Motor control method and device, controller, air compressor and medium

Abstract

The embodiment of the invention relates to a motor control method, a motor control device, a controller, an air compressor and a computer readable storage medium. The motor control method includes: starting a motor using a voltage-to-frequency ratio (V / F) mode; detecting the starting current of the motor; if the start-up current is greater than a threshold, a flag is stored indicating that the motor is switched to a current frequency ratio (I / F) mode. On the basis of the mode, under the condition that the starting load fluctuates or the load is large, the risk of locked-rotor or overcurrent can be recognized in time, the starting mode of the motor is switched from the V / F mode to the I / F mode, and the situation that large current appears in a motor coil for a long time, and consequently the motor is burnt out is prevented.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of motors, and more particularly, to a motor control method, a motor control device, a controller, an air compressor, and a computer-readable storage medium. Background Art

[0002] Traditional air compressors use a constant voltage-frequency ratio (V / F) starting mode. This starting mode uses an open-loop control mechanism with simple control logic and no current closed loop, avoiding current interference and other problems. It is adopted by most air compressor controllers. The V / F starting mode is suitable for low-power motors and light loads.

[0003] Under some working conditions, as the number of starts increases, the air compressor will experience mechanical wear and increased resistance. The fixed initial voltage in the V / F mode is already difficult to start the air compressor, and it is particularly prone to stalling. This will cause large currents in the motor coils and increase the motor temperature, and in severe cases, the air compressor will burn out. Some air compressors use a current-frequency ratio (I / F) starting mode. This starting mode uses an open-loop speed and a closed-loop current to adapt to high-power motors and heavy loads. However, for the three-level controller in the air compressor, the I / F starting mode is prone to speed loss or neutral point voltage loss. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure provide an improved solution that can select an appropriate starting mode according to real-time working conditions. Compared with the traditional method, the embodiments of the present disclosure can timely identify the risk of stalling or overcurrent when the starting load fluctuates or the load is relatively large, and switch the starting mode of the motor from the V / F mode to the I / F mode to prevent the motor coil from having a large current for a long time, causing the motor to burn out.

[0005] According to a first aspect of the present disclosure, a motor control method is provided. The method includes: starting the motor using a voltage-frequency ratio (V / F) mode; detecting a starting current of the motor; and if the starting current is greater than a threshold, storing a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode.

[0006] According to a second aspect of the present disclosure, a controller is provided. The controller includes: a processing unit and a memory. The memory is coupled to the processing unit and stores instructions for execution by the processing unit. When the instructions are executed by the processing unit, the controller executes a method. The method includes: starting a motor using a voltage-frequency ratio (V / F) mode; detecting a starting current of the motor; and if the starting current is greater than a threshold, storing a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode.

[0007] According to a third aspect of the present disclosure, an air compressor is provided. The air compressor includes: a motor; a controller coupled to the motor; and a non-volatile memory, which is included in or coupled to the controller. The controller is configured to: start the motor using a voltage-frequency ratio (V / F) mode; detect a starting current of the motor; and if the starting current is greater than a threshold, store a flag in the non-volatile memory indicating that the motor is switched to a current-frequency ratio (I / F) mode.

[0008] According to a fourth aspect of the present disclosure, a fuel cell system is provided, comprising the air compressor according to the third aspect of the present disclosure.

[0009] According to a fifth aspect of the present disclosure, a motor control device is provided. The motor control device includes: a motor starting unit configured to start the motor using a voltage-frequency ratio (V / F) mode; a current detection unit configured to detect a starting current of the motor; and a mode switching unit configured to store a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode if the starting current is greater than a threshold value.

[0010] According to a sixth aspect of the present disclosure, a computer-readable storage medium is provided, comprising machine-executable instructions, which, when executed by a device, cause the device to perform the method according to the first aspect of the present disclosure.

[0011] This summary is provided to introduce a selection of concepts in a simplified form, which will be further described in the following detailed description. This summary is not intended to identify key features or essential features of the present disclosure, nor is it intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present disclosure.

