Dual-motor driving system and vehicle

Abstract

The utility model discloses a dual-motor driving system and a vehicle. The dual-motor driving system comprises a first motor and a second motor, the first driving circuit is connected with the first motor, the first driving circuit comprises a SiC-Si hybrid switch tube, and the first motor is driven by controlling the SiC-Si hybrid switch tube to be switched on or switched off; and the second driving circuit is connected with the second motor, the second driving circuit comprises a SiC-Si hybrid switch tube, and the second motor is driven by controlling the connection or disconnection of the SiC-Si hybrid switch tube. According to the dual-motor driving system of the utility model, different control of the dual motors is realized through the SiC-Si hybrid switch tube, advantages and disadvantages of the Si-based switch tube and the SiC-based switch tube can be balanced, and both efficiency and cost are considered.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, in particular to a dual-motor drive system and a vehicle. Background Art

[0002] In the related art, currently, in the whole vehicle dual-motor control scheme, Si-based switching tubes, such as IGBT power devices, are used; or SiC-based switching tubes, such as MOSFET power devices, are used to control the drive motor. However, only using IGBT power devices has a large on-state loss, resulting in low efficiency of the electric drive system; only using MOSFET power devices, whose cost is 3-5 times that of IGBT, makes the cost of the electric drive system very high. Summary of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems in the related art to some extent. For this reason, the first object of the utility model is to propose a dual-motor drive system, which can achieve different controls for the dual motors through SiC-Si hybrid switching tubes, balance the advantages and disadvantages of Si-based switching tubes and SiC-based switching tubes, and take into account both efficiency and cost.

[0004] The second object of the utility model is to propose a vehicle.

[0005] To achieve the above object, an embodiment of the first aspect of the utility model proposes a dual-motor drive system, including: a first motor and a second motor; a first drive circuit, the first drive circuit is connected to the first motor, the first drive circuit includes SiC-Si hybrid switching tubes, and drives the first motor by controlling the conduction or disconnection of the SiC-Si hybrid switching tubes; a second drive circuit, the second drive circuit is connected to the second motor, the second drive circuit includes the SiC-Si hybrid switching tubes, and drives the second motor by controlling the conduction or disconnection of the SiC-Si hybrid switching tubes.

[0006] According to the dual-motor drive system of the embodiment of the utility model, the first drive circuit can invert the direct current output by the DC power supply into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switching tubes and provide it to the first motor to drive the first motor; the second drive circuit can invert the direct current output by the DC power supply into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switching tubes and provide it to the second motor to drive the second motor M2. Thus, the system can achieve different controls for the dual motors through SiC-Si hybrid switching tubes, balance the advantages and disadvantages of Si-based switching tubes and SiC-based switching tubes, and take into account both efficiency and cost.

[0007] In addition, according to the dual-motor drive system of the above embodiment of the utility model, it may also have the following additional technical features:

[0008] Specifically, the SiC-Si hybrid switch tube includes a SiC switch tube and a Si switch tube, and the SiC switch tube and the Si switch tube are connected in parallel.

[0009] Specifically, the SiC switch tube is a MOSFET, the Si switch tube is an IGBT, and a freewheeling diode is connected in parallel with the IGBT.

[0010] Specifically, both the first drive circuit and the second drive circuit include a three-phase inverter circuit. The DC side of the three-phase inverter circuit is connected to a DC bus capacitor, the AC side of the three-phase inverter circuit is connected to a corresponding motor, and each power switch tube of the three-phase inverter circuit is the SiC-Si hybrid switch tube.

[0011] Specifically, the three-phase inverter circuit is a three-phase full-bridge inverter circuit or a three-phase multi-level inverter circuit.

[0012] Specifically, the above system further includes an overvoltage protection circuit. The overvoltage protection circuit is connected in parallel with the DC bus capacitor to perform overvoltage protection on the first drive circuit and the second drive circuit when the DC bus voltage is overvoltage. Wherein, the DC bus voltage is the voltage across the DC bus capacitor.

[0013] Specifically, the above system further includes: a first overcurrent protection circuit connected to the first drive circuit to perform overcurrent protection on the first motor when the first motor is overcurrent; a second overcurrent protection circuit connected to the second drive circuit to perform overcurrent protection on the second motor when the second motor is overcurrent.

