Method, device, storage medium and program product for voltage reduction starting of an electric machine

Abstract

Embodiments of this disclosure provide a method, apparatus, storage medium, and program product for reduced-voltage starting of a motor. The method includes: in response to receiving a start command instructing the motor to start, determining the line voltage between a first phase and a second phase in the circuit; determining the zero-crossing point of the line voltage; in response to reaching the zero-crossing point of the line voltage, initiating a first timing; in response to the first timing satisfying a first predetermined duration, closing a first switch of the first phase and a second switch of the second phase, the first predetermined duration being determined at least based on the zero-crossing point of the line voltage and the motor's closing angle information; in response to the closure of the first and second switches, initiating a second timing; and in response to the second timing satisfying a second predetermined duration, closing a third switch of the third phase in the circuit relative to the first and second phases. This reduces the peak value of the first current surge during motor startup, decreasing the risk of circuit breaker false triggering.

Description

Technical Field

[0001] The exemplary embodiments disclosed herein generally relate to the field of electrical equipment, and particularly to methods, apparatus, storage media, and program products for reduced-voltage starting of motors. Background Technology

[0002] A semiconductor switch is an electronic switching device made using the properties of semiconductor materials, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) switch. It has the advantages of easy control and rapid response, and is therefore widely used in electrical equipment in various fields.

[0003] However, semiconductor devices have short short-circuit withstand time, and some electrical appliances may experience excessively high current peaks when starting up, which can easily trigger short-circuit protection falsely. Summary of the Invention

[0004] In a first aspect of this disclosure, a method for reduced-voltage starting of a motor is provided. The method includes: in response to receiving a start command instructing the motor to start, determining a line voltage between a first phase and a second phase in a circuit; determining a zero-crossing point of the line voltage; in response to reaching the zero-crossing point of the line voltage, initiating a first timing; in response to the first timing satisfying a first predetermined duration, closing a first switch of the first phase and a second switch of the second phase, the first predetermined duration being determined at least based on the zero-crossing point of the line voltage and closing angle information of the motor; in response to the closure of the first and second switches, initiating a second timing; and in response to the second timing satisfying a second predetermined duration, closing a third switch of a third phase in the circuit relative to the first and second phases.

[0005] In some embodiments, the method further includes: disconnecting the three-phase power supply to the line in response to receiving an abnormality signal indicating a line abnormality; and initializing a first timing and / or a second timing.

[0006] In some embodiments, the method further includes: in response to the closing of the third switch, acquiring voltage information at the ends of the first switch, the second switch and the third switch respectively; and in response to the voltage information at the ends of the first switch, the second switch and the third switch exceeding a predetermined threshold, disconnecting the three-phase power supply of the line.

[0007] In some embodiments, the method further includes issuing a warning message in response to the disconnection of the three-phase power supply to the line.

[0008] In some embodiments, the method further includes: determining a first predetermined duration, including: acquiring closing angle information of the motor; determining a closing time related to the closing angle information based on the closing angle information and the frequency of power supply; and determining the first predetermined duration based on the closing time and the zero-crossing point of the line voltage.

[0009] In some embodiments, obtaining the motor's closing angle information includes: obtaining the motor's power factor; and determining the motor's closing angle information based on the motor's power factor.

[0010] In some embodiments, the second predetermined duration is determined based on the characteristic parameters of the motor.

[0011] According to the method for reduced-voltage starting of a motor according to embodiments of this disclosure, the first and second phases of the line are connected by closing the first and second switches at the optimal closing angle positions of the line voltages of the first and second phases. Subsequently, the third switch is closed after a second predetermined time, connecting the third phase of the line. In this manner, the peak value of the first current surge during motor startup can be reduced, thereby reducing false triggering of the circuit breaker and extending the service life of the semiconductor switch.