[0013] Figure 1 A schematic diagram showing an exemplary environment in which some embodiments of the present disclosure may be implemented;

[0014] Figure 2 A schematic flow chart of a motor control method according to some embodiments of the present disclosure is shown;

[0015] Figure 3 A schematic flow chart of a motor starting method according to some embodiments of the present disclosure is shown;

[0016] Figure 4 A detailed schematic diagram of a motor control method according to some embodiments of the present disclosure is shown;

[0017] Figure 5 A schematic block diagram showing a motor control device according to some embodiments of the present disclosure; and

[0018] Figure 6 Schematic block diagrams of example devices that can be used to implement embodiments of the present disclosure are shown. DETAILED DESCRIPTION

[0019] It is understandable that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and relevant provisions.

[0020] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0021] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0022] It should be noted that the numbers or numerical values ​​used in this document are intended to facilitate understanding of the technology of the present disclosure, rather than to limit the scope of the present disclosure.

[0023] As mentioned above, conventional air compressors use either the V / F starting mode or the I / F starting mode. These two starting modes have their own advantages and disadvantages. The V / F starting mode is simple to control and is suitable for air compressors with low-power motors and low loads, but it is not suitable for air compressors with low-power motors and low loads. Changes in operating conditions or When the starting load increases, it is easy to cause stalling, or even burn out the air compressor. On the other hand, the I / F starting mode is more suitable for air compressors with high-power motors and high loads, but it is easy to cause speed loss or neutral point voltage loss.

[0024] In view of this, an embodiment of the present disclosure provides a solution that can flexibly switch the starting mode of the motor of the air compressor according to the actual working conditions. In an example method, when the motor is powered on, the V / F mode is used to start the motor. In this process, the starting current of the motor is detected. If the detected starting current is greater than the set threshold, a flag will be stored to indicate that the motor is switched to the I / F mode for starting. Based on this approach, it is possible to promptly identify the risk of stalling or overcurrent when the starting load fluctuates or the load is relatively large, and the starting mode of the motor can be smoothly switched from the V / F mode to the I / F mode to prevent large currents from appearing in the motor coil for a long time, causing the motor or air compressor to burn out.

[0025] It should be noted that although the proposed motor control method is described herein using an air compressor (e.g., in a fuel cell system) as an example, it should be understood that this method is also applicable to motors of other types or uses, and is not limited to air compressors. The scope of the present disclosure is not limited in this respect. Figures 1 to 6 Detailed description of implementation details of the embodiments of the present disclosure.

[0026] Figure 1 A schematic diagram of an exemplary environment in which some embodiments of the present disclosure may be implemented is shown. Figure 1 An exemplary environment includes a fuel cell system 100, including an air compressor 110 and a stack 140. The stack 140 is a core component of the fuel cell system, which is composed of a number of fuel cell monomers, each of which includes a fuel electrode and an oxidant electrode, which are separated by an electrolyte. In the stack 140, the fuel and the oxidant diffuse to the electrodes through the electrolyte, and chemical reactions occur on the electrodes to generate current and heat energy. The air compressor 110 can obtain air 115 from the natural environment and generate compressed air 125 as an oxidant to provide to the cathode of the stack 140. As a result, the stack 140 can obtain enough oxygen for the reaction. The stack 140 can discharge the reaction products 135, including water and other gases.

[0027] As shown, the air compressor 110 includes a motor 120 and a controller coupled to the motor 120. The controller 130 can be any type of electronic device with computing capabilities. In some implementations, the controller 130 can include or be coupled to a non-volatile memory (e.g., an electrically erasable programmable read-only memory (EEPROM)). The non-volatile memory can store control instructions or control data for the motor 120, such as a predefined startup program and related setting data. When the air compressor 110 is powered on, the controller 130 can control the startup of the motor 120 according to the predefined startup program and setting data. The startup program of the motor 120 can include two startup modes: a V / F startup mode and an I / F startup mode.

[0028] The V / F starting mode uses the changing characteristics of voltage and frequency to guide the performance of the motor to change or maintain it at a certain value, where the ratio of voltage to frequency remains constant. During the starting process, the motor 120 is first started using a constant V / F value. As the voltage and frequency increase, the coil current and output torque also increase until the static rotational inertia and friction of the motor 120 are overcome and the motor is started. Afterwards, the controller 130 can automatically adjust the V / F value according to the change in current to keep the motor at the target speed.

