Device for detecting disconnection of power cable of motor, motor system and vehicle

Abstract

The invention relates to a device for detecting disconnection of a power cable of a motor, a motor system and a vehicle. The apparatus for detecting disconnection of a power cable of an electric machine may include: a computing device including a processor and a storage medium on which one or more programs configured to be executed by the processor are recorded; wherein the one or more programs may include: obtaining a plurality of sensed current values from a plurality of current sensors respectively sensing currents flowing in a plurality of windings of the motor corresponding to a plurality of phases of the motor; determining a plurality of corrected current values by removing a common mode current from each of the plurality of sensed current values; a disconnection of each of the plurality of phases is detected based on a cable disconnection index according to the plurality of corrected current values.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2024-0067776, filed on May 24, 2024, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] This invention relates to a device for detecting the breakage of a power cable in an electric motor, an electric motor system, and a vehicle. Background Technology

[0004] Permanent magnet motors are typically used as drive units in electric vehicles, hybrid vehicles, fuel cell vehicles, and the like. An inverter converts directional current voltage into three-phase AC voltage (U-phase, V-phase, W-phase) and supplies it to the motor via power cables. The motor controller can control the inverter using pulse width modulation (PWM).

[0005] However, when the power cable connecting the inverter and the motor is disconnected, not only may the motor fail to run smoothly, but it may also cause fatal problems such as overcurrent, overvoltage, or damage to the inverter and / or motor.

[0006] The information included in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] Various aspects of the present invention are intended to provide a device, motor system, and vehicle for detecting the disconnection of a power cable in an electric motor.

[0008] According to one aspect of the invention, the apparatus for detecting the disconnection of a power cable of a motor comprises: a computing device including a processor and a storage medium, wherein one or more programs configured to be executed by the processor are recorded on the storage medium; wherein the one or more programs may include instructions for performing the following steps: obtaining a plurality of sensed current values ​​from a plurality of current sensors that respectively sense currents flowing in a plurality of windings of a motor corresponding to a plurality of phases of the motor; determining a plurality of correction current values ​​by removing a common-mode current from each of the plurality of sensed current values; and detecting a disconnection of each of the plurality of phases based on a cable disconnection index according to the plurality of correction current values.

[0009] According to one aspect of the invention, the motor system includes: a first inverter connected to a first end of a plurality of windings of a motor corresponding to a plurality of phases of the motor, and including a plurality of first switching elements; a second inverter connected to a second end of the plurality of windings, and including a plurality of second switching elements; a controller configured to control the switching of the plurality of first switching elements or the plurality of second switching elements; and a plurality of current sensors, each sensing current flowing in the plurality of windings, wherein the controller may be configured to obtain a plurality of sensed current values ​​from the plurality of current sensors, determine a plurality of corrected current values ​​by removing a common-mode current from each of the plurality of sensed current values, and detect a disconnection of each of the plurality of phases based on a cable disconnection index according to the plurality of corrected current values.

[0010] According to one aspect of the invention, the vehicle may include a device for detecting the disconnection of the power cable of the motor and / or a motor system and may be driven by the motor system.

[0011] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0012] Figure 1A and Figure 1B This is a block diagram illustrating an apparatus, motor system, and vehicle for detecting the disconnection of a power cable for a motor according to an exemplary embodiment of the present invention.

[0013] Figure 2 This is a circuit diagram illustrating a device and motor system for detecting the disconnection of a power cable in a motor according to an exemplary embodiment of the present invention.

[0014] Figure 3 This is a circuit diagram illustrating the location of a device for detecting the disconnection of a power cable in a motor and the sensor of a motor system according to an exemplary embodiment of the present invention.

[0015] Figure 4 This is a graph illustrating multiple sensed current values ​​detected by multiple current sensors in a device and motor system for detecting the disconnection of a power cable of a motor according to an exemplary embodiment of the present invention.

[0016] Figure 5 This is a block diagram illustrating the control logic of a device for detecting the disconnection of a power cable of a motor and a controller for a motor system according to an exemplary embodiment of the present invention.

[0017] Figure 6 This is a flowchart illustrating the steps performed by a device and motor system for detecting the disconnection of a motor's power cable according to an exemplary embodiment of the present invention.

[0018] Figure 7A The current values ​​of the stationary reference frame are shown when the U-phase power cable is disconnected, the V-phase power cable is disconnected, and the W-phase power cable is disconnected.

[0019] Figure 7B The cable disconnection index is shown when the U-phase power cable is disconnected, the V-phase power cable is disconnected, and the W-phase power cable is disconnected.

[0020] It should be understood that the accompanying drawings are not drawn to scale, but are merely appropriately simplified depictions to illustrate the various features of the basic principles of the invention. Specific design features of the invention disclosed herein (including, for example, specific dimensions, orientations, positions, and shapes) will be determined in part by the specific environment in which they will be applied and used.

[0021] Throughout these figures, the same reference numerals refer to the same or equivalent parts of the invention. Detailed Implementation

[0022] Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings and the following description. While the invention will be described in conjunction with exemplary embodiments, it will be understood that this specification is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments but also various variant embodiments, modified embodiments, equivalent embodiments, and other embodiments that may be included within the spirit and scope of the invention as defined by the appended claims.

