Method for detecting open phase in a synchronous machine and related device
By detecting speed fluctuations and torque current fluctuations in permanent magnet synchronous motors and injecting direct-axis current in combination with rotor angle, the accuracy problem of phase loss detection under no-load or light-load conditions is solved, and high-precision phase loss detection is achieved without affecting the motor load.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN HPMONT TECH
- Filing Date
- 2026-04-27
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies make it difficult to accurately detect phase loss faults when a permanent magnet synchronous motor is running under no-load or light-load conditions.
Phase loss faults are identified by detecting speed fluctuations or torque current fluctuations. Direct-axis current is injected when the rotor reaches a specific angle, and phase current is sampled to determine the phase loss situation. The current injection angle is calculated using rotor speed and current loop stabilization time. Pulsed direct-axis current injection is used to amplify current changes. The phase loss is confirmed by combining differential judgment and periodic detection.
Accurately detect phase loss faults under light load or no-load conditions, reduce the impact on motor load, improve detection accuracy and avoid misjudgment, and ensure motor safety.
Smart Images
Figure CN122109815A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of synchronous motor control technology, and in particular to a method and related device for detecting phase loss in a synchronous motor. Background Technology
[0002] Permanent magnet synchronous motors are widely used in industrial drives, new energy vehicles and other fields due to their high efficiency and high power density. When a permanent magnet synchronous motor is running, its stator three-phase windings are powered and controlled by a three-phase power supply circuit. When a phase power supply circuit of one of the three phase windings of the stator fails, a phase loss occurs, which will lead to a stator winding control failure and cause safety hazards when the synchronous motor is working.
[0003] In existing methods for detecting defects in permanent magnet synchronous motors, the detection method usually relies on measuring the current output of the motor. However, this method is not suitable for accurately detecting phase loss faults in synchronous motors when the motor is running under no-load or light-load conditions (i.e., when the output current is very small). Summary of the Invention
[0004] In view of the above problems, this application provides a method and related device for detecting phase loss in synchronous motors, so as to achieve the purpose of detecting phase loss in synchronous motors. The specific solution is as follows:
[0005] The first aspect of this application provides a method for detecting phase loss in a synchronous motor, comprising:
[0006] When the synchronous motor is operating under light load or no load, the synchronous motor is judged to have a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
[0007] After determining that the synchronous motor has a phase loss fault, the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection are calculated based on the current rotor speed of the synchronous motor and the current loop stabilization time of the synchronous motor.
[0008] When the rotor of the synchronous motor rotates to the first rotor angle, a direct-axis current is injected into the synchronous motor and the first phase current of the synchronous motor is sampled; when the rotor of the synchronous motor rotates to the second rotor angle, the direct-axis current is injected into the synchronous motor and the second phase current of the synchronous motor is sampled; when the rotor of the synchronous motor rotates to the third rotor angle, the direct-axis current is injected into the synchronous motor and the third phase current of the synchronous motor is sampled.
[0009] The phase loss status of the synchronous motor is determined based on the first phase current, the second phase current, and the third phase current.
[0010] Furthermore, the calculation of the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection based on the current rotational speed of the synchronous motor and the current loop settling time of the synchronous motor includes:
[0011] The current pre-injection angle is determined based on the current loop settling time and the rotor speed of the synchronous motor.
[0012] The first rotor angle is determined based on the current pre-injection angle and the preset first phase current injection target angle; the second rotor angle is determined based on the current pre-injection angle and the preset second phase current injection target angle; the third rotor angle is determined based on the current pre-injection angle and the preset third phase current injection target angle.
[0013] Furthermore, after determining the phase loss condition of the synchronous motor based on the first phase current, the second phase current, and the third phase current, the method further includes:
[0014] After determining the Nth phase loss of the synchronous motor based on the phase loss situation, the direct-axis current is periodically injected for a first duration when the rotor reaches the Nth rotor angle corresponding to the Nth phase; where N includes one, two, and three.
