Safety path detection method of motor system and vehicle

Abstract

The invention provides a safety path detection method of a motor system and a vehicle, and relates to the technical field of safety detection of the motor system.The method comprises the steps that under the condition that a voltage signal is applied between the first input end and the second input end of an inverter, a conduction signal is provided for the control end of an upper bridge arm switch in each bridge arm, a disconnection signal is provided for the control end of the lower bridge arm switch in each bridge arm; collecting the current flowing through the first end of each phase of winding in a first time period to obtain an N-phase first current value; and under the condition that each phase of first current value in the N phases of first current values is within a first current threshold range, determining that a first safety path of the motor system passes detection. The first safety path refers to that the upper bridge arm switch of each bridge arm is in an on state and the lower bridge arm switch of each bridge arm is in an off state. According to the invention, the accuracy of safe path detection can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor system safety detection, and in particular to a motor system safety path detection method and a vehicle. Background Art

[0002] In order to ensure driving safety, during the startup of the vehicle's motor system, at least one safe path of the motor system needs to be detected, and the motor system can only enter the working state to drive the vehicle when at least one safe path passes the detection. Based on this, during the operation of the vehicle, if the motor system fails, the motor system can be controlled to enter the safe path to avoid the motor system outputting unexpected torque, thereby avoiding personal injury and property damage. However, the existing safe path detection method of the motor system has the problem of low detection accuracy. Therefore, a method that can improve the accuracy of safe path detection is urgently needed. Summary of the invention

[0003] The present invention provides a safe path detection method and a vehicle for a motor system, which can improve the accuracy of safe path detection and avoid the output of unexpected torque to a certain extent during the detection process, thereby improving the safety of the detection process to a certain extent.

[0004] In a first aspect, the present application provides a safe path detection method for a motor system, wherein the motor system comprises an inverter and a motor, the inverter comprises N bridge arms, each of the N bridge arms comprises an upper bridge arm switch and a lower bridge arm switch, each of the bridge arms is connected between a first input terminal and a second input terminal of the inverter, the motor comprises N-phase windings and a first capacitor, the N-phase windings correspond one-to-one to the N bridge arms, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N-phase windings is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the ground terminal of the motor system, and the first capacitor is a capacitor formed by the N-phase windings and the housing of the motor;

[0005] The safety path detection method comprises:

[0006] In the case where a voltage signal is applied between the first input terminal and the second input terminal of the inverter, a conduction signal is provided to the control terminal of the upper bridge arm switch in each bridge arm, and a disconnection signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, so that at least the voltage signal charges the first capacitor through the upper bridge arm switch that is turned on in the N bridge arms; within a first time period, the current flowing through the first end of each phase winding is collected to obtain an N-phase first current value; wherein the N-phase first current value corresponds to the first end of the N-phase winding one by one, and the first time period is a time period in which a conduction signal is provided to the control terminal of the upper bridge arm switch in each bridge arm and a disconnection signal is provided to the control terminal of the lower bridge arm switch in each bridge arm; when each phase first current value of the N-phase first current value is within a first current threshold range, it is determined that the first safety path of the motor system passes the detection; wherein the first safety path refers to the upper bridge arm switch in each bridge arm being in a conducting state and the lower bridge arm switch in each bridge arm being in a disconnected state.

[0007] Optionally, the method also includes: after determining that the first safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter, providing a disconnect signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm; within a second time period, collecting the current flowing through the first end of each phase winding to obtain an N-phase second current value; wherein the N-phase second current value corresponds one-to-one to the first end of the N-phase winding, and the second time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm; when each phase second current value of the N-phase second current value is within a second current threshold range, determining that the second safety path of the motor system passes the detection; wherein the second safety path refers to that the upper bridge arm switch and the lower bridge arm switch in each bridge arm are both in a disconnected state.

[0008] Optionally, the method further includes: after determining that the second safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter, providing a disconnect signal to the control end of the upper bridge arm switch in each bridge arm, and providing a conduction signal to the control end of the lower bridge arm switch in each bridge arm, so that the first capacitor discharges through the conductive lower bridge arm switch in the N bridge arms; within a third time period, collecting the current flowing through the first end of each phase winding to obtain an N-phase third current value; wherein the N-phase third current value corresponds one-to-one to the first end of the N-phase winding, and the third time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch in each bridge arm and providing a conduction signal to the control end of the lower bridge arm switch in each bridge arm; when each phase third current value of the N-phase third current value is within the third current threshold range, determining that the third safety path of the motor system passes the detection; wherein the third safety path refers to the upper bridge arm switch in each bridge arm being in a disconnected state and the lower bridge arm switch in each bridge arm being in a conductive state.

[0009] Optionally, the voltage value of the voltage signal is greater than a preset voltage value.

[0010] Optionally, the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the first time period; or the first current value of each phase is the value of the current flowing through the first end of the corresponding winding at the first moment; wherein the first moment is a moment within the first time period.

[0011] Optionally, the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding within the first time period; the method also includes: obtaining N-phase fourth current values; wherein the N-phase fourth current values ​​correspond one-to-one to the first end of the N-phase winding, and each phase of the N-phase fourth current value is the value of the current flowing through the first end of the corresponding winding at a second moment, and the second moment is a moment within the first time period; when the first current value of each phase in the N-phase first current values ​​is within the first current threshold range, determining that the first safety path of the motor system has passed the detection includes: determining that the first safety path has passed the detection when the first current value of each phase is within the first current threshold range and at least one of the following items is satisfied: the sum of the N-phase first current values ​​is less than or equal to the first current threshold; the sum of the N-phase fourth current values ​​is less than or equal to the second current threshold; the fourth current value of each phase is within the fourth current threshold range.

[0012] Optionally, the second current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the second time period; or the second current value of each phase is the value of the current flowing through the first end of the corresponding winding at a third moment; wherein the third moment is a moment within the second time period.

[0013] Optionally, the third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the third time period; or the third current value of each phase is the value of the current flowing through the first end of the corresponding winding at a fourth moment; wherein the fourth moment is a moment within the third time period.

[0014] Optionally, the third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding within the third time period; the method also includes: obtaining the fifth current value of the N phases; wherein the fifth current value of the N phases corresponds one-to-one to the first end of the N phase winding, and the fifth current value of each phase in the N phase fifth current values ​​is the value of the current flowing through the first end of the corresponding winding at a fifth moment, and the fifth moment is a moment within the third time period; when the third current value of each phase in the N phase third current values ​​is within the third current threshold range, determining that the third safety path of the motor system has passed the detection includes: determining that the third safety path has passed the detection when the third current value of each phase is within the third current threshold range and at least one of the following items is satisfied: the sum of the N phase third current values ​​is less than or equal to the third current threshold; the sum of the N phase fifth current values ​​is less than or equal to the fourth current threshold; the fifth current value of each phase is within the fifth current threshold range.

[0015] In a second aspect, the present application provides an electronic device comprising a memory and a processor, wherein: the memory is configured to store a computer program; and the processor is configured to execute the safe path detection method for the motor system described in any one of the first aspects when executing the computer program.

[0016] In a third aspect, the present application provides a computer-readable storage medium, characterized in that a computer program is stored on the storage medium, and when the computer program is executed by a processor, the safe path detection method for the motor system described in any one of the first aspects is executed.

[0017] In a fourth aspect, the present application provides a vehicle, comprising: a motor system and a controller, wherein: the motor system comprises an inverter and a motor, the inverter comprises N bridge arms, each of the N bridge arms comprises an upper bridge arm switch and a lower bridge arm switch, each bridge arm is connected between a first input terminal and a second input terminal of the inverter, the motor comprises N-phase windings and a first capacitor, the N-phase windings correspond one-to-one to the N bridge arms, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N-phase windings is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the ground terminal of the motor system, and the first capacitor is a capacitor formed by the N-phase windings and the housing of the motor; the controller is used to execute the safe path detection method for the motor system described in any one of the first aspects.