[0012] In a second aspect of this disclosure, an apparatus for reduced-voltage starting of a motor is provided. The apparatus includes: a task module configured to: acquire a start command instructing the motor to start; a data processing module configured to: determine the line voltage between a first phase and a second phase in a circuit based on the start command; and determine the zero-crossing point of the line voltage; a control module configured to: initiate a first timing at the zero-crossing point of the line voltage; close a first switch of the first phase and a second switch of the second phase in response to the first timing satisfying a first predetermined duration, the first predetermined duration being determined based on the zero-crossing point of the line voltage and the motor's closing angle information; initiate a second timing in response to the closure of the first and second switches; and close a third switch of a third phase in the circuit relative to the first and second phases in response to the second timing satisfying a second predetermined duration.

[0013] In some embodiments, the task module is further configured to: disconnect the three-phase power supply to the line in response to receiving an abnormal signal indicating a line abnormality; and initialize a first timing and / or a second timing.

[0014] In some embodiments, the task module is further configured to: in response to the closing of the third switch, acquire voltage information at both ends of the first switch, the second switch and the third switch respectively; and in response to the voltage information at both ends of the first switch, the second switch and the third switch exceeding a predetermined threshold respectively, disconnect the three-phase power supply of the line.

[0015] In some embodiments, the task module is also configured to issue a warning message in response to the disconnection of the three-phase power supply to the line.

[0016] In some embodiments, the data processing module is further configured to: determine a first predetermined duration, including: acquiring motor closing angle information; determining a closing time related to the closing angle information based on the closing angle information and the frequency of power supply; and determining the first predetermined duration based on the closing time and the zero-crossing point of the line voltage.

[0017] In some embodiments, obtaining the closing angle information of the motor includes: obtaining the power factor of the motor; and determining the closing angle information of the motor based on the power factor of the motor.

[0018] In some embodiments, the second predetermined duration is determined based on the characteristic parameters of the motor.

[0019] In some embodiments, the latency of the data processing module is lower than that of the task module; and the latency of the control module is lower than that of the data processing module.

[0020] In a third aspect of this disclosure, an electronic device is provided. The device includes at least one processing unit; and at least one memory coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit. When executed by the at least one processing unit, the instructions cause the device to perform the method of the first aspect.

[0021] In a fourth aspect of this disclosure, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program that can be executed by a processor to implement the method of the first aspect.

[0022] It should be understood that the content described in this content section is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0023] 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. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0024] Figure 1 A simplified circuit diagram of a switching device for a motor according to some embodiments of the present disclosure is shown;

[0025] Figure 2 A schematic diagram of an apparatus for reduced-voltage starting of a motor is shown according to some embodiments of the present disclosure;

[0026] Figure 3 A flowchart illustrating a reduced-voltage starting process for a motor according to some embodiments of the present disclosure is shown;

[0027] Figure 4 A schematic diagram illustrating communication interactions of an apparatus according to some embodiments of the present disclosure during motor startup is shown;

[0028] Figure 5 A schematic block diagram of a method for step-down starting of a motor according to some embodiments of the present disclosure is shown; and

[0029] Figure 6 A schematic block diagram of an electronic device suitable for implementing embodiments of the present disclosure is shown. Detailed Implementation

[0030] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0031] It should be noted that the headings of any section / subsection provided herein are not limiting. Various embodiments are described throughout this document, and embodiments of any type may be included under any section / subsection. Furthermore, embodiments described in any section / subsection may be combined in any way with any other embodiments described in the same section / subsection and / or different sections / subsections.

[0032] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". Other explicit and implicit definitions may also be included below. The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0033] As briefly mentioned above, due to the short short-circuit withstand time of semiconductor devices, the first current peak of some electrical appliances (e.g., high-efficiency motors) during startup is too high and may trigger a short circuit, thus preventing the appliance from starting normally.

[0034] The present disclosure provides a solution for reduced-voltage starting of a motor to solve, or at least partially solve, the aforementioned problems and other potential problems existing in conventional solutions. According to some embodiments of the present disclosure, a method for reduced-voltage starting of a motor includes, in response to receiving a start command instructing the motor to start, determining the line voltage between a first phase and a second phase in the circuit; determining the zero-crossing point of the line voltage; in response to reaching the zero-crossing point of the line voltage, initiating a first timing; in response to the first timing satisfying a first predetermined duration, closing a first switch of the first phase and a second switch of the second phase, the first predetermined duration being determined at least based on the zero-crossing point of the line voltage and the motor's closing angle information; in response to the closure of the first and second switches, initiating a second timing; and in response to the second timing satisfying a second predetermined duration, closing a third switch of the third phase in the circuit relative to the first and second phases.

