and back electromotive force, the voltage utilization rate is improved, the PWM harmonic loss is greatly reduced, and the average efficiency of the motor can be improved by, for example, 1-3 percentage points.

[0055] When the motor speed increases and reaches high speed, the motor controller sends a turn-on signal to the switch circuit 120 to turn on the switch circuit 120. Since the switch circuit 120 is turned on, the winding belonging to the UVW2 winding of the phase winding corresponding to the node (N1-N3) connected to the switch circuit 120 is short-circuited. At this time, only the UVW1 winding works, and the UVW2 winding does not work (part of the winding is connected in series). Since the number of series turns is small, the back electromotive force is relatively small, which reduces the depth of weak magnetic field, thereby meeting the demand for back electromotive force when the motor runs at high speed.

[0056] Therefore, when the motor runs at high speed, with the help of the inverter topology structure of this embodiment, some windings are connected in series, which can greatly reduce the series resistance and weak magnetic current of each phase, thereby effectively improving the high-speed operation efficiency and reducing the risk of magnetic steel demagnetization.

[0057] According to the inverter topology of the present embodiment, it includes a switch circuit connected to an output terminal drawn from the middle node of each phase winding of the first to third phase windings, and the motor's demand for high-speed drive windings and low-speed drive windings is realized by turning on and off the switch circuit, wherein the motor's demand for high-speed drive windings is realized when the switch circuit is turned on, and the motor's demand for low-speed drive windings is realized when the switch circuit is turned off. Thus, the inverter topology of the present embodiment can meet the motor's demand for high-speed drive windings and low-speed drive windings. In addition, compared with the large number of switches required in the related art, since the present embodiment draws out an output terminal from the middle node of each of the first to third phase windings to connect the switch circuit, the switch circuit can be shared among the multi-phase windings, thereby effectively reducing the number of switches, and further suppressing the increase in the cost and volume of the drive unit due to the excessive number of required switches.

[0058] In one possible implementation, see Figure 5 and 8 , the inverter 110 may include a first bridge arm, a second bridge arm, and a third bridge arm connected in parallel. The first bridge arm may include a first transistor Q1 and a second transistor Q2 connected in series, the second bridge arm may include a third transistor Q3 and a fourth transistor Q4 connected in series, and the third bridge arm may include a fifth transistor Q5 and a sixth transistor Q6 connected in series. A node shared by the first transistor Q1 and the second transistor Q2 is connected to one end of the first winding UB1, a node shared by the third transistor Q3 and the fourth transistor Q4 is connected to one end of the third winding VB1, and a node shared by the fifth transistor Q5 and the sixth transistor Q6 is connected to one end of the fifth winding WB1. The other end of the first winding UB1 is connected to the first node N1, the other end of the third winding VB1 is connected to the second node N2, the other end of the fifth winding WB1 is connected to the third node N3, one end of the second winding UB2 is connected to the first node N1, one end of the fourth winding VB2 is connected to the second node N2, one end of the sixth winding WB2 is connected to the third node N3, and the other end of the second winding UB2, the other end of the fourth winding VB2 and the other end of the sixth winding WB2 are connected to each other.

[0059] In one possible implementation, the inverter 110 may be a three-phase current-type inverter, and may be composed of six power tubes and six reverse blocking diodes connected in series with each power tube. In another implementation, the inverter 110 may be a three-phase voltage-type inverter, and may be composed of six power tubes and six freewheeling diodes connected in parallel with each power tube. The inverter 110 may use a switch control signal to alternately turn off and on the power tubes in the three bridge arms to form a three-phase voltage at the output end.

[0060] By expanding the switch circuit 120 in the first embodiment, the following second embodiment, third embodiment and fourth embodiment can be obtained. The switch circuit 120 in these embodiments may include at least one switch device, and the switch device may be one of a switch, a relay and a contactor. For ease of description, the technical solution of the present disclosure is described in detail below using a switch as a switch device.

[0061] Embodiment 2:

[0062] See also Figure 5 The switch circuit 120 may include a first switch S1, a second switch S2 and a third switch S3, one end of the first switch S1 is connected to the first node N1, one end of the second switch S2 is connected to the second node N2, one end of the third switch S3 is connected to the third node N3, and the other ends of the first switch S1, the second switch S2 and the third switch S3 are connected to each other.