[0018] The beneficial effects of the safe path detection method of the motor system of the present invention are:

[0019] Since the first safety path refers to the upper bridge arm switch in each bridge arm being in the on state and the lower bridge arm switch in each bridge arm being in the off state, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter, a conduction signal is provided to the control terminal of the upper bridge arm switch in each bridge arm and a disconnection signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, and the current flowing through the first end of each phase winding is collected, so as to verify whether each upper bridge arm switch and the lower bridge arm switch can be in the corresponding state in response to the signal at its control terminal through the collected N-phase first current value and in combination with the first current threshold range, thereby determining whether the first safety path has passed the verification based on the verification result, thereby realizing the verification of the first safety path.

[0020] Furthermore, since the current at the first end of each phase winding can indicate whether the upper bridge arm switch and the lower bridge arm switch in the corresponding bridge arm can respond to the signal at its control end and be in the corresponding state, therefore, by detecting the first safety path through the collected current flowing through the first end of each phase winding (i.e., the N-phase first current value), it can be understood that by determining whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm can respond to the signal at its control end and be in the corresponding state, the first safety path is detected, thereby improving the detection accuracy.

[0021] Furthermore, when a conduction signal is provided to the control end of the upper bridge arm switch in each bridge arm and a disconnection signal is provided to the control end of the lower bridge arm switch in each bridge arm, if the lower bridge arm switches in each bridge arm can be disconnected in response to the disconnection signal, the current flowing to the corresponding winding through the upper bridge arm switch will charge the first capacitor, and the directions of the currents in different windings are the same, so that the motor will not generate an alternating magnetic field, and thus will not generate an undesirable torque. In this way, when detecting the first safety path in the above manner, if all the lower bridge arm switches can be turned off, the motor will not generate an alternating magnetic field during the detection of the first safety path, which avoids the output of undesirable torque to a certain extent, thereby improving the safety of the detection process to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application;

[0023] Figure 2 A schematic diagram of a circuit for supplying power to a motor system from a battery provided in an embodiment of the present application;

[0024] Figure 3 The embodiment of the present application provides Figure 2 Add a schematic diagram of the charging path;

[0025] Figure 4 A schematic flow chart of a first safety path detection method for a motor system provided in an embodiment of the present application;

[0026] Figure 5 A schematic flow chart of a second safety path detection method for a motor system provided in an embodiment of the present application;

[0027] Figure 6 A schematic flow chart of a third safety path detection method for a motor system provided in an embodiment of the present application;

[0028] Figure 7 A current schematic diagram of a safe path detection provided by an embodiment of the present application;

[0029] Figure 8 A schematic diagram of the structure of a safe path detection device for a motor system provided in an embodiment of the present application;

[0030] Fig. 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0032] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0033] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, etc., and are not used to limit the order or interdependence of the functions performed by these devices, modules or units, etc.

[0034] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0035] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0036] With the continuous development of electric vehicles and hybrid vehicles, ensuring the driving safety of vehicles has become one of the main research and development directions of electric vehicles and hybrid vehicles. At present, setting a safe path for the motor system of the vehicle is a way to ensure the driving safety of the vehicle. Specifically, when the motor system of the vehicle enters the safe path, the motor system will not output undesirable torque. Therefore, during the operation of the vehicle, if the motor system fails, the motor system can be controlled to enter the safe path to avoid the motor system outputting undesirable torque, thereby avoiding personal injury and property damage.

[0037] Figure 1This is a schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 100 may include: a battery 110 and a motor system 120. The battery 110 may supply power to the motor system 120, and the motor system 120 may convert electrical energy into kinetic energy to drive the vehicle 100 to operate.

[0038] Figure 2 This is a schematic diagram of a circuit for a battery to supply power to a motor system according to an embodiment of the present application. Figure 2 As shown, the circuit may include a battery 110 , a relay S1 , a relay S2 , and a motor system 120 .

[0039] The motor system 120 may include an inverter 121, a motor and a controller 123. The inverter 121 may include N bridge arms and a voltage stabilizing capacitor C2, each of the N bridge arms may include an upper bridge arm switch and a lower bridge arm switch, each bridge arm and the voltage stabilizing capacitor C2 are connected between the first input terminal and the second input terminal of the inverter 121, and the connection point between the upper bridge arm switch and the lower bridge arm switch in each bridge arm is the midpoint of the bridge arm. It should be noted that the voltage stabilizing capacitor C2 is an optional device.

[0040] Below, the connection method of the nth bridge arm is described by taking the upper bridge arm switch and the lower bridge arm switch as N-type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) as an example, wherein 1≤n≤N.

[0041] like Figure 2 As shown, the nth bridge arm may include an upper bridge arm switch Qn and a lower bridge arm switch Qn'. The drain of the upper bridge arm switch Qn is connected to the first input terminal of the inverter 121, the source of the upper bridge arm switch Qn is connected to the drain of the lower bridge arm switch Qn', and the source of the lower bridge arm switch Qn' is connected to the second input terminal of the inverter 121.

[0042] It should be noted that the connection point between the source of the upper bridge arm switch Qn and the drain of the lower bridge arm switch Qn′ is the midpoint of the nth bridge arm.

[0043] The motor may include an N-phase winding 122 and a first capacitor C1, such as Figure 2 As shown, the N-phase winding may include windings 1221-122N, and the N-phase winding corresponds to the N bridge arms one by one. Specifically, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N-phase winding is connected to the first end of the first capacitor C1, and the second end of the first capacitor C1 is connected to the ground terminal GND of the motor system 120. The first capacitor C1 is a capacitor formed by the N-phase winding of the motor and the housing of the motor.

[0044] like Figure 2 As shown, the controller 123 is connected to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm, and the controller 123 can control the on-off state of the upper bridge arm switch and the lower bridge arm switch in each bridge arm.

[0045] The positive electrode of the battery 110 is connected to the first input terminal of the inverter 121 through the relay S1 , and the negative electrode of the battery 110 is connected to the second input terminal of the inverter 121 through the relay S2 .

[0046] The process of starting the motor system 120 may be as follows: firstly close the relay S1 and the relay S2, so that the battery 110 supplies power to the first input terminal and the second input terminal of the inverter 121 through the closed relay S1 and the relay S2. The controller 123 then controls the upper bridge arm switches and the lower bridge arm switches in the N bridge arms to be alternately turned on and off, so that the current at the first input terminal of the inverter 121 flows into the winding corresponding to the bridge arm to which the upper bridge arm switch belongs through the turned-on upper bridge arm switch, and flows out to the second input terminal of the inverter 121 through the winding corresponding to the bridge arm to which the lower bridge arm switch belongs and the turned-on lower bridge arm switch, so that the motor generates an alternating magnetic field, thereby converting electrical energy into kinetic energy to output torque and drive the electric vehicle 100 to run.

[0047] In some embodiments, in order to avoid the situation in which the current at the first input terminal and the second input terminal of the inverter 121 is too large due to the direct closing of the relay S1 and the relay S2 during the startup of the motor system 120, thereby damaging the relay S1 and the relay S2, the voltage-stabilizing capacitor C2 may be charged first, so that the relay S1 and the relay S2 can be closed after the voltage of the voltage-stabilizing capacitor C2 reaches a certain value.

[0048] Figure 3 The embodiment of the present application provides Figure 2 Add a schematic diagram of the charging path. Figure 3 As shown, one charging method is: first close the relay S3 and the relay S2, so that the battery 110, the closed relay S3, the resistor R, the voltage-stabilizing capacitor C2 and the closed relay S2 form a charging circuit, so that the battery 110 charges the voltage-stabilizing capacitor C2 through the charging circuit, and after the voltage of the voltage-stabilizing capacitor C2 reaches a certain value, open the relay S3 and close the relay S1, so that the battery 110 supplies power to the first input terminal and the second input terminal of the inverter 121 through the closed relay S1 and the relay S2.

[0049] Due to the existence of the resistor R, after the relay S3 and the relay S2 are closed, the current on the charging path will not be too large, which can avoid damage to the relay S3 and the relay S2 due to excessive current during the charging process. After the voltage of the voltage-stabilizing capacitor C2 reaches a certain value, the relay S3 is opened and the relay S1 is closed. At this time, the battery 110 directly supplies power to the first input terminal and the second input terminal of the inverter 121 through the closed relay S1 and the relay S2. Since the voltage-stabilizing capacitor C2 is charged in advance, when the relay S1 is closed, no excessive current will be generated, thereby avoiding damage to the relay S1 and the relay S2.