[0023] Because the present invention can have various variations and can have various exemplary embodiments, specific embodiments are shown and described in detail in the accompanying drawings. However, it is not intended to limit the invention to specific embodiments, but should be understood to include all modifications, equivalents, and alternatives included within the spirit and scope of the invention.

[0024] Terms such as "first," "second," etc., may be used to describe various elements, but elements should not be limited to these terms. The terms above may be used only to distinguish one component from another. For example, without departing from the scope of the invention, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. The term "and / or" may include a combination of or any one of the associated listed items.

[0025] The terminology used in this invention is intended to describe specific embodiments only and is not intended to limit the invention. Unless the context clearly specifies otherwise, singular expressions may include plural expressions. In this application, it should be understood that terms such as “comprising,” “including,” or “having” are intended to indicate the presence of the features, values, steps, operations, components, parts, or combinations thereof described in the specification, but do not exclude the presence or addition of one or more other features, values, steps, operations, components, parts, or combinations thereof.

[0026] Unless otherwise defined, all terms used herein (including technical or scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in common dictionaries should be interpreted to include meanings consistent with their meanings in the relevant technical context and should not be interpreted in an ideal or overly formal manner unless explicitly defined in this application.

[0027] In this specification, a vehicle (including electric vehicles) means any vehicle used to move an object (e.g., a person, animal, or cargo) from a starting point to a destination. These vehicles are not limited to those that travel on roads or tracks.

[0028] In the following description, exemplary embodiments of the invention will be described in more detail with reference to the accompanying drawings.

[0029] refer to Figure 1A and Figure 1B According to an exemplary embodiment of the present invention, an apparatus for detecting the disconnection of a power cable of a motor may include a computing device 120 and / or a motor system 132 and may be included in a vehicle (EV).

[0030] The motor system 132 can receive power from the battery 110 and apply torque to the wheels of the vehicle (EV). By design, the motor system 132 can be configured to generate energy by performing regenerative braking on the rotating wheels and supply the generated energy to the battery 110.

[0031] The vehicle (EV) can be implemented as one of the following: hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), electric vehicle, and fuel cell electric vehicle (FCEV), but the present invention is not limited thereto.

[0032] refer to Figure 2 and Figure 3According to an exemplary embodiment of the present invention, the motor system 132 may include a first inverter 10, a second inverter 20, a controller 70, and a sensor unit 80, and may be configured to control the motor 30. For example, similar to the computing device 120, the controller 70 may include at least one of a processor, a computer-readable storage medium, a communication bus, an input / output interface, a communication interface, and an input / output device.

[0033] The motor 30 may include multiple windings C1, C2, and C3, and may be included in the motor system 132. For example, the motor 30 may be implemented as an induction motor, a permanent magnet synchronous motor, etc. A force can be applied to the magnetic field element of the motor 30 based on the magnetic field of the current flowing in the multiple windings C1, C2, and C3, so as to cause the motor 30 to rotate. As the motor 30 rotates, the wheels of the vehicle can also rotate.

[0034] The first inverter 10 can be connected to the first terminals of multiple windings C1, C2, and C3 corresponding to multiple phases (U phase, V phase, and W phase) of the motor 30, and includes multiple first switching elements S11, S12, S13, S14, S15, and S16. The phase difference between the multiple phases (U phase, V phase, and W phase) can be 120 degrees.

[0035] The first inverter 10 can be electrically connected to the battery 110, and the DC voltage of the battery 110 can be transmitted to the first inverter 10 through the DC link capacitor 60. The first inverter 10 can convert the DC voltage into AC phase currents Iu, Iv, and Iw based on the switching on and off of multiple first switching elements S11, S12, S13, S14, S15, and S16. The AC phase currents Iu, Iv, and Iw can flow to multiple windings C1, C2, and C3 through power cables.

[0036] The second inverter 20 can be connected to the second terminals of multiple windings C1, C2, and C3, and includes multiple second switching elements S21, S22, S23, S24, S25, and S26. The second inverter 20 can be electrically connected to the battery 110 via the first inverter 10, and converts DC voltage into AC phase currents Iu, Iv, and Iw based on the switching of the multiple second switching elements S21, S22, S23, S24, S25, and S26. The AC phase currents Iu, Iv, and Iw can flow to the multiple windings C1, C2, and C3 via power cables.

[0037] Each of the plurality of first switching elements S11, S12, S13, S14, S15 and S16 and the plurality of second switching elements S21, S22, S23, S24, S25 and S26 may include a power semiconductor device (e.g., an insulated gate bipolar transistor (IGBT)) and a diode. The power semiconductor device can switch the presence of an electrical connection between the emitter terminal and the collector terminal based on a signal at the gate terminal, and the diode may be connected between the emitter terminal and the collector terminal.

[0038] Sensor unit 80 may include multiple current sensors 81, 82, and 83, a voltage sensor 84, a temperature sensor 85, and a rotation sensor. Figure 5 At least one of (86). Voltage sensor 84 can detect the DC voltage between battery 110 and first inverter 10, and temperature sensor 85 can detect the temperature of each of a plurality of first switching elements S11, S12, S13, S14, S15 and S16 and a plurality of second switching elements S21, S22, S23, S24, S25 and S26.

