Variable frequency driver output open-phase detection method and system
By using a current closed-loop regulator in the variable frequency driver for phase loss detection before starting and running stages of the motor, the problem of incomplete phase loss detection of the variable frequency driver output in the prior art is solved, the detection stability is improved and the motor and variable frequency driver are protected.
Patent Information
- Application Number
- CN202411951920.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, the phase-deletion detection method for the output of variable frequency drivers is incomplete, resulting in the motor being damaged.
A phase loss detection method for output variable frequency drivers is adopted, including phase loss detection before starting the motor and operating stages. The current closed-loop regulator inside the variable frequency driver determines whether there is a phase loss before the motor starts, and determines whether there is a phase loss through the motor output current during the motor operation stage. If it exists, stop the output of the variable frequency driver.
Improves the stability of phase-deficiency detection of the variable frequency driver output, minimizes abnormal operation caused by phase-deficiency, and protects the variable frequency driver and motor.
Smart Images
Figure CN119986171A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of variable frequency drive output phase loss detection, and in particular to a variable frequency drive output phase loss detection method and system. Background Art
[0002] As people's living standards improve, variable frequency household air conditioners are becoming more and more popular. The core components of air conditioners, compressors and fans, are controlled by variable frequency drives. Due to the large number of internal components of variable frequency drives, many protection measures are added to the drives to ensure the stability and safety of the drive. Among them, the output phase loss detection of the drive is an important protection measure to ensure the stability and safety of the compressor.
[0003] The driver output phase loss detection module is completed by the current detection circuit and the internal control algorithm. In order to meet the needs of the air conditioning unit, there are generally two implementation methods: Route 1: Apply current to the motor before starting, and determine whether the driver output is missing a phase by judging the state of the three-phase current; Route 2: During the operation of the motor, determine whether the driver output is missing a phase based on the state of the three-phase current; Single Route 1 and Route 2 are inevitably flawed in the process of determining output phase loss.
[0004] Line 1 cannot cover the situation where the driver output is missing a phase during the operation of the motor. The motor will continue to run in this case until other fault measures are taken or the motor is damaged.
[0005] Line 2 must determine the phase loss of the driver output during the operation of the motor. In the case of a phase loss of the driver output, the driver cannot immediately determine the fact of the phase loss, and the motor needs to be running to perform the driver output phase loss detection. During the process of determining the phase loss, the motor will be in an abnormal operating state. This abnormal operating state is uncertain and will inevitably affect the performance of the driver and motor. In the long run, the loss of the driver and motor life cannot be ignored.
[0006] In summary, the existing phase loss detection method for variable frequency drives is not perfect, and the motor may still be damaged. Summary of the invention
[0007] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the existing phase loss detection method for the variable frequency drive in the prior art is not perfect and the motor may still be damaged.
[0008] In order to solve the above technical problems, the present invention provides a method for detecting phase loss in the output of a variable frequency drive, including a first phase loss detection and a second phase loss detection, wherein: The first phase loss detection is the phase loss detection of the variable frequency drive output before the motor starts, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting; if there is no phase loss, the detection continues; The second phase loss detection is the phase loss detection of the variable frequency drive output during the motor operation phase, specifically: The motor output current is obtained, and the output of the variable frequency drive is judged according to the motor output current whether there is a phase loss during the motor operation phase. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop running; if there is no phase loss, the detection is continued.
[0009] In one embodiment of the present invention, in the phase loss detection of the variable frequency drive output before the motor starts, the method for judging whether there is a phase loss in the variable frequency drive output before the motor starts according to the current closed-loop regulator inside the variable frequency drive includes: Obtain the saturation state signal of the current closed-loop regulator, and determine whether the saturation state signal of the current closed-loop regulator is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; Determine whether the output phase loss count exceeds the first threshold. If not, there is no phase loss in the variable frequency drive output and the pre-motor start-up stage is completed; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop starting.
[0010] In one embodiment of the present invention, in the phase loss detection of the variable frequency drive output during the motor operation phase, a method for judging whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current includes: Get the motor output current and determine whether the motor output current exceeds the current threshold. If not, the output phase loss count is reduced by one; if exceeded, the output phase loss count is increased by one. Determine whether the output phase loss count exceeds the second threshold. If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running.
[0011] In one embodiment of the present invention, when the first phase loss detection result is that there is no phase loss, the second phase loss detection is performed.
