Circuit system of three-phase inverter unit, method, medium and three-phase inverter

Abstract

Embodiments of the present disclosure relate to circuitry for a three-phase inverter unit, a method for diagnosing a connection state of a three-phase inverter unit, a machine-readable storage medium, a computer program product, and a three-phase inverter. A three-phase inverter unit is connected between the power battery and the electric machine and includes three phases connected to the electric machine. The circuitry includes a diagnostic circuit configured to be connected to a respective phase of three phases; and a controllable power supply circuit configured to be connected to the diagnostic circuit to supply power to the diagnostic circuit, where the diagnostic circuit is further configured to receive different input voltages from respective phases in different connection states of the three phases, and output different output voltages corresponding to the different connection states. According to the circuit system disclosed by the embodiment of the invention, different connection states of three phases of the three-phase inverter unit can be diagnosed by diagnosing different output voltages of the circuit.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the electro-mechanical field, and more particularly to a circuit system and method for a three-phase inverter unit, a three-phase inverter including the circuit system and the three-phase inverter unit, a machine-readable storage medium, and a computer program product. Background Art

[0002] A three-phase motor is a type of induction motor that is powered by simultaneously connecting to three-phase alternating current (with a 120-degree phase difference). Therefore, the three-phase windings in the three-phase motor need to be correctly connected to the corresponding phases in the three-phase alternating current. To better control the motor, the current electrical control unit (ECU) of a high-speed motor vehicle (such as a high-speed motorcycle) usually includes a three-phase inverter unit (power stage), a gate drive unit (GDU), a power supply unit, a peripheral interface unit, and control and protection circuits to control the motor. Generally, the three-phase inverter unit is used to control the motor, and corresponding monitoring components are required to check whether the corresponding phases of the three-phase inverter unit are connected to the corresponding phases of the motor, and to check whether the metal-oxide-semiconductor field-effect transistors (MOSFETs) of the three-phase inverter unit are damaged. Summary of the Invention

[0003] Embodiments of the present disclosure provide a circuit system for a three-phase inverter unit, a method for diagnosing the connection state of a three-phase inverter unit, a machine-readable storage medium, a computer program product, and a three-phase inverter including the circuit system and the three-phase inverter unit.

[0004] According to a first aspect of the present disclosure, there is provided a circuit system for a three-phase inverter unit. The three-phase inverter unit is connected between a power battery and a motor and includes three phases connected to the motor. The circuit system includes: a diagnostic circuit configured to be connected to a corresponding one of the three phases; and a controllable power supply circuit configured to be connected to the diagnostic circuit to supply power to the diagnostic circuit, wherein the diagnostic circuit is further configured to: receive different input voltages from the corresponding phase in different connection states of the three phases, and output different output voltages corresponding to the different connection states.

[0005] According to a second aspect of the present disclosure, there is provided a method for diagnosing a connection state of a three-phase inverter unit, the three-phase inverter unit being connected between a power battery and an electric motor and including three phases connected to the electric motor. The method includes: providing a start signal for a controllable power supply circuit to turn on the controllable power supply circuit to supply power to a diagnostic circuit, where the diagnostic circuit is configured to be connected to the controllable power supply circuit and to a corresponding one of the three phases in the three-phase inverter unit; obtaining an output voltage of the diagnostic circuit, where the output voltage varies according to different connection states of the three-phase inverter unit; and determining the connection state of the three-phase inverter unit based on the obtained output voltage.

[0006] According to a third aspect of the present disclosure, there is provided a three-phase inverter including a three-phase inverter unit and a circuit system described in accordance with the first aspect of the present disclosure.

[0007] According to a fourth aspect of the present disclosure, there is provided a machine-readable storage medium. Machine-executable instructions are stored on the machine-readable storage medium, and the machine-executable instructions are executed by a processor to implement the steps of the method described in accordance with the second aspect of the present disclosure.

[0008] According to a fifth aspect of the present disclosure, there is provided a computer program product. The computer program product is tangibly stored on a non-volatile computer-readable medium and includes machine-executable instructions that, when executed, cause a machine to perform the steps of the method described in accordance with the second aspect of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. In the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0010] Figure 1 FIG. is a schematic diagram illustrating an example environment in which a circuit system according to an embodiment of the present disclosure may be implemented;

[0011] Figure 2 FIG. is a schematic diagram illustrating a connection manner of a circuit system and a three-phase inverter unit according to an embodiment of the present disclosure;

[0012] Figure 3 FIG. is a schematic diagram illustrating a connection manner of a controllable power supply circuit and a diagnostic circuit in a case where one phase of a three-phase inverter unit is short-circuited to a power battery according to an embodiment of the present disclosure;

[0013] Figure 4 FIG. is a schematic diagram illustrating a connection manner of a controllable power supply circuit and a diagnostic circuit in a case where one phase of a three-phase inverter unit is short-circuited to ground according to an embodiment of the present disclosure;

[0014] Figure 5 A schematic diagram showing the connection mode of a controllable power supply circuit and a diagnostic circuit when all three phases of a three - phase inverter unit are connected to a motor according to an embodiment of the present disclosure.