[0039] For example, the temperature value sensed by temperature sensor 85 can be sent to... Figure 1A and Figure 1B The computing device 120 can be configured to control whether to turn relays MRLY1 and MRLY2 on or off based on a sensed temperature value. When relays MRLY1 and MRLY2, which may be included in the battery 110, are in the on state, the battery 110 can provide energy to the first inverter 10 and the second inverter 20. When relays MRLY1 and MRLY2 are in the off state, relays MRLY1 and MRLY2 can prevent energy transfer between the first inverter 10, the second inverter 20, and the battery 110.

[0040] Multiple current sensors 81, 82, and 83 can respectively detect the currents Iu, Iv, and Iw flowing in multiple windings C1, C2, and C3. For example, the multiple current sensors 81, 82, and 83 can be disposed on the power cable extending from the multiple windings C1, C2, and C3 to the first inverter 10, or they can be disposed on the power cable extending from the multiple windings C1, C2, and C3 to the second inverter 20.

[0041] The controller 70 can obtain multiple sensed current values ​​from multiple current sensors 81, 82, and 83, sensed voltage values ​​from voltage sensor 84, and sensed voltage values ​​from a rotation sensor ( Figure 5 86) Obtains the sensed motor angle value and receives the motor's required output value. For example, controller 70 can obtain the value from the sensed motor angle. Figure 1A and Figure 1B The computing device 120 receives the output value required by the motor.

[0042] The controller 70 can be configured to control the switching of multiple first switching elements S11, S12, S13, S14, S15, and S16 and / or multiple second switching elements S21, S22, S23, S24, S25, and S26 based on the obtained sensed values ​​and the motor's required output values. For example, the controller 70 can be configured to control the switching by sending a signal to the gate terminal of the power semiconductor device. For example, the controller 70 can be configured to control the switching using pulse width modulation (PWM). For example, the PWM method may include space vector pulse width modulation (SVPWM) control and remote state pulse width modulation (RSPWM) control, but the invention is not limited thereto.

[0043] refer to Figure 2 and Figure 3 According to an exemplary embodiment of the present invention, the motor system 132 may further include a motor mode changing unit 40, which can switch between an open end winding (OEW) mode and a closed end winding (CEW) mode. The motor mode changing unit 40 may include a plurality of third switches S31, S32 and S33 connected between a plurality of windings C1, C2 and C3.

[0044] When multiple third switches S31, S32, and S33 are in the ON state, multiple windings C1, C2, and C3 can be directly connected to each other, and multiple windings C2 and C3 can form a Y-connection. That is, inverter system 1 can operate in closed end winding (CEW) mode. In this case, controller 70 can be configured to control the switching of multiple first switching elements S11, S12, S13, S14, S15, and S16, and can not control the switching of multiple second switching elements S21, S22, S23, S24, S25, and S26. Therefore, inverter system 1 can operate in a mode that utilizes only the first inverter 10 in the first inverter 10 and the second inverter 20.

[0045] When the multiple third switches S31, S32, and S33 are in the open state, the multiple windings C1, C2, and C3 do not need to be directly connected to each other, and the inverter system 1 can operate in open-end winding (OEW) mode. In this case, the controller 70 can be configured to control all switching of the multiple first switching elements S11, S12, S13, S14, S15, and S16 and the multiple second switching elements S21, S22, S23, S24, S25, and S26. Therefore, the inverter system 1 can operate in a mode utilizing both the first inverter 10 and the second inverter 20, and the battery 110 can be used for both the first inverter 10 and the second inverter 20.

[0046] The controller 70 can switch the mode of the inverter system 1 by controlling the switching of multiple third switches S31, S32, and S33. According to the design, the computing device 120 of FIG. 1 can switch the mode of the inverter system 1 directly or through the controller 70. According to the design, the motor mode changing unit 40 can be omitted, and the inverter system 1 can operate only in the OEW mode of the CEW mode and OEW mode.

[0047] Compared to the case where inverter system 1 operates in CEW mode, the current value of inverter system 1 operating in OEW mode may generally be larger, and motor 30 can convert electrical energy into torque more efficiently. However, unlike CEW mode, inverter system 1 operating in OEW mode does not include a Y connection for offsetting common mode factor, which may cause common mode factor. Therefore, inverter system 1 operating in OEW mode may cause common mode factor due to a small difference in impedance between the first inverter 10 and the second inverter 20, and a small difference in switching timing based on this difference.

[0048] For example, the common-mode voltage (V) caused by the difference in the combined voltage and dead time of the first inverter 10 and the second inverter 20 of the inverter system 1 operating in OEW mode. c V can be defined by the following equation 1. Here, V an1 V bn1 and V cn1 It is the voltage of each phase of the first inverter 10, V an2 V bn2 and V cn2 These are the voltages of each phase of the second inverter 20.