[0015] In any cycle, based on the sampled Nth phase current, it is determined whether the synchronous motor experiences a phase loss of the Nth phase in that cycle;
[0016] If it is determined that the Nth phase is missing, record a phase loss fault; if it is determined that the Nth phase is not missing, record a non-phase loss fault.
[0017] When the number of recorded phase loss faults exceeds the first safety threshold, a phase loss fault alarm signal is output; when the number of recorded non-phase loss faults exceeds the safety threshold, the injection of the direct shaft current into the synchronous motor is terminated, and the process returns to the step of determining whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
[0018] Furthermore, after determining the phase loss condition of the synchronous motor based on the first phase current, the second phase current, and the third phase current, the method further includes:
[0019] After determining the Nth phase loss of the synchronous motor based on the aforementioned phase loss situation, the direct-axis current is periodically injected for a duration of the second duration; wherein, N includes one, two, and three;
[0020] In any cycle, based on the maximum and minimum current values corresponding to the three-phase current of the synchronous motor, it is determined whether the synchronous motor has experienced a phase loss of the Nth phase.
[0021] If it is determined that the Nth phase is missing, record a phase loss fault; if it is determined that the Nth phase is not missing, record a non-phase loss fault.
[0022] When the number of recorded phase loss faults exceeds the safety threshold, a phase loss fault alarm signal is output; when the number of recorded non-phase loss faults exceeds the safety threshold, the injection of the direct shaft current into the synchronous motor is terminated, and the process returns to the step of determining whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
[0023] Furthermore, before the step of determining whether a phase loss fault exists in the synchronous motor based on the speed fluctuation or torque current fluctuation when the synchronous motor is operating under light load or no load, the method further includes:
[0024] Monitor the torque current value of the synchronous motor, and monitor whether the synchronous motor is under light load or under control based on the torque current value of the synchronous motor.
[0025] Furthermore, determining the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current includes:
[0026] The difference between the first phase current and the preset first standard phase current is used to determine whether the first phase current is missing a phase;
[0027] Whether the second phase current is missing is determined based on the difference between the second phase current and the preset second standard phase current;
[0028] Whether the third phase current is missing is determined based on the difference between the third phase current and the preset third standard phase current.
[0029] Furthermore, determining the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current also includes:
[0030] After determining that the synchronous motor has at least one phase loss fault, an alarm signal is output and the drive signal received by the synchronous motor is blocked.
[0031] The second aspect of this application provides a synchronous motor phase loss detection device, including: a central processing unit, a memory, an input / output interface, a wired or wireless network interface, and a power supply;
[0032] The memory is either a short-term storage memory or a persistent storage memory;
[0033] The central processing unit is configured to communicate with the memory and execute instructions in the memory to perform the synchronous motor phase loss detection method of the first aspect or any implementation thereof.
[0034] A third aspect of this application provides a computer program product including computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the synchronous motor phase loss detection method described in the first aspect or any implementation thereof.
[0035] The fourth aspect of this application provides a computer storage medium carrying one or more computer programs, which, when executed by an electronic device, enable the electronic device to implement the synchronous motor phase loss detection method described in the first aspect or any implementation thereof.
[0036] By means of the above technical solution, the synchronous motor phase loss detection method provided in this application can determine whether a phase loss fault exists when the synchronous motor is in a light load or no-load operation state by means of speed fluctuation or torque current. After determining that a phase loss fault exists, the method further amplifies the influence of the phase loss on the phase current change of the synchronous motor by injecting a direct-axis current at a specific angle corresponding to the current of each phase of the synchronous motor. The injection time of the direct-axis current is short and pulse-like. When injected at the corresponding angle, the phase current change of the corresponding phase is large. The specific phase loss situation of the synchronous motor can be accurately confirmed by means of the corresponding phase current with minimal impact on the synchronous motor. Attached Figure Description
[0037] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.