[0015] Figure 6 A schematic diagram showing the connection mode of a controllable power supply circuit and a diagnostic circuit when the U - phase, U - V phase, U - W phase, U - V - W phase, or V - W phase of a three - phase inverter unit is not connected to a motor according to an embodiment of the present disclosure;

[0016] Figure 7 A schematic diagram showing the connection mode of a controllable power supply circuit and a diagnostic circuit when the V - phase of a three - phase inverter unit is not connected to a motor according to an embodiment of the present disclosure;

[0017] Figure 8 A schematic diagram showing the connection mode of a controllable power supply circuit and a diagnostic circuit when the W - phase of a three - phase inverter unit is not connected to a motor according to an embodiment of the present disclosure;

[0018] Figure 9 A schematic diagram showing the voltage distribution of the output of the diagnostic circuit under different connection modes according to an embodiment of the present disclosure; and

[0019] Figure 10 A flowchart showing a method for diagnosing the connection state of a three - phase inverter unit according to an embodiment of the present disclosure.

[0020] In each of the drawings, the same or corresponding reference numerals denote the same or corresponding parts. Detailed embodiments

[0021] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure. The embodiments of the present disclosure described below with reference to the accompanying drawings are only for exemplary purposes.

[0022] As described above, the three - phase inverter unit is used to control a motor, and corresponding monitoring elements are required to check whether the corresponding phases of the three - phase inverter unit are connected to the corresponding phases of the motor, and to check whether the metal - oxide - semiconductor field - effect transistor (MOSFET) of the three - phase inverter unit is damaged.

[0023] In the conventional technology, a short - circuit fault of a power - electronic component (e.g., MOSFET) in a three - phase inverter unit can only be detected by large - current injection after power - on, which poses a potential risk to the battery. In addition, in the conventional technology, it is impossible to detect whether the U, V, and W phases of the three - phase inverter unit are connected to the corresponding phases of the motor after power - on, and such disconnection will affect the output of the motor. Therefore, it is necessary to diagnose whether there is a short - circuit fault in each MOSFET of the three - phase inverter unit and whether the U, V, and W phases of the three - phase inverter unit are connected to the corresponding phases of the motor so that the motor can output normally.

[0024] To solve at least the above - mentioned and other potential problems, embodiments of the present disclosure provide a circuit system for a three - phase inverter unit. The three - phase inverter unit is connected between a power battery and a motor and includes three phases connected to the motor. The circuit system includes: a diagnostic circuit configured to be connected to a corresponding one of the three phases; and a controllable power - supply circuit configured to be connected to the diagnostic circuit to supply power to the diagnostic circuit, wherein the diagnostic circuit is further configured to: receive different input voltages from the corresponding phase in different connection states of the three phases and output different output voltages corresponding to the different connection states. Through the circuit system of the embodiments of the present disclosure, by obtaining the output voltage of the diagnostic circuit, the connection state of the three - phase inverter unit can be judged based on the output voltage. For example, it can diagnose whether there is a short - circuit fault in the MOSFET of the three - phase inverter unit and whether the U, V, and W phases of the three - phase inverter unit are connected to the corresponding phases of the motor so that the motor can output normally.

[0025] Embodiments of the present disclosure will be described in further detail below in conjunction with the accompanying drawings, where Figure 1 shows an example environment in which the devices of the embodiments of the present disclosure can be implemented.

[0026] As Figure 1 shown, the three - phase inverter unit 100 is connected between the power battery B and the motor M and includes three phases (e.g., electrically connected) to the motor M, such as the three phases U, V, and W.

