Motor open-phase fault detection method, servo driver, servo system and medium

Abstract

The invention discloses a motor open-phase fault detection method, a servo driver, a servo system and a medium, and relates to the technical field of servo driver control, and the method comprises the steps: obtaining a direct-axis current instruction value and a quadrature-axis current instruction value of a target motor; performing coordinate transformation on the direct-axis current instruction value and the quadrature-axis current instruction value to obtain a current instruction value of at least one phase in the three phases of the target motor; according to the current instruction value of each phase, determining whether the current of each phase of the target motor is in a zero-crossing region; and taking the phase of which the current is not in the zero-crossing region as a target phase, and controlling the target motor to enter a default phase fault detection process of the target phase. According to the invention, the problem of false alarm of the open-phase fault caused by the fact that the three-phase current is in the zero-crossing region can be well solved, so that the detection accuracy of the open-phase fault of the motor is improved.

Description

Technical Field

[0001] This application relates to the field of servo drive control technology, and in particular to a method for detecting motor phase loss faults, a servo drive, a servo system, and a medium. Background Technology

[0002] Phase loss faults are a common problem in motor operation. To accurately detect phase loss faults, the current method typically involves first using an encoder to detect the motor's electrical angle, thereby determining whether the three-phase current is in the zero-crossing region. Subsequently, during the phase loss fault detection process, the system pauses the detection of phase loss faults for motor phases with current in the zero-crossing region to avoid false alarms caused by the three-phase current being in the zero-crossing region.

[0003] However, the electrical angle detected by the encoder usually has a certain deviation, which can lead to misjudgment of the zero-crossing state of the three-phase current. As a result, the problem of false alarms of phase loss faults caused by the three-phase current being in the zero-crossing region has not been well resolved, and the detection accuracy of phase loss faults is low. Summary of the Invention

[0004] The main purpose of this application is to provide a method for detecting motor phase loss faults, a servo driver, a servo system, and a medium, which aims to better solve the problem of false phase loss faults caused by the three-phase current being in the zero-crossing region, so as to improve the detection accuracy of motor phase loss faults.

[0005] To achieve the above objectives, this application provides a method for detecting a phase loss fault in a motor, the method comprising:

[0006] Obtain the direct-axis current command value and quadrature-axis current command value of the target motor;

[0007] The direct-axis current command value and the quadrature-axis current command value are transformed by coordinate transformation to obtain the current command value of at least one phase of the three phases of the target motor;

[0008] Based on the current command value of each phase, determine whether the current of each phase of the target motor is in the zero-crossing region;

[0009] The phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

[0010] In one embodiment, the step of determining whether the current of each phase of the target motor is in the zero-crossing region based on the current command value of each phase includes:

[0011] For any phase of the target motor, if the current command value of the target motor in that phase is less than a preset command threshold, then it is determined that the current of that phase of the target motor is in the zero-crossing region.

[0012] If the current command value of the target motor in a phase is greater than or equal to the preset command threshold, then it is determined that the current of the target motor in that phase is not in the zero-crossing region.

[0013] In one embodiment, after the step of controlling the target motor to enter the phase loss fault detection process of the target phase, the method further includes:

[0014] Obtain the current feedback value of the target phase;

[0015] Based on the current feedback value of the target phase, determine whether the target phase has a phase loss fault;

[0016] If the target phase has a phase loss fault, a phase loss fault alarm message will be output.

[0017] In one embodiment, the step of determining whether a phase loss fault exists in the target phase based on the current feedback value of the target phase includes:

[0018] If the absolute value of the current feedback value of the target phase is less than the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be a phase loss fault condition.

[0019] If the absolute value of the current feedback value of the target phase is greater than or equal to the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be a normal operating condition.

[0020] Based on the target operating conditions satisfied by the target phase, determine whether the target phase has a phase loss fault.

[0021] In one embodiment, the step of determining whether a phase loss fault exists in the target phase based on the target operating conditions satisfied by the target phase includes:

[0022] Based on the target operating conditions satisfied by the target phase, adjust the count value of the phase loss fault counter associated with the target phase to obtain the target count value;

[0023] If the target count value is greater than or equal to the preset count threshold, then it is determined that the target phase has a phase loss fault;

[0024] If the target count value is less than the preset count threshold, then it is determined that the target phase does not have a phase loss fault.

[0025] In one embodiment, the step of adjusting the count value of the phase loss fault counter associated with the target phase according to the target operating conditions satisfied by the target phase to obtain the target count value includes:

[0026] If the target operating condition satisfied by the target phase is a phase loss fault condition, then the count value of the phase loss fault counter associated with the target phase is incremented by one to obtain the target count value;

[0027] If the target operating conditions met by the target phase are normal operating conditions, then the count value of the phase loss fault counter associated with the target phase is set to zero to obtain the target count value.

[0028] In one embodiment, the step of determining whether a phase loss fault exists in the target phase based on the target operating conditions satisfied by the target phase includes:

[0029] Based on the target operating conditions satisfied by the target phase, adjust the timing duration of the phase loss fault timer associated with the target phase to obtain the target timing duration;

[0030] If the target timing duration is greater than or equal to a preset duration threshold, then it is determined that the target phase has a phase loss fault;

[0031] If the target timing duration is less than the preset duration threshold, then it is determined that the target phase does not have a phase loss fault.