[0050] Another charging method is: a voltage converter 130 can be connected between the first input terminal and the second input terminal of the inverter 121, and the 12V DC power supply is connected to the voltage converter 130. The voltage converter 130 is a DC / DC voltage converter. In this way, the charging process can be: first, the voltage provided by the 12V DC power supply is converted into a charging voltage by the voltage converter 130 to charge the voltage stabilizing capacitor C2, and, after the voltage stabilizing capacitor C2 reaches a certain value, the charging is stopped, and the relay S1 and the relay S2 are closed, so that the battery 110 supplies power to the first input terminal and the second input terminal of the inverter 121 through the closed relay S1 and the relay S2.

[0051] Since the voltage stabilizing capacitor C2 is charged, after the voltage stabilizing capacitor C2 reaches a certain value, closing the relay S1 and the relay S2 will not generate excessive current, thereby avoiding damage to the relay S1 and the relay S2.

[0052] It should be noted that the 12V DC power supply can also be used to supply power to other low-voltage devices in the vehicle 100. The voltage of the battery 110 can also be converted by the voltage converter 130 to charge the 12V DC power supply.

[0053] The safety paths of the motor system 120 include but are not limited to the following three:

[0054] The upper arm ASC (Active short circuit), the lower arm ASC and Free-Wheeling (three-phase open circuit), where:

[0055] The upper arm ASC means that the upper arm switch in each arm is in the on state and the lower arm switch in each arm is in the off state.

[0056] When the motor system 120 enters the upper bridge arm ASC, the lower bridge arm switches in each bridge arm are in the off state and the upper bridge arm switches in each bridge arm are in the on state, so that the current on the first input terminal of the inverter 121 flows into each phase winding through each upper bridge arm switch that is turned on, and charges the first capacitor C1 through each phase winding. In this case, since the direction of the current in each phase winding is the same, both flow to the first capacitor C1 and charge the first capacitor C1, the motor will not generate an alternating magnetic field, and will not output an unexpected torque, thereby ensuring the safety of driving.

[0057] The lower arm ASC means that the upper arm switch in each arm is in the off state and the lower arm switch in each arm is in the on state.

[0058] When the motor system 120 enters the lower bridge arm ASC, the lower bridge arm switches in each bridge arm are in the on state and the upper bridge arm switches of each bridge arm are in the off state, so that the current on the first input terminal of the inverter 121 cannot flow into the winding. Based on this, when there is charge stored in the first capacitor C1, the first capacitor C1 is discharged through the lower bridge arm switches that are turned on in each phase winding and each bridge arm. In this case, since the direction of the current in each phase winding is the same, both flow to the second input terminal of the inverter 121, the motor will not generate an alternating magnetic field, and thus will not output an unexpected torque, thereby ensuring the safety of driving.

[0059] Free-Wheeling means that both the upper arm switch and the lower arm switch in each bridge arm are in the off state.

[0060] When the motor system 120 enters the Free-Wheeling state, the lower bridge arm switch and the upper bridge arm switch in each bridge arm are both in the disconnected state. Figure 2 It can be seen that there is no current flowing in the winding, so the motor will not generate an alternating magnetic field, and will not output unexpected torque, thereby ensuring driving safety.

[0061] As can be seen from the above, when the motor system 120 enters any safe path, the motor will not generate an alternating magnetic field, and thus will not generate an unexpected torque. In this way, when the motor system 120 fails, by controlling the motor system 120 to enter any safe path, the motor system 120 can be prevented from outputting an unexpected torque, thereby preventing personal injury or property damage.

[0062] Based on this, in order to ensure driving safety, when the motor system 120 is started, the safety path needs to be detected, and when at least one safety path passes the detection, the motor system 120 is controlled to work, that is, output torque, thereby driving the vehicle.

[0063] In the related art, a method for detecting a safe path is: providing a control signal for entering the safe path to the control ends of the upper bridge arm switches and the lower bridge arm switches in the N bridge arms in the inverter 121 through the controller 123, and reading back the control signal provided by the controller 123 to ensure that the read-back control signal is the same as the control signal required to enter the safe path, thereby determining that the safe path passes the detection.

[0064] In this way, the control signal provided by the controller 123 is the same as the control signal required to enter the safe path, which does not mean that the upper arm switches and the lower arm switches in the N bridge arms can be in the corresponding state under the drive of the corresponding control signal. Therefore, reading back the control signal provided by the controller 123 cannot ensure that the safe path has passed the detection, thereby reducing the detection accuracy of the safe path.

[0065] Another way to detect the safety path is: when the battery 110 supplies power to the first input terminal and the second input terminal of the inverter 121 and the motor enters zero torque, determine whether each upper bridge arm switch and lower bridge arm switch can be started normally by reading the current at the first end of each phase winding.

[0066] In this way, it can only be verified whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm can be started normally, but it cannot be verified whether the safe path can be started normally. Therefore, the detection accuracy of the safe path is low.

[0067] In order to solve the above technical problems, the embodiment of the present application provides a safe path detection method for a motor system, which can be executed by the controller 123 or by other processors, and the embodiment of the present application does not specifically limit this. The safe path detection method for a motor system provided by the embodiment of the present application can improve the detection accuracy of the safe path, and in the detection process, the output of undesired torque can be avoided to a certain extent, thereby improving the safety of the detection process to a certain extent.

[0068] It should be noted that the motor system can be seen from the above description and will not be described in detail here.

[0069] Figure 4 A flow chart of a safe path detection method for a motor system provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the safe path detection method of the motor system may include:

[0070] 401. When a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a turn-on signal is provided to the control terminal of the upper bridge arm switch in each bridge arm, and a turn-off signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, so that the voltage signal can at least charge the first capacitor C1 through the turned-on upper bridge arm switches in the N bridge arms.

[0071] The scenario in which a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121 may be: during the process of charging the voltage stabilizing capacitor C2 or during the process of closing the relay S1 and the relay S2. That is, during the process of closing the relay S1 and the relay S2 or during the process of charging the voltage stabilizing capacitor C2, a turn-on signal is provided to the control end of the upper bridge arm switch in each bridge arm, and a turn-off signal is provided to the control end of the lower bridge arm switch in each bridge arm.

[0072] Since the first safety path (i.e., the upper bridge arm ASC) may refer to the upper bridge arm switch in each bridge arm being in the on state and the lower bridge arm switch in each bridge arm being in the off state. Therefore, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a conduction signal is provided to the control terminal of the upper bridge arm switch in each bridge arm, and a disconnection signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, so as to collect the current flowing through the first end of each phase winding, verify whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm are in the corresponding state (i.e., the on state or the off state) in response to the signal at its control terminal, thereby determining whether the first safety path of the motor system 120 passes the detection according to the verification result, that is, determining whether the first safety path can be started normally according to the verification result.

[0073] When a turn-on signal is provided to the control terminal of the upper bridge arm switch in each bridge arm and a turn-off signal is provided to the control terminal of the lower bridge arm switch in each bridge arm:

[0074] If the upper bridge arm switches in each bridge arm can be in the on state under the action of the on signal and the lower bridge arm switches in each bridge arm can be in the off state under the action of the off signal, that is, the first safety path can be started normally (that is, the motor system 120 can enter the first safety path when necessary), then the voltage signal applied between the first input terminal and the second input terminal of the inverter 121 can charge the first capacitor C1 through the upper bridge arm switches and the corresponding windings in each bridge arm. In this case, the magnitude of the current flowing through the first end of each phase winding can be understood as the current flowing through the upper bridge arm switch in the corresponding bridge arm, and the magnitude of the current has a certain range, and the direction of the current is from the inverter 121 to the winding.

[0075] If at least one upper bridge arm switch and / or at least one lower bridge arm switch among the N bridge arms cannot enter the corresponding state under the action of the signal at its control end, that is, at least one upper bridge arm switch and / or at least one lower bridge arm switch is abnormal, that is, the first safety path of the motor system 120 cannot be started normally, resulting in the motor system 120 being unable to enter the first safety path when it needs to, then the magnitude or direction of the current flowing through the first end of the winding corresponding to the abnormal upper bridge arm switch or lower bridge arm switch will become abnormal.