[0029] The I / F mode uses the changing characteristics of current and frequency to guide the performance of the motor to change or maintain it at a certain value. In the I / F mode, the current Is is applied. During the motor starting process, the applied current Is will generate a current id on the positive excitation component and a current iq on the positive torque component on the current vector. The current iq on the torque component will generate positive torque and drag the motor to rotate. As the motor frequency continues to increase, the id and iq on the current vector are also continuously adjusted to adapt to the motor speed. Eventually the motor reaches the target speed. The I / F mode has good self-regulation capabilities and is easy to calibrate. It can prevent overcurrent and prevent the occurrence of air compressor startup stall problems.

[0030] According to an embodiment of the present disclosure, the controller 130 can automatically select one of the V / F starting mode and the I / F starting mode to start the motor 120 to adapt to different working conditions. Figures 2 to 6 Elaborate on this further.

[0031] It should be understood that Figure 1 The exemplary environment shown is merely exemplary and should not constitute any limitation on the functionality and scope of the implementation described in the present disclosure. The exemplary environment may be any application environment other than a fuel cell system, and may include Figure 1 Any components not shown or omitted Figure 1 Some of the components.

[0032] Figure 2 2 shows a schematic flow chart of a motor control method 200 according to some embodiments of the present disclosure. The control method 200 may be Figure 1 For convenience of explanation, the controller 130 shown in FIG. Figure 1 The control method 200 will be described.

[0033] At 210, the controller 130 controls the voltage-frequency ratio (V / F) mode to start the motor 120. In response to the air compressor 100 being powered on, the controller 130 may read the start-up program of the motor 120 from the memory. In some embodiments, the start-up program may indicate that the V / F mode is used by default to start the motor 120, or an explicit instruction may be given. In addition, the controller 130 may also obtain control commands, such as a speed mode command, a desired speed command, etc.

[0034] In the V / F start mode, the controller 130 can maintain a constant voltage-frequency ratio. In the initial state, the target frequency of the motor 120 is increased at a given voltage until the constant voltage-frequency ratio is reached. Then, when the voltage-frequency ratio is met, the voltage and frequency are continuously increased until the motor 120 overcomes the static rotation inertia and friction and starts.

[0035] In block 220, the controller 130 may detect the starting current of the motor. The starting current refers to the effective value of the actual current at the moment when the motor 120 overcomes the static rotation inertia and friction and leaves the static state. A current sensor and a sensor for detecting the motion state of the motor may be provided in the air compressor 110 to detect the starting current.

[0036] In box 230, if the starting current is greater than the threshold, the controller 130 stores a flag that the motor 120 is switched to the current-frequency ratio (I / F) mode. A smaller starting current means a smaller starting load, so the V / F mode can be applied to such working conditions, and no excessive current will be generated during the starting process of the motor. In this case, the motor 120 or the air compressor 110 can continue to be started according to the default V / F mode. However, if the starting current is greater than the set threshold, it means that the starting load is large, the V / F mode is no longer applicable, and there is a risk of stalling or overcurrent if the V / F mode is continued to be used for starting. Therefore, the starting mode of the motor 120 can be switched from the V / F mode to the I / F mode. The next time the air compressor 110 is powered on, the I / F mode will be used to start the motor 120.

[0037] In some embodiments, the controller 130 may store a flag indicating that the motor 120 is switched to the I / F mode in a non-volatile memory. The non-volatile memory may be included in the controller 130 or coupled to the controller 130. In some implementations, the non-volatile memory may be, for example, an electrically erasable programmable read-only memory (EEPROM). In some embodiments, the flag may be one or more bits in the memory with a specified value. For example, a single bit of "TRUE" (e.g., value "1") is used to indicate that the motor is switched to the I / F mode, and it should be understood that other values ​​or more bits are also possible.