[0032] In one embodiment, the step of adjusting the timing duration of the phase loss fault timer associated with the target phase according to the target operating conditions satisfied by the target phase to obtain the target timing duration includes:

[0033] If the target operating condition satisfied by the target phase is a phase loss fault condition, then the timing duration of the phase loss fault timer associated with the target phase is added to the preset duration to obtain the target timing duration;

[0034] If the target operating conditions met by the target phase are normal operating conditions, then the timing duration of the phase loss fault timer associated with the target phase is set to zero to obtain the target timing duration.

[0035] Furthermore, to achieve the above objectives, this application also provides a servo driver, the servo driver comprising:

[0036] The coordinate transformation module is used to obtain the direct-axis current command value and the quadrature-axis current command value of the target motor; and to perform coordinate transformation on the direct-axis current command value and the quadrature-axis current command value to obtain the current command value of at least one phase of the three phases of the target motor.

[0037] The zero-crossing region determination module is used to determine whether the current of each phase of the target motor is in the zero-crossing region based on the current command value of each phase; the phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

[0038] In addition, to achieve the above objectives, this application also provides a servo system, which includes a servo driver and a motor, wherein the servo driver is connected to the motor and is used to perform the steps of implementing the motor phase loss fault detection method as described above.

[0039] In addition, to achieve the above objectives, this application also provides a medium, which is a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the motor phase loss fault detection method described above.

[0040] In addition, to achieve the above objectives, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the motor phase loss fault detection method described above.

[0041] This application provides a method for detecting phase loss faults in a motor. First, the direct-axis current command value and quadrature-axis current command value of the target motor are obtained. Then, coordinate transformation is performed on the direct-axis and quadrature-axis current command values ​​to obtain the current command value of at least one of the three phases of the target motor. Since the motor's electrical angle is effectively canceled during the coordinate transformation, the final current command value of at least one of the three phases of the target motor will no longer be affected by the motor's electrical angle. Next, based on the current command value of each phase, it can be determined whether the current of each phase of the target motor is in the zero-crossing region. Since the current command value of a phase changes when its current is in the zero-crossing region, the current command values ​​of each phase can be used to accurately analyze whether the current of each phase of the target motor is in the zero-crossing region. After accurately analyzing whether the current of each phase of the target motor is in the zero-crossing region, the phase whose current is not in the zero-crossing region is selected as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase, thus achieving accurate detection of the motor phase loss fault.

[0042] Therefore, this application proposes a method for determining whether the three-phase current of a motor is in the zero-crossing region using the three-phase current command value of the motor, thereby assisting in the detection of motor phase loss faults. Because this method is not affected by the motor's electrical angle, it effectively overcomes the technical defect of conventional techniques that use the electrical angle detected by encoders, which easily leads to misjudgments of the zero-crossing state of the motor's three-phase current. This better solves the problem of falsely reported phase loss faults caused by the three-phase current being in the zero-crossing region, thus improving the detection accuracy of motor phase loss faults. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A schematic diagram showing the relationship between the quadrature-axis current, direct-axis current, and A-phase current of a motor provided in an embodiment of this application;

[0046] Figure 2 This is a schematic diagram of the internal structure of the servo system involved in the embodiments of this application;

[0047] Figure 3 This is a flowchart illustrating the motor phase loss fault detection method provided in the first embodiment of this application;

[0048] Figure 4 This is a flowchart illustrating the overall implementation of the motor phase loss fault detection method provided in the embodiments of this application.

[0049] Figure 5 This is a schematic diagram of a phase loss alarm under conventional technology provided in the embodiments of this application;

[0050] Figure 6 A schematic diagram of a phase loss alarm after using the motor phase loss fault detection method provided in this application, as an embodiment of this application;

[0051] Figure 7 Another phase loss alarm diagram provided as an embodiment of this application after using the motor phase loss fault detection method provided in this application;

[0052] Figure 8 A schematic diagram of the module structure of the servo driver provided in an embodiment of this application;

[0053] Figure 9 This is a schematic diagram of the module structure of the servo system provided in the embodiments of this application;

[0054] Figure 10 This is a schematic diagram of the hardware operating environment involved in the embodiments of this application.

[0055] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0056] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0057] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0058] In servo motor applications, human factors, environmental corrosion, vibration, and other factors can cause poor contact, loosening, or disconnection at the motor's three-phase wire interfaces or connectors. This results in unstable or broken connections between the motor and the servo driver, affecting the transmission of drive current and the acquisition of feedback signals. Simultaneously, this has a significant negative impact on the servo system's application equipment, causing noise and vibration in the equipment and motor, torque fluctuations in the motor, and distortion of the current waveform. Therefore, the servo driver needs to have a phase loss fault detection function to detect whether the motor has experienced a phase loss and issue a warning.

[0059] For vertical axis applications in servo systems, during vertical axis positioning, the motor's three-phase current is DC. At specific rotor positions, one phase current may approach zero, leading to false phase loss faults. Currently, a common method to address this issue is to first use an encoder to detect the motor's electrical angle to determine if the motor's three-phase current is in the zero-crossing region. Subsequently, during phase loss fault detection, the system pauses the detection mechanism for phases with current in the zero-crossing region to avoid false phase loss faults caused by the three-phase current being in the zero-crossing region.

[0060] However, the electrical angle detected by the encoder usually has a certain deviation and does not take into account the influence of the direct-axis current command value, which can lead to misjudgment of the zero-crossing state of the three-phase current. As a result, the problem of false alarms of phase loss faults caused by the three-phase current being in the zero-crossing region has not been well resolved, and the detection accuracy of phase loss faults is low.