[0076] In this way, during the time period when a conduction signal is provided to the control end of the upper bridge arm switch in each bridge arm and a disconnection signal is provided to the control end of the lower bridge arm switch in each bridge arm, by collecting the current flowing through the first end of each phase winding and verifying whether the current flowing through the first end of each phase winding is within a certain range, it is determined whether the first safety path of the motor system 120 has passed the verification.

[0077] 402. In a first time period, the current flowing through the first end of each phase winding is collected to obtain an N-phase first current value.

[0078] The first current value of the N phases corresponds one-to-one to the first ends of the N windings, and the first time period is a time period for providing a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and providing a turn-off signal to the control end of the lower bridge arm switch in each bridge arm.

[0079] The current flowing through the first end of each phase winding can be collected by connecting a sampling resistor in series to the first end of each phase winding, collecting the voltage on the sampling resistor and the current flowing through the first end of each phase winding in combination with the resistance value of the sampling resistor.

[0080] The current flowing through the first end of each phase winding may also be collected by using a Hall element to collect the current flowing through the first end of each phase winding.

[0081] Exemplarily, the first current value of each phase may be an accumulated value of the current flowing through the first end of the corresponding winding in the first time period.

[0082] Based on this, the current flowing through the first end of each phase winding can be collected at a sampling frequency in the first time period to obtain an N-phase current value sequence. The N-phase current value sequence corresponds one-to-one to the first end of the N-phase winding. Each phase current value sequence in the N-phase current value sequence includes multiple current values. The multiple current values ​​in a phase current value sequence are obtained by collecting the current flowing through the first end of the corresponding winding at the sampling frequency in the first time period. Based on this, the multiple current values ​​in each phase current value sequence in the N-phase current value sequence are summed up respectively to obtain the N-phase first current value.

[0083] Exemplarily, the first current value of each phase may be the value of the current flowing through the first end of the corresponding winding at the first moment, wherein the first moment is a moment within the first time period.

[0084] Based on this, the current flowing through the first end of each phase winding can be collected at the first moment to obtain the N-phase first current value.

[0085] It should be noted that the first current value may indicate the direction and magnitude of the first current. For example, if the first current value is greater than zero, it indicates that the direction of the current flowing through the first end of the corresponding winding is flowing into the winding. If the first current value is less than zero, it indicates that the direction of the current flowing through the first end of the corresponding winding is flowing out of the winding.

[0086] 403. When each of the N-phase first current values ​​is within the first current threshold range, determine that the first safety path of the motor system 120 passes the detection.

[0087] Specifically, when the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the first time period, the first current threshold range can be calculated based on at least the maximum cumulative value and the minimum cumulative value of the current flowing through the first end of each phase winding when the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state and when a voltage signal is applied to the first input terminal and the second input terminal of the inverter 121.

[0088] It should be noted that the calculation time of the cumulative value is the first time period. The first current threshold range not only indicates the magnitude range of the current, but also indicates the direction of the current.

[0089] It should be noted that, in other embodiments, the first voltage threshold range may also be obtained through measurement.

[0090] Based on this, the first current value of each phase is compared with the first current threshold range respectively. When the first current value of each phase is within the first current threshold range, it is determined that the first safety path passes the detection, that is, it is determined that the first safety path can be started normally.

[0091] Since when an abnormality exists in the upper bridge arm switch and / or the lower bridge arm switch, the current (i.e., the first current value) flowing through the first end of the corresponding winding also carries the abnormality of the upper bridge arm switch and / or the lower bridge arm switch. Since the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the first time period, when an abnormality exists in the upper bridge arm switch and / or the lower bridge arm switch, the accumulation of the current value will amplify the abnormality of the upper bridge arm switch and / or the lower bridge arm switch, that is, when an abnormality exists in the upper bridge arm switch and / or the lower bridge arm switch, the corresponding first current value amplifies the abnormality of the upper bridge arm switch and / or the lower bridge arm switch. In this way, based on the first current value and the first current threshold range, the accuracy of verifying whether each upper bridge arm switch and the lower bridge arm switch is abnormal can be improved, thereby improving the accuracy of detecting the first safety path.

[0092] When each first current value is the value of the current flowing through the first end of the corresponding winding at the first moment, the first current threshold range can be determined according to the maximum current value and the minimum current value flowing through the first end of each phase winding when the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state, and when a voltage signal is applied to the first input terminal and the second input terminal of the inverter 121.

[0093] It should be noted that the first current threshold range not only indicates the magnitude range of the current, but also indicates the direction of the current. In other embodiments, the first current threshold range can also be obtained by measurement.

[0094] Obviously, since the first safety path refers to the upper bridge arm switch in each bridge arm being in the on state and the lower bridge arm switch in each bridge arm being in the off state, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, an on signal is provided to the control terminal of the upper bridge arm switch in each bridge arm and an off signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, and then the current flowing through the first end of each phase winding is collected, so as to verify whether each upper bridge arm switch and the lower bridge arm switch can be in the corresponding state in response to the signal at its control terminal through the collected N-phase first current value and the first current threshold range, thereby determining whether the first safety path has passed the verification based on the verification result, thereby realizing the verification of the first safety path.

[0095] Furthermore, since the current at the first end of each phase winding can indicate whether the upper bridge arm switch and the lower bridge arm switch in the corresponding bridge arm can respond to the signal at its control end and be in the corresponding state, therefore, by detecting the first safety path through the collected current flowing through the first end of each phase winding (i.e., the N-phase first current value), it can be understood that by determining whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm can respond to the signal at its control end and be in the corresponding state, the first safety path is detected, thereby improving the accuracy of the detection.

[0096] Furthermore, when a conduction signal is provided to the control end of the upper bridge arm switch in each bridge arm and a disconnection signal is provided to the control end of the lower bridge arm switch in each bridge arm, if the lower bridge arm switches in each bridge arm can be disconnected in response to the disconnection signal, the current flowing to the corresponding winding through the upper bridge arm switch will charge the first capacitor, and the directions of the currents in different windings are the same, so that the motor will not generate an alternating magnetic field, and thus will not generate an undesirable torque. In this way, in the process of detecting the first safety path in the above manner, if all the lower bridge arm switches can be turned off, the motor will not generate an alternating magnetic field during the detection of the first safety path, which avoids the output of undesirable torque to a certain extent, thereby improving the safety of the detection process to a certain extent.

[0097] In some embodiments, the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the first time period. Based on this, the safety path detection method may also include:

[0098] Obtaining the N-phase fourth current value, wherein the N-phase fourth current value corresponds to the first end of the N-phase winding one by one, and each phase fourth current value of the N-phase fourth current value is the value of the current flowing through the first end of the corresponding winding at the second moment, and the second moment is a moment in the first time period.

[0099] On this basis, the specific implementation process of the above 403 can be as follows:

[0100] When the first current value of each phase is within the first current threshold range and at least one of the following three items is satisfied, it is determined that the first safety path passes the detection.

[0101] The three conditions are:

[0102] The first item: the sum of the first current values ​​of the N phases is less than or equal to the first current threshold.

[0103] The first current threshold may be determined according to the sum of the maximum accumulated values ​​of the currents flowing through the first end of the N-phase winding in the first time period when each upper bridge arm switch is in the on state and each lower bridge arm switch is in the off state. In other embodiments, the first current threshold may also be obtained by measurement.

[0104] Second item: the sum of the fourth current values ​​of the N phases is less than or equal to the second current threshold.

[0105] The second current threshold can be determined according to the sum of the maximum values ​​of the current flowing through the first end of the N-phase winding in the first time period when each upper bridge arm switch is in the on state and each lower bridge arm switch is in the off state. In other embodiments, the second current threshold can also be obtained by measurement.

[0106] Item 3: The fourth current value of each phase is within the fourth current threshold range.

[0107] The fourth current threshold range can be determined according to the maximum value and the minimum value of the current flowing through the first end of each phase winding in the N-phase winding in the first time period when each upper bridge arm switch is in the on state and each lower bridge arm switch is in the off state. In other embodiments, the fourth current threshold range can also be obtained by measurement.

[0108] Obviously, when each first current value is within the first current threshold range and satisfies at least one of the above three items, it is determined that the first safety path passes the test. In other words, multiple tests are performed on the first safety path through multiple conditions, and after multiple conditions are met, it is determined that the first safety path passes the test, which further improves the accuracy of the test.