[0027] As Figure 1 shown, the three - phase inverter unit 100 includes MOS transistors Q1 and Q2 connected in series, and the mid - point of these two MOS transistors is connected to the U phase of the motor M. Therefore, this branch is referred to as the U phase of the three - phase inverter unit 100. The three - phase inverter unit 100 includes MOS transistors Q3 and Q4 connected in series, and the mid - point of these two MOS transistors is connected to the V phase of the motor M. Therefore, this branch is referred to as the V phase of the three - phase inverter unit 100. The three - phase inverter unit 100 includes MOS transistors Q5 and Q6 connected in series, and the mid - point of these two MOS transistors is connected to the W phase of the motor M. Therefore, this branch is referred to as the W phase of the three - phase inverter unit 100.

[0028] In the conventional technology, if the MOS transistor Q1 of the U phase is short-circuited, the U phase is short-circuited to the power battery B, and the MOS transistor Q1 is in a normally closed state. In order to detect whether the MOS transistor Q1 is short-circuited, in the conventional technology, by providing a voltage to the gate of the MOS transistor Q2 within a very short time to turn on the MOS transistor Q2, if the U phase is short-circuited to the power battery B due to the short circuit of the MOS transistor Q1, then a very large current will flow through this branch, and by detecting this large current, it can be detected that the MOS transistor Q1 is in a short-circuit state. Similarly, if Q2 is short-circuited, it can be detected by the same method. For example, at this time, a voltage needs to be provided to the gate of the MOS transistor Q1 within a very short time to turn on the MOS transistor Q1 to detect whether a large current flows through this branch. The same method can also be used to detect the other MOS transistors Q3 to Q6 of other phases.

[0029] Although the above method can be used to detect whether the MOS transistors of the three phases of the three-phase inverter unit 100 are short-circuited, the instantaneous large current generated will have an adverse effect on the power battery B and affect the service life of the power battery. In addition, in the conventional technology, it is impossible to detect whether the three phases U, V, and W of the three-phase inverter unit 100 are connected to the corresponding phases of the motor M through the above-mentioned power-on method.

[0030] The following will refer to Figure 2 to describe a circuit system for diagnosing the connection state of a three-phase inverter unit according to the present disclosure. As Figure 2 shown, the circuit system includes a diagnostic circuit 1 and a controllable power supply circuit 2. The controllable power supply circuit 2 is configured to be connected to the diagnostic circuit 1 during diagnosis, for example, to provide a diagnostic voltage to the diagnostic circuit. The controllable power supply circuit 2 is configured not to be connected to the diagnostic circuit 1 during non-diagnosis to avoid consuming electrical energy. The diagnostic circuit 1 is connected to one of the three phases of the three-phase inverter unit 100. In Figure 2 the illustrated embodiment, the diagnostic circuit 1 is connected to the U phase of the three phases of the three-phase inverter unit 100, so that the diagnostic circuit 1 can diagnose whether the MOS transistors Q1 and Q2 in the U phase are short-circuited.

[0031] Similarly, when it is necessary to diagnose the MOS transistors Q3 and Q4 in the V phase, the diagnostic circuit 1 can be connected to the V phase, for example, between the MOS transistors Q3 and Q4. Although in Figure 2 the illustrated embodiment, the diagnostic circuit 1 is connected to the U phase to detect whether the U phase is correctly connected to the corresponding phase of the motor M, but even if the diagnostic circuit 1 is connected to the U phase, in this connection state, the connection states of the V phase and the W phase can also be detected, which will be described in detail below.

[0032] During diagnosis, the diagnostic circuit 1 can respond to various different connection states of the three phases of U, V, and W to receive different input voltages at its input terminals connected to the corresponding phases, and output different output voltages corresponding to different connection states. That is, during diagnosis, the input voltage received by the diagnostic circuit 1 corresponds to a connection state of the three phases of U, V, and W, so that the output voltage also corresponds to this connection state. Therefore, by measuring the output voltage of the diagnostic circuit 1 (for example, at the Figure 2 output terminal OUT), the corresponding connection state can be known.

[0033] In some embodiments, different connection states may include: the phase to which the diagnostic circuit 1 is connected is shorted to ground, the phase to which the diagnostic circuit 1 is connected is shorted to the power battery, at least one of the three phases of the three-phase inverter unit 100 is not connected to the corresponding phase of the motor M (for example, one or two or three of the three phases of U, V, and W are not connected to the corresponding phase of the motor M), and the three phases of the three-phase inverter unit 100 are all connected to the motor M.