[0061] Furthermore, in conventional technologies, the quadrature-axis current command value needs to exceed a preset command threshold before phase loss fault detection of the motor can begin. However, the quadrature-axis current command value varies under different motor operating conditions. Therefore, to ensure accurate detection of phase loss faults under various motor operating conditions, the preset command threshold usually needs to be set relatively high.

[0062] To illustrate the understanding of conventional technology, let's take phase A of a motor as an example. Assuming the direct-axis current command value is zero, the zero-crossing regions of the three-phase currents can be set to -5° to 5° and 175° to 185°. Assuming the preset alarm threshold is 60mA, and considering factors such as sampling noise, the prerequisite for phase loss fault detection is that the quadrature-axis current command value is greater than the preset command threshold. Taking a quadrature-axis current command value of 0.8A as an example... Figure 1As shown in the figure (Iq is the quadrature axis current command value, Iα is the A-phase current, θ is the motor electrical angle, q is the quadrature axis, and d is the direct axis), the actual electrical angle of the motor is -5°, so the A-phase current is 0.8*sin5°=0.07A, which is greater than the preset alarm threshold of 60mA; while the electrical angle detected by the encoder is -4°, so the A-phase current is 0.8*sin4°=0.056A, which is less than the preset alarm threshold of 60mA. However, the actual A-phase current is not less than the preset alarm threshold of 60mA, which leads to a false alarm of a phase loss fault.

[0063] Based on this, this application provides a method for detecting phase loss faults in motors. First, the direct-axis current command value and quadrature-axis current command value of the target motor are obtained. Then, coordinate transformation is performed on the direct-axis and quadrature-axis current command values ​​to obtain the current command value of at least one of the three phases of the target motor. Since the motor electrical angle is effectively canceled during the coordinate transformation, the final current command value of at least one of the three phases of the target motor will no longer be affected by the motor electrical angle. Next, based on the current command value of each phase, it can be determined whether the current of each phase of the target motor is in the zero-crossing region. Since the current command value of a phase changes when its current is in the zero-crossing region, the current command value of each phase can be used to accurately analyze whether the current of each phase of the target motor is in the zero-crossing region. After accurately analyzing whether the current of each phase of the target motor is in the zero-crossing region, by taking the phase whose current is not in the zero-crossing region as the target phase and controlling the target motor to enter the phase loss fault detection process of the target phase, accurate detection of motor phase loss faults can be achieved.

[0064] Therefore, this application proposes a method for determining whether the three-phase current of a motor is in the zero-crossing region using the three-phase current command value of the motor, thereby assisting in the detection of motor phase loss faults. Because this method is not affected by the motor's electrical angle, it effectively overcomes the technical defect of conventional techniques that use the electrical angle detected by encoders, which easily leads to misjudgments of the zero-crossing state of the motor's three-phase current. This better solves the problem of falsely reported phase loss faults caused by the three-phase current being in the zero-crossing region, thus improving the detection accuracy of motor phase loss faults.

[0065] The subject executing the motor phase loss fault detection method of this application can be a servo driver, household appliance, industrial equipment, etc. with data processing, network communication and program running functions, or a control system, control circuit, etc. that can realize the above functions, or a servo system. This embodiment does not specifically limit it.

[0066] In implementing the motor phase loss fault detection methods of the following embodiments using a servo system, the servo system can be augmented with additional structures to implement these methods. For example, please refer to... Figure 2 ,in, Figure 2 The part shown within the dashed box is the newly added structure in the servo system. Specifically, the newly added components include: a coordinate transformation module 100 for realizing the coordinate transformation from a two-phase rotating coordinate system to a three-phase coordinate system; a zero-crossing region determination module 200 for determining whether the current of the three phases of the motor is in the zero-crossing region; a feedback current comparison module 300 for comparing the absolute value of the current feedback value of the three phases of the motor with the size of the preset feedback threshold to determine whether there is a phase loss risk in each phase of the motor; a phase loss fault counting module 400 for recording the number of times each phase of the motor is determined to have a phase loss risk; and a phase loss fault alarm module 500 for outputting a phase loss fault alarm message when there is a phase loss fault in the motor.

[0067] The following description uses a servo driver as the execution subject to illustrate the various embodiments.

[0068] Based on this, this application proposes a motor phase loss fault detection method according to the first embodiment, please refer to... Figure 3 The method for detecting motor phase loss faults includes steps S10 to S40:

[0069] Step S10: Obtain the direct-axis current command value and quadrature-axis current command value of the target motor;

[0070] It should be noted that the target motor refers to the motor that needs to be detected for phase loss faults. The number of target motors can be one or more, and this embodiment does not specifically limit this. The direct-axis current command value refers to the current setting value of the target motor on the direct axis (also known as the d-axis or magnetic axis), and the quadrature-axis current command value refers to the current setting value of the target motor on the quadrature axis (also known as the q-axis or torque axis). In the dq coordinate system, the d-axis coincides with or is parallel to the direction of the rotor magnetic field, and the q-axis is perpendicular to the direction of the rotor magnetic field (that is, perpendicular to the d-axis).

[0071] When acquiring the direct-axis current command value and quadrature-axis current command value of the target motor, they can be acquired in real time or periodically at certain time intervals. This embodiment does not make specific limitations on this.

[0072] In one feasible implementation, before the servo driver executes step S10, it can first monitor whether the servo driver has enabled the phase loss fault detection function; if it is detected that the servo driver has enabled the phase loss fault detection function, then step S10 is executed.

[0073] Step S20: Perform coordinate transformation on the direct-axis current command value and the quadrature-axis current command value to obtain the current command value of at least one phase of the three phases of the target motor.