[0038] In addition to the starting current, the controller 130 can also change the starting mode to the I / F mode based on other factors. In some embodiments, if the starting current is less than or equal to the threshold, the controller 130 can further determine whether the motor 120 is successfully started. For example, the controller 130 can check whether the motor 120 has reached the target speed. If it has not reached it, it is determined that there is a stall and the start-up has failed. The failure of the motor 120 to start means that the V / F mode is not sufficient to support the current operating conditions. In this case, even if the motor is restarted, it may still fail, resulting in a poor user experience. Therefore, in the case that the motor 120 is not successful, the controller 130 can store a flag that the motor is switched to the I / F mode. In this way, it can cooperate with the fuel cell system controller (FCCU), and in the case of a startup failure, it can switch from V / F startup to I / F startup in a very short time, without manual intervention, increasing the probability of successful startup, thereby optimizing the user experience.

[0039] In some embodiments, once the startup mode is changed to I / F mode (whether caused by excessive startup current or motor startup failure), the controller 130 can also report corresponding information. For example, the controller 130 can give a prompt or notification on the user interface, or record this information in a log. In the case where the startup current is greater than the threshold, the controller 130 can report that the motor startup load is too large. In the case of motor startup failure, the controller 130 can report that the motor has a stall or overcurrent fault. Based on this information, the user can promptly understand the working condition of the equipment and perform equipment maintenance, reducing the risk of equipment damage.

[0040] After equipment maintenance, the user can manually reset the startup mode to the V / F mode, for example, by clearing the flag for switching to the I / F mode from the non-volatile memory. In some embodiments, the controller 130 can also continue to monitor the startup current in the I / F mode. If the startup current can be restored to below a certain threshold (lower than the threshold for switching to the I / F mode), for example, N times in a row (N is an arbitrary integer), the controller 130 can clear the flag for switching to the I / F mode and restore the V / F mode.

[0041] Figure 3 1 shows a schematic flow chart of a motor starting method 300 according to some embodiments of the present disclosure. The method 300 may be Figure 1 For convenience of explanation, the controller 130 shown in FIG. Figure 1 The control method 300 will be described.

[0042] In response to the air compressor powering on, at block 310, the controller 130 accesses the non-volatile memory to obtain information about the startup mode of the motor 120. In some embodiments, the controller 130 may read one or more bits of the EEPROM to check for a flag regarding the I / F mode.

[0043] At block 320, it is determined whether there is a flag indicating that the motor is switched to the I / F mode. If the flag has a specified value of "TRUE" (e.g., a value of "1"), the controller 130 can determine that the motor 120 is switched to the I / F mode. The method 300 can proceed to block 330 to start the motor 120 using the I / F mode.

[0044] Otherwise, the method 300 may proceed to block 340 to start the motor 120 using the V / F mode. In some embodiments, during the process of starting the motor 120 using the V / F mode, the controller 130 may detect the starting current and determine whether the motor 120 is successfully started, thereby being able to change the starting mode to the V / F mode in a timely manner when the load or working condition of the air compressor 110 or the motor 120 changes. That is, for each V / F mode starting process, refer to Figure 2 The described method 200 may be performed.

[0045] Figure 4 FIG. 4 is a detailed schematic diagram of a motor control method 400 according to some embodiments of the present disclosure. The method 400 may be an exemplary specific implementation of the method 200 .

[0046] At block 410, the controller 130 uses the V / F mode to start the motor 120. In some implementations, the controller 130 determines that the start mode of the motor 120 is the V / F mode by accessing a coupled non-volatile memory, for example, there is no indication of the I / F mode in the memory or the data in the memory explicitly indicates the use of the V / F mode.

[0047] At block 420, the controller 130 detects the effective value of the actual starting current of the motor 120. In the V / F mode, the current and torque of the motor 120 gradually increase until the transfer inertia and friction of the motor 120 are overcome, so that the motor 120 changes from a stationary state to a rotating state. The controller 130 obtains the effective value of the actual starting current corresponding to the time.

[0048] In box 430, the controller 130 compares the detected effective value of the actual starting current with the set threshold. If the effective value of the actual starting current is greater than the set threshold, it means that the starting load of the air compressor has increased, and the current V / F mode can no longer meet the starting requirements. In box 404, the controller 130 can report that the starting load is too large, for example, giving a prompt on the user interface, or generating corresponding log data.