[0034] In some embodiments, for the phase to which the diagnostic circuit 1 is connected being shorted to ground, the output voltage at the output terminal OUT of the diagnostic circuit 1 is in a first voltage range; for at least one of the three phases of the three-phase inverter unit 100 not being connected to the corresponding phase of the motor M, the output voltage at the output terminal OUT of the diagnostic circuit 1 is in a second voltage range; for the three phases of the three-phase inverter unit 100 all being connected to the motor M, the output voltage at the output terminal OUT of the diagnostic circuit 1 is in a third voltage range; and for the phase to which the diagnostic circuit 1 is connected being shorted to the power battery, the output voltage at the output terminal OUT of the diagnostic circuit 1 is in a fourth voltage range. Hereinafter, reference will be made to Figure 9 to describe the first to fourth voltage ranges.

[0035] In some embodiments, the first to fourth voltage ranges gradually increase. In some embodiments, the output voltage at the output terminal OUT includes first to fifth voltages that increase in sequence. The above-mentioned first voltage range is between the first and second voltages, the second voltage range is between the second and third voltages, the third voltage range is between the third and fourth voltages, and the fourth voltage range is between the fourth and fifth voltages. By setting the output voltages corresponding to different connection states in different voltage ranges, then when measuring the voltage range in which the voltage at the output terminal OUT of the diagnostic circuit 1 is located, the connection state of the three-phase inverter unit 100 can be diagnosed. This voltage range

[0036] such as Figure 2As shown, the controllable power supply circuit 2 includes a power supply circuit 21. The power supply circuit includes a controllable switch S1 (such as a triode). The controllable switch S1 is turned on during diagnosis to provide a diagnostic voltage to the diagnostic circuit 1, enabling the diagnostic circuit 1 to output a certain voltage, such as outputting a certain voltage at the output terminal OUT. In one example, the controllable switch S1 is a triode. During diagnosis, a voltage is received at the PRE_DIAG terminal of the controllable power supply circuit 2, causing another switch S2 (such as a triode) to conduct. When switch S2 conducts, since there is a 15V voltage in the first power supply P1, current will flow through resistors R562 and R557. Due to the voltage division of resistors R562 and R557, the voltage at the node between R562 and R557 is supplied to the controllable switch S1 (such as a triode), causing the controllable switch S1 to conduct, so that another power supply P2 (with a supply voltage of 15V) can supply power to the diagnostic circuit 1 via the power supply circuit 21. Since the power supply circuit 21 is connected to the diagnostic circuit 1, during diagnosis, the power supply circuit 21 can provide a diagnostic voltage to the diagnostic circuit 1.

[0037] As Figure 2 shown, the power supply circuit 21 may further include a diode D1. Due to the directivity of the current of the diode D1, the reverse voltage (such as a voltage higher than 15V at the connection point of the diagnostic circuit 1 and the power supply circuit 21) will not affect the power supply P2. That is to say, current can only flow from the anode to the cathode of the diode D1, rather than from the cathode to the anode. Therefore, when the voltage at the anode of the diode D1 is higher than the voltage at the cathode, current will flow through the diode; conversely, when the voltage at the anode of the diode D1 is lower than the voltage at the cathode, the power supply circuit 21 will not be conducted.

[0038] During non-diagnosis, the supply of voltage at the PRE_DIAG terminal of the controllable power supply circuit 2 is stopped. Therefore, switch S2 does not conduct, and no voltage is supplied to the controllable switch S1, so that the controllable switch S1 is also in the off state, and the voltage of the power supply P2 is not supplied to the diagnostic circuit 1, thereby reducing energy consumption.

[0039] The following will refer to Figure 3 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of a three-phase inverter unit when the U phase of the three-phase inverter unit 100 is short-circuited to the power battery B.

[0040] As Figure 3As shown, if the MOS transistor Q1 is short-circuited, then the U-phase will be short-circuited to the power battery B, and thus the voltage of the U-phase will be equal to the voltage of the power battery B. In one example, the voltage of the power battery B is 48 volts. Therefore, in this example, the voltage at the input terminal IN of the diagnostic circuit 1 is 48V. Since this 48-volt voltage is higher than the 15V voltage of the power supply P2, the diode D1 is in the cut-off state, and the 15V of the power supply P2 will not be supplied to the diagnostic circuit 1. The diagnostic circuit 1 receives an input voltage of 48V. Due to the voltage division of the resistors R559 and R560, a certain output voltage will be output at the output terminal OUT. In one example, the resistance of the resistor R559 is 121K ohms, the resistance of R560 is 10K ohms, and due to the function of the Zener diode D2, the output voltage at the output terminal OUT will be stabilized at about 3.3V. This Zener diode D2 will be used to limit the voltage and ensure that the output voltage at the output terminal OUT is stabilized at about 3.3V or less than 3.3V to prevent damage to the main control unit due to overvoltage. Therefore, as described above, when the U-phase is short-circuited to the power battery B, the voltage of the power supply P2 of the power supply circuit 21 cannot be input to the diagnostic circuit 1, and this diagnostic circuit 1 can output a voltage corresponding to this state. In one example, this output voltage is approximately equal to 3.3V.