[0035] By closing the first and second switches at the optimal closing angle positions of the line voltages of the first and second phases, the first and second phases of the line are made conductive. Subsequently, the third switch is closed after a second predetermined time, making the third phase of the line conductive. In this way, the peak value of the first current surge during motor startup can be reduced, thereby reducing circuit breaker false triggering and extending the service life of the semiconductor switches.

[0036] Figure 1 A simplified circuit diagram of a switching device 100 for a motor according to some embodiments of the present disclosure is shown. Figure 1 As shown, the motor switching device 100 generally includes a mechanical switch 110, an electrical switch 120, a control unit 130 coupled to the mechanical switch 110 and the electrical switch 120, and a sensor unit 140. The control unit 130 controls the closing or opening of the mechanical switch 110 and / or the electrical switch 120 to connect or disconnect the motor's power supply line (hereinafter also referred to as the line). In some embodiments, the electrical switch 120 includes three semiconductor switches, each coupled to one of the three phases of the line's power supply. The control module 230 can control the connection and disconnection of the three phases of the power supply using the three semiconductor switches. The sensor unit 140 is arranged between the control unit 130 and the line and is adapted to acquire electrical signals from the line, such as voltage or current signals. In some embodiments, the sensor unit 140 can acquire electrical signals at multiple locations on the line. For example, the sensor unit 140 can acquire the voltage signal across the mechanical switch 110, the voltage signal across the electrical switch 120, and the current signal at the motor's power supply terminal. The sensor unit 140 is coupled to the control unit 130 and is adapted to send the acquired electrical signals of the circuit to the control unit 130.

[0037] The device for step-down starting of a motor according to embodiments of this disclosure is at least partially coupled to or constitutes at least a part of the aforementioned switching device 100. For example, the device for step-down starting of a motor may be at least a part of the control unit 130 of the switching device 100, or it may be a separate component coupled to the control unit 130 of the switching device 100. The device can acquire electrical signals from the circuit through the control unit 130 and control the switching of semiconductor switches in the circuit. Figure 2 A schematic diagram of a device 200 for reduced-voltage starting of a motor according to some embodiments of the present disclosure is shown. Figure 2As shown, the device 200 generally includes a task module 210, a data processing module 220, and a control module 230. The task module 210 is adapted to acquire a start command from the user instructing the motor to start. The data processing module 220 is adapted to determine the line voltage between the first and second phases in the line based on the electrical signals in the line, and to determine the zero-crossing point of the line voltage and the closing timing of the first and second phases based on the line voltage. The control module 230 is adapted to control the closing of the three semiconductor switches of the electrical switch at the appropriate closing timing to achieve reduced-voltage starting of the motor. That is, to reduce the inrush current during motor starting, thereby reducing the short-circuit false triggering of the solid-state circuit breaker. The reduced-voltage starting method for the motor will be described in more detail below.

[0038] Figure 3 A flowchart of a motor reduced-voltage starting process 300 according to some embodiments of the present disclosure is shown. In some embodiments, Figure 3 The process 300 shown can be implemented by device 200. For example... Figure 3 As shown, the user sends a start command to device 200 instructing the motor to start. In block 310, device 200 receives the start command. In block 320, device 200 determines the zero-crossing point of the line voltage between the first and second phases in the circuit. In block 330, device 200 determines a first predetermined duration based on the zero-crossing point of the line voltage and the motor's closing angle information. In block 340, device 200 starts a timer at the zero-crossing point of the line voltage and performs a first timing related to the first predetermined duration. In block 350, after the first timing satisfies the first predetermined duration, device 200 closes the first and second phases of the circuit, simultaneously resets the timer, and starts a second timing. In block 360, after the second timing satisfies the second predetermined duration, device 200 closes the third phase of the circuit, thereby normally supplying power to the motor.