[0049] In block 405, the controller 130 may set a flag to switch the motor startup mode to the I / F mode, for example, by setting a Boolean variable to TRUE and then storing it in a non-volatile storage. In some implementations, the controller 130 may store the flag in a non-volatile storage (e.g., EEPROM) in real time, or may store the flag in a non-volatile storage during power-off.

[0050] In response to the air compressor 110 or the motor 120 being powered on again, the controller 130 reads the flag for switching to the I / F mode from the nonvolatile memory at block 406 . Then, at block 407 , the controller 130 switches to start the motor 120 using the I / F mode.

[0051] Returning to box 403, if the effective value of the actual starting current is less than or equal to the set threshold value, then in box 408, the controller 130 further determines whether the motor 120 is successfully started (for example, whether the motor reaches the expected speed). If unsuccessful, the method 400 proceeds to box 409, and sets a flag for switching to I / F mode in the non-volatile memory. In some implementations, the controller 130 can also report information about the existence of a stall or process in the motor 120. Then, the method 400 proceeds to box 407, and the power is turned on and off again, and the controller 130 switches to using the I / F mode to start the motor 120. If it is determined in box 408 that the startup is successful, indicating that the startup load of the air compressor has not changed significantly, and it runs normally after startup, the method 400 proceeds to box 410, and the V / F mode can continue to be used to start the motor 120 in the subsequent startup process.

[0052] References Figures 1 to 4 The motor control method of the embodiment of the present disclosure is described. Compared with the traditional motor starting mode, the embodiment of the present disclosure can timely identify the risk of stalling or overcurrent when the starting load fluctuates or the load is relatively large, and switch the starting mode of the motor from V / F mode to I / F mode to prevent the motor from burning out due to the large current in the motor coil for a long time. In some embodiments, it is also possible to switch from V / F starting to I / F starting in a very short time when starting fails, without manual intervention, thereby increasing the probability of successful starting and optimizing the user experience.

[0053] Figure 5 1 shows a schematic block diagram of a motor control device 500 according to some embodiments of the present disclosure. The device 500 may be arranged in Figure 1At the controller 130 shown. As shown in the figure, the control device 500 includes a motor starting unit 510, a current detection unit 520 and a mode control unit 530. The motor starting unit 510 is configured to start the motor using a voltage-frequency ratio (V / F) mode. The current detection unit 520 is configured to detect the starting current of the motor. The mode switching unit 530 is configured to: if the starting current is greater than a threshold value, store a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode.

[0054] In some embodiments, the mode switching unit 530 may be further configured to: determine whether the motor is successfully started in response to the starting current being less than or equal to the threshold; and if the motor is not successfully started, store a flag indicating that the motor is switched to the I / F mode.

[0055] In some embodiments, the apparatus 500 may further include a reporting unit configured to report that the motor has a stall or overcurrent fault if the motor fails to start.

[0056] In some embodiments, the mode switching unit 530 may be further configured to: store the flag in a non-volatile memory. The mode switching unit 530 may be further configured to: set a bit in the non-volatile memory to a specified value.

[0057] In some embodiments, the motor starting unit 510 may be further configured to start the motor using the I / F mode based on determining that the flag is detected in response to the motor being powered on again.

[0058] In some embodiments, the motor starting unit 510 may be further configured to start the motor using a V / F mode based on determining that the flag is not detected.

[0059] In some embodiments, the reporting unit may be further configured to report that the starting load of the motor is too large if the starting current is greater than a threshold value.

[0060] In some embodiments, the motor is included in the air compressor.