[0012] In order to solve the above technical problems, the present invention provides a variable frequency drive output phase loss detection system, comprising a first phase loss detection module and a second phase loss detection module, wherein: The first phase loss detection module is used for phase loss detection of the variable frequency drive output before the motor starts, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting; if there is no phase loss, the detection continues; The second phase loss detection module is used for phase loss detection of the variable frequency drive output during the motor operation phase, specifically: The motor output current is obtained, and the output of the variable frequency drive is judged according to the motor output current whether there is a phase loss during the motor operation phase. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop running; if there is no phase loss, the detection is continued.
[0013] In one embodiment of the present invention, in the first phase loss detection module, in the phase loss detection of the variable frequency drive output before the motor starts, judging whether there is a phase loss in the variable frequency drive output before the motor starts according to the current closed-loop regulator inside the variable frequency drive includes: The first acquisition unit is used to acquire the saturation state signal of the current closed-loop regulator, and judge whether the saturation state signal of the current closed-loop regulator is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; The first judgment unit is used to judge whether the output phase loss count exceeds the first threshold value. If not, there is no phase loss in the output of the variable frequency drive, and the pre-starting stage of the motor is completed; if exceeded, there is a phase loss in the output of the variable frequency drive, and the drive output is stopped, thereby controlling the motor to stop starting.
[0014] In one embodiment of the present invention, in the second phase loss detection module, in the phase loss detection of the variable frequency drive output during the motor operation phase, judging whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current includes: The second acquisition unit is used to acquire the motor output current and determine whether the motor output current exceeds the current threshold. If not, the output phase loss count is reduced by one; if exceeded, the output phase loss count is increased by one. The second judgment unit is used to judge whether the output phase loss count exceeds the second threshold value. If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running.
[0015] In order to solve the above technical problem, the present invention provides a variable frequency drive, including the steps of using the above variable frequency drive output phase loss detection method.
[0016] To solve the above technical problems, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the above-mentioned variable frequency drive output phase loss detection method are implemented.
[0017] In order to solve the above technical problem, the present invention provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned variable frequency drive output phase loss detection method are implemented.
[0018] The above technical solution of the present invention has the following advantages compared with the prior art: The present invention designs a new variable frequency drive output phase loss detection method for both the existing variable frequency drive output phase loss fact and the variable frequency drive output phase loss event occurring during operation, thereby improving the stability of the variable frequency drive output phase loss detection, and can minimize the abnormal operation caused by the variable frequency drive output phase loss, thereby protecting the variable frequency drive and the motor; The present invention innovatively adopts the saturation state of the current closed-loop regulator as the input signal for the variable frequency drive output phase loss detection in the pre-motor starting stage, thereby improving the safety and stability of the variable frequency drive output phase loss detection in the pre-motor starting stage; In the process of detecting the output phase loss of the variable frequency drive, the present invention adopts the method of output phase loss counting for detection and judgment, thereby improving the fault tolerance and stability of the detection method. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.
[0020] Figure 1 1 is a general schematic diagram of a method for detecting phase loss in a variable frequency drive output according to an embodiment of the present invention; Figure 2 The invention is a flow chart of a specific method of detecting phase loss in the output of a variable frequency drive before starting a motor and detecting phase loss in the output of a variable frequency drive during the operation phase of a motor. DETAILED DESCRIPTION
[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1
[0022] Reference Figure 1As shown, the present invention relates to a method for detecting phase loss in the output of a variable frequency drive. The variable frequency drive of this embodiment is applied to an air conditioner. Before the motor is started and during operation, it can detect whether the variable frequency drive outputs phase loss, and stop the variable frequency drive output in time, so as to achieve the effect of protecting the drive and the motor. The method specifically includes a first phase loss detection and a second phase loss detection, wherein: (1) The first phase loss detection is the phase loss detection 101 of the variable frequency drive output before the motor starts, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting, thereby protecting the variable frequency drive and the motor; if there is no phase loss, the detection continues (until the motor starts to start running, the phase loss detection of the variable frequency drive before starting can be ended); (2) The second phase loss detection is the phase loss detection 102 of the variable frequency drive output during the motor operation phase, specifically: The motor output current 202 is obtained, and it is determined whether there is a phase loss in the output of the variable frequency drive during the motor operation stage according to the motor output current 202. If there is a phase loss, the variable frequency drive output is stopped, and then the motor is controlled to stop running, so as to protect the variable frequency drive and the motor; if there is no phase loss, the detection is continued (detection is continued until the motor stops running).