[0039] In some embodiments, the device 200 can also detect abnormal states in the line. For example, at block 370, the device 200 can detect whether an abnormal state has occurred in the line. For example, whether a short circuit or other problem occurs in the line during the closing of the semiconductor switches of the three phases of the line (i.e., at least one of the first switch of the first phase, the second switch of the second phase, and the third switch of the third phase is closed). If the device 200 determines that an abnormality has occurred in the line, at block 371, the device 200 disconnects the three-phase power supply to the line (i.e., disconnects the first, second, and third switches), initializes a timer, and simultaneously issues a warning indicating a line abnormality.

[0040] In some embodiments, after all three phases of the power supply to the line are closed, the device 200 can also detect the voltage across the first switch, the second switch, and the third switch respectively. In block 380, the device 200 compares the voltage across the semiconductor switch with a predetermined voltage threshold to determine whether the semiconductor switch has been closed. If the voltage across the semiconductor switch is higher than the predetermined voltage threshold, then in block 381, the device 200 disconnects the three phases of the power supply to the line (i.e., disconnects the first switch, the second switch, and the third switch), initializes the timer, and simultaneously issues a warning indicating a switch malfunction.

[0041] Figure 4 A schematic diagram of communication interaction 400 of a device 200 according to some embodiments of the present disclosure during motor startup is shown. Figure 4 As shown, when the user issues a start command to start the motor, the bus task sends a start command (410) to the data model. After verifying the start command (415), the task module 210 obtains the start command (420) from the data model. The task module 210 sends a trigger signal (425) regarding the closing switch to the data processing module 220 via a message mechanism such as a critical section. The data processing module 220 can start the timing of the control module 230 (430) when the line voltage of the first phase and the second phase crosses zero. The control module 230 executes the first timing (435) and closes the first switch of the first phase and the second switch of the second phase (440) after the first timing meets the first predetermined duration. At the same time, the control module 230 executes the second timing (445). After the second timing meets the second predetermined duration, the control module 230 closes the third switch of the third phase (450).

[0042] In some embodiments, if an abnormality occurs in the line or switch (e.g., a short circuit or the switch cannot close properly), an abnormality signal indicating the abnormality is sent to the task module 210. The task module 210 quickly disconnects (460) the switch and terminates (465) the closing action of the control module 230 through a message mechanism such as a critical section. After receiving the termination signal indicating the termination of the closing action of the control module 230, the control module 230 resets (470) the timer.

[0043] In some embodiments, the delay of the control module 230 is lower than that of the data processing module 220, and the delay of the data processing module 220 is lower than that of the task module 210. Exemplarily, in some embodiments, the refresh period of the control module 230 can be 1 ms, and the refresh period of the data processing module 220 can be 125 μs (i.e., the refresh frequency of the data processing module 220 is 8000 / s). The control module 230 has the highest response speed, meaning its delay is less than 125 μs. In this way, the control accuracy of the device 200 can be improved, and the error between the closing timing of the first and second switches and the optimal closing angle can be reduced. In some embodiments, the closing accuracy of the device 200 for the first and second switches can be controlled within an error range of ±4° of the optimal closing angle.

[0044] Figure 5 A schematic block diagram of a method 500 for step-down starting of a motor according to some embodiments of the present disclosure is shown. In some embodiments, method 500 may be performed by device 200, and in some more specific embodiments, method 500 may also be performed by a task module 210, a data processing module 220, and / or a control module 230 integrated within device 200.

[0045] like Figure 4 As shown, in block 510, in response to receiving a start command instructing the motor to start, device 200 determines the line voltage between the first phase and the second phase in the circuit. In some embodiments, a user issues a start command to device 200. The start command may be issued by the user through a mechanical structure such as a handle or knob. In some other embodiments, the start command may also be issued remotely by the user through a wired data connection, a wireless data connection, or other means.