[0038] Figure 1 A flowchart of a phase loss detection method for a synchronous motor provided in this application;
[0039] Figure 2 This application provides a structural block diagram of a synchronous motor phase loss detection device. Detailed Implementation
[0040] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.
[0041] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.
[0042] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.
[0043] In existing methods for detecting defects in permanent magnet synchronous motors, the method typically relies on detecting the current output of the permanent magnet synchronous motor. However, this detection method is difficult to accurately detect phase loss faults in synchronous motors (i.e., permanent magnet synchronous motors, hereinafter referred to as synchronous motors) when the synchronous motor is running under no-load or light-load conditions (i.e., when the output current itself is very small). In view of this, this application provides a method and related apparatus for detecting phase loss in synchronous motors.
[0044] This application provides a method for detecting phase loss in a synchronous motor, the steps of which include:
[0045] 101. When the synchronous motor is operating under light load or no load, determine whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
[0046] When a synchronous motor is operating under light load or no load, the changes in its speed and torque current are relatively gradual. If a phase is lost, the output torque of the synchronous motor will fluctuate periodically, causing the speed to fluctuate as well. This fluctuation is more pronounced compared to when the synchronous motor is operating under normal light load or no load. In addition, after a phase is lost, the three-phase current of the synchronous motor becomes asymmetrical, causing the corresponding torque current to fluctuate as well. By detecting the fluctuations in the speed or torque current of the synchronous motor, it can be determined whether the synchronous motor has a phase loss fault.
[0047] 102. After determining that there is a phase loss fault in the synchronous motor, calculate the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection based on the current rotor speed of the synchronous motor and the current loop settling time of the synchronous motor.
[0048] After determining that a synchronous motor has a phase loss fault, since the output current of a synchronous motor operating under light load or no load is generally small, directly detecting the specific phase loss through current detection is inaccurate. Therefore, additional current can be injected to improve accuracy. The angle at which the injected current affects the current output differently. For example, under a certain operating condition of the synchronous motor, when the rotor angle of the injected current is 0°, the impact on the U-phase current of the three-phase current is greatest; when the rotor angle is 120°, the injected current has the greatest impact on the V-phase current; and when the rotor angle is 240°, the injected current has the greatest impact on the V-phase current. The current has the greatest impact on the W-phase current of the three-phase current of the synchronous motor. When the current is injected, the rotor of the synchronous motor is in the running state. After the control command for the corresponding injection current is issued, it takes a certain amount of time for the current to stabilize after the synchronous motor injects the current (this time is the current loop stabilization time). Therefore, after the rotor rotates to the target angle and the current is in a stable state, the current needs to be injected in advance when the rotor reaches a certain angle. Based on the rotor speed of the synchronous motor and the current loop stabilization time of the synchronous motor, the first rotor angle for the first phase current injection, the second rotor angle for the second phase current injection, and the third rotor angle for the third phase current injection can be determined respectively.
[0049] 103. When the rotor of the synchronous motor rotates to the first rotor angle, inject direct-axis current into the synchronous motor and sample the first phase current of the synchronous motor; when the rotor of the synchronous motor rotates to the second rotor angle, inject direct-axis current into the synchronous motor and sample the second phase current of the synchronous motor; when the rotor of the synchronous motor rotates to the third rotor angle, inject direct-axis current into the synchronous motor and sample the third phase current of the synchronous motor.
[0050] When a synchronous motor is running, either direct-axis current or quadrature-axis current can be injected. Injecting quadrature-axis current will cause the rotor phase to shift, generating additional torque and causing unnecessary motion control of the load, thus affecting the load. Injecting direct-axis current has no effect on the rotor phase and will not cause additional mechanical shock. Therefore, in this embodiment, direct-axis current can be injected when the rotor of the synchronous motor rotates to the corresponding rotor angle, and the corresponding synchronous motor phase current can be collected. The time for injecting direct-axis current is sufficient to sample a stable phase current. The entire current injection method is pulse-type.