[0063] In this embodiment, the switch circuit 120 is connected to the first to third nodes N1 - N3 .

[0064] When the motor is running at a low speed, the motor controller sends a shutdown signal to the switch circuit 120 for shutting down the switch circuit 120 to shut down the switch circuit 120. At this time, the first to third switches S1 to S3 are all turned off, and the first to sixth transistors Q1 to Q6 are all operating normally. Since the first to third switches S1 to S3 are all turned off, the U-phase winding corresponding to the node N1 connected to the first switch S1 is connected in series, the V-phase winding corresponding to the node N2 connected to the second switch S2 is connected in series, and the W-phase winding corresponding to the node N3 connected to the third switch S3 is connected in series.

[0065] Winding connection relationship is as follows Figure 6 As shown, the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, and the WB1 winding is connected in series with the WB2 winding. The UVW1 winding and the UVW2 winding both participate in the work (all windings are connected in series), and the number of turns of each phase winding is the sum of the number of turns of the two windings included in the phase winding, so that a large torque can be generated, thereby meeting the torque demand of the motor when running at a low speed.

[0066] When the motor speed increases and reaches a high speed, the motor controller sends a turn-on signal to the switch circuit 120 for turning on the switch circuit 120 to turn on the switch circuit 120. At this time, the first to third switches S1 to S3 are all turned on, and the first to sixth transistors Q1 to Q6 are all operating normally. Since the first to third switches S1 to S3 are all turned on, the UB2 winding belonging to the UVW2 winding in the U-phase winding corresponding to the node N1 connected to the first switch S1 is short-circuited, the VB2 winding belonging to the UVW2 winding in the V-phase winding corresponding to the node N2 connected to the second switch S2 is short-circuited, and the WB2 winding belonging to the UVW2 winding in the W-phase winding series connection corresponding to the node N3 connected to the third switch S3 is short-circuited.

[0067] Winding connection relationship is as follows Figure 7 As shown, the UB2 winding, VB2 winding and WB2 winding are all short-circuited, so only the UB1 winding, VB1 winding and WB1 winding work, while the UB2 winding, VB2 winding and WB2 winding do not work. Due to the small number of series turns, the back EMF is relatively small, which reduces the depth of weak magnetic field, thereby meeting the back EMF requirement when the motor runs at high speed.

[0068] When the motor is decelerated from high speed to run at low speed again, the motor controller sends a shut-down signal to the switch circuit 120 to shut down the switch circuit 120, so that the first to third switches S1 to S3 are shut down again, so that the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, the WB1 winding is connected in series with the WB2 winding, and the UVW1 winding and the UVW2 winding are both connected in series (all windings are connected in series).

[0069] According to the inverter topology of the present embodiment, it includes three switches (which constitute a switch circuit) connected to three output terminals respectively drawn from the middle node of each phase winding from the first to the third phase winding, and the requirements of the motor for high-speed drive winding and low-speed drive winding are realized by turning on and off the three switches, wherein the requirements of the motor for high-speed drive winding are realized when the three switches are turned on, and the requirements of the motor for low-speed drive winding are realized when the three switches are turned off. Thus, the inverter topology of the present embodiment can meet the requirements of the motor for high-speed drive winding and low-speed drive winding. In addition, compared with the number of switches required in the related art (for example, at least 6 switches are required), in the present embodiment, since an output terminal is drawn from the middle node of each phase winding to connect the three switches, each of the three switches is shared among the three-phase windings, thereby effectively reducing the number of switches, and further suppressing the increase in the cost and volume of the drive unit due to the excessive number of required switches.

[0070] In a possible implementation, the switches in the switch circuit 120 may include power tubes. In other words, the first to third switches S1 to S3 may be power tubes.

[0071] In one possible embodiment, the switching circuit 120 may include a first relay (not shown), a second relay (not shown) and a third relay (not shown), one end of the first relay is connected to the first node N1, one end of the second relay is connected to the second node N2, one end of the third relay is connected to the third node N3, and the other end of the first relay, the other end of the second relay and the other end of the third relay are connected to each other.