[0046] In some embodiments, after receiving a start command, the device 200 collects the electrical information of the first and second phases in the line. It should be understood that the first and second phases in this embodiment of the disclosure should be understood as any two phases in a three-phase (U, V, W) power supply, and the third phase should be understood as a phase in the three-phase power supply that is different from the first and second phases. The device 200 can determine the line voltage of the first and second phases based on the acquired electrical information of the first and second phases.

[0047] In block 520, device 200 determines the zero-crossing point of the line voltage. In block 530, device 200 initiates a first timing in response to reaching the zero-crossing point of the line voltage. In some embodiments, if data processing module 220 determines that the line voltages of the first phase and the second phase have reached the zero-crossing point, control module 230 initiates the first timing.

[0048] In frame 540, device 200, in response to a first timing satisfying a first predetermined duration, closes the first switch of the first phase and the second switch of the second phase, the first predetermined duration being determined at least based on the zero-crossing point of the line voltage and the closing angle information of the motor.

[0049] In some embodiments, determining the first predetermined duration includes: the device 200 acquiring the closing angle information of the motor; the device 200 determining the closing time related to the closing angle information based on the closing angle information and the frequency of the power supply; and the device 200 determining the first predetermined duration based on the closing time and the zero-crossing point of the line voltage.

[0050] In some embodiments, obtaining the motor's closing angle information includes: the device 200 obtaining the motor's power factor; and the device 200 determining the motor's closing angle information based on the motor's power factor. Specifically, the device 200 can determine the closing angle information of a motor through a correspondence table between the power factor and the optimal closing angle. In some embodiments, the motor's power factor can be manually input to the device 200 by the user. In some other embodiments, the motor's power factor can also be determined by the device 200 or the control unit 130 based on the motor's operating voltage and operating current obtained in real time.

[0051] In block 550, device 200 initiates a second timing in response to the closure of the first and second switches. In block 560, device 200 closes a third switch of the third phase in the circuit relative to the first and second phases in response to the second timing satisfying a second predetermined duration.

[0052] If the control module 230 completes the first timing, the timing of the control module 230 is reset, and the second timing begins. After the second timing satisfies a second predetermined duration, the control module 230 closes the third switch of the third phase. In some embodiments, the second predetermined duration is determined based on the characteristic parameters of the motor. For example, after the first and second switches are closed, the first and second phase coils of the motor are energized. The second predetermined duration can be determined as an appropriate value that does not affect the establishment of the overall magnetic field of the motor, such as 5 ms.

[0053] The device 200 can perform time-domain conversion on the obtained closing angle information in conjunction with the current power supply frequency to determine the optimal closing timing (i.e., closing time). Based on the optimal closing timing and the zero-crossing point of the line voltage, a first predetermined duration related to the first timing is determined.

[0054] In some embodiments, method 500 further includes: device 200 disconnecting the three-phase power supply to the line in response to receiving an abnormality signal indicating a line abnormality. Device 200 initializes a first timing and / or a second timing. If, during the timing period of control module 230 (including the first and second timings), device 200 determines that an abnormality exists in the line (e.g., a short circuit occurs in the line), device 200 may disconnect the first switch, the second switch, and the third switch (if the third switch is already open, no operation is performed on the third switch), and initialize the timing of control module 230, thereby interrupting the motor start-up operation. In some embodiments, device 200 may also issue a warning to the user to indicate the abnormality in the line.

[0055] In some embodiments, method 500 further includes: in response to the closing of the third switch, device 200 acquires voltage information across the first switch, the second switch, and the third switch, respectively. In response to the voltage information across the first switch, the second switch, and the third switch exceeding a predetermined threshold, device 200 disconnects the three-phase power supply to the line.

[0056] The closed state of the first, second, and third switches is determined by detecting the voltage difference across them. Taking the first switch as an example, if the voltage difference across the first switch is lower than a predetermined threshold, it means that the first switch is closed. If the voltage difference across the first switch exceeds the predetermined threshold, it means that the first switch is not closed. If the device 200 determines that at least one of the first, second, and third switches is not closed, then the device 200 disconnects all switches and initializes the timing of the control module 230, thereby interrupting the motor start-up operation. In some embodiments, the device 200 can also issue a warning to the user to indicate an abnormality in the circuit.