[0051] 104. Determine the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current.
[0052] If a phase of the synchronous motor does not have a phase loss fault, the sampled phase current will be similar to the preset standard phase current. If a phase of the synchronous motor has a phase loss fault, the sampled phase current will be much smaller than the preset standard phase current. The specific phase loss situation of the synchronous motor can be determined by sampling the first phase current, the second phase current and the third phase current.
[0053] The above-described method for detecting phase loss in synchronous motors allows for the assessment of potential phase loss faults by observing fluctuations in the motor's speed or torque current when the motor is operating under light or no load conditions. If a phase loss fault is detected, a direct-axis current at a specific angle is injected into each phase of the synchronous motor. This amplifies the impact of the phase loss on the phase current changes. This detection method involves a short injection time (pulse-type), and the corresponding phase current changes significantly at the injection angle. This allows for precise identification of the specific phase loss condition of the synchronous motor with minimal impact on the motor itself.
[0054] Specifically, in some embodiments of this application, the calculation of the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection, based on the rotor speed of the synchronous motor and the current loop settling time of the synchronous motor, includes:
[0055] The current pre-injection angle is determined based on the current loop settling time and rotor speed of the synchronous motor.
[0056] Synchronous motors typically employ FOC (Field-Oriented Control) control. The FOC control outputs a corresponding current injection command. However, it takes a certain amount of time for the synchronous motor to reach a current stabilization state after the current injection command is issued. To ensure that a stable phase current can be sampled while minimizing the duration of the injected current, the current pre-injection angle (i.e., the angle at which the rotor injects the current in advance) can be determined by the current loop stabilization time and the rotor speed of the synchronous motor.
[0057] The first rotor angle is determined based on the current pre-injection angle and the preset first phase current injection target angle; the second rotor angle is determined based on the current pre-injection angle and the second phase current injection target angle; the third rotor angle is determined based on the current pre-injection angle and the preset third phase current injection target angle.
[0058] To ensure that the injected direct-axis current is small (to minimize the impact on the load) but the corresponding phase current changes significantly (to meet the detection requirements), that is, to minimize the impact on the synchronous motor when injecting the direct-axis current while meeting the requirements for detecting missing phases, the direct-axis current needs to be injected when the rotor rotates to the corresponding angle. This ensures that the phase current is stable when the phase current is collected, and the change in the phase current meets the detection accuracy requirements. To ensure that the phase current meets the detection accuracy requirements, current can be injected at specific angles. The corresponding angles are determined based on the corresponding current phases. The target angles for injecting the phase current are the preset target angles for the first, second, and third phase currents (e.g., the target angle for the first phase current is 0°, the target angle for the second phase current is 120°, and the target angle for the third phase current is 240°, i.e., the angles that will cause significant changes in the current of the corresponding phase of the synchronous motor). Based on the above target angles for injecting the phase current and the pre-injection angle of the current that needs to be injected in advance, the first, second, and third rotor angles are determined. By injecting direct-axis current at the determined first rotor angle, second rotor angle, and third rotor angle, the acquired phase current can meet the requirements for determining the specific phase loss detection of the synchronous motor.
[0059] By using the above-mentioned angle confirmation method, the rotor angle for current injection that meets the actual current injection requirements can be determined, thereby ensuring that the corresponding phase voltage is stable and can accurately reflect the phase loss situation of the corresponding phase.
[0060] In some embodiments of this application, after the phase loss detection steps described above, and after determining the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current, if it is determined that the synchronous motor has at least one phase loss fault, an alarm signal is output and the drive signals received by the synchronous motor are blocked (such as controlling related devices to stop outputting pulse width modulation signals to the power module, LGBT power transistor, etc. of the synchronous motor), to ensure that the synchronous motor stops and protect the safety of the synchronous motor.