[0109] In some embodiments, Figure 5 As shown, the safe path detection method provided in the embodiment of the present application may also include:

[0110] 501. After determining that the first safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnect signal is provided to the control terminal of the upper bridge arm switch and the control terminal of the lower bridge arm switch in each bridge arm.

[0111] The first safety path indicates that all lower bridge arm switches can be disconnected and all upper bridge arm switches can be turned on by detection. Therefore, 501 can be understood as: after determining that all lower bridge arm switches can be disconnected and all upper bridge arm switches can be turned on, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnection signal is provided to the control terminal of the upper bridge arm switch and the control terminal of the lower bridge arm switch in each bridge arm.

[0112] In 501, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, it can be understood that: in the process of charging the voltage-stabilizing capacitor C2, or in the process of closing the relay S1 and the relay S2, or in the process of only the voltage-stabilizing capacitor C2 supplying power between the first input terminal and the second input terminal of the inverter 121.

[0113] Since the first safety path indicates that all lower bridge arm switches can be disconnected and all upper bridge arm switches can be turned on through detection, it can be determined that each lower bridge arm switch is in an off state during the execution of 501. In this case, if each upper bridge arm switch can be in an off state, the current flowing through the first end of each phase winding can be the leakage current of the upper bridge arm switch, and the leakage current is very small. The direction of the leakage current can be determined according to the relative size of the voltage at the first input terminal of the inverter 121 and the voltage on the first capacitor C1. If at least one upper bridge arm switch is abnormal (i.e., not disconnected), a current flows through the first end of the winding corresponding to the bridge arm to which the abnormal upper bridge arm switch belongs, and the current is large. The direction of the current can be determined according to the relative size of the voltage at the first input terminal of the inverter 121 and the voltage on the first capacitor C1.

[0114] Based on this, since the second safety path refers to that the upper bridge arm switch and the lower bridge arm switch in each bridge arm are both in the disconnected state, by executing 501 and verifying whether the upper bridge arm switch and the lower bridge arm switch are disconnected based on the current flowing through the first end of each phase winding, it is determined whether the second safety path passes the detection based on the verification result.

[0115] 502. In the second time period, the current flowing through the first end of each phase winding is collected to obtain a second current value of the N phase.

[0116] The N-phase second current value corresponds one-to-one to the first end of the N-phase winding, and the second time period is a time period for providing a disconnection signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm.

[0117] The method of collecting current has been explained above and will not be repeated here.

[0118] Exemplarily, the second current value of each phase may be an accumulated value of the current flowing through the first end of the corresponding winding in the second time period.

[0119] Exemplarily, the second current value of each phase may be the value of the current flowing through the first end of the corresponding winding at a third moment, wherein the third moment is a moment within the second time period.

[0120] It should be noted that the method for determining the second current value in the above two cases can refer to the relevant description of the first current value above, and will not be repeated here.

[0121] 503. When each of the N-phase second current values ​​is within the second current threshold range, determine that the second safety path of the motor system passes the detection.

[0122] Since when each upper bridge arm switch and each lower bridge arm switch are in the disconnected state, the current at the first end of each phase winding can be understood as the leakage current of each upper bridge arm switch. Therefore, the second current threshold range can be set according to the direction and magnitude of the leakage current.

[0123] Specifically, when the second current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the second time period, the second current threshold range can be determined according to the maximum cumulative value and the minimum cumulative value of the leakage current in the second time period. The maximum cumulative value and the minimum cumulative value carry the direction and magnitude of the leakage current.

[0124] Since the second current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the second time period, and since the cumulative value can amplify the abnormality of the upper bridge arm switch and / or the lower bridge arm switch, the detection accuracy is improved.

[0125] When the second current value of each phase is the value of the current flowing through the first end of the corresponding winding at the third moment, the second current threshold range can be determined based on the maximum and minimum values ​​of the leakage current in the second time period, wherein the maximum and minimum values ​​carry the direction and magnitude of the leakage current.

[0126] The second current value of each phase is compared with the second current threshold range respectively. When the second current value of each phase is within the second current threshold range, it is determined that each upper bridge arm switch and each lower bridge arm switch can be disconnected, thereby determining that the second safety path passes the detection.

[0127] It should be noted that if the second current value of at least one phase is not within the second current threshold range, the faulty upper bridge arm switch and / or lower bridge arm switch can be located according to the second current value.

[0128] Obviously, since the second safety path refers to the upper bridge arm switch and the lower bridge arm switch in each bridge arm being in the disconnected state, after determining that the first safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnection signal is provided to the control terminal of the upper bridge arm switch and the control terminal of the lower bridge arm switch in each bridge arm, and the current flowing through the first end of each phase winding is collected, so as to verify whether each upper bridge arm switch and the lower bridge arm switch can be in the disconnected state in response to the disconnection signal at its control terminal through the collected N-phase second current value and the second current threshold range, thereby determining whether the second safety path passes the verification based on the verification result, thereby realizing the verification of the second safety path.

[0129] Furthermore, since the current at the first end of each phase winding can indicate whether the upper bridge arm switch and the lower bridge arm switch in the corresponding bridge arm can be in the disconnected state in response to the disconnection signal of its control end, therefore, by detecting the second safety path through the collected current flowing through the first end of each phase winding (i.e., the N-phase second current value), it can be understood that by determining whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm can be in the disconnected state in response to the disconnection signal of its control end, the second safety path is detected, thereby improving the detection accuracy.

[0130] Furthermore, after the first safety path is detected, the second safety path is detected, that is, the second safety path is detected while ensuring that each lower bridge arm switch can be in the disconnected state. In this way, during the detection of the second safety path, due to the blocking of the disconnected lower bridge arm switch, no matter whether the upper bridge arm switch is abnormal (i.e., disconnected), the motor will not generate an alternating magnetic field, and thus will not generate an unexpected torque, thereby further improving the safety of the detection process to a certain extent.

[0131] In some embodiments, Figure 6 As shown, the safe path detection method provided in the embodiment of the present application may also include:

[0132] 601. After determining that the second safety path has passed the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnect signal is provided to the control end of the upper bridge arm switch in each bridge arm, and a turn-on signal is provided to the control end of the lower bridge arm switch in each bridge arm, so that the first capacitor C1 is discharged through the turned-on lower bridge arm switches in the N bridge arms.

[0133] The second safety path indicates that each lower bridge arm switch can be disconnected and each upper bridge arm switch can be turned on and off by detection. Therefore, 601 can be understood as: after determining that each lower bridge arm switch can be disconnected and each upper bridge arm switch can be turned on and off, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnection signal is provided to the control terminal of the upper bridge arm switch in each bridge arm, and a conduction signal is provided to the control terminal of the lower bridge arm switch in each bridge arm.

[0134] In 601, when a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, it can be understood that: in the process of charging the voltage-stabilizing capacitor C2, or in the process of closing the relay S1 and the relay S2, or in the process of only the voltage-stabilizing capacitor C2 supplying power between the first input terminal and the second input terminal of the inverter 121.

[0135] Since the second safety path indicates through detection that each lower bridge arm switch can be disconnected and each upper bridge arm switch can be turned on and off, it can be determined that each upper bridge arm switch is in the disconnected state during the execution of 601. In this case, if each lower bridge arm switch can be in the on state, the current flowing through the first end of each phase winding can be the current discharged by the first capacitor C1 to the second input end of the inverter 121 through the winding and the turned-on lower bridge arm switch, and the discharge current is within a certain range. If at least one lower bridge arm switch is abnormal (i.e., disconnected or short-circuited), the current on the first end of the winding corresponding to the bridge arm to which the abnormal lower bridge arm switch belongs is abnormal. The abnormal current is either greater than the maximum value of the discharge current (corresponding to a short circuit) or less than the minimum value of the discharge current (corresponding to a disconnection).

[0136] Based on this, since the third safety path refers to the upper bridge arm switch in each bridge arm being in the off state and the lower bridge arm switch in each bridge arm being in the on state, by executing 601 and verifying whether the upper bridge arm switch and the lower bridge arm switch are in corresponding states in response to the signal at their control terminals according to the current flowing through the first end of each phase winding, it is determined whether the third safety path passes the detection according to the verification result.