[0074] It should be noted that the three phases of the target motor refer to the U-phase, V-phase, W-phase / A-phase, B-phase, and C-phase. When performing coordinate transformation on the direct-axis and quadrature-axis current command values, the essence is to convert the direct-axis and quadrature-axis current command values ​​from a two-phase rotating coordinate system (dq coordinate system) to a three-phase coordinate system (abc coordinate system) to obtain the current command value of at least one of the three phases of the target motor. The principle of this coordinate transformation can be referred to in the following formula:

[0075]

[0076] Where ia is the current command value of the motor in phase A, ib is the current command value of the motor in phase B, ic is the current command value of the motor in phase C, θ is the electrical angle of the motor, id is the direct axis current command value, and iq is the quadrature axis current command value.

[0077] Understandably, the direct-axis and quadrature-axis current command values ​​of the motor are defined in the dq coordinate system based on the motor's electrical angle. Therefore, by performing a coordinate transformation from the dq coordinate system to the three-phase coordinate system (e.g., performing an inverse Park transformation) on the direct-axis and quadrature-axis current command values, the influence of the motor's electrical angle on the direct-axis and quadrature-axis current command values ​​can be decoupled, thereby obtaining the current command values ​​of phase A, phase B, and / or phase C of the target motor that are unaffected by the motor's electrical angle.

[0078] Step S30: Based on the current command value of each phase, determine whether the current of each phase of the target motor is in the zero-crossing region.

[0079] It should be noted that when the current of a certain phase of the motor is in the zero-crossing region, it means that the current value of that phase is close to or equal to zero.

[0080] In one feasible implementation, step S30 may include steps S31 to S32:

[0081] Step S31: For any phase of the target motor, if the current command value of the target motor in that phase is less than the preset command threshold, then it is determined that the current of the phase of the target motor is in the zero-crossing region.

[0082] It should be noted that any phase of the target motor refers to phase A, B, or C, or phase U, V, or W. The preset command threshold is used to determine whether the current in the three phases of the motor is in the zero-crossing region. The preset command threshold can be a default value, such as 120mA; it can also be flexibly set by the user according to actual conditions, and this embodiment does not impose specific limitations on this. Generally speaking, setting the preset command threshold above 100mA is more appropriate.

[0083] Step S32: If the current command value of the target motor in that phase is greater than or equal to the preset command threshold, then it is determined that the current of the target motor in that phase is not in the zero-crossing region.

[0084] Understandably, when the current in a certain phase of the motor is in the zero-crossing region, in order to maintain current stability and avoid unnecessary energy loss, the current command value of that phase will decrease to a certain level. Therefore, if the current command value of the target motor in a certain phase is greater than or equal to the preset command threshold, it means that the current command value of the target motor in that phase has not decreased to a certain level, and it can be determined that the current of the target motor in that phase is not in the zero-crossing region.

[0085] Step S40: The phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

[0086] It should be noted that the number of target phases can be one or more. After the target motor is controlled to enter the phase loss fault detection process, the phase loss fault detection of the target phase will begin.

[0087] This embodiment provides a method for detecting phase loss faults in a motor. First, the direct-axis current command value and quadrature-axis current command value of the target motor are obtained. Then, coordinate transformation is performed on the direct-axis and quadrature-axis current command values ​​to obtain the current command value of at least one of the three phases of the target motor. Since the motor electrical angle is effectively canceled during the coordinate transformation, the final current command value of at least one of the three phases of the target motor will no longer be affected by the motor electrical angle. Next, based on the current command value of each phase, it can be determined whether the current of each phase of the target motor is in the zero-crossing region. Since the current command value of a phase changes when its current is in the zero-crossing region, the current command values ​​of each phase can be used to accurately analyze whether the current of each phase of the target motor is in the zero-crossing region. After accurately analyzing whether the current of each phase of the target motor is in the zero-crossing region, the phase whose current is not in the zero-crossing region is selected as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase, thus achieving accurate detection of the motor phase loss fault.

[0088] Therefore, this embodiment proposes a method to determine whether the three-phase current of the motor is in the zero-crossing region using the three-phase current command value of the motor, thereby assisting in the detection of motor phase loss faults. Because this method is not affected by the motor's electrical angle, it effectively overcomes the technical defect of conventional techniques that use the electrical angle detected by the encoder, which easily leads to misjudgments of the zero-crossing state of the motor's three-phase current. This better solves the problem of falsely reported phase loss faults caused by the three-phase current being in the zero-crossing region, thus improving the detection accuracy of motor phase loss faults.

[0089] Furthermore, because this embodiment considers the influence of both the direct-axis current command value and the quadrature-axis current command value during the determination of the three-phase current command value, it solves the problem of low accuracy in zero-crossing region determination caused by the failure to consider the influence of the direct-axis current in conventional technology. Additionally, compared to conventional technology, the preset command threshold value required in this embodiment is set for the three-phase current command value of the motor, rather than for the quadrature-axis current command value. This threshold value is significantly lower than the preset command threshold value required in conventional technology, thus allowing for a wider range of applicable loads.

[0090] Based on the first embodiment described above, a second embodiment of the motor phase loss fault detection method of this application is proposed. In the second embodiment, after step S40, the motor phase loss fault detection method may further include steps S50 to S70:

[0091] Step S50: Obtain the current feedback value of the target phase;

[0092] It should be noted that the current feedback value refers to the actual value of the current in the target phase of the target motor, measured in real time by a current sampling device during the operation of the target motor. This value directly reflects the actual operating state of the target motor at a specific moment. The current sampling device can be a current sensor, sampling resistor, or other device capable of collecting current.