[0049] [Equation 1]

[0050] V c1 =(V an1 +V bn1 +V cn1 ) / 3

[0051] V c2 =(V an2 +V bn2 +V cn2 ) / 3

[0052] V c =V c1 -V c2

[0053] Common-mode voltage (V) c This can cause common-mode current. (See reference) Figure 4 Composed of multiple sensors ( Figure 3The current I detected in (81, 82 and 83) u I v and I w The waveform can have a focus on current I u I v and I w Distortion occurs when the absolute value of the current is close to 0. This distortion may be due to common-mode current. When the detected current I is directly used... u I v and I w When used to detect breaks in power cables, the accuracy of the break detection may be reduced.

[0054] Because it can be obtained from multiple sensors ( Figure 3 The current I detected in 81, 82 and 83) u I v and I w By removing common-mode current, the device for detecting the disconnection of the power cable of the motor and the motor system 132 according to the exemplary embodiment of the present invention can improve the accuracy of detecting the disconnection of the power cable, regardless of the mode of the inverter system 1, or can improve the accuracy of detecting the disconnection of the power cable when the inverter system 1 is running in OEW mode.

[0055] refer to Figure 2 , Figure 3 and Figure 6 According to an exemplary embodiment of the present invention, the device for detecting the disconnection of the power cable of a motor can perform the following steps: sensing the current I flowing in multiple windings C1, C2 and C3 corresponding to multiple phases (U phase, V phase and W phase) of the motor 30 respectively. u I v and I w Multiple current sensors 81, 82, and 83 acquire multiple sensed current values ​​(S121), determine a common-mode current based on the multiple sensed current values ​​(S122), determine multiple correction current values ​​by removing the common-mode current from each sensed current value (S123), determine a cable breakage index (K) based on the current values ​​in a stationary reference frame based on the multiple correction current values ​​(S124), and detect a breakage in each of the multiple phases based on the cable breakage index (K) (S125, S126, and S127). Determining the multiple correction current values ​​(S123) may include determining the common-mode current (S122), and detecting a breakage (S125, S126, and S127) may include determining the cable breakage index (K) (S124).

[0056] These steps can be performed by Figure 1A and Figure 1B The computing device 120 performs the operation. According to the design, instead of the computing device 120 in Figure 1, Figure 2The controller 70 of the motor system 132 can perform the above steps.

[0057] When determining the common-mode current (S122), the device and / or controller 70 for detecting the disconnection of the motor's power cable can be configured to determine the common-mode current (I) according to the following equation 2. n Here, I u I v and I w The current values ​​can be the U-phase current value, V-phase current value, and W-phase current value detected by multiple current sensors 81, 82, and 83, respectively.

[0058] [Equation 2]

[0059]

[0060] When determining multiple correction current values ​​(S123), the device and / or controller 70 for detecting the disconnection of the power cable of the motor can be configured to determine multiple correction current values ​​(I' u 、I' v and I' w ).

[0061] [Equation 3]

[0062] I' u =I u -I n I' v =I v -I n I' w =I w -I n

[0063] When determining the cable breakage index (K) (S124), the device and / or controller 70 for detecting the breakage of the power cable of the motor can be configured to, according to the following equation 4, pass multiple correction current values ​​(I' u 、I' v and I' w Determine the d-axis current (Idss) and q-axis current (Iqss) of the stationary reference frame.

[0064] [Equation 4]

[0065]

[0066] The device and / or controller 70 for detecting the disconnection of the power cable of the motor can pre-store the d-axis current (Idss) and q-axis current (Iqss) of the stationary reference frame when the U-phase power cable is disconnected, the V-phase power cable is disconnected, and the W-phase power cable is disconnected. The device and / or controller 70 for detecting the disconnection of the power cable of the motor can pre-store according to... Figure 7A The equations predetermine the d-axis current (Idss) and q-axis current (Iqss) of the stationary reference frame, or can be based on... Figure 7A The equations determine the d-axis current (Idss) and q-axis current (Iqss) of the stationary reference frame. Figure 7A In this diagram, since Izero is the current value of the disconnected phase (ideally 0), and Iopen is the current value of one of the two non-disconnected phases, the current value of the other non-disconnected phase can be -Iopen. Ideally, the sum of the three-phase current values ​​is 0. Here, it is assumed that there is an unbalanced current between the three phases, and Iub is the unbalanced current.

[0067] Subsequently, when determining the cable breakage index (K) (S124), the device and / or controller 70 for detecting the breakage of the power cable of the motor can be configured to determine the cable breakage index according to the following equation 5.

[0068] [Equation 5]

[0069]

[0070] The device and / or controller 70 for detecting the disconnection of the power cable of the motor can pre-store the cable disconnection index (K) when the U-phase power cable is disconnected, the V-phase power cable is disconnected, and the W-phase power cable is disconnected. The device and / or controller 70 for detecting the disconnection of the power cable of the motor can pre-store according to... Figure 7B The cable breakage index (K) is predetermined by the equation, or it can be determined according to... Figure 7B The equation determines the cable breakage index (K).