[0014] Specifically, the circuit structures of the first overcurrent protection circuit and the second overcurrent protection circuit are the same. Wherein, the first overcurrent protection circuit includes: a current sampling circuit connected to the first drive circuit to sample the operating current of the first motor and output a corresponding voltage signal; an amplification circuit connected to the current sampling circuit to amplify the voltage signal; a comparison circuit, the first input end of the comparison circuit is connected to the amplification circuit, and the other end of the comparison circuit is connected to a voltage reference circuit to compare the amplified voltage signal with a reference signal and output a comparison signal; wherein, the voltage reference circuit is used to provide a reference signal corresponding to the preset operating current; a filtering circuit connected to the output end of the comparison circuit to filter the comparison signal to obtain an overcurrent detection signal.

[0015] Specifically, the above system further includes a pre-charging circuit, which is connected to the DC bus capacitor to pre-charge the DC bus capacitor.

[0016] To achieve the above object, a second aspect embodiment of the present invention proposes a vehicle, including the above dual-motor drive system.

[0017] According to the vehicle of the embodiment of the present invention, through the above dual-motor drive system, the advantages and disadvantages of Si-based switching tubes and SiC-based switching tubes can be balanced, taking into account both efficiency and cost.

[0018] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0019] Figure 1 It is a hardware topology diagram of a dual-motor drive system according to an embodiment of the present invention;

[0020] Figure 2 It is a hardware topology diagram of a dual-motor drive system according to another embodiment of the present invention;

[0021] Figure 3 It is a block schematic diagram of a first overcurrent protection circuit according to an embodiment of the present invention;

[0022] Figure 4 It is a hardware topology diagram of a dual-motor drive system according to yet another embodiment of the present invention;

[0023] Figure 5 It is a block schematic diagram of a vehicle according to an embodiment of the present invention. Detailed Embodiments

[0024] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] The dual-motor drive system and vehicle proposed by the embodiments of the present invention will be described below with reference to the drawings.

[0026] Figure 1 It is a hardware topology diagram of a dual-motor drive system according to an embodiment of the present invention.

[0027] As Figure 1As shown, the dual-motor drive system 100 of the embodiment of the present utility model may include: a first motor M1 and a second motor M2; a first drive circuit 110, the first drive circuit 110 is connected to the first motor M1, the first drive circuit 110 includes a SiC-Si hybrid switch tube, and drives the first motor M1 by controlling the conduction or disconnection of the SiC-Si hybrid switch tube; a second drive circuit 120, the second drive circuit 120 is connected to the second motor M2, the second drive circuit 120 includes a SiC-Si hybrid switch tube, and drives the second motor M2 by controlling the conduction or disconnection of the SiC-Si hybrid switch tube.

[0028] Specifically, as Figure 1 shown, the first drive circuit 110 can convert the direct current output by the DC power supply DC into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switch tube and supply it to the first motor M1 to drive the first motor M1. The second drive circuit 120 can convert the direct current output by the DC power supply DC into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switch tube and supply it to the second motor M2 to drive the second motor M2.

[0029] It should be noted that the first drive circuit 110 and the second drive circuit 120 can correspond to the same DC power supply DC or different DC power supplies DC. For example, the first drive circuit 110 corresponds to one DC power supply DC, and the second drive circuit 120 corresponds to another DC power supply DC. In practical applications, when the application scenario is an electric vehicle, the DC power supply DC can be the power battery pack of the electric vehicle. When the first drive circuit 110 and the second drive circuit 120 correspond to the same DC power supply DC, the electric vehicle includes one power battery pack. When the first drive circuit 110 and the second drive circuit 120 correspond to two different DC power supplies DC, the electric vehicle can include two power battery packs.

[0030] According to an embodiment of the present utility model, the SiC-Si hybrid switch tube includes a SiC switch tube and a Si switch tube, and the SiC switch tube and the Si switch tube are connected in parallel. Among them, the packaging form of the SiC-Si hybrid switch tube can be HPD packaging, TO-247 packaging, TPAK packaging, etc.

[0031] Furthermore, as Figure 1 shown, according to an embodiment of the present utility model, the SiC switch tube is a MOSFET, the Si switch tube is an IGBT, and a freewheeling diode is connected in parallel with the IGBT.

[0032] Specifically, during the turn-off process of the power device, the IGBT can conduct freewheeling through the freewheeling diode, thereby preventing the high potential generated by the motor load during turn-off from damaging the IGBT by impact. Since the MOSFET has a built-in body diode, there is no need for an external freewheeling diode.

[0033] According to an embodiment of the present invention, the switching frequency of the MOSFET is greater than or equal to the switching frequency of the IGBT.