[0137] 602. In a third time period, the current flowing through the first end of each phase winding is collected to obtain a third current value of the N phase.

[0138] The third current value of the N phase corresponds one-to-one to the first end of the N phase winding, and the third time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch in each bridge arm and providing a conduction signal to the control end of the lower bridge arm switch in each bridge arm.

[0139] The method of collecting current has been explained above and will not be repeated here.

[0140] Exemplarily, the third current value of each phase may be an accumulated value of the current flowing through the first end of the corresponding winding in the third time period.

[0141] Exemplarily, the third current value of each phase may be the value of the current flowing through the first end of the corresponding winding at a fourth moment, wherein the fourth moment is a moment within the third time period.

[0142] It should be noted that the determination method of the third current value in the above two cases can refer to the relevant description of the first current value above, which will not be repeated here.

[0143] 603. When each of the N-phase third current values ​​is within the third current threshold range, determine that the third safety path of the motor system passes the detection.

[0144] Since when each upper bridge arm switch is in the off state and each lower bridge arm switch is in the on state, the current flowing through the first end of each phase winding may be the current that discharges the first capacitor C1 to the second input end of the inverter 121 through the winding and the turned-on lower bridge arm switch. Therefore, the third current threshold range may be set according to the direction and magnitude of the discharge current.

[0145] Specifically, when each third current value is the cumulative value of the current flowing through the first end of the corresponding winding in the third time period, the third current threshold range can be determined according to the maximum cumulative value and the minimum cumulative value of the discharge current in the third time period.

[0146] Since each third current value is the cumulative value of the current flowing through the first end of the corresponding winding in the third time period, and since the cumulative value can amplify the abnormality of the upper bridge arm switch and / or the lower bridge arm switch, the detection accuracy is further improved.

[0147] When the third current value of each phase is the value of the current flowing through the first end of the corresponding winding at the fourth moment, the third current threshold range can be determined according to the maximum value and the minimum value of the discharge current in the third time period.

[0148] It should be noted that the third current threshold range may also be obtained through measurement, and the embodiment of the present application does not impose any special limitation on this.

[0149] Each third current value is compared with the third current threshold range respectively. When the third current value of each phase is within the third current threshold range, it is determined that each upper bridge arm switch can be turned off and each lower bridge arm switch can be turned on, thereby determining that the third safety path passes the detection.

[0150] It should be noted that if at least one third current value is not within the third current threshold range, the faulty upper bridge arm switch and / or lower bridge arm switch may be located according to the third current value.

[0151] Obviously, since the third safety path refers to that the upper bridge arm switches in each bridge arm are in the disconnected state and the lower bridge arm switches in each bridge arm are in the on state, therefore, after determining that the second safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter 121, a disconnect signal is provided to the control terminal of the upper bridge arm switch in each bridge arm and an on signal is provided to the control terminal of the lower bridge arm switch in each bridge arm, and the current flowing through the first end of each phase winding is collected, so as to verify whether each upper bridge arm switch and the lower bridge arm switch can be in the corresponding state in response to the signal at its control terminal through the collected N-phase third current value and in combination with the third current threshold range, thereby determining whether the third safety path passes the verification based on the verification result, thereby realizing the verification of the third safety path.

[0152] Furthermore, since the current at the first end of each phase winding can indicate whether the upper bridge arm switch and the lower bridge arm switch in the corresponding bridge arm can respond to the signal at its control end and be in the corresponding state, therefore, detecting the third safety path by collecting the current flowing through the first end of each phase winding can be understood as detecting the third safety path by determining whether the upper bridge arm switch and the lower bridge arm switch in each bridge arm can respond to the signal at its control end and be in the corresponding state, thereby improving the detection accuracy.

[0153] Moreover, after the second safety path is detected, the third safety path is detected again, that is, the third safety path is detected while ensuring that each lower bridge arm switch can be disconnected and each upper bridge arm switch can be turned on and off. In this way, in the process of detecting the third safety path, due to the blocking of the disconnected upper bridge arm switch, no matter whether there is an abnormality in the lower bridge arm switch, the motor will not generate an alternating magnetic field, thereby not generating unexpected torque, thereby further improving the safety of the detection process to a certain extent.

[0154] In some embodiments, the third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the third time period. Based on this, the safety path detection method may also include:

[0155] Obtain the fifth current value of the N phase; wherein the fifth current value of the N phase corresponds one-to-one to the first end of the N phase winding, and the fifth current value of each phase in the N phase fifth current value is the value of the current flowing through the first end of the corresponding winding at the fifth moment, and the fifth moment is a moment within the third time period.

[0156] On this basis, the specific implementation process of 603 can also be:

[0157] When the third current value of each phase is within the third current threshold range and at least one of the following three items is satisfied, it is determined that the third safety path passes the detection.

[0158] The first item: the sum of the third current values ​​of the N phases is less than or equal to the third current threshold.

[0159] The third current threshold can be determined according to the sum of the maximum accumulated values ​​of the currents flowing through the N-phase windings in the third time period when each upper bridge arm switch is in the off state and each lower bridge arm switch is in the on state. In other embodiments, the third current threshold can also be obtained by measurement.

[0160] Second item: the sum of the fifth current values ​​of the N phases is less than or equal to the fourth current threshold.

[0161] The fourth current threshold can be determined according to the sum of the maximum values ​​of the current flowing through the first end of the N-phase winding in the third time period when each upper bridge arm switch is in the off state and each lower bridge arm switch is in the on state. In other embodiments, the fourth current threshold can also be obtained by measurement.

[0162] Item 3: The fifth current value of each phase is within the fifth current threshold range.

[0163] The fifth current threshold range can be determined according to the maximum and minimum values ​​of the current flowing through the first end of each phase winding in the third time period when each upper bridge arm switch is in the off state and each lower bridge arm switch is in the on state. In other embodiments, the fifth current threshold range can also be obtained by measurement.

[0164] Obviously, when the third current value of each phase is within the third current threshold range and satisfies at least one of the above items, it is determined that the third safety path passes the test. In other words, the third safety path is tested multiple times through multiple conditions, and after multiple conditions are met, it is determined that the third safety path passes the test, which further improves the accuracy of the test.

[0165] In some embodiments, the voltage value of the voltage signal is greater than a preset voltage value. The preset voltage value can be obtained according to experimental measurements. By setting the voltage value of the voltage signal to be greater than the preset voltage value, it is ensured that the value of the current on the first input terminal of the inverter 121 is greater than the preset current value, thereby ensuring that the current flowing to the first end of the winding through the turned-on upper bridge arm switch is not too small, thereby reducing the difficulty of detecting the current at the first end of each phase winding and improving the accuracy of detecting the current at the first end of each phase winding.

[0166] Figure 7 This is a schematic diagram of the current for the safety path detection provided in the embodiment of the present application. It should be noted that: Figure 7 The inverter 121 includes three bridge arms, and the motor includes three-phase windings, namely, a first winding, a second winding, and a third winding. Figure 7 , U indicates the current at the first end of the first winding, V indicates the current at the first end of the second winding, and W indicates the current at the first end of the third winding.

[0167] exist Figure 7 In the figure, time t1 to time t2 is the first time period, time t2 to time t3 is the second time period, and time t3 to time t4 is the third time period.

[0168] At time t0 to time t1, the upper bridge arm switch and the lower bridge arm switch in each bridge arm are in the disconnected state. At this time, the current at the first end of the three-phase winding is approximately zero. At time t1, a conduction signal is provided to the control end of the upper bridge arm switch in each bridge arm, and a disconnection signal is provided to the control end of the lower bridge arm switch in each bridge arm. Figure 7 It can be seen that in the first time period, the currents at the first ends of the three-phase windings are all greater than zero and the current values ​​are within the first current threshold range, wherein the current greater than zero indicates that the current is flowing into the winding, thus determining that the first safe path passes the detection. At time t2, a disconnect signal is provided to the control ends of the upper bridge arm switch and the lower bridge arm switch in each bridge arm. Figure 7 It can be seen that in the second time period, the currents at the first ends of the three-phase windings are all close to zero (that is, it can be understood that the leakage current is very small). In this way, it is determined that the second safe path passes the test. At time t3, a disconnect signal is provided to the upper bridge arm switch in each bridge arm and a conduction signal is provided to the control end of the lower bridge arm switch in each bridge arm. Figure 7 It can be seen that in the third time period, the current at the first end of the three-phase winding is less than zero, and the current value is within the third current threshold range, wherein the current less than zero indicates that the direction of the current is flowing out of the winding, thus determining that the third safety path passes the detection.