[0041] The following will refer to Figure 4 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of a three-phase inverter unit when the U-phase of the three-phase inverter unit 100 is short-circuited to ground.

[0042] As shown in the figure, if the MOS transistor Q2 is short-circuited, then the U-phase will be short-circuited to ground, and the voltage of the U-phase will be close to the ground voltage, that is, 0V. Therefore, as Figure 4 shown, the voltage at the input terminal IN of the diagnostic circuit 1 is also 0V. Then the output voltage at the output terminal OUT is also close to 0V at this time. Therefore, when the U-phase is short-circuited to ground, the output of the diagnostic circuit 1 will be close to 0V.

[0043] Although the above refers to Figure 3 and Figure 4 to describe how to detect whether the U-phase of the three-phase inverter unit 100 is short-circuited to the power battery or to ground, those skilled in the art should understand that when it is necessary to check the V-phase and W-phase, the diagnostic circuit 1 can be connected to the V-phase and W-phase.

[0044] The following will refer to Figure 5 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of a three-phase inverter unit when all three phases of the three-phase inverter unit 100 are connected to the motor. In one example, the V-phase and W-phase are grounded through resistors R2 and R3 respectively. In an alternative embodiment, the U-phase will be grounded through resistor R1.

[0045] As Figure 5 shown, when the three-phase inverter unit 100 does not include the resistor R1, since the three phases of U, V, and W are all connected to the motor M, then both the resistors R2 and R3 are connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1. It should be clear that, as Figure 5 shown, when the three-phase inverter unit 100 includes the resistor R1, since the three phases of U, V, and W are all connected to the motor M, then the resistors R1, R2, and R3 are all connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1.

[0046] In this case, when the three-phase inverter unit 100 does not include the resistor R1, the output voltage (in volts) of the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (1):

[0047] 15*R2*R3*R560 / [R2*R3*(R559+R560)+(R2+R3+R559+R560)*(R563+R558)](1)

[0048] When the three-phase inverter unit 100 includes the resistor R1, the output voltage (in volts) of the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (2): 15*R1*R2*R3*R560 / [R1*R2*R3*(R559+R560)+(R1+R2+R3+R559+R560)*(R563+R558 )](2)

[0050] The following will refer to Figure 6 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of the three-phase inverter unit when at least one phase including the U phase of the three-phase inverter unit 100 connected to the diagnostic circuit 1 is not connected to the motor. In one example, the V phase and the W phase are grounded through the resistors R2 and R3 respectively. In an alternative embodiment, the U phase will be grounded through the resistor R1.

[0051] In Figure 6 the illustrated embodiment, the cases where at least one phase including the U phase of the three-phase inverter unit 100 is not connected to the motor M include that the U phase, the UV phase, the UW phase, and the UVW phase are not connected to the motor M. In the above cases and when both the V and W phases are not connected to the motor M, neither R2 nor R3 is connected in the three-phase inverter unit 100. When the U phase is grounded through the resistor R1, since the input terminal IN of the diagnostic circuit 1 is connected to the U phase of the three-phase inverter unit 100, the resistor R1 is connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1.

[0052] In this case, when the three-phase inverter unit 100 does not include the resistor R1, the output voltage (in volts) at the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (3):

[0053] 15*R560 / (R563+R558+R559+R560)(3)

[0054] When the three-phase inverter unit 100 includes the resistor R1, the output voltage (in volts) at the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (4):

[0055] 15*R1*R560 / [R1*(R559+R560)+(R1+R559+R560)*(R563+R558)](4)

[0056] The following will refer to Figure 7 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of the three-phase inverter unit 100 when the V-phase of the three-phase inverter unit 100 is not connected to the motor. In one example, the V-phase and the W-phase are grounded through resistors R2 and R3 respectively. In an alternative embodiment, the U-phase will be grounded through the resistor R1.

[0057] In the embodiment as Figure 7 shown, the V-phase of the three-phase inverter unit 100 is not connected to the motor M, so R2 is not connected in the three-phase inverter unit 100. However, R1 and R3 are connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1.