[0057] Return to reference Figure 2 In some embodiments, task module 210 is configured to: acquire a start command indicating motor start. Data processing module 220 is configured to: determine the line voltage between the first phase and the second phase in the line based on the start command; and determine the zero-crossing point of the line voltage. Control module 230 is configured to: initiate a first timing at the zero-crossing point of the line voltage; in response to the first timing satisfying a first predetermined duration, close a first switch of the first phase and a second switch of the second phase, the first predetermined duration being determined based on the zero-crossing point of the line voltage and the motor's closing angle information; initiate a second timing in response to the closure of the first and second switches; and close a third switch of the third phase in the line relative to the first and second phases in response to the second timing satisfying a second predetermined duration.

[0058] In some embodiments, the task module 210 is further configured to: disconnect the three-phase power supply to the line in response to receiving an abnormal signal indicating a line abnormality; and initialize a first timing and / or a second timing.

[0059] In some embodiments, the task module 210 is further configured to: in response to the closing of the third switch, acquire voltage information at both ends of the first switch, the second switch and the third switch respectively; and in response to the voltage information at both ends of the first switch, the second switch and the third switch exceeding a predetermined threshold respectively, disconnect the three-phase power supply of the line.

[0060] In some embodiments, task module 210 is further configured to issue a warning message in response to the disconnection of the three-phase power supply to the line.

[0061] In some embodiments, the data processing module 220 is further configured to: determine a first predetermined duration, including: acquiring motor closing angle information; determining a closing time related to the closing angle information based on the closing angle information and the frequency of power supply; and determining the first predetermined duration based on the closing time and the zero-crossing point of the line voltage.

[0062] Obtaining the motor's closing angle information includes: obtaining the motor's power factor; and determining the motor's closing angle information based on the motor's power factor.

[0063] Figure 6 A schematic block diagram of an electronic device suitable for implementing embodiments of the present disclosure is shown. Figure 6 As shown, according to an electronic device provided in this disclosure, the electronic device 600 may be a circuit breaker or other suitable device mentioned above for controlling motor starting. The electronic 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 storage unit into a random access memory (RAM) 603. The RAM 603 may also store various programs and data required for device operation. The CPU 601, ROM 602, and RAM 603 are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0064] Multiple components in the device are connected to I / O interface 605, including: input unit 606, such as a touch screen, buttons, etc.; output unit 607, such as various types of displays, speakers, etc.; storage unit 608, such as a disk, optical disk, etc.; and communication unit 609, such as a network card, modem, wireless transceiver, etc. Communication unit 609 allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0065] The various processes and procedures described above, such as method 500 mentioned earlier, can be executed by processing unit 601. For example, in some embodiments, the above-described methods or processes can be implemented as computer software programs tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program can be loaded and / or installed on the device via ROM 602 and / or communication unit 609. When the computer program is loaded into RAM 603 and executed by CPU 601, one or more actions of the above-described methods or processes can be performed.

[0066] Embodiments of this disclosure relate to methods, electronic devices, and / or computer program products. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for performing various aspects of this disclosure.

[0067] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example, (but not limited to) electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0068] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0069] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status 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 the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving 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., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0070] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0071] 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 apparatus to produce a machine such that, when executed by the processing unit of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0072] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be 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 perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0073] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0074] Various implementations of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed implementations. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described implementations. The terminology used herein is chosen to best explain the principles, practical applications, or improvements to technology in the market, or to enable others skilled in the art to understand the various implementations disclosed herein.