[0072] In one possible embodiment, the switching circuit 120 may include a first contactor (not shown), a second contactor (not shown) and a third contactor (not shown), one end of the first contactor is connected to the first node N1, one end of the second contactor is connected to the second node N2, one end of the third contactor is connected to the third node N3, and the other end of the first contactor, the other end of the second contactor and the other end of the third contactor are connected to each other.

[0073] The implementation principle of the inverter topology structure in which the switching circuit 120 includes three relays and the implementation principle of the inverter topology structure in which the switching circuit 120 includes three contactors are the same as the implementation principle of the inverter topology structure in which the switching circuit 120 includes three switches. Due to space limitations, they will not be repeated here.

[0074] Embodiment three:

[0075] See also Figure 8 The switch circuit 120 may include a first switch S1 having one end connected to the first node N1 and the other end connected to the third node N3, and a second switch S2 having one end connected to the second node N2 and the other end connected to the third node N3.

[0076] When the motor is running at a low speed, the motor controller sends a shutdown signal to the switch circuit 120 for shutting down the switch circuit 120 so as to shut down the switch circuit 120. At this time, the first and second switches S1-S2 are all turned off, and the first to sixth transistors Q1-Q6 are all operating normally. Since the first and second switches S1-S2 are all turned off, the U-phase winding corresponding to the node N1 connected to the first switch S1 is connected in series, the V-phase winding corresponding to the node N2 connected to the second switch S2 is connected in series, and the W-phase winding corresponding to the node N3 connected to both the first switch S1 and the second switch S2 is connected in series.

[0077] Winding connection relationship is as follows Figure 6As shown, the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, and the WB1 winding is connected in series with the WB2 winding. The UVW1 winding and the UVW2 winding both participate in the work (all windings are connected in series), and the number of turns of each phase winding is the sum of the number of turns of the two windings included in the phase winding, so that a large torque can be generated, thereby meeting the torque demand of the motor when running at a low speed.

[0078] When the motor speed increases and reaches a high speed, the motor controller sends a turn-on signal to the switch circuit 120 for turning on the switch circuit 120 to turn on the switch circuit 120. At this time, the first and second switches S1-S2 are all turned on, and the first to sixth transistors Q1-Q6 are all operating normally. Since the first and second switches S1-S2 are all turned on, the UB2 winding belonging to the UVW2 winding in the U-phase winding corresponding to the node N1 connected to the first switch S1 is short-circuited, the VB2 winding belonging to the UVW2 winding in the V-phase winding corresponding to the node N2 connected to the second switch S2 is short-circuited, and the WB2 winding belonging to the UVW2 winding in the W-phase winding series connection corresponding to the node N3 connected to both the first switch S1 and the second switch S2 is short-circuited.

[0079] Winding connection relationship is as follows Figure 7 As shown, the UB2 winding, VB2 winding and WB2 winding are all short-circuited, so only the UB1 winding, VB1 winding and WB1 winding work, while the UB2 winding, VB2 winding and WB2 winding do not work. Due to the small number of series turns, the back EMF is relatively small, which reduces the depth of weak magnetic field, thereby meeting the back EMF requirement when the motor runs at high speed.

[0080] When the motor is decelerated from high speed to run at low speed again, the motor controller sends a shut-down signal to the switch circuit 120 to shut down the switch circuit 120, so that the first switch S1 and the second switch S2 are shut down again, so that the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, the WB1 winding is connected in series with the WB2 winding, and the UVW1 winding and the UVW2 winding are both connected in series (all windings are connected in series).

[0081] According to the inverter topology of the present embodiment, it includes two switches (which constitute a switch circuit) connected to three output terminals respectively drawn from the middle node of each phase winding from the first to the third phase winding, and the requirements of the motor for high-speed drive winding and low-speed drive winding are realized by turning on and off the two switches, wherein the requirements of the motor for high-speed drive winding are realized when the two switches are turned on, and the requirements of the motor for low-speed drive winding are realized when the two switches are turned off. Thus, the inverter topology of the present embodiment can meet the requirements of the motor for high-speed drive winding and low-speed drive winding. In addition, compared with the number of switches required in the related art (for example, at least 6 switches are required), in the present embodiment, since an output terminal is drawn from the middle node of each phase winding to connect the two switches, each of the two switches is shared among the three-phase windings, thereby effectively reducing the number of switches, and further suppressing the increase in the cost and volume of the drive unit due to the excessive number of required switches.