[0071] exist Figure 7B In this context, since the absolute value of Iopen may be much larger than the absolute value of Izero, and also much larger than the absolute value of Iub, when the U-phase power cable is disconnected, the cable disconnection index (K) may approach 0 (corresponding to a special character); when the V-phase power cable is disconnected, the cable disconnection index (K) may approach a positive number close to the square root of 3 (corresponding to a special character); and when the W-phase power cable is disconnected, the cable disconnection index (K) may approach a negative number close to the square root of 3 (corresponding to a special character). Figure 7B (Special characters).

[0072] Therefore, the U-phase disconnection detection reference range may include 0, the V-phase disconnection detection reference range may include a positive number that is the square root of 3, and the W-phase disconnection detection reference range may include a negative number that is the square root of 3. These reference ranges may be pre-stored in the device and / or controller 70 for detecting the disconnection of the power cable of the motor, or may be determined by the device and / or controller 70 for detecting the disconnection of the power cable of the motor.

[0073] In the steps of detecting disconnection (S125, S126, and S127), the device and / or controller 70 for detecting the disconnection of the power cable of the motor may include: determining that phase U has disconnected when the determined cable disconnection index (K) falls within the U-phase disconnection detection reference range within a predetermined time period (e.g., 30ms); determining that phase V has disconnected when the determined cable disconnection index (K) falls within the V-phase disconnection detection reference range within a predetermined time period (e.g., 30ms); and determining that phase W has disconnected when the determined cable disconnection index (K) falls within the W-phase disconnection inspection reference range within a predetermined time period (e.g., 30ms).

[0074] Here, since the U-phase disconnection detection reference range, the V-phase disconnection detection reference range, and the W-phase disconnection detection reference range can be non-overlapping, the device and / or controller 70 for detecting the disconnection of the power cable of the motor can be configured to determine which of the U-phase, V-phase, and W-phase phases the disconnection occurred based on the value of the cable disconnection index (K), which remains almost constant over a predetermined time period (e.g., 30 ms).

[0075] According to the design, when a disconnection is detected by detecting the disconnection of each of the multiple phases (S125, S126, and S127), the apparatus and motor system for detecting the disconnection of the motor's power cable according to an exemplary embodiment of the present invention can further run steps to execute subsequent logic (S128, S129, and S130). For example, the steps to execute subsequent logic (S128, S129, and S130) may include sending information about the disconnection of the motor's power cable to the vehicle (EV of FIG. 1) or external to the vehicle (e.g., external networks and servers). Therefore, the driver or vehicle administrator can accurately identify that the power cable of a specific phase of the vehicle's motor system has been disconnected.

[0076] At the same time, refer to Figure 2 and Figure 5 According to an exemplary embodiment of the present invention, the controller 70 of the motor system 132 may be configured to control the switching of a plurality of first switching elements (S11, S12, S13, S14, S15 and S16) and / or a plurality of second switching elements (S21, S22, S23, S24, S25 and S26) based on the plurality of correction current values ​​(I'u, I'v and I'w).

[0077] The controller 70 can convert multiple correction current values ​​(I'u, I'v, and I'w) into current values ​​(idsr and iqsr) of the synchronous reference system, determine the pulse width modulation (PWM) duty cycle based on the current values ​​(idsr and iqsr) of the synchronous reference system, and control the switching of multiple first switching elements (S11, S12, S13, S14, S15, and S16) and / or multiple second switching elements (S21, S22, S23, S24, S25, and S26) based on the PWM duty cycle.

[0078] For example, the controller 70 may include a current command mapping 71, a current control unit 72, a first coordinate transformation unit 73, a pulse width modulation unit 74, a phase transformation unit 75, a phase current transformation unit 76, a second coordinate transformation unit 77, and a third coordinate transformation unit 78.

[0079] Phase current converter 76 can obtain multiple sensed current values ​​(I0) from multiple current sensors 81, 82 and 83. u I v and I w Based on multiple sensed current values ​​(I) u I v I w Determine the common-mode current I n By obtaining multiple sensed current values ​​(I u I v I w Each sensed current value in the equation is used to remove the common-mode current In to determine multiple correction current values ​​(I'). u 、I' v and I' w ), and multiple correction current values ​​(I' u 、I' v and I' w The values ​​of the current (idss and iqss) are converted to the current values ​​in the stationary reference frame.

[0080] The second coordinate transformation unit 77 can convert the current values ​​(idss and iqss) in the stationary reference frame into current values ​​(idsr and iqsr) in the synchronous reference frame, and provide the converted current values ​​(idsr and iqsr) in the synchronous reference frame to the current control unit 72. For example, the second coordinate transformation unit 77 can obtain the sensing motor angle (θr) from the rotation sensor 86, and can apply the trigonometric function of the sensing motor angle (θr) to the current values ​​(idss and iqss) in the stationary reference frame, and convert them into current values ​​(idsr and iqsr) in the synchronous reference frame.

[0081] The current command mapping 71 can be configured to generate corresponding current commands (Ids) based on the motor demand output (motor demand torque (Te*) and the motor back electromotive force generated by the driver's operation, etc.). r* and IQS r* ).