[0093] Step S60: Determine whether there is a phase loss fault in the target phase based on the current feedback value of the target phase;

[0094] Step S70: If a phase loss fault exists in the target phase, output a phase loss fault alarm message.

[0095] It should be noted that the phase loss fault alarm message is used to remind the user that the current target motor has a phase loss fault.

[0096] In this embodiment, after the target motor is controlled to enter the phase loss fault detection process of the target phase, the phase loss fault detection of the target phase is realized by acquiring the current feedback value of the target phase; then, when there is a phase loss fault in the target phase, the phase loss fault alarm message is output to promptly remind the user that the current target motor has a phase loss fault, thereby avoiding the safety risks caused by the phase loss fault of the motor in the equipment using the target motor (such as automobile) to a certain extent, and improving the safety of the equipment using the target motor.

[0097] In one feasible implementation, step S60 may include steps S61 to S63:

[0098] Step S61: If the absolute value of the current feedback value of the target phase is less than the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be the phase loss fault condition.

[0099] Step S62: If the absolute value of the current feedback value of the target phase is greater than or equal to the preset feedback threshold, then the target working condition satisfied by the target phase is determined to be the normal working condition.

[0100] Step S63: Determine whether there is a phase loss fault in the target phase based on the target operating conditions met by the target phase.

[0101] It should be noted that the preset feedback threshold is used as the basis for determining whether the three-phase operating conditions of the motor constitute a phase loss fault. The preset feedback threshold can be a default value, such as 60mA; it can also be flexibly set by the user according to the actual situation (for example, it can be set according to the error value of the current sampling device, such as using the product of the error of the current sampling device and a coefficient value as the preset feedback threshold). This embodiment does not impose specific limitations on this. A phase loss fault condition is used to characterize that the current of the motor in the target phase deviates from the normal operating range at a certain moment, thus forming a potential phase loss risk. A normal operating condition is used to characterize that the current of the motor in the target phase is within the normal operating range at a certain moment.

[0102] In one possible implementation of step S63, step S63 may include steps S631 to S633:

[0103] Step S631: Based on the target operating conditions met by the target phase, adjust the count value of the phase loss fault counter associated with the target phase to obtain the target count value;

[0104] It should be noted that the target count value is the adjusted count value of the phase loss fault counter, and the initial value of the phase loss fault counter is zero. Each phase of the target motor is associated with a phase loss fault counter, which are independent of each other and do not affect each other.

[0105] In one feasible implementation, step S631 may include: if the target operating condition satisfied by the target phase is a phase loss fault condition, then increment the count value of the phase loss fault counter associated with the target phase by one to obtain the target count value; if the target operating condition satisfied by the target phase is a normal operating condition, then reset the count value of the phase loss fault counter associated with the target phase to zero to obtain the target count value.

[0106] In another feasible implementation, step S631 may include: if the target operating condition satisfied by the target phase is a phase loss fault condition, then increment the count value of the phase loss fault counter associated with the target phase by one to obtain the target count value; if the target operating condition satisfied by the target phase is a normal operating condition, then decrement the count value of the phase loss fault counter associated with the target phase by one to obtain the target count value.

[0107] The above are only two feasible implementations of step S631 provided in this embodiment. This embodiment does not specifically limit the specific implementation of step S631.

[0108] Step S632: If the target count value is greater than or equal to the preset count threshold, it is determined that there is a phase loss fault in the target phase.

[0109] Step S633: If the target count value is less than the preset count threshold, it is determined that there is no phase loss fault in the target phase.

[0110] It should be noted that the preset counting threshold is used to determine whether the current of the three phases of the motor frequently deviates from the normal operating range, thereby determining whether there is a phase loss fault in the three phases of the motor. The preset counting threshold can be a default value, such as 10 times; it can also be flexibly set by the user according to the actual situation, and this embodiment does not impose specific limitations on it.

[0111] Additionally, it should be noted that if the target count value is greater than or equal to the preset count threshold, it indicates that the current of the target motor in the target phase frequently deviates from the normal operating range, and it can be determined that there is a phase loss fault in the target phase; if the target count value is less than the preset count threshold, it indicates that the current of the target motor in the target phase does not frequently deviate from the normal operating range, and it can be determined that there is no phase loss fault in the target phase.

[0112] It is understandable that the current in each phase of a motor can deviate from the normal operating range due to external interference, but in this case, no phase loss has occurred. Therefore, this implementation improves the reliability of motor phase loss fault detection by requiring a situation where the current in a certain phase frequently deviates from the normal operating range before finally determining that a phase loss fault exists in that phase.

[0113] In another possible implementation of step S63, step S63 may include steps S634 to S636:

[0114] Step S634: Based on the target operating conditions met by the target phase, adjust the timing duration of the phase loss fault timer associated with the target phase to obtain the target timing duration;

[0115] It should be noted that the target timing duration is the adjusted timing duration of the phase loss fault timer, and the initial value of the phase loss fault timer is zero. Each phase of the target motor is associated with a phase loss fault timer, which are independent of each other and do not affect each other.

[0116] In one feasible implementation, step S634 may include: if the target operating condition satisfied by the target phase is a phase loss fault condition, then add a preset duration to the timing duration of the phase loss fault timer associated with the target phase to obtain the target timing duration; if the target operating condition satisfied by the target phase is a normal operating condition, then set the timing duration of the phase loss fault timer associated with the target phase to zero to obtain the target timing duration.

[0117] It should be noted that the preset duration can be one sampling cycle of the current sampling device.