[0061] In some embodiments of this application, in the above-described method for detecting phase loss by injecting direct-axis current via angle pulses, determining the phase loss status of the synchronous motor based on the first-phase current, the second-phase current, and the third-phase current includes:
[0062] The difference between the first phase current and the preset first standard phase current determines whether the first phase current is missing; the difference between the second phase current and the preset second standard phase current determines whether the second phase current is missing; the difference between the third phase current and the preset third standard phase current determines whether the third phase current is missing. The first, second, and third phase currents are sampled when a direct-axis current is injected at the corresponding angle. When the synchronous motor is not missing a phase, each of the first, second, and third phase currents has a corresponding standard phase current value based on the magnitude of the injected direct-axis current. The specific phase loss condition of the synchronous motor can be determined by the differences between the first phase current and the preset first standard phase current, the second phase current and the preset second standard phase current, and the third phase current and the preset third standard phase current.
[0063] The specific phase loss situation of the synchronous motor can be quickly and accurately determined by comparing the differences mentioned above, without consuming too many computing resources.
[0064] In some embodiments of this application, to further ensure detection accuracy and avoid false alarms, after determining the phase loss status of the synchronous motor based on the first phase current, second phase current, and third phase current, a further confirmation detection is performed, such as:
[0065] After determining that the Nth phase of the synchronous motor is missing based on the phase loss situation, a direct-axis current with a duration of the first duration is injected periodically when the rotor reaches the Nth rotor angle corresponding to the Nth phase; where N includes one, two, and three. In any period, it is determined whether the synchronous motor has experienced a phase loss of the Nth phase based on the sampled Nth phase current. If it is determined to be a phase loss of the Nth phase, a phase loss fault is recorded; if it is determined not to be a phase loss of the Nth phase, a non-phase loss fault is recorded. When the number of phase loss fault records exceeds the safety threshold number, a phase loss fault alarm signal is output. When the number of non-phase loss fault records exceeds the safety threshold number, the injection of the direct-axis current into the synchronous motor is terminated, and the normal detection state is returned (i.e., the step of determining whether the synchronous motor has a phase loss fault based on the synchronous motor speed fluctuation or torque current fluctuation is returned to the execution).
[0066] Based on the actual working conditions and accuracy requirements of the synchronous motor, the number of cycles can be adjusted accordingly. Through the above-mentioned further detection, after detecting the specific Nth phase loss, the direct shaft current is repeatedly injected from the rotor angle corresponding to the Nth phase loss to confirm the effective number of phase loss detections (i.e., the number of phase loss fault records mentioned above). When the effective number of phase loss exceeds the safety threshold, it is confirmed that the synchronous motor has experienced a phase loss fault. By confirming the effective number, the situation of misjudging the phase loss fault of the synchronous motor due to current disturbance can be avoided, further improving the accuracy of synchronous motor phase loss detection.
[0067] In some embodiments of this application, after the step of determining the phase loss condition of the synchronous motor based on the first phase current, the second phase current, and the third phase current, the method further includes:
[0068] After determining that the Nth phase of the synchronous motor is missing based on the phase loss situation, a direct-axis current with a duration of the second duration is periodically injected; where N includes the first, second, and third phases. In any cycle, based on the maximum and minimum current values corresponding to the three-phase currents of the synchronous motor, it is determined whether the synchronous motor has experienced a phase loss of the Nth phase. If it is determined to be a phase loss of the Nth phase, a phase loss fault is recorded; if it is determined not to be a phase loss of the Nth phase, a non-phase loss fault is recorded. When the number of recorded phase loss faults exceeds the safety threshold, a phase loss fault alarm signal is output. When the number of recorded non-phase loss faults exceeds the safety threshold, the injection of the direct-axis current into the synchronous motor is terminated, and the normal detection state is returned (i.e., the step of determining whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor is returned to the execution state).