[0034] Furthermore, according to an embodiment of the present invention, the switching frequency of the IGBT ranges from 2 kHz to 12 kHz, and the switching frequency of the MOSFET ranges from 20 kHz to 100 kHz.

[0035] Specifically, due to material characteristics, the switching frequency of the IGBT is usually 2K - 12KHz; while the switching frequency of the MOSFET is generally in the range of 20kHz - 100kHz. The IGBT and MOSFET in the first drive circuit 110 and the second drive circuit 120 can be controlled by the same driving PWM signal, and the switching frequency ranges from 2KHz to 12KH. In addition, the IGBT and SMOSFET in the first drive circuit 110 and the second drive circuit 120 can also be controlled by different driving PWM signals, that is, the IGBT switching frequency is recommended to be in the range of 2KHz - 12KHz; the MOSFET switching frequency is recommended to be in the range of 20KHz - 100KHz, so as to fully reflect the performance of the device and achieve the optimal effect.

[0036] According to an embodiment of the present invention, as Figure 2 shown, both the first drive circuit 110 and the second drive circuit 120 include a three-phase inverter circuit. The DC side of the three-phase inverter circuit is connected to the DC bus capacitor C1, the AC side of the three-phase inverter circuit is connected to the corresponding motor, and each power switch tube of the three-phase inverter circuit is a SiC-Si hybrid switch tube.

[0037] Exemplarily, the three-phase inverter circuit is a three-phase full-bridge inverter circuit or a three-phase multilevel inverter circuit, which is not limited here.

[0038] Specifically, taking the three-phase inverter circuit as a three-phase full-bridge inverter circuit as an example. For the sake of easy understanding, Figure 1 and Figure 2 the letter Q in is used to identify the IGBT, the letter D is used to identify the freewheeling diode, and the letter T is used to identify the MOSFET. As Figure 2As shown, the first drive circuit 110 includes a three-phase full-bridge circuit composed of (Q1, D1, T1), (Q2, D2, T2), (Q3, D3, T3), (Q4, D4, T4), (Q5, D5, T5), and (Q6, D6, T6). It can invert the direct current output by the DC power supply DC into alternating current and supply it to the first motor M1 to drive the first motor M1. Among them, (Q1, D1, T1), (Q3, D3, T3), and (Q5, D5, T5) are the three upper bridge arms of the first drive circuit 110, and (Q2, D2, T2), (Q4, D4, T4), and (Q6, D6, T6) are the three lower bridge arms of the first drive circuit 110. The upper and lower bridge arms can achieve four-quadrant operation control of the first motor M1 through control methods such as FOC.

[0039] The second drive circuit 120 includes a three-phase full-bridge circuit composed of (Q7, D7, T7), (Q8, D8, T8), (Q9, D9, T9), (Q10, D10, T10), (Q11, D11, T11), and (Q12, D12, T12). It can invert the direct current output by the DC power supply DC into alternating current and supply it to the second motor M2 to drive the second motor M2. Among them, (Q7, D7, T7), (Q9, D9, T9), and (Q11, D11, T11) are the three upper bridge arms of the second drive circuit 120, and (Q8, D8, T8), (Q10, D10, T10), and (Q12, D12, T12) are the three lower bridge arms of the second drive circuit 120. The upper and lower bridge arms can achieve four-quadrant operation control of the second motor M2 through control methods such as FOC.

[0040] It should be noted that Figure 1 and Figure 2 In the circuit shown, the SiC-Si hybrid switch tube composed of a parallel connection of an IGBT and a MOSFET is only a topological schematic. The quantity should not be understood as a limitation to this application. For example, in practical applications, the SiC-Si hybrid switch tube can be composed of 2 MOSFETs and 6 IGBTs packaged together. During the operation of the system 100, the advantages of both the MOSFET and the IGBT can be utilized simultaneously. Through the control of the system 100, the MOSFET can be made to operate in the switching mode and the IGBT in the conducting mode. Since the MOSFET device has low losses in the switching mode and the IGBT has low losses in the conducting mode, this mode may achieve a reduction in the usage amount of the MOSFET while maintaining the efficiency, thereby reducing the overall cost of the power module.

[0041] According to an embodiment of the present invention, as Figure 2As shown, the above-mentioned system 100 further includes an overvoltage protection circuit 150. The overvoltage protection circuit 150 is connected in parallel with the DC bus capacitor C1 to perform overvoltage protection on the first drive circuit 110 and the second drive circuit 120 when the DC bus voltage is overvoltage. Here, the DC bus voltage is the voltage across the DC bus capacitor C1.