[0082] In one possible embodiment, the switching circuit 120 may include a first relay (not shown) and a second relay (not shown), wherein one end of the first relay is connected to the first node and the other end is connected to the third node, and one end of the second relay is connected to the second node and the other end is connected to the third node.

[0083] In one possible embodiment, the switching circuit 120 may include a first contactor (not shown) and a second contactor (not shown), wherein one end of the first contactor is connected to the first node and the other end is connected to the third node, and one end of the second contactor is connected to the second node and the other end is connected to the third node.

[0084] The implementation principle of the inverter topology structure in which the switching circuit 120 includes two relays and the implementation principle of the inverter topology structure in which the switching circuit 120 includes two contactors are the same as the implementation principle of the inverter topology structure in which the switching circuit 120 includes two switches. Due to space limitations, they will not be repeated here.

[0085] Embodiment 4:

[0086] See also Fig. 9 The switch circuit 120 may include a first switch S1 having one end connected to the first node N1 and the other end connected to the second node N2 and the third node N3.

[0087] When the motor is running at a low speed, the motor controller sends a shutdown signal to the switch circuit 120 for shutting down the switch circuit 120 to shut down the switch circuit 120. At this time, the first switch S1 is turned off, and the first to sixth transistors Q1 to Q6 are all operating normally. Since the first switch S1 is turned off, the U-phase winding corresponding to the node N1 connected to the first switch S1 is connected in series, the V-phase winding corresponding to the node N2 connected to the first switch S1 is connected in series, and the W-phase winding corresponding to the node N3 connected to the first switch S1 is connected in series.

[0088] Winding connection relationship is as follows Figure 6 As shown, the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, and the WB1 winding is connected in series with the WB2 winding. The UVW1 winding and the UVW2 winding both participate in the work (all windings are connected in series), and the number of turns of each phase winding is the sum of the number of turns of the two windings included in the phase winding, so that a large torque can be generated, thereby meeting the torque demand of the motor when running at a low speed.

[0089] When the motor speed increases and reaches a high speed, the motor controller sends a turn-on signal to the switch circuit 120 for turning on the switch circuit 120 to turn on the switch circuit 120. At this time, the first switch S1 is turned on, and the first to sixth transistors Q1 to Q6 are all operating normally. Since the first switch S1 is turned on, the UB2 winding belonging to the UVW2 winding in the U-phase winding corresponding to the node N1 connected to the first switch S1 is short-circuited, the VB2 winding belonging to the UVW2 winding in the V-phase winding corresponding to the node N2 connected to the first switch S1 is short-circuited, and the WB2 winding belonging to the UVW2 winding in the W-phase winding series connection corresponding to the node N3 connected to the first switch S1 is short-circuited.

[0090] Winding connection relationship is as follows Figure 7 As shown, the UB2 winding, VB2 winding and WB2 winding are all short-circuited, so only the UB1 winding, VB1 winding and WB1 winding work, while the UB2 winding, VB2 winding and WB2 winding do not work. Due to the small number of series turns, the back EMF is relatively small, which reduces the depth of weak magnetic field, thereby meeting the back EMF requirement when the motor runs at high speed.

[0091] When the motor is decelerated from high speed to run at low speed again, the motor controller sends a shut-down signal to the switch circuit 120 to shut down the switch circuit 120, so that the first switch is shut down again, so that the UB1 winding is connected in series with the UB2 winding, the VB1 winding is connected in series with the VB2 winding, the WB1 winding is connected in series with the WB2 winding, and the UVW1 winding and the UVW2 winding are both connected in series (all windings are connected in series).