[0169] Figure 8 A structural schematic diagram of a safe path detection device for a motor system provided in an embodiment of the present application, wherein the motor system may include an inverter and a motor, the inverter including N bridge arms, each of the N bridge arms including an upper bridge arm switch and a lower bridge arm switch, each bridge arm being connected between a first input terminal and a second input terminal of the inverter, the motor may include N-phase windings and a first capacitor, the N-phase windings corresponding one-to-one to the N bridge arms, the midpoint of each bridge arm being connected to the first end of the corresponding winding, the second end of each phase winding in the N-phase windings being connected to the first end of the first capacitor, the second end of the first capacitor being connected to the ground terminal of the motor system, and the first capacitor being a capacitor formed by the N-phase windings and the housing of the motor.

[0170] Based on this, the safe path detection device 800 may include: a providing module 801, a collecting module 802 and a determining module 803, wherein:

[0171] Providing a module 801, which can be used to provide a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and provide a turn-off signal to the control end of the lower bridge arm switch in each bridge arm when a voltage signal is applied between the first input end and the second input end of the inverter, so as to at least allow the voltage signal to charge the first capacitor through the turned-on upper bridge arm switches in the N bridge arms;

[0172] The acquisition module 802 may be used to acquire the current flowing through the first end of each phase winding within a first time period to obtain a first current value of the N phase;

[0173] The N-phase first current value corresponds to the first end of the N-phase winding one by one, and the first time period is a time period for providing a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and providing a turn-off signal to the control end of the lower bridge arm switch in each bridge arm;

[0174] A determination module 803, which can be used to determine that a first safety path of the motor system passes the detection when each of the N-phase first current values ​​is within a first current threshold range;

[0175] The first safety path refers to that the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state.

[0176] Optionally, the determination module 803 is also used to provide a disconnect signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm after determining that the first safety path passes the detection and a voltage signal is applied between the first input end and the second input end of the inverter; within a second time period, the current flowing through the first end of each phase winding is collected to obtain an N-phase second current value; wherein the N-phase second current value corresponds one-to-one to the first end of the N-phase winding, and the second time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm; when each phase second current value of the N-phase second current value is within the second current threshold range, it is determined that the second safety path of the motor system passes the detection; wherein the second safety path refers to that the upper bridge arm switch and the lower bridge arm switch in each bridge arm are both in a disconnected state.

[0177] Optionally, the determination module 803 is also used to provide a disconnect signal to the control end of the upper bridge arm switch in each bridge arm and a conduction signal to the control end of the lower bridge arm switch in each bridge arm after determining that the second safety path passes the detection and a voltage signal is applied between the first input end and the second input end of the inverter, so that the first capacitor is discharged through the conductive lower bridge arm switch in the N bridge arms; in a third time period, the current flowing through the first end of each phase winding is collected to obtain an N-phase third current value; wherein the N-phase third current value corresponds one-to-one to the first end of the N-phase winding, and the third time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch in each bridge arm and providing a conduction signal to the control end of the lower bridge arm switch in each bridge arm; when each phase third current value of the N-phase third current value is within the third current threshold range, it is determined that the third safety path of the motor system passes the detection; wherein the third safety path refers to the upper bridge arm switch in each bridge arm being in a disconnected state and the lower bridge arm switch in each bridge arm being in a conductive state.

[0178] Optionally, the voltage value of the voltage signal is greater than a preset voltage value.

[0179] Optionally, the first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the first time period; or the first current value of each phase is the value of the current flowing through the first end of the corresponding winding at the first moment; wherein the first moment is a moment within the first time period.

[0180] Optionally, the first current value of each phase is a cumulative value of the current flowing through the first end of the corresponding winding in the first time period;

[0181] The determination module 803 is also used to obtain the N-phase fourth current value; wherein the N-phase fourth current value corresponds one-to-one to the first end of the N-phase winding, and each phase of the N-phase fourth current value is the value of the current flowing through the first end of the corresponding winding at the second moment, and the second moment is a moment within the first time period.

[0182] The determination module 803 is specifically configured to determine that the first safety path passes the detection when the first current value of each phase is within the first current threshold range and at least one of the following is satisfied:

[0183] The sum of the N-phase first current values ​​is less than or equal to the first current threshold;

[0184] The sum of the fourth current values ​​of the N phases is less than or equal to the second current threshold;

[0185] The fourth current value of each phase is within a fourth current threshold range.

[0186] Optionally, the second current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the second time period; or the second current value of each phase is the value of the current flowing through the first end of the corresponding winding at a third moment; wherein the third moment is a moment within the second time period.

[0187] Optionally, the third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding during the third time period; or the third current value of each phase is the value of the current flowing through the first end of the corresponding winding at a fourth moment; wherein the fourth moment is a moment within the third time period.

[0188] Optionally, the third current value of each phase is a cumulative value of the current flowing through the first end of the corresponding winding in the third time period;

[0189] The determination module 803 is also used to obtain the fifth current value of the N phase; wherein the fifth current value of the N phase corresponds one-to-one to the first end of the N phase winding, and the fifth current value of each phase in the N phase fifth current value is the value of the current flowing through the first end of the corresponding winding at the fifth moment, and the fifth moment is a moment within the third time period.

[0190] The determination module 803 is specifically configured to determine that the third safety path passes the detection when the third current value of each phase is within the third current threshold range and at least one of the following items is satisfied:

[0191] The sum of the third current values ​​of the N phases is less than or equal to the third current threshold;

[0192] The sum of the fifth current values ​​of the N phases is less than or equal to the fourth current threshold;

[0193] The fifth current value of each phase is within a fifth current threshold range.

[0194] It should be noted that the safe path detection device of the motor system can achieve similar effects as the corresponding safe path detection method of the motor system, which will not be described in detail here.

[0195] like Fig. 9 As shown, an electronic device 900 provided by an embodiment of the present invention includes a memory 910 and a processor 920; the memory 910 is used to store a computer program; the processor 920 is used to implement the safe path detection method of the motor system as described above when executing the computer program.

[0196] In other words, an electronic device 900 includes a memory 910 and a processor 920 coupled to the memory 910; the memory 910 is configured to store a computer program; and the processor 920 is configured to perform the following operations when executing the computer program:

[0197] When a voltage signal is applied between the first input terminal and the second input terminal of the inverter, a turn-on signal is provided to a control terminal of an upper bridge arm switch in each bridge arm, and a turn-off signal is provided to a control terminal of a lower bridge arm switch in each bridge arm, so that at least the voltage signal is charged to the first capacitor through the turned-on upper bridge arm switches in the N bridge arms;

[0198] In a first time period, the current flowing through the first end of each phase winding is collected to obtain a first current value of the N phase;

[0199] The N-phase first current value corresponds to the first end of the N-phase winding one by one, and the first time period is a time period for providing a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and providing a turn-off signal to the control end of the lower bridge arm switch in each bridge arm;

[0200] When each of the N-phase first current values ​​is within a first current threshold range, determining that a first safety path of the motor system passes the detection;

[0201] The first safety path refers to that the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state.

[0202] It should be noted that the electronic device can achieve similar effects as the safe path detection method of the motor system, which will not be described in detail here.

[0203] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the safety path detection method for the motor system as described above is implemented.

[0204] In other words, a non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following operations:

[0205] When a voltage signal is applied between the first input terminal and the second input terminal of the inverter, a turn-on signal is provided to a control terminal of an upper bridge arm switch in each bridge arm, and a turn-off signal is provided to a control terminal of a lower bridge arm switch in each bridge arm, so that at least the voltage signal is charged to the first capacitor through the turned-on upper bridge arm switches in the N bridge arms;

[0206] In a first time period, the current flowing through the first end of each phase winding is collected to obtain a first current value of the N phase;

[0207] The N-phase first current value corresponds to the first end of the N-phase winding one by one, and the first time period is a time period for providing a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and providing a turn-off signal to the control end of the lower bridge arm switch in each bridge arm;

[0208] When each of the N-phase first current values ​​is within a first current threshold range, determining that a first safety path of the motor system passes the detection;

[0209] The first safety path refers to that the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state.