[0058] When the three-phase inverter unit 100 does not include the resistor R1, only R3 is connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1. The output voltage (in volts) at the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (5):

[0059] 15*R3*R560 / [R3*(R559+R560)+(R3+R559+R560)*(R563+R558)](5)

[0060] When the three-phase inverter unit 100 includes the resistor R1, both R1 and R3 are connected from the three-phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1. The output voltage (in volts) at the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (6):

[0061] 15*R1*R3*R560 / [R1*R3*(R559+R560)+(R1+R3+R559+R560)*(R563+R558)](6)

[0062] The following will refer to Figure 8 to illustrate a schematic diagram of a circuit system for diagnosing the connection state of a three - phase inverter unit 100 when the V - phase of the three - phase inverter unit is not connected to the motor. In one example, the V - phase and the W - phase are grounded through resistors R2 and R3 respectively. In an alternative embodiment, the U - phase will be grounded through resistor R1.

[0063] In the embodiment as Figure 8 shown, the W - phase of the three - phase inverter unit 100 is not connected to the motor M, so R3 is not connected in the three - phase inverter unit 100. However, R1 and R2 are connected from the three - phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1.

[0064] When the three - phase inverter unit 100 does not include resistor R1, only R2 is connected from the three - phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1. The output voltage (in volts) of the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (7):

[0065] 15*R2*R560 / [R2*(R559 + R560)+(R2 + R559 + R560)*(R563 + R558)](7)

[0066] When the three - phase inverter unit 100 includes resistor R1, both R1 and R2 are connected from the three - phase inverter unit 100 to the input terminal IN of the diagnostic circuit 1. The output voltage (in volts) of the output terminal OUT of the diagnostic circuit 1 can be expressed by the following formula (8):

[0067] 15*R1*R2*R560 / [R1*R2*(R559 + R560)+(R1 + R2 + R559 + R560)*(R563 + R558)](8)

[0068] By appropriately selecting the resistance values of resistors R563, R558, R559, R560, R563, R1, R2, and R3, it is possible to make the output voltage of the output terminal OUT of the diagnostic circuit 1 fall within a first range when all of the U, V, and W phases are connected to the motor M, and the output voltage of the output terminal OUT of the diagnostic circuit 1 fall within a second range when at least one of the U, V, and W phases is not connected to the motor M. In some embodiments, the voltage in the first range can be greater than the voltage in the second range. The voltage in the first range and the voltage in the second range are both greater than the output voltage when the U - phase is short - circuited to ground and both less than the output voltage when the U - phase is short - circuited to the power battery B.

[0069] Figure 9 A schematic diagram showing the distribution of multiple different voltage ranges of the output voltage of the diagnostic circuit according to an embodiment of the present disclosure is shown.

[0070] As Figure 9 shown, the output voltage of the diagnostic circuit includes voltages V1 to V5. In the embodiment as Figure 9 shown, when the U-phase is shorted to ground, the output voltage is in the range of V1 to V2. For example, the voltage at the output terminal OUT of the diagnostic circuit 2 measured in this connection state is as shown by curve L1. When at least one of the three phases is not connected to the motor M, the output voltage is in the range of V2 to V3. For example, the voltage at the output terminal OUT of the diagnostic circuit 2 measured in this connection state is as shown by curve L2. When all three phases are connected to the motor M, the output voltage is in the range of V3 to V4. For example, the voltage at the output terminal OUT of the diagnostic circuit 2 measured in this connection state is as shown by curve L3. When the U-phase is shorted to the power battery B, the output voltage is in the range of V4 to V5. For example, the voltage at the output terminal OUT of the diagnostic circuit 2 measured in this connection state is as shown by curve L4. It should be clear that curves L1 to L4 are merely schematic, and the amplitude of this curve may vary within a small range or may not change over time.

[0071] In a preferred embodiment, the voltage of V1 is 0V and the voltage of V5 is 3.3V. Those skilled in the art should understand that by selecting other resistor values, the voltages within each output voltage range may change under different circumstances, and the difference between the upper limit voltage and the lower limit voltage of each range may be different or the same.

[0072] Figure 10 shows a flowchart of a method 1000 for diagnosing the connection state of a three-phase inverter unit according to an embodiment of the present disclosure. The three-phase inverter unit 100 is connected between the power battery B and the motor M and includes three phases connected to the motor, as Figure 1 shown.