[0082] The current control unit 72 can be configured to generate voltage commands (Vds). r* and Vqs r* This voltage command can reduce the amount of current received (Ids) r* and IQS r* The difference between the actual current supplied to the motor and the detected value is obtained. Since the current control unit 72 can receive the current values ​​(idsr and iqsr) of the synchronous reference system, the output signals of the current control unit 72 and the pulse width modulation unit 74 can be determined based on the current values ​​(idsr and iqsr) of the synchronous reference system. Therefore, the controller 70 can be configured to control the motor 30 more accurately, thereby further improving the lifespan of the motor 30.

[0083] The first coordinate transformation unit 73 can convert the voltage command (Vds) of the synchronous reference system. r* and Vqs r* The third coordinate transformation unit 78 can convert the voltages (Vdss and Vqss) of the stationary reference system into the voltages (Vdsr and Vqsr) of the synchronous reference system and feed them back to the current control unit 72.

[0084] The pulse width modulation unit 74 can be configured to use pulse width modulation (PWM) to control the switching of multiple switching elements of the first inverter 10 and / or the second inverter. For example, the PWM method may include space vector pulse width modulation (SVPWM) control and parity vector modulation (RSPWM) control, but the invention is not limited thereto. The phase converter 75 can convert the output signal of the stationary reference frame of the pulse width modulation unit 74 into control signals for each phase.

[0085] At the same time, refer to Figure 1A and Figure 1B According to an exemplary embodiment of the present invention, an apparatus for detecting the disconnection of a power cable of a motor may include a computing device 500 disposed in a vehicle (EV), and the computing device 500 may include at least one processor 501, a computer-readable storage medium 502, and a communication bus 503. The communication bus 503 may interconnect various other components of the computing device 500, including the processor 501 and the computer-readable storage medium 502.

[0086] Processor 501 can cause computing device 500 to operate according to the above exemplary embodiments of the present invention. For example, processor 501 can execute one or more programs stored in computer-readable storage medium 502. The one or more programs may include one or more computer-executable instructions, wherein, when executed by processor 501, the computer-executable instructions can be configured to cause computing device 500 to perform operations according to the exemplary embodiments of the present invention.

[0087] Computer-readable storage medium 502 may be configured to store computer-executable instructions or program code, program data, and / or other suitable forms of information. Program 502a stored in computer-readable storage medium 502 includes a set of instructions executable by processor 501. In exemplary embodiments of the invention, computer-readable storage medium 502 may include memory (e.g., volatile memory, non-volatile memory, or suitable combinations thereof), one or more disk storage devices, optical disk storage devices, flash memory devices, other forms of storage media accessible by computing device 500 and storing target information, or suitable combinations thereof.

[0088] The computing device 500 may also include one or more input / output interfaces 505 and one or more network communication interfaces 506 that provide interfaces for one or more input / output devices 504. The input / output interfaces 505 and network communication interfaces 506 are connected to a communication bus 503. The network may be one or more of the following cellular networks: Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Time Division CDMA (TD-CDMA), Universal Mobile Telecommunications System (UMTS), and Long Term Evolution (LTE).

[0089] Input / output device 504 can be connected to other components of computing device 500 via input / output interface 505. Exemplary input / output device 504 may include input devices such as pointing devices (mouse, touchpad, etc.), keyboards, touch input devices (touchpad, touchscreen, etc.), voice or sound input devices, various types of sensor devices and / or imaging devices, and output devices such as display devices, printers, speakers, and / or network cards. Exemplary input / output device 504 may be included within computing device 500 as a component constituting computing device 500, or it may be connected to computing device 500 as a separate device distinct from computing device 500.

[0090] Furthermore, various exemplary embodiments of the present invention may include a program for performing the methods described herein on a computer, and a computer-readable recording medium including the program. A non-transitory computer-readable recording medium may include program instructions, local data files, local data structures, etc., individually or in combination. The medium may be specifically designed and configured for the present invention, or may be generally available in the field of computer software. Examples of computer-readable media may include magnetic media (e.g., hard disks, floppy disks, and magnetic tapes), optical recording media (e.g., CD-ROMs and DVDs), and hardware devices (e.g., ROMs, RAMs, and flash memory) specifically configured to store and execute program instructions. Examples of programs may include not only machine language code generated by a compiler, but also high-level language code executed by a computer using an interpreter.

[0091] As described above, according to exemplary embodiments of the present invention, in devices, motor systems, and vehicles for detecting the disconnection of power cables in motors, the accuracy of detecting the disconnection of power cables can be improved regardless of the mode (or structure) of the inverter system, and the accuracy of detecting the disconnection of power cables can be improved when the inverter system is operating in open end winding (OEW) mode (or OEW structure).

[0092] In various exemplary embodiments of the present invention, the memory and processor may be configured as a single chip or as separate chips.

[0093] In various exemplary embodiments of the invention, the scope of the invention includes software or machine-executable instructions (e.g., operating system, application, firmware, program, etc.) for enabling the steps of the method according to various embodiments to be executed on a device or computer, including non-transitory computer-readable media on which such software or instructions are stored and can be executed on said device or computer.

[0094] In various exemplary embodiments of the present invention, the control device may be implemented in hardware or software, or in a combination of hardware and software.