[0092] According to the inverter topology of the present embodiment, it includes a switch (which constitutes a switch circuit) connected to each of the three output terminals drawn from the middle node of each phase winding in the first to third phase windings, and the motor's demand for high-speed drive windings and low-speed drive windings is realized by turning on and off the switch, wherein the motor's demand for high-speed drive windings is realized when the switch is turned on, and the motor's demand for low-speed drive windings is realized when the switch is turned off. Thus, the inverter topology of the present embodiment can meet the motor's demand for high-speed drive windings and low-speed drive windings. In addition, compared with the number of switches required in the related art (for example, at least 6 switches are required), in the present embodiment, since an output terminal is drawn from the middle node of each phase winding to connect a switch, a switch can be shared among the three-phase windings, thereby effectively reducing the number of switches, and further suppressing the increase in the cost and volume of the drive unit due to the excessive number of required switches.

[0093] In a possible implementation, the switch circuit 120 may include a first relay (not shown), one end of the first relay being connected to the first node and the other end of the first relay being connected to the second node and the third node.

[0094] In one possible implementation, the switch circuit 120 may include a first contactor (not shown), one end of the first contactor being connected to the first node and the other end of the first contactor being connected to the second node and the third node.

[0095] The implementation principle of the inverter topology structure in which the switching circuit 120 includes a relay and the implementation principle of the inverter topology structure in which the switching circuit 120 includes a contactor are the same as the implementation principle of the inverter topology structure in which the switching circuit 120 includes a switch, and will not be repeated here due to space limitations.

[0096] The electric vehicle may include the above motor and the above inverter topology structure 100 , wherein the motor may include a U-phase winding, a V-phase winding, and a W-phase winding.

[0097] Thus, the number of required switches can be reduced while meeting the requirements of the motor for the high-speed drive winding and the low-speed drive winding.

[0098] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An inverter topology structure, applied to a motor, characterized in that: The motor includes a first phase winding, a second phase winding and a third phase winding, wherein the first phase winding includes a first winding and a second winding connected via a first node, the second phase winding includes a third winding and a fourth winding connected via a second node, and the third phase winding includes a fifth winding and a sixth winding connected via a third node, The inverter topology structure comprises: An inverter, used for converting direct current into alternating current to drive the motor; a switch circuit, used to control the connection between the inverter and the first phase winding, the second phase winding and the third phase winding, The switch circuit is connected to the first node, the second node and the third node.

2. The inverter topology structure according to claim 1, characterized in that: The switching circuit includes a first switching device having one end connected to the first node and the other end connected to the second node and the third node.

3. The inverter topology structure according to claim 1, characterized in that: The switch circuit includes a first switch device having one end connected to the first node and the other end connected to the third node, and a second switch device having one end connected to the second node and the other end connected to the third node.

4. The inverter topology structure according to claim 1, characterized in that: The switching circuit includes a first switching device, a second switching device and a third switching device, one end of the first switching device is connected to the first node, one end of the second switching device is connected to the second node, one end of the third switching device is connected to the third node, and the other ends of the first switching device, the second switching device and the third switching device are connected to each other.

5. The inverter topology structure according to any one of claims 1 to 4, characterized in that: The inverter comprises a first bridge arm, a second bridge arm and a third bridge arm connected in parallel, The first bridge arm includes a first transistor and a second transistor connected in series, The second bridge arm comprises a third transistor and a fourth transistor connected in series; The third bridge arm includes a fifth transistor and a sixth transistor connected in series, A node common to the first transistor and the second transistor is connected to one end of the first winding, A node common to the third transistor and the fourth transistor is connected to one end of the third winding, A node common to the fifth transistor and the sixth transistor is connected to one end of the fifth winding, The other end of the first winding is connected to the first node, the other end of the third winding is connected to the second node, the other end of the fifth winding is connected to the third node, one end of the second winding is connected to the first node, one end of the fourth winding is connected to the second node, one end of the sixth winding is connected to the third node, and the other end of the second winding, the other end of the fourth winding and the other end of the sixth winding are connected to each other.

6. The inverter topology structure according to any one of claims 2 to 4, characterized in that: The switching device included in the switching circuit includes one of a power tube, a relay and a contactor.

7. A motor, applied to an electric vehicle, characterized in that: include: A first phase winding, a second phase winding and a third phase winding according to any one of claims 1 to 6; as well as The inverter topology according to any one of claims 1 to 6.

8. An electric vehicle, characterized in that: Comprising an electric machine according to claim 7.

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