[0069] In this embodiment, after confirming the specific phase loss by injecting direct-axis current via angle pulses (i.e., after determining the phase loss status of the synchronous motor based on the first-phase current, second-phase current, and third-phase current), to avoid misjudgment, direct-axis current can also be periodically injected into the synchronous motor at a certain injection time (a longer time can accurately detect changes) (without limiting the injection angle). By continuously injecting direct-axis current for a certain duration and collecting the current of each phase of the synchronous motor (i.e., the three-phase current) during the injection of direct-axis current, the maximum phase current (the maximum value of the three-phase current) and the minimum phase current (the minimum value of the three-phase current) are identified. By calculating the difference between the maximum and minimum values of the three-phase current within this period, it is determined whether the difference is greater than a preset imbalance threshold. If it is greater than the preset imbalance threshold, the synchronous motor is judged to be in phase loss, and the specific phase loss status of the synchronous motor is determined based on the minimum value of the three-phase current. At the same time, a phase loss fault is recorded. When the number of recorded phase loss faults exceeds the safety threshold number, a phase loss fault alarm signal is output.
[0070] This method allows for further determination of the phase loss status of a synchronous motor by continuously injecting current when a phase loss is detected using the angle pulse current injection method. The two methods are cross-checked to ensure that a false diagnosis of a phase loss fault does not occur.
[0071] In some embodiments of this application, the operating status of the synchronous motor can be monitored by monitoring the torque current value of the synchronous motor, thereby enabling the aforementioned synchronous motor phase loss detection when the synchronous motor is lightly loaded or unloaded.
[0072] See Figure 2This application embodiment also provides a synchronous motor phase loss detection device 200, including:
[0073] Central processing unit 201, power supply 202, wired or wireless network interface 203, input / output interface 204, and memory 205;
[0074] Power supply 202 is used to provide power, and memory 205 is either a short-term storage memory or a persistent storage memory;
[0075] The central processing unit 201 can be connected to the synchronous motor through the input / output interface 204. The central processing unit 201 also communicates with the memory 205, thereby performing phase loss detection on the synchronous motor according to the instructions in the memory.
[0076] This application also provides a computer program product, including computer-readable instructions, which, when executed on an electronic device, cause the electronic device to implement any of the synchronous motor phase loss detection methods provided in this application.
[0077] This application also provides a computer-readable storage medium carrying one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any of the synchronous motor phase loss detection methods provided in this application.
[0078] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the device embodiment drawings provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.
[0079] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.
[0080] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.
[0081] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line DSL) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk, SSD), etc.
Claims
1. A method for detecting phase loss in a synchronous motor, characterized in that, include: When the synchronous motor is operating under light load or no load, the synchronous motor is judged to have a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor. After determining that the synchronous motor has a phase loss fault, the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection are calculated based on the current rotor speed of the synchronous motor and the current loop stabilization time of the synchronous motor. When the rotor of the synchronous motor rotates to the first rotor angle, a direct-axis current is injected into the synchronous motor and the first phase current of the synchronous motor is sampled; when the rotor of the synchronous motor rotates to the second rotor angle, the direct-axis current is injected into the synchronous motor and the second phase current of the synchronous motor is sampled; when the rotor of the synchronous motor rotates to the third rotor angle, the direct-axis current is injected into the synchronous motor and the third phase current of the synchronous motor is sampled. The phase loss status of the synchronous motor is determined based on the first phase current, the second phase current, and the third phase current.
2. The synchronous motor phase loss detection method according to claim 1, characterized in that, The calculation of the first rotor angle of the first phase current injection, the second rotor angle of the second phase current injection, and the third rotor angle of the third phase current injection, based on the current rotational speed of the synchronous motor and the current loop settling time of the synchronous motor, includes: The current pre-injection angle is determined based on the current loop settling time and the rotor speed of the synchronous motor. The first rotor angle is determined based on the current pre-injection angle and the preset first phase current injection target angle; the second rotor angle is determined based on the current pre-injection angle and the preset second phase current injection target angle; the third rotor angle is determined based on the current pre-injection angle and the preset third phase current injection target angle.