[0042] That is to say, when the voltage across the DC bus capacitor C1 is too high and greater than the protection voltage of the first drive circuit 110 and the second drive circuit 120, the overvoltage protection circuit 150 can perform overvoltage protection on the first drive circuit 110 and the second drive circuit 120, preventing the input voltage of the first drive circuit 110 and the second drive circuit 120 from being too high, avoiding damage to the devices in the first drive circuit 110 and the second drive circuit 120, and improving the service life of the system 100. In an embodiment of the present invention, the overvoltage protection circuit 150 can be a zener diode.

[0043] According to an embodiment of the present invention, as Figure 2 shown, the above-mentioned system 100 further includes: a first overcurrent protection circuit 130, which is connected to the first drive circuit 110 to perform overcurrent protection on the first motor M1 when the first motor M1 is overcurrent. For example, the working current of the first motor M1 is obtained through the first overcurrent protection circuit 130, and overcurrent protection is performed on the first motor M1 when the working current is greater than the preset working current; a second overcurrent protection circuit 140, which is connected to the second drive circuit 120 to perform overcurrent protection on the second motor M2 when the second motor M2 is overcurrent. For example, the working current of the second motor M2 is obtained through the second overcurrent protection circuit 140, and overcurrent protection is performed on the second motor M2 when the working current is greater than the preset working current. Here, the preset working current can be calibrated according to the actual situation and is not limited here.

[0044] That is to say, during the operation of the first motor M1, the first overcurrent protection circuit 130 can continuously obtain the working current of the first motor M1. When the working current is greater than the preset working current, the first overcurrent protection circuit 130 outputs an overcurrent detection signal, and the controller controls the first drive circuit 110 to stop working based on the overcurrent detection signal, so that the first motor M1 stops working. Similarly, during the operation of the second motor M2, the second overcurrent protection circuit 140 can continuously obtain the working current of the second motor M2. When the working current is greater than the preset working current, the second overcurrent protection circuit 140 outputs an overcurrent detection signal, and the controller controls the second drive circuit 120 to stop working based on the overcurrent detection signal, so that the second motor M2 stops working.

[0045] According to an embodiment of the present utility model, the circuit structures of the first overcurrent protection circuit 130 and the second overcurrent protection circuit 140 are the same. Among them, as Figure 3 shown, the first overcurrent protection circuit 130 includes: a current sampling circuit 131, which is connected to the first drive circuit 110 to sample the operating current of the first motor M1 and output a corresponding voltage signal; an amplification circuit 132, which is connected to the current sampling circuit 131 to amplify the voltage signal; a comparison circuit 133, the first input terminal of the comparison circuit 133 is connected to the amplification circuit 132, and the other end of the comparison circuit 133 is connected to the voltage reference circuit 134 to compare the amplified voltage signal with the reference signal and output a comparison signal; among them, the voltage reference circuit 134 is used to provide a reference signal corresponding to the preset operating current; a filtering circuit 135, which is connected to the output terminal of the comparison circuit 133 to filter the comparison signal to obtain an overcurrent detection signal.

[0046] Specifically, during the operation of the first motor M1, the current sampling circuit 131 can obtain the operating current of the first motor M1 in real time, convert the operating current of the first motor M1 into a corresponding voltage signal and transmit it to the amplification circuit 132. The amplification circuit 132 amplifies the voltage signal and transmits it to the first input terminal of the comparison circuit 133. The comparison circuit 133 compares the amplified voltage signal with the reference signal and outputs a corresponding comparison signal. The filtering circuit 135 filters the comparison signal to filter out the clutter signal in the comparison signal to obtain an overcurrent detection signal. In some embodiments of the present utility model, the current sampling circuit 131 can be a sampling resistor, the sampling resistor is connected in series between the AC side of the corresponding drive circuit and the corresponding motor, the comparison circuit 133 can be a comparator, and the filtering circuit 135 can be an RC filtering circuit.

[0047] According to an embodiment of the present utility model, as Figure 4 shown, the above system 100 further includes: a pre-charge circuit 160, which is connected to the DC bus capacitor C1 to pre-charge the DC bus capacitor C1, and can avoid the impact on the circuit caused by directly applying the power supply during charging.

[0048] According to an embodiment of the present utility model, as Figure 4 shown, the above system 100 further includes: a PFC circuit 170, which is respectively connected to the DC power supply DC and the DC bus capacitor C1 to convert the direct current output by the DC power supply DC into another direct current and perform power factor correction to improve the power factor of the system and enhance the efficiency of the system.