[0095] Software implementation can include software components (or elements), object-oriented software components, class components, task components, processes, functions, properties, programs, subroutines, program code segments, drivers, firmware, microcode, data, databases, data structures, tables, arrays, and variables. Software, data, etc., can be stored in memory and executed by a processor. Memory or processor can be implemented using various means well known to those skilled in the art.

[0096] Furthermore, terms such as “unit” and “module” included in this specification refer to a unit for performing at least one function or operation, which can be implemented by hardware, software or a combination thereof.

[0097] In the flowchart described with reference to the accompanying drawings, the flowchart can be executed by a controller or a processor. The order of the steps in the flowchart can be changed, multiple steps can be combined, or arbitrary steps can be divided, and predetermined steps may not be executed. Furthermore, the steps in the flowchart can be executed sequentially, but not necessarily in order. For example, the order of the steps can be changed, and at least two steps can be executed in parallel.

[0098] In the following text, hardware operative connectivity may include establishing direct and / or indirect connections between hardware via wired and / or wireless means.

[0099] In exemplary embodiments of the present invention, a vehicle may be referred to as a concept encompassing various means of transportation. In some cases, a vehicle may be interpreted as a concept encompassing not only various land vehicles that travel on roads (e.g., passenger cars, motorcycles, trucks, and buses), but also various other means of transportation such as airplanes, drones, and ships.

[0100] For ease of interpretation and precise definition in the appended claims, the terms “upper,” “lower,” “inner,” “outer,” “upper part,” “lower part,” “upward,” “downward,” “front,” “back,” “behind,” “internal,” “external,” “inward,” “outward,” “inside,” “outside,” “intrinsic,” “external,” “forward,” and “backward” are used with reference to the positions of these features shown in the figures to describe features of the exemplary embodiments. It should be further understood that the term “connection” or its derivatives refer to both direct and indirect connections between the two.

[0101] The term “and / or” can include a combination of multiple related listed items or any one of multiple related listed items. For example, “A and / or B” includes all three cases such as “A”, “B”, and “A and B”.

[0102] In an exemplary embodiment of the present invention, "at least one of A and B" may refer to "at least one of A or B" or "at least one of a combination of at least one of A and B". Furthermore, "one or more of A and B" may refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0103] In this specification, unless the context clearly indicates otherwise, singular expressions include plural expressions.

[0104] In exemplary embodiments of the present invention, it should be understood that terms such as “comprising” or “having” are intended to specify the presence of features, values, steps, operations, elements, components or combinations thereof described in the specification, and do not exclude the possibility of adding or having one or more other features, values, steps, operations, elements, components or combinations thereof.

[0105] According to an exemplary embodiment of the present invention, components may be combined with each other to form a single entity, or some components may be omitted.

[0106] For purposes of illustration and description, the foregoing description of specific exemplary embodiments of the invention has been presented. These descriptions are not intended to be exhaustive or to limit the invention to the precise forms disclosed; obviously, many modifications and alterations are possible in light of the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to implement and utilize various exemplary embodiments of the invention, as well as various alternatives and modifications thereof. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A device for detecting the breakage of a power cable of a motor, comprising: A computing device including a processor and a storage medium, wherein one or more programs configured to be executed by the processor are stored on the storage medium; The computing device executes the following by utilizing one or more of the aforementioned programs: Multiple sensed current values ​​are obtained from multiple current sensors that respectively sense the current flowing in multiple windings of a motor corresponding to multiple phases of the motor. Multiple correction current values ​​are determined by removing the common-mode current from each of the multiple sensed current values; Disconnection of each phase in multiple phases is detected based on a cable disconnection index according to the multiple correction current values.

2. The device for detecting the disconnection of a power cable of a motor according to claim 1, wherein, The common-mode current corresponds to the average of the plurality of sensed current values. The cable disconnection index is based on the current value of a static reference system of the plurality of corrected current values.

3. The device for detecting the disconnection of a power cable of a motor according to claim 2, wherein, Detecting the disconnection of each phase in a multi-phase system includes: In response to the cable breakage index falling within the U-phase breakage detection reference range within a predetermined time period, a U-phase breakage is determined to have occurred; In response to the cable breakage index falling within the V-phase breakage detection reference range within a predetermined time period, a V-phase breakage is determined to have occurred. In response to the cable breakage index falling within the W-phase breakage detection reference range within a predetermined time period, it is determined that a W-phase breakage has occurred. The U-phase disconnection detection reference range, the V-phase disconnection detection reference range, and the W-phase disconnection detection reference range do not overlap with each other.

4. The device for detecting the disconnection of a power cable for a motor according to claim 2, wherein, Detecting the disconnection of each phase in a multi-phase system includes: The cable breakage index is determined by dividing the d-axis current of the stationary reference frame by the q-axis current.

5. The device for detecting the disconnection of a power cable for a motor according to claim 4, wherein, Detecting the disconnection of each phase in a multi-phase system further includes: In response to the cable breakage index falling within the U-phase breakage detection reference range within a predetermined time period, a U-phase breakage is determined to have occurred; In response to the cable breakage index falling within the V-phase breakage detection reference range within a predetermined time period, a V-phase breakage is determined to have occurred. In response to the cable breakage index falling within the W-phase breakage detection reference range within a predetermined time period, it is determined that a W-phase breakage has occurred. The U-phase disconnection detection reference range, the V-phase disconnection detection reference range, and the W-phase disconnection detection reference range do not overlap with each other; The U-phase disconnection detection reference range includes 0, The reference range for V-phase disconnection detection includes positive numbers that are the square root of 3. The W-phase disconnection detection reference range includes negative numbers equal to the square root of 3.