[0023] It is worth noting that this embodiment can design a variable frequency drive output phase loss detection method before the motor starts and during operation, thereby improving the safety factor of the variable frequency drive and reducing the damage probability of the variable frequency drive and the motor. This embodiment can effectively intercept the existing phase loss fact and the phase loss detection of the variable frequency drive output before the motor starts. Before the motor starts, an additional current closed loop stage is adopted to identify the phase loss phenomenon of the variable frequency drive output based on the saturation state of the current closed loop regulator. The phase loss event of the variable frequency drive output can be determined before the motor starts, and the variable frequency drive output can be stopped immediately, thereby protecting the variable frequency drive and the motor.
[0024] In this embodiment, for the phase loss event that occurs during the operation process, the variable frequency drive can monitor the output of the variable frequency drive in real time during the operation of the motor, and promptly identify the phase loss event of the variable frequency drive output. The current determination logic in the operation stage is used to identify the phase loss phenomenon of the variable frequency drive output. The phase loss event of the variable frequency drive output can be determined during the operation of the motor, and the variable frequency drive output can be stopped immediately, thereby protecting the variable frequency drive and the motor.
[0025] The following is a detailed introduction to this embodiment: (1) In the variable frequency drive output phase loss detection 101 before the motor starts, the method of determining whether there is a phase loss in the variable frequency drive output before the motor starts based on the current closed-loop regulator inside the variable frequency drive includes: Obtain the current closed-loop regulator saturation state signal 201, and determine whether the current closed-loop regulator saturation state signal 201 is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; It is determined whether the output phase loss count exceeds a first threshold value (in this embodiment, the first threshold value can be set to 50-500 times). If not, there is no phase loss in the output of the variable frequency drive, and the pre-start stage of the motor is completed; if exceeded, there is a phase loss in the output of the variable frequency drive, and the drive output is stopped, thereby controlling the motor to stop starting.
[0026] (2) In the variable frequency drive output phase loss detection 102 during the motor operation phase, the method for determining whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current 202 includes: Get the motor output current 202, and determine whether the motor output current 202 exceeds the current threshold (the current threshold is a dynamically adjusted value, which is the current effective value corresponding to the peak value of the real-time motor current value sampled, that is, the real-time motor current peak value / ), if it does not exceed, the output phase loss count decreases by one; if it exceeds, the output phase loss count increases by one; It is determined whether the output phase loss count exceeds the second threshold (in this embodiment, the second threshold can be set to 500-2000 times). If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running.
[0027] Further, when the first phase loss detection result is that there is no phase loss, the second phase loss detection is performed. Embodiment 2
[0028] This embodiment provides a variable frequency drive output phase loss detection system, including a first phase loss detection module and a second phase loss detection module, wherein: The first phase loss detection module is used for detecting phase loss of the variable frequency drive output before the motor starts 101, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting; if there is no phase loss, the detection continues; The second phase loss detection module is used for phase loss detection 102 of the variable frequency drive output during the motor operation phase, specifically: The motor output current 202 is obtained, and whether there is a phase loss in the output of the variable frequency drive during the motor operation phase is determined according to the motor output current 202. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop running; if there is no phase loss, the detection is continued.
[0029] Furthermore, in the first phase loss detection module, in the phase loss detection 101 of the variable frequency drive output before the motor starts, judging whether there is a phase loss in the variable frequency drive output before the motor starts according to the current closed-loop regulator inside the variable frequency drive, including: The first acquisition unit is used to acquire the current closed-loop regulator saturation state signal 201, and determine whether the current closed-loop regulator saturation state signal 201 is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; The first judgment unit is used to judge whether the output phase loss count exceeds the first threshold value. If not, there is no phase loss in the output of the variable frequency drive, and the pre-starting stage of the motor is completed; if exceeded, there is a phase loss in the output of the variable frequency drive, and the drive output is stopped, thereby controlling the motor to stop starting.
[0030] Furthermore, in the second phase loss detection module, in the phase loss detection 102 of the variable frequency drive output during the motor operation phase, a method for judging whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current 202 includes: The second acquisition unit is used to acquire the motor output current 202 and determine whether the motor output current 202 exceeds the current threshold. If not, the output phase loss count is reduced by one; if exceeded, the output phase loss count is increased by one; The second judgment unit is used to judge whether the output phase loss count exceeds the second threshold value. If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running. Embodiment 3
[0031] This embodiment provides a variable frequency drive, including the steps of using the variable frequency drive output phase loss detection method described in the first embodiment. Embodiment 4
[0032] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the variable frequency drive output phase loss detection method described in Embodiment 1 are implemented. Embodiment 5
[0033] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the variable frequency drive output phase loss detection method described in the first embodiment are implemented.