3. The synchronous motor phase loss detection method according to claim 1, characterized in that, The step of determining the phase loss condition of the synchronous motor based on the first phase current, the second phase current, and the third phase current further includes: After determining the Nth phase loss of the synchronous motor based on the phase loss situation, the direct-axis current is periodically injected for a first duration when the rotor reaches the Nth rotor angle corresponding to the Nth phase; where N includes one, two, and three. In any cycle, based on the sampled Nth phase current, it is determined whether the synchronous motor experiences a phase loss of the Nth phase in that cycle; If it is determined that the Nth phase is missing, record a phase loss fault; if it is determined that the Nth phase is not missing, record a non-phase loss fault. When the number of recorded phase loss faults exceeds the first safety threshold, a phase loss fault alarm signal is output; when the number of recorded non-phase loss faults exceeds the safety threshold, the injection of the direct shaft current into the synchronous motor is terminated, and the process returns to the step of determining whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
4. The synchronous motor phase loss detection method according to claim 1, characterized in that, The step of determining the phase loss condition of the synchronous motor based on the first phase current, the second phase current, and the third phase current further includes: After determining the Nth phase loss of the synchronous motor based on the aforementioned phase loss situation, the direct-axis current is periodically injected for a duration of the second duration; wherein, N includes one, two, and three; In any cycle, based on the maximum and minimum current values corresponding to the three-phase current of the synchronous motor, it is determined whether the synchronous motor has experienced a phase loss of the Nth phase. If it is determined that the Nth phase is missing, record a phase loss fault; if it is determined that the Nth phase is not missing, record a non-phase loss fault. When the number of recorded phase loss faults exceeds the safety threshold, a phase loss fault alarm signal is output; when the number of recorded non-phase loss faults exceeds the safety threshold, the injection of the direct shaft current into the synchronous motor is terminated, and the process returns to the step of determining whether the synchronous motor has a phase loss fault based on the speed fluctuation or torque current fluctuation of the synchronous motor.
5. The synchronous motor phase loss detection method according to claim 1, characterized in that, Before the step of determining whether a phase loss fault exists in the synchronous motor based on the speed fluctuation or torque current fluctuation when the synchronous motor is operating under light load or no load, the method further includes: Monitor the torque current value of the synchronous motor, and monitor whether the synchronous motor is under light load or under control based on the torque current value of the synchronous motor.
6. The synchronous motor phase loss detection method according to claim 1, characterized in that, Determining the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current includes: The difference between the first phase current and the preset first standard phase current is used to determine whether the first phase current is missing a phase; Whether the second phase current is missing is determined based on the difference between the second phase current and the preset second standard phase current; Whether the third phase current is missing is determined based on the difference between the third phase current and the preset third standard phase current.
7. The synchronous motor phase loss detection method according to claim 1, characterized in that, Determining the phase loss status of the synchronous motor based on the first phase current, the second phase current, and the third phase current further includes: After determining that the synchronous motor has at least one phase loss fault, an alarm signal is output and the drive signal received by the synchronous motor is blocked.
8. A phase loss detection device for a synchronous motor, characterized in that, include: Central processing unit, memory, input / output interfaces, wired or wireless network interfaces, and power supply; The memory is either a short-term storage memory or a persistent storage memory; The central processing unit is configured to communicate with the memory and execute instructions in the memory to perform the synchronous motor phase loss detection method according to any one of claims 1 to 7.
9. A computer program product, characterized in that, It includes computer-readable instructions that, when executed on an electronic device, cause the electronic device to implement the synchronous motor phase loss detection method as described in any one of claims 1 to 7.
10. A computer storage medium, characterized in that, The storage medium carries one or more computer programs that, when executed by an electronic device, enable the electronic device to implement the synchronous motor phase loss detection method as described in any one of claims 1 to 7.