[0073] As Figure 10 shown, in block 1010, a start signal for the controllable power supply circuit is provided, and this start signal can enable the controllable power supply circuit 2 to be turned on to supply power to the diagnostic circuit 1 connected to the controllable power supply circuit. The diagnostic circuit 1 is connected to the corresponding phase among the three phases UVW, for example, it can be connected to the U-phase. This start signal can be, for example, the start voltage of a triode.

[0074] In block 1020, the output voltage of the diagnostic circuit 2 is obtained. The output voltage of this diagnostic circuit 2 can be, for example, the output voltage at the output terminal OUT as Figure 2 described. This output voltage can change according to the different connection states of the three-phase inverter unit 100.

[0075] In block 1030, based on the obtained output voltage, the connection state of the three-phase inverter unit is determined. For example, different connection states of the three-phase inverter unit 100 can correspond to different voltage ranges. By determining the voltage range in which the output voltage lies, the connection state of the three-phase inverter unit 100 can be determined.

[0076] In some embodiments, different connection states of the three-phase inverter unit 100 include: the phase to which the diagnostic circuit 1 is connected is shorted to ground, the phase to which the diagnostic circuit 1 is connected is shorted to the power battery, at least one of the three phases of the three-phase inverter unit 100 is not connected to the corresponding phase of the motor M (for example, one phase or two phases or three phases of the U, V, and W phases are not connected to the corresponding phase of the motor M), and all three phases of the three-phase inverter unit 100 are connected to the motor M. During diagnosis, the diagnostic circuit 1 can receive different input voltages from the corresponding phase to which it is connected in response to various different connection states of the three U, V, and W phases, so as to output different output voltages corresponding to different connection states. That is, during diagnosis, the input voltage received by the diagnostic circuit 1 corresponds to a connection state of the three U, V, and W phases, and thus the output voltage also corresponds to this connection state. Therefore, by measuring the output voltage of the diagnostic circuit 1, the corresponding connection state can be known.

[0077] The present disclosure can be a method, apparatus, system, and / or computer program product. The computer program product can include a computer-readable storage medium having thereon computer-readable program instructions for performing various aspects of the present disclosure.

[0078] A computer-readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punched card or raised structures in a groove having instructions stored thereon, and any suitable combination of the foregoing. The computer-readable storage medium used herein is not construed as an instantaneous signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (for example, an optical pulse through an optical fiber cable), or an electrical signal transmitted through a wire.

[0079] The computer-readable program instructions described herein can be downloaded to various computing / processing devices from a computer-readable storage medium or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical fiber transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in each computing / processing device.

[0080] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, by using the state information of the computer-readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer-readable program instructions to implement various aspects of the present disclosure.

[0081] Aspects of the present disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0082] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that the instructions, when executed by the processing unit of the computer or other programmable data processing apparatus, create an apparatus for implementing the functions / acts specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer-readable medium storing the instructions comprises a manufacture including instructions for implementing various aspects of the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0083] The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, such that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, so that the instructions executed on the computer, other programmable data processing apparatus, or other device implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0084] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, a segment of a program, or a portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the boxes may occur out of the order noted in the figures. For example, two consecutive boxes may in fact be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each box of the block diagrams and / or flowcharts, and combinations of boxes in the block diagrams and / or flowcharts, can be implemented by special-purpose hardware-based systems that perform the specified functions or acts, or by combinations of special-purpose hardware and computer instructions.

[0085] The embodiments of the present disclosure have been described above. 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 choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A circuit system for a three - phase inverter unit, the three - phase inverter unit being connected between a power battery and an electric motor and including three phases connected to the electric motor, the circuit system comprising: A diagnostic circuit configured to be connected to a corresponding one of the three phases; And A controllable power supply circuit configured to be connected to the diagnostic circuit to supply power to the diagnostic circuit, Wherein the diagnostic circuit is further configured to: receive different input voltages from the corresponding phase in different connection states of the three phases, and output different output voltages corresponding to the different connection states.

2. The circuit system according to claim 1, wherein the different connection states include the following items: the corresponding phase is short - circuited to ground, at least one of the three phases is not connected to the corresponding phase of the electric motor, all three phases are connected to the corresponding phase of the electric motor, and the corresponding phase is short - circuited to the power battery.

3. The circuit system according to claim 2, wherein: The output voltage includes a first voltage, a second voltage, a third voltage, a fourth voltage, and a fifth voltage that increase in sequence, When the corresponding phase is short - circuited to ground, the output voltage of the diagnostic circuit is between the first voltage and the second voltage; When at least one of the three phases is not connected to the corresponding phase of the electric motor, the output voltage of the diagnostic circuit is between the second voltage and the third voltage; When all three phases are connected to the corresponding phase of the electric motor, the output voltage of the diagnostic circuit is between the third voltage and the fourth voltage; And When the corresponding phase is short - circuited to the power battery, the output voltage of the diagnostic circuit is between the fourth voltage and the fifth voltage.