Claims

1. A method for reduced-voltage starting of a motor, comprising: In response to receiving a start command instructing the motor to start, the line voltage between the first phase and the second phase in the circuit is determined; Determine the zero-crossing point of the line voltage; In response to reaching the zero-crossing point of the line voltage, the first timing is initiated; In response to the first timing satisfying a first predetermined duration, the first switch of the first phase and the second switch of the second phase are closed, the first predetermined duration being determined at least based on the zero-crossing point of the line voltage and the closing angle information of the motor; In response to the closure of the first switch and the second switch, a second timing is initiated; as well as In response to the second timing satisfying a second predetermined duration, the third switch of the third phase in the line relative to the first phase and the second phase is closed.

2. The method according to claim 1, further comprising: In response to receiving an abnormal signal indicating an abnormality in the line, the three-phase power supply to the line is disconnected; as well as Initialize the first timer and / or the second timer.

3. The method according to claim 1, further comprising: In response to the closing of the third switch, voltage information at the ends of the first switch, the second switch, and the third switch is acquired respectively; as well as In response to the voltage information at both ends of the first switch, the second switch and the third switch exceeding a predetermined threshold, the three-phase power supply of the line is disconnected.

4. The method according to claim 2 or 3, further comprising: A warning message is issued in response to the disconnection of the three-phase power supply to the line.

5. The method according to claim 1, further comprising: Determine the first scheduled duration, including: Obtain the closing angle information of the motor; Based on the closing angle information and the power supply frequency, determine the closing time related to the closing angle information; and The first predetermined duration is determined based on the closing time and the zero-crossing point of the line voltage.

6. The method according to claim 5, wherein obtaining the closing angle information of the motor includes: Obtain the power factor of the motor; as well as The closing angle information of the motor is determined based on the power factor of the motor.

7. The method according to claim 1, wherein the second predetermined duration is determined based on the characteristic parameters of the motor.

8. A device for reduced-voltage starting of a motor, comprising: The task module is configured as follows: Obtain a start command that instructs the motor to start; The data processing module is configured as follows: The line voltage between the first phase and the second phase in the line is determined based on the start command; as well as Determine the zero-crossing point of the line voltage; The control module is configured as follows: The first timing is initiated at the zero-crossing point of the line voltage; In response to the first timing satisfying a first predetermined duration, the first switch of the first phase and the second switch of the second phase are closed, the first predetermined duration being determined based on the zero-crossing point of the line voltage and the closing angle information of the motor; In response to the closure of the first switch and the second switch, a second timing is initiated; as well as In response to the second timing satisfying a second predetermined duration, the third switch of the third phase in the line relative to the first phase and the second phase is closed.

9. The apparatus of claim 8, wherein the task module is further configured to: In response to receiving an abnormal signal indicating an abnormality in the line, the three-phase power supply to the line is disconnected; and Initialize the first timer and / or the second timer.

10. The apparatus of claim 8, wherein the task module is further configured to: In response to the closing of the third switch, voltage information across the first switch, the second switch, and the third switch is acquired respectively; and In response to the voltage information at both ends of the first switch, the second switch and the third switch exceeding a predetermined threshold, the three-phase power supply of the line is disconnected.

11. The apparatus of claim 9 or 10, wherein the task module is further configured to issue a warning message in response to the disconnection of the three-phase power supply to the line.

12. The apparatus of claim 8, wherein the data processing module is further configured to: determine a first predetermined duration, including: Obtain the closing angle information of the motor; Based on the closing angle information and the power supply frequency, determine the closing time related to the closing angle information; as well as The first predetermined duration is determined based on the closing time and the zero-crossing point of the line voltage.

13. The apparatus according to claim 12, wherein obtaining the closing angle information of the motor includes: Obtain the power factor of the motor; The closing angle information of the motor is determined based on the power factor of the motor.

14. The apparatus of claim 8, wherein the second predetermined duration is determined based on characteristic parameters of the motor.

15. The apparatus according to any one of claims 8-10 and 12-14, wherein the latency of the data processing module is lower than the latency of the task module; and The delay of the control module is lower than that of the data processing module.

16. A computer-readable storage medium having stored thereon one or more computer instructions, wherein the one or more computer instructions are executed by a processor to implement the method according to any one of claims 1-7.

17. A computer program product comprising computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement the method according to any one of claims 1-7.

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