[0034] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present application may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.
[0035] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0036] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.
[0037] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.
[0038] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.
[0039] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.
Claims
1. A method for detecting phase loss in output of a variable frequency drive, characterized in that: It includes a first phase loss detection and a second phase loss detection, wherein: The first phase loss detection is the phase loss detection of the variable frequency drive output before the motor starts, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting; if there is no phase loss, the detection continues; The second phase loss detection is the phase loss detection of the variable frequency drive output during the motor operation phase, specifically: The motor output current is obtained, and the output of the variable frequency drive is judged according to the motor output current whether there is a phase loss during the motor operation phase. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop running; if there is no phase loss, the detection is continued.
2. The method for detecting phase loss of a variable frequency drive output according to claim 1, characterized in that: In the phase loss detection of the variable frequency drive output before the motor starts, the method of judging whether there is a phase loss in the variable frequency drive output before the motor starts based on the current closed-loop regulator inside the variable frequency drive includes: Obtain the saturation state signal of the current closed-loop regulator, and determine whether the saturation state signal of the current closed-loop regulator is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; Determine whether the output phase loss count exceeds the first threshold. If not, there is no phase loss in the variable frequency drive output and the pre-motor start-up stage is completed; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop starting.
3. The method for detecting phase loss of a variable frequency drive output according to claim 1, characterized in that: In the phase loss detection of the variable frequency drive output during the motor operation phase, the method of judging whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current includes: Get the motor output current and determine whether the motor output current exceeds the current threshold. If not, the output phase loss count is reduced by one; if exceeded, the output phase loss count is increased by one. Determine whether the output phase loss count exceeds the second threshold. If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running.
4. The method for detecting phase loss of a variable frequency drive output according to claim 1, characterized in that: When the first phase loss detection result is that there is no phase loss, the second phase loss detection is performed.
5. A variable frequency drive output phase loss detection system, characterized in that: It includes a first phase loss detection module and a second phase loss detection module, wherein: The first phase loss detection module is used for phase loss detection of the variable frequency drive output before the motor starts, specifically: The current closed-loop regulator inside the variable frequency drive is used to determine whether there is a phase loss in the variable frequency drive output before the motor starts. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop starting; if there is no phase loss, the detection continues; The second phase loss detection module is used for phase loss detection of the variable frequency drive output during the motor operation phase, specifically: The motor output current is obtained, and the output of the variable frequency drive is judged according to the motor output current whether there is a phase loss during the motor operation phase. If there is a phase loss, the variable frequency drive output is stopped, and the motor is controlled to stop running; if there is no phase loss, the detection is continued.
6. The variable frequency drive output phase loss detection system according to claim 5, characterized in that: In the first phase loss detection module, in the phase loss detection of the variable frequency drive output before the motor starts, judging whether there is a phase loss in the variable frequency drive output before the motor starts according to the current closed-loop regulator inside the variable frequency drive includes: The first acquisition unit is used to acquire the saturation state signal of the current closed-loop regulator, and judge whether the saturation state signal of the current closed-loop regulator is saturated. If it is saturated, the output phase loss count is increased by one; if it is not saturated, the output phase loss count is decreased by one; The first judgment unit is used to judge whether the output phase loss count exceeds the first threshold value. If not, there is no phase loss in the output of the variable frequency drive, and the pre-starting stage of the motor is completed; if exceeded, there is a phase loss in the output of the variable frequency drive, and the drive output is stopped, thereby controlling the motor to stop starting.
7. The variable frequency drive output phase loss detection system according to claim 5, characterized in that: In the second phase loss detection module, in the phase loss detection of the variable frequency drive output during the motor operation phase, judging whether there is a phase loss in the variable frequency drive output during the motor operation phase according to the motor output current includes: The second acquisition unit is used to acquire the motor output current and determine whether the motor output current exceeds the current threshold. If not, the output phase loss count is reduced by one; if exceeded, the output phase loss count is increased by one. The second judgment unit is used to judge whether the output phase loss count exceeds the second threshold value. If not, there is no phase loss in the variable frequency drive output, and the motor is controlled to continue running; if exceeded, there is a phase loss in the variable frequency drive output, and the drive output is stopped, thereby controlling the motor to stop running.
8. A variable frequency drive, characterized in that: The method comprises the steps of using the variable frequency drive output phase loss detection method as claimed in any one of claims 1 to 4.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the variable frequency drive output phase loss detection method according to any one of claims 1 to 4 are implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the variable frequency drive output phase loss detection method according to any one of claims 1 to 4 are implemented.