[0118] Step S635: If the target timing duration is greater than or equal to the preset duration threshold, then it is determined that there is a phase loss fault in the target phase.

[0119] Step S636: If the target timing duration is less than the preset duration threshold, then it is determined that there is no phase loss fault in the target phase.

[0120] It should be noted that the preset duration threshold is used to determine whether the three-phase current of the motor frequently deviates from the normal operating range, thereby determining whether there is a phase loss fault in the three phases of the motor. The preset duration can be a default value, such as 30 seconds; it can also be flexibly set by the user according to the actual situation, and this embodiment does not impose specific limitations on it.

[0121] Additionally, it should be noted that if the target timing duration is greater than or equal to the preset timing threshold, it indicates that the current of the target motor in the target phase frequently deviates from the normal operating range, and it can be determined that there is a phase loss fault in the target phase; if the target timing duration is less than the preset timing threshold, it indicates that the current of the target motor in the target phase does not frequently deviate from the normal operating range, and it can be determined that there is no phase loss fault in the target phase.

[0122] This implementation improves the reliability of motor phase loss fault detection by requiring that the motor's current in a certain phase frequently deviates from the normal operating range before finally determining that the motor has a phase loss fault in that phase.

[0123] The above are only two feasible implementations of step S63 provided in this embodiment. This embodiment does not specifically limit the specific implementation of step S63. For example, in other feasible implementations, step S63 may also include: if the target operating condition satisfied by the target phase is a phase loss fault condition, then it is determined that the target phase has a phase loss fault; if the target operating condition satisfied by the target phase is a normal operating condition, then it is determined that the target phase does not have a phase loss fault.

[0124] For example, to help understand the implementation process of the motor phase loss fault detection method obtained by combining the above embodiments, please refer to... Figure 4 , specifically:

[0125] After monitoring that the servo drive has enabled the phase loss fault detection function, the system first acquires the direct-axis current command value and quadrature-axis current command value of the target motor, and then performs coordinate transformation on the direct-axis and quadrature-axis current command values ​​to obtain the A-phase current command value, B-phase current command value, and C-phase current command value of the target motor. Next, it checks whether each of the A-phase, B-phase, and C-phase current command values ​​is less than a preset command threshold. Taking the A-phase of the target motor as an example, if the A-phase current command value is greater than or equal to the preset command threshold, the system acquires the A-phase current feedback value of the target motor and then determines... If the absolute value of the current feedback value of phase A is less than the preset feedback threshold, then the count value of the phase loss fault counter associated with phase A is set to zero; if it is, then the count value of the phase loss fault counter associated with phase A is incremented by one to obtain the target count value, and it is determined whether the target count value is greater than or equal to the preset count threshold; if the target count value is greater than or equal to the preset count threshold, then it is determined that there is a phase loss fault in phase A of the target motor (the phase loss fault detection process of phases B and C is the same as that of phase A, and will not be described in detail here). The servo driver can output a phase loss fault alarm message to perform a phase loss alarm.

[0126] Furthermore, to aid in understanding the motor phase loss fault detection method provided in this application, which, compared to conventional techniques, better solves the problem of false phase loss faults caused by the three-phase current being in the zero-crossing region, please refer to... Figure 5 , Figure 6 and Figure 7 .in, Figure 5 This is a schematic diagram of a phase loss alarm using conventional technology. Figure 6 and Figure 7 All are schematic diagrams of phase loss alarms after using the motor phase loss fault detection method provided in this application. Figure 5 and Figure 6 It is evident that conventional techniques often result in false alarms when the motor does not actually experience a phase loss fault. However, the motor phase loss fault detection method provided in this application does not exhibit this problem. Figure 7It is understood that the motor phase loss fault detection method provided in this application can output a phase loss fault alarm signal (corresponding to phase loss fault alarm prompt information) in a timely manner when a phase loss fault occurs in the motor.

[0127] It should be noted that this example is only for the purpose of assisting in understanding this application and does not constitute a limitation on the motor phase loss fault detection method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0128] This application also provides a servo driver, please refer to... Figure 8 The servo driver includes:

[0129] The coordinate transformation module 100 is used to obtain the direct-axis current command value and quadrature-axis current command value of the target motor; and to perform coordinate transformation on the direct-axis current command value and quadrature-axis current command value to obtain the current command value of at least one phase of the three phases of the target motor.

[0130] The zero-crossing region determination module 200 is used to determine whether the current of each phase of the target motor is in the zero-crossing region according to the current command value of each phase; the phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

[0131] In one embodiment, the zero-crossing region determination module 20 is further configured to:

[0132] For any phase of the target motor, if the current command value of the target motor in that phase is less than the preset command threshold, then the current of that phase of the target motor is determined to be in the zero-crossing region.

[0133] If the current command value of the target motor in a phase is greater than or equal to the preset command threshold, it is determined that the current of the target motor in a phase is not in the zero-crossing region.

[0134] In one embodiment, the servo driver further includes:

[0135] The feedback current comparison module 300 is used to acquire the current feedback value of the target phase; based on the current feedback value of the target phase, it determines whether there is a phase loss fault in the target phase.

[0136] The phase loss fault alarm module 500 is used to output a phase loss fault alarm message if a phase loss fault exists in the target phase.

[0137] In one embodiment, the feedback current comparison module 300 is further configured to:

[0138] If the absolute value of the current feedback value of the target phase is less than the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be the phase loss fault condition.

[0139] If the absolute value of the current feedback value of the target phase is greater than or equal to the preset feedback threshold, then the target operating conditions met by the target phase are determined to be normal operating conditions.