[0210] It should be noted that the computer-readable storage medium can achieve similar effects as the safe path detection method of the motor system, which will not be described in detail here.

[0211] An embodiment of the present application also provides a vehicle, comprising: a motor system and a controller, wherein: the motor system may include an inverter and a motor, the inverter includes N bridge arms, each of the N bridge arms includes an upper bridge arm switch and a lower bridge arm switch, each bridge arm is connected between a first input terminal and a second input terminal of the inverter, the motor includes N-phase windings and a first capacitor, the N-phase windings correspond one-to-one to the N bridge arms, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N-phase windings is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the ground terminal of the motor system, and the first capacitor is a capacitor formed by the N-phase windings and the housing of the motor; the controller is used to execute the safe path detection method for the motor system as described above.

[0212] An electronic device 900 that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic device 900 is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic device 900 can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present invention described herein and / or required.

[0213] Electronic device 900 includes a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In RAM, various programs and data required for device operation can also be stored. The computing unit, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0214] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. In the present application, the unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be arranged on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present invention. In addition, each functional unit in each embodiment of the present invention can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0215] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A safe path detection method for a motor system, characterized in that: The motor system includes an inverter and a motor, the inverter includes N bridge arms, each of the N bridge arms includes an upper bridge arm switch and a lower bridge arm switch, each of the bridge arms is connected between a first input terminal and a second input terminal of the inverter, the motor includes N phase windings and a first capacitor, the N phase windings correspond to the N bridge arms one by one, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N phase windings is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the ground terminal of the motor system, and the first capacitor is a capacitor formed by the N phase windings and the housing of the motor; The safety path detection method comprises: When a voltage signal is applied between the first input terminal and the second input terminal of the inverter, a turn-on signal is provided to a control terminal of an upper bridge arm switch in each bridge arm, and a turn-off signal is provided to a control terminal of a lower bridge arm switch in each bridge arm, so that at least the voltage signal is charged to the first capacitor through the turned-on upper bridge arm switches in the N bridge arms; In a first time period, the current flowing through the first end of each phase winding is collected to obtain a first current value of the N phase; The N-phase first current value corresponds to the first end of the N-phase winding one by one, and the first time period is a time period for providing a turn-on signal to the control end of the upper bridge arm switch in each bridge arm and providing a turn-off signal to the control end of the lower bridge arm switch in each bridge arm; When each of the N-phase first current values ​​is within a first current threshold range, determining that a first safety path of the motor system passes the detection; The first safety path refers to that the upper bridge arm switch in each bridge arm is in the on state and the lower bridge arm switch in each bridge arm is in the off state.

2. The method according to claim 1, characterized in that: The method further comprises: After determining that the first safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter, providing a disconnection signal to the control terminal of the upper bridge arm switch and the control terminal of the lower bridge arm switch in each bridge arm; In a second time period, the current flowing through the first end of each phase winding is collected to obtain an N-phase second current value; The N-phase second current value corresponds one-to-one to the first end of the N-phase winding, and the second time period is a time period for providing a disconnection signal to the control end of the upper bridge arm switch and the control end of the lower bridge arm switch in each bridge arm; When each of the N-phase second current values ​​is within a second current threshold range, determining that a second safety path of the motor system passes the detection; The second safety path refers to that both the upper bridge arm switch and the lower bridge arm switch in each bridge arm are in the disconnected state.

3. The method according to claim 2, characterized in that The method further comprises: After determining that the second safety path passes the detection and a voltage signal is applied between the first input terminal and the second input terminal of the inverter, providing a disconnection signal to the control terminal of the upper bridge arm switch in each bridge arm, and providing a conduction signal to the control terminal of the lower bridge arm switch in each bridge arm, so that the first capacitor is discharged through the conducted lower bridge arm switches in the N bridge arms; In a third time period, the current flowing through the first end of each phase winding is collected to obtain a third current value of the N phase; The N-phase third current value corresponds one-to-one to the first end of the N-phase winding, and the third time period is a time period for providing a disconnect signal to the control end of the upper bridge arm switch in each bridge arm and providing a conduction signal to the control end of the lower bridge arm switch in each bridge arm; When each of the N-phase third current values ​​is within a third current threshold range, determining that a third safety path of the motor system passes the detection; The third safety path refers to that the upper bridge arm switch in each bridge arm is in an off state and the lower bridge arm switch in each bridge arm is in an on state.

4. The method according to any one of claims 1 to 3, characterized in that The voltage value of the voltage signal is greater than a preset voltage value.

5. The method according to any one of claims 1 to 3, characterized in that: The first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the first time period; or The first current value of each phase is the value of the current flowing through the first end of the corresponding winding at the first moment; The first moment is a moment in the first time period.

6. The method according to any one of claims 1 to 3, characterized in that: The first current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the first time period; The method further comprises: Obtaining an N-phase fourth current value; wherein the N-phase fourth current value corresponds one-to-one to the first end of the N-phase winding, and each phase fourth current value of the N-phase fourth current value is a value of a current flowing through the first end of the corresponding winding at a second moment, and the second moment is a moment within the first time period; In the case where each phase first current value of the N-phase first current values ​​is within the first current threshold range, determining that the first safety path of the motor system passes the detection includes: When the first current value of each phase is within the first current threshold range and at least one of the following conditions is satisfied, it is determined that the first safety path passes the detection: The sum of the N-phase first current values ​​is less than or equal to the first current threshold; The sum of the fourth current values ​​of the N phases is less than or equal to the second current threshold; The fourth current value of each phase is within a fourth current threshold range.

7. The method according to claim 2 or 3, characterized in that: The second current value of each phase is the accumulated value of the current flowing through the first end of the corresponding winding in the second time period; or The second current value of each phase is the value of the current flowing through the first end of the corresponding winding at the third moment; The third moment is a moment in the second time period.

8. The method according to claim 3, characterized in that The third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the third time period; or The third current value of each phase is the value of the current flowing through the first end of the corresponding winding at the fourth moment; The fourth moment is a moment within the third time period.

9. The method according to claim 3, characterized in that: The third current value of each phase is the cumulative value of the current flowing through the first end of the corresponding winding in the third time period; The method further comprises: Obtaining a fifth current value of the N phase; wherein the fifth current value of the N phase corresponds to the first end of the N phase winding one by one, and the fifth current value of each phase in the fifth current value of the N phase is the value of the current flowing through the first end of the corresponding winding at a fifth moment, and the fifth moment is a moment within the third time period; In the case where each phase third current value of the N phase third current values ​​is within the third current threshold range, determining that the third safety path of the motor system passes the detection includes: When the third current value of each phase is within the third current threshold range and at least one of the following conditions is satisfied, it is determined that the third safety path passes the detection: The sum of the third current values ​​of the N phases is less than or equal to the third current threshold; The sum of the fifth current values ​​of the N phases is less than or equal to the fourth current threshold; The fifth current value of each phase is within a fifth current threshold range.

10. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is configured to store a computer program; The processor is configured to perform the safe path detection method for the motor system according to any one of claims 1 to 9 when executing the computer program.

11. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the safe path detection method for the motor system according to any one of claims 1 to 9 is executed.

12. A vehicle, characterized in that: include: A motor system and a controller, wherein: The motor system includes an inverter and a motor, the inverter includes N bridge arms, each of the N bridge arms includes an upper bridge arm switch and a lower bridge arm switch, each of the bridge arms is connected between a first input terminal and a second input terminal of the inverter, the motor includes N phase windings and a first capacitor, the N phase windings correspond to the N bridge arms one by one, the midpoint of each bridge arm is connected to the first end of the corresponding winding, the second end of each phase winding in the N phase windings is connected to the first end of the first capacitor, the second end of the first capacitor is connected to the ground terminal of the motor system, and the first capacitor is a capacitor formed by the N phase windings and the housing of the motor; The controller is used to execute the safe path detection method for the motor system according to any one of claims 1 to 9.

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