4. The circuit system according to claim 3, wherein the first voltage is 0V and the fifth voltage is 3.3V.

5. The circuit system according to any one of claims 1 to 4, wherein: The controllable power supply circuit includes a power supply circuit, the power supply circuit including a controllable switch and a power supply, The controllable switch is turned on during diagnosis so that the power supply of the controllable power supply circuit is connected to the diagnostic circuit during diagnosis; And The controllable switch is turned off during non - diagnosis so that the power supply of the controllable power supply circuit is not connected to the diagnostic circuit during non - diagnosis.

6. The circuit system according to claim 1, wherein the voltage of the power battery is higher than the supply voltage of the power supply of the controllable power supply circuit; and The power supply circuit further includes a diode, the cathode of the diode is connected to the diagnostic circuit, and the anode of the diode is connected to the power supply of the controllable power supply circuit, so that when the corresponding phase is short - circuited to the power battery, the input voltage of the diagnostic circuit is the voltage of the power battery.

7. The circuit system according to claim 6, wherein: The diagnostic circuit includes a plurality of first resistors connected in series, so that when the corresponding phase is short - circuited to the power battery, the output voltage of the diagnostic circuit is equal to the voltage across the first resistor among the plurality of first resistors.

8. The circuit system according to claim 7, wherein: The diagnostic circuit further includes a Zener diode, such that when the corresponding phase is short-circuited to the power battery, the output voltage of the diagnostic circuit is stabilized at a predetermined voltage value.

9. The circuit system according to claim 2, wherein: The diagnostic circuit includes a plurality of first resistors connected in series; The controllable power supply circuit includes a power supply circuit, and the power supply circuit includes at least one second resistor; At least one of the three phases is grounded through a corresponding number of third resistors; and The resistance values of the plurality of first resistors, the at least one second resistor, and the third resistor are selected such that: the output voltage of the diagnostic circuit when all three phases are connected to the corresponding phases of the motor is greater than the output voltage of the diagnostic circuit when at least one of the three phases is not connected to the corresponding phase of the motor.

10. The circuit system according to claim 9, wherein: The three phases are grounded through three third resistors, and the resistance values of the three third resistors are the same.

11. A method for diagnosing the connection state of a three-phase inverter unit, the three-phase inverter unit being connected between a power battery and a motor and including three phases connected to the motor, the method comprising: Providing a start signal for a controllable power supply circuit, such that the controllable power supply circuit is turned on to supply power to a diagnostic circuit, wherein the diagnostic circuit is configured to be connected to the controllable power supply circuit and to the corresponding phase of the three phases in the three-phase inverter unit; Obtaining the output voltage of the diagnostic circuit, wherein the output voltage varies according to different connection states of the three-phase inverter unit; And Based on the obtained output voltage, determining the connection state of the three-phase inverter unit.

12. The method according to claim 11, wherein the connection state of the three-phase inverter unit includes at least one of the following items: the corresponding phase is short-circuited to ground, at least one of the three phases is not connected to the corresponding phase of the motor, all three phases are connected to the corresponding phases of the motor, and the corresponding phase is short-circuited to the power battery.

13. The method according to claim 12, wherein: The output voltage includes a first voltage, a second voltage, a third voltage, a fourth voltage, and a fifth voltage that increase in sequence, When the corresponding phase is short-circuited to ground, the output voltage of the diagnostic circuit is between the first voltage and the second voltage; When at least one of the three phases is not connected to the corresponding phase of the motor, the output voltage of the diagnostic circuit is between the second voltage and the third voltage; When all three phases are connected to the corresponding phases of the motor, the output voltage of the diagnostic circuit is between the third voltage and the fourth voltage; And When the corresponding phase is short-circuited to the power battery, the output voltage of the diagnostic circuit is between the fourth voltage and the fifth voltage.

14. A three-phase inverter, comprising a three-phase inverter unit and the circuit system according to claim 1.

15. A machine-readable storage medium having machine-executable instructions stored thereon, wherein the machine-executable instructions are executed by a processor to implement the steps of the method according to claim 11.

16. A computer program product tangibly stored on a non-transitory computer-readable medium and comprising machine-executable instructions that, when executed, cause a machine to perform the method according to claim 11.

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