[0140] Based on the target operating conditions met by the target phase, determine whether the target phase has a phase loss fault.

[0141] In one embodiment, the servo driver further includes a phase failure counting module 400, which is used to adjust the count value of the phase failure counter associated with the target phase according to the target operating conditions met by the target phase, so as to obtain the target count value;

[0142] The feedback current comparison module 300 is also used to: determine that there is a phase loss fault in the target phase if the target count value is greater than or equal to the preset count threshold; and determine that there is no phase loss fault in the target phase if the target count value is less than the preset count threshold.

[0143] In one embodiment, the phase loss fault counting module 400 is further configured to:

[0144] If the target operating condition satisfied by the target phase is a phase loss fault condition, then the count value of the phase loss fault counter associated with the target phase is incremented by one to obtain the target count value.

[0145] If the target operating conditions met by the target phase are normal operating conditions, then the count value of the phase loss fault counter associated with the target phase is set to zero to obtain the target count value.

[0146] In one embodiment, the phase failure counting module 400 is further configured to: adjust the timing duration of the phase failure timer associated with the target phase according to the target operating conditions satisfied by the target phase, so as to obtain the target timing duration;

[0147] The feedback current comparison module 300 is also used to: determine that there is a phase loss fault in the target phase if the target timing duration is greater than or equal to the preset timing threshold; and determine that there is no phase loss fault in the target phase if the target timing duration is less than the preset timing threshold.

[0148] In one embodiment, the phase loss fault counting module 400 is further configured to:

[0149] If the target operating condition met by the target phase is a phase loss fault condition, then the timing duration of the phase loss fault timer associated with the target phase is added to the preset duration to obtain the target timing duration;

[0150] If the target operating conditions met by the target phase are normal operating conditions, then the timing duration of the phase loss fault timer associated with the target phase is set to zero to obtain the target timing duration.

[0151] The servo driver provided in this application adopts the motor phase loss fault detection method in the above embodiments, which can effectively solve the problem of false phase loss faults caused by the three-phase current being in the zero-crossing region, thereby improving the detection accuracy of motor phase loss faults. Compared with the prior art, the beneficial effects of the servo driver provided in this application are the same as those of the motor phase loss fault detection method provided in the above embodiments, and will not be repeated here.

[0152] This application also provides a servo system, please refer to... Figure 9 The servo system includes a servo driver 10 and a motor 20. The servo driver 10 is connected to the motor 20 and is used to execute the motor phase loss fault detection method in the above embodiment.

[0153] The servo system provided in this application adopts the motor phase loss fault detection method in the above embodiments, which can effectively solve the problem of false phase loss faults caused by the three-phase current being in the zero-crossing region, thereby improving the detection accuracy of motor phase loss faults. Compared with the prior art, the beneficial effects of the servo system provided in this application are the same as those of the motor phase loss fault detection method provided in the above embodiments, and will not be repeated here.

[0154] This application also provides a servo driver, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the motor phase loss fault detection method in the above embodiments.

[0155] The following is for reference. Figure 10 It shows a schematic diagram of a servo driver suitable for implementing embodiments of this application. Figure 10 The servo driver shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of this application.

[0156] like Figure 10As shown, the servo drive may include a processing unit 101 (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 102 or a program loaded from storage device 103 into random access memory (RAM) 104. RAM 104 also stores various programs and data required for the operation of the servo drive. The processing unit 101, ROM 102, and RAM 104 are interconnected via bus 105. Input / output (I / O) interface 106 is also connected to the bus. Typically, the following systems can be connected to I / O interface 106: input devices 107 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 108 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 103 including, for example, magnetic tapes, hard disks, etc.; and communication devices 109. Communication device 109 allows the servo drive to communicate wirelessly or wiredly with other devices to exchange data. While the figures show servo drives with various systems, it should be understood that implementing or having all of the systems shown is not required. More or fewer systems may be implemented alternatively.

[0157] In particular, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 103, or installed from ROM 102. When the computer program is executed by processing device 101, it performs the functions defined in the methods of the embodiments of this application.

[0158] The servo driver provided in this application adopts the motor phase loss fault detection method in the above embodiments, which can effectively solve the problem of false phase loss faults caused by the three-phase current being in the zero-crossing region, thereby improving the detection accuracy of motor phase loss faults. Compared with the prior art, the beneficial effects of the servo driver provided in this application are the same as those of the motor phase loss fault detection method provided in the above embodiments, and other technical features of the servo driver are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0159] It should be understood that various parts of the embodiments of this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0160] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the above claims.

[0161] This application also provides a computer-readable storage medium storing a computer program that can run on a processor. The computer program is used to execute the motor phase loss fault detection method in the above embodiments.

[0162] The computer-readable storage medium provided in this application embodiment may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0163] The aforementioned computer-readable storage medium may be included in the servo drive; or it may exist independently and not be assembled into the servo drive.

[0164] The aforementioned computer-readable storage medium carries one or more programs. When the aforementioned one or more programs are executed by the servo driver, the servo driver causes the servo driver to: acquire the direct-axis current command value and quadrature-axis current command value of the target motor; perform coordinate transformation on the direct-axis current command value and quadrature-axis current command value to obtain the current command value of at least one of the three phases of the target motor; determine whether the current of each phase of the target motor is in the zero-crossing region according to the current command value of each phase; take the phase whose current is not in the zero-crossing region as the target phase, and control the target motor to enter the phase loss fault detection process of the target phase.