6. The apparatus for detecting the disconnection of a power cable in a motor as described in claim 1, wherein, The computing device further performs: In response to the detection of a disconnection through the step of detecting disconnections in each of the multiple phases, subsequent logic is executed. The subsequent logic includes sending information about disconnecting the motor's power cable to the vehicle or an external part of the vehicle.

7. The apparatus for detecting the disconnection of a power cable of a motor according to claim 1, further comprising: The motor system includes a motor, a first inverter, a second inverter, the plurality of current sensors, and a controller. The first inverter is connected to the first end of the plurality of windings and includes a plurality of first switching elements. The second inverter is connected to the second end of the plurality of windings and includes a plurality of second switching elements. The controller is operatively connected to the plurality of first switching elements or the plurality of second switching elements and is configured to control the switching of the plurality of first switching elements or the plurality of second switching elements.

8. The apparatus for detecting the disconnection of a power cable of a motor according to claim 7, further comprising: Multiple third switching elements, It is connected between the plurality of windings.

9. The apparatus for detecting the disconnection of a power cable of a motor according to claim 8, further comprising: The first inverter and the second inverter share a battery.

10. The apparatus for detecting the disconnection of a power cable of a motor according to claim 7, wherein, The controller is further configured to: convert the plurality of correction current values ​​into current values ​​of a synchronous reference system, determine the pulse width modulation duty cycle based on the current values ​​of the synchronous reference system, and control the switching of the plurality of first switching elements or the plurality of second switching elements based on the pulse width modulation duty cycle.

11. A vehicle comprising: The device for detecting the disconnection of the power cable of a motor according to claim 1.

12. An electric motor system comprising: A first inverter is connected to the first terminals of multiple windings of a motor corresponding to multiple phases of the motor, and includes multiple first switching elements; A second inverter is connected to the second end of the plurality of windings and includes a plurality of second switching elements; A controller operatively connected to the plurality of first switching elements or the plurality of second switching elements, and configured to control the switching of the plurality of first switching elements or the plurality of second switching elements; as well as Multiple current sensors, each sensing the current flowing in the multiple windings. The controller is operatively connected to the plurality of current sensors and is configured to: obtain a plurality of sensed current values ​​from the plurality of current sensors, determine a plurality of corrected current values ​​by removing common-mode current from each of the plurality of sensed current values, and detect disconnection of each of the plurality of phases based on a cable disconnection index according to the plurality of corrected current values.

13. The motor system according to claim 12, wherein, The common-mode current corresponds to the average of the plurality of sensed current values. The cable disconnection index is based on the current value of a static reference system of the plurality of corrected current values.

14. The motor system according to claim 12, wherein, The controller is further configured to: convert the plurality of correction current values ​​into current values ​​of a synchronous reference system, determine the pulse width modulation duty cycle based on the current values ​​of the synchronous reference system, and control the switching of the plurality of first switching elements or the plurality of second switching elements based on the pulse width modulation duty cycle.

15. The motor system according to claim 13, in, The controller is further configured as follows: In response to the cable breakage index falling within the U-phase breakage detection reference range within a predetermined time period, a U-phase breakage is determined to have occurred; In response to the cable breakage index falling within the V-phase breakage detection reference range within a predetermined time period, a V-phase breakage is determined to have occurred. In response to the cable breakage index falling within the W-phase breakage detection reference range within a predetermined time period, it is determined that a W-phase breakage has occurred. The U-phase disconnection detection reference range, the V-phase disconnection detection reference range, and the W-phase disconnection detection reference range do not overlap with each other.

16. The motor system according to claim 13, wherein, The controller is further configured to determine the cable disconnection index based on a value obtained by dividing the d-axis current of the stationary reference frame by the q-axis current.

17. The motor system according to claim 16, in, The controller is further configured as follows: In response to the cable breakage index falling within the U-phase breakage detection reference range within a predetermined time period, a U-phase breakage is determined to have occurred; In response to the cable breakage index falling within the V-phase breakage detection reference range within a predetermined time period, a V-phase breakage is determined to have occurred. In response to the cable breakage index falling within the W-phase breakage detection reference range within a predetermined time period, it is determined that a W-phase breakage has occurred. The U-phase disconnection detection reference range, the V-phase disconnection detection reference range, and the W-phase disconnection detection reference range do not overlap with each other; The U-phase disconnection detection reference range includes 0, The reference range for V-phase disconnection detection includes positive numbers that are the square root of 3. The W-phase disconnection detection reference range includes negative numbers equal to the square root of 3.

18. The motor system according to claim 12, further comprising: Multiple third switching elements are connected between the multiple windings.

19. The motor system according to claim 18, further comprising: The first inverter and the second inverter share a battery.

20. A vehicle that travels using the electric motor system of claim 12.

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