[0061] Figure 6A schematic block diagram of an example device 600 that can be used to implement an embodiment of the present disclosure is shown. For example, the method 200, 300 and 400 according to the embodiment of the present disclosure can be implemented by the device 600, the controller 130 is embodied as the device 600, and the control device 500 can be implemented at the device 600. As shown in the figure, the device 600 includes a central processing unit (CPU) 601, which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) 602 or loaded from a 600 storage unit 608 to a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the device 600 can also be stored. The CPU 601, the ROM 602 and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0062] Multiple components in the device 600 are connected to the I / O interface 605. The types of I / O interfaces include, but are not limited to, peripheral component interconnect (PCIe), universal serial bus (USB), high-definition multimedia interface (HDMI), serial connection (SAS), etc. The components based on the I / O interface 605 may include, but are not limited to: input unit 606, such as keyboard, mouse, etc.; output unit 607, such as respective types of display, speaker, etc.; storage unit 608, such as disk, optical disk, etc.; and communication unit 609, such as network adapter, modem, wireless communication transceiver, etc. The communication unit 609 allows the device 600 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0063] The various processes and processing described above, such as methods 200, 300, and / or 400, may be performed by a processing unit in the device 600, such as the processing unit 601 and / or other processing units (e.g., a microprocessor on a mainboard of the device 600). For example, in some embodiments, the methods or processes 200, 300, and / or 400 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 608. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 600 via the ROM 602 and / or the communication unit 609. When the computer program is loaded into the RAM 603 and executed, one or more actions of the methods 200, 300, and / or 400 described above may be performed.

[0064] The present disclosure may be a method, an apparatus, a system and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing various aspects of the present disclosure.

[0065] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the foregoing. As used herein, a computer-readable storage medium is not to be interpreted as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0066] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0067] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may 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 may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be customized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0068] Various aspects of the present disclosure are described herein 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 disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0069] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processing unit of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0070] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0071] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of special hardware and computer instructions.

[0072] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A motor control method, comprising: Use voltage-frequency ratio (V / F) mode to start the motor; Detecting the starting current of the motor; as well as If the starting current is greater than a threshold, a flag is stored indicating that the motor is switched to a current-to-frequency ratio (I / F) mode.

2. The method according to claim 1, further comprising: In response to the starting current being less than or equal to the threshold, determining whether the motor is successfully started; as well as If the motor is not successfully started, a flag indicating that the motor is switched to the I / F mode is stored.

3. The method according to claim 2, further comprising: If the motor fails to start, it is reported that the motor has a stall or overcurrent fault.

4. The method according to claim 1, wherein storing a flag indicating that the motor is switched to the I / F mode comprises: The flag is stored in a non-volatile memory.

5. The method of claim 4, wherein storing the flag in the non-volatile memory comprises: Sets a bit in the nonvolatile memory to a specified value.

6. The method according to any one of claims 1 to 5, further comprising: In response to the motor being powered on again, the motor is started using the I / F mode based on a determination that the flag is detected.

7. The method according to claim 6, further comprising: Based on determining that the flag is not detected, the motor is started using the V / F pattern.

8. The method according to claim 1, further comprising: If the starting current is greater than the threshold, it is reported that the starting load of the motor is too large.

9. The method of any one of claims 1 to 7, wherein the electric motor is included in an air compressor.

10. A controller comprising: Processing unit; and a memory coupled to the processing unit and storing instructions for execution by the processing unit, the instructions, when executed by the processing unit, causing the controller to perform a method comprising: Use voltage-frequency ratio (V / F) mode to start the motor; detecting a starting current of the motor; and If the starting current is greater than a threshold, a flag is stored indicating that the motor is switched to a current-to-frequency ratio (I / F) mode.

11. The controller according to claim 10, wherein the controller is further configured to: In response to the starting current being less than or equal to the threshold, determining whether the motor is successfully started; and If the motor is not successfully started, a flag indicating that the motor is switched to the I / F mode is stored.

12. An air compressor comprising: Motor; a controller coupled to the motor; a non-volatile memory included in or coupled to the controller; The controller is configured to: Using a voltage-to-frequency (V / F) ratio mode to start the motor; Detecting the starting current of the motor; as well as If the starting current is greater than a threshold value, a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode is stored in the nonvolatile memory.

13. A fuel cell system comprising the air compressor according to claim 12.

14. A motor control device, comprising: a motor starting unit configured to start the motor using a voltage-to-frequency (V / F) mode; a current detection unit configured to detect a starting current of the motor; as well as A mode switching unit is configured to store a flag indicating that the motor is switched to a current-frequency ratio (I / F) mode if the starting current is greater than a threshold value.

15. A computer-readable storage medium comprising machine-executable instructions which, when executed by a device, cause the device to perform the method according to any one of claims 1 to 9.

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