[0165] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0166] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0167] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0168] The computer-readable storage medium provided in this application embodiment stores computer-readable program instructions for executing the above-described motor phase loss fault detection method. This effectively solves the problem of false phase loss fault reports caused by the three-phase current being in the zero-crossing region, thereby improving the detection accuracy of motor phase loss faults. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application embodiment are the same as those of the motor phase loss fault detection method provided in the above embodiments, and will not be repeated here.

[0169] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the motor phase loss fault detection method described above.

[0170] The computer program product provided in this application can effectively solve the problem of false alarms for phase loss faults caused by the three-phase current being in the zero-crossing region, thereby improving the detection accuracy of motor phase loss faults. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the motor phase loss fault detection method provided in the above embodiments, and will not be repeated here.

[0171] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent scope of this application.

Claims

1. A method for detecting a phase loss fault in a motor, characterized in that, The method includes: Obtain the direct-axis current command value and quadrature-axis current command value of the target motor; The direct-axis current command value and the quadrature-axis current command value are transformed by coordinate transformation to obtain the current command value of at least one phase of the three phases of the target motor; Based on the current command value of each phase, determine whether the current of each phase of the target motor is in the zero-crossing region; The phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

2. The motor phase loss fault detection method as described in claim 1, characterized in that, The step of determining whether the current of each phase of the target motor is in the zero-crossing region based on the current command value of each phase includes: For any phase of the target motor, if the current command value of the target motor in that phase is less than a preset command threshold, then the current of that phase of the target motor is determined to be in the zero-crossing region. If the current command value of the target motor in a phase is greater than or equal to the preset command threshold, then it is determined that the current of the target motor in that phase is not in the zero-crossing region.

3. The method for detecting motor phase loss faults as described in claim 1 or 2, characterized in that, After the step of controlling the target motor to enter the phase loss fault detection process of the target phase, the method further includes: Obtain the current feedback value of the target phase; Based on the current feedback value of the target phase, determine whether the target phase has a phase loss fault; If the target phase has a phase loss fault, a phase loss fault alarm message will be output.

4. The motor phase loss fault detection method as described in claim 3, characterized in that, The step of determining whether a phase loss fault exists in the target phase based on the current feedback value of the target phase includes: If the absolute value of the current feedback value of the target phase is less than the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be a phase loss fault condition. If the absolute value of the current feedback value of the target phase is greater than or equal to the preset feedback threshold, then the target operating condition satisfied by the target phase is determined to be a normal operating condition. Based on the target operating conditions satisfied by the target phase, determine whether the target phase has a phase loss fault.

5. The motor phase loss fault detection method as described in claim 4, characterized in that, The step of determining whether a phase loss fault exists in the target phase based on the target operating conditions satisfied by the target phase includes: Based on the target operating conditions met by the target phase, adjust the count value of the phase loss fault counter associated with the target phase to obtain the target count value; If the target count value is greater than or equal to the preset count threshold, then it is determined that the target phase has a phase loss fault; If the target count value is less than the preset count threshold, then it is determined that the target phase does not have a phase loss fault.

6. The motor phase loss fault detection method as described in claim 5, characterized in that, The step of adjusting the count value of the phase loss fault counter associated with the target phase according to the target operating conditions satisfied by the target phase to obtain the target count value includes: If the target operating condition satisfied by the target phase is a phase loss fault condition, then the count value of the phase loss fault counter associated with the target phase is incremented by one to obtain the target count value; If the target operating conditions met by the target phase are normal operating conditions, then the count value of the phase loss fault counter associated with the target phase is set to zero to obtain the target count value.

7. The motor phase loss fault detection method as described in claim 4, characterized in that, The step of determining whether a phase loss fault exists in the target phase based on the target operating conditions satisfied by the target phase includes: Based on the target operating conditions satisfied by the target phase, adjust the timing duration of the phase loss fault timer associated with the target phase to obtain the target timing duration; If the target timing duration is greater than or equal to a preset duration threshold, then it is determined that the target phase has a phase loss fault; If the target timing duration is less than the preset duration threshold, then it is determined that the target phase does not have a phase loss fault.

8. The method for detecting motor phase loss faults as described in claim 7, characterized in that, The step of adjusting the timing duration of the phase loss fault timer associated with the target phase according to the target operating conditions satisfied by the target phase to obtain the target timing duration includes: If the target operating condition satisfied by the target phase is a phase loss fault condition, then the timing duration of the phase loss fault timer associated with the target phase is added to the preset duration to obtain the target timing duration; If the target operating conditions met by the target phase are normal operating conditions, then the timing duration of the phase loss fault timer associated with the target phase is set to zero to obtain the target timing duration.

9. A servo driver, characterized in that, The servo driver includes: The coordinate transformation module is used to obtain the direct-axis current command value and the quadrature-axis current command value of the target motor; and to perform coordinate transformation on the direct-axis current command value and the quadrature-axis current command value to obtain the current command value of at least one phase of the three phases of the target motor. The zero-crossing region determination module is used to determine whether the current of each phase of the target motor is in the zero-crossing region based on the current command value of each phase; the phase whose current is not in the zero-crossing region is taken as the target phase, and the target motor is controlled to enter the phase loss fault detection process of the target phase.

10. A servo system, characterized in that, The servo system includes a servo driver and a motor, the servo driver being connected to the motor, and the servo driver being used to perform the steps of implementing the motor phase loss fault detection method as described in any one of claims 1 to 8.

11. A medium, characterized in that, The medium is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the motor phase loss fault detection method as described in any one of claims 1 to 8.

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