[0049] In summary, for the dual-motor drive system according to the embodiments of the present utility model, the first drive circuit can convert the direct current output by the DC power supply into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switch tube and supply it to the first motor to drive the first motor; the second drive circuit can convert the direct current output by the DC power supply into alternating current by controlling the conduction or disconnection of the SiC-Si hybrid switch tube and supply it to the second motor to drive the second motor M2. Thus, the system can achieve different controls for the dual motors through the SiC-Si hybrid switch tube, balance the advantages and disadvantages of Si-based switch tubes and SiC-based switch tubes, and take into account both efficiency and cost.

[0050] Corresponding to the above embodiments, the present utility model also proposes a vehicle.

[0051] Figure 5 It is a block diagram of a vehicle according to the embodiments of the present utility model.

[0052] As Figure 5 shown, the vehicle 200 according to the embodiments of the present utility model includes the above-mentioned dual-motor drive system 100.

[0053] For the vehicle according to the embodiments of the present utility model, through the above-mentioned dual-motor drive system, the advantages and disadvantages of Si-based switch tubes and SiC-based switch tubes can be balanced, and both efficiency and cost can be taken into account.

[0054] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0055] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0056] In the present utility model, unless otherwise clearly specified or defined, the terms "installation", "connection", "attachment", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model may be understood according to specific circumstances.

[0057] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A dual-motor drive system, characterized in that: include: a first motor and a second motor; A first drive circuit, wherein the first drive circuit is connected to the first motor, and the first drive circuit comprises a SiC-Si hybrid switch tube, and drives the first motor by controlling the SiC-Si hybrid switch tube to be turned on or off; The second drive circuit is connected to the second motor, and the second drive circuit includes the SiC-Si hybrid switch tube, and drives the second motor by controlling the SiC-Si hybrid switch tube to be turned on or off.

2. The system according to claim 1, characterized in that The SiC-Si hybrid switch tube includes a SiC switch tube and a Si switch tube, and the SiC switch tube and the Si switch tube are connected in parallel.

3. The system according to claim 2, characterized in that The SiC switch tube is a MOSFET, the Si switch tube is an IGBT, and a freewheeling diode is connected in parallel to the IGBT.

4. The system according to any one of claims 1 to 3, characterized in that: The first drive circuit and the second drive circuit both include a three-phase inverter circuit, the DC side of the three-phase inverter circuit is connected to a DC bus capacitor, the AC side of the three-phase inverter circuit is connected to a corresponding motor, and each power switch tube of the three-phase inverter circuit is the SiC-Si hybrid switch tube.

5. The system according to claim 4, characterized in that The three-phase inverter circuit is a three-phase full-bridge inverter circuit or a three-phase multi-level inverter circuit.

6. The system according to claim 4, characterized in that It also includes an overvoltage protection circuit, which is connected in parallel with the DC bus capacitor to perform overvoltage protection on the first drive circuit and the second drive circuit when the DC bus voltage is overvoltage, wherein the DC bus voltage is the voltage across the DC bus capacitor.

7. The system according to claim 4, characterized in that Also includes: a first overcurrent protection circuit, wherein the first overcurrent protection circuit is connected to the first drive circuit to perform overcurrent protection on the first motor when an overcurrent occurs in the first motor; A second overcurrent protection circuit is connected to the second drive circuit to perform overcurrent protection on the second motor when the second motor has an overcurrent.

8. The system according to claim 7, characterized in that The first overcurrent protection circuit and the second overcurrent protection circuit have the same circuit structure, wherein the first overcurrent protection circuit includes: A current sampling circuit, the current sampling circuit is connected to the first driving circuit to sample the working current of the first motor and output a corresponding voltage signal; an amplifier circuit, the amplifier circuit being connected to the current sampling circuit to amplify the voltage signal; A comparison circuit, wherein a first input terminal of the comparison circuit is connected to the amplifier circuit, and the other terminal of the comparison circuit is connected to a voltage reference circuit, so as to compare the amplified voltage signal with the reference signal and output a comparison signal; A filter circuit is connected to the output end of the comparison circuit and is used to filter the comparison signal to obtain an overcurrent detection signal.

9. The system according to claim 4, characterized in that Also includes: A pre-charging circuit is connected to the DC bus capacitor to pre-charge the DC bus capacitor.

10. A vehicle, characterized in that: Comprising a dual-motor drive system according to any one of claims 1-9.

Images