Motor state detection method and device based on current, equipment and storage medium

Abstract

The embodiment of the invention discloses a current-based motor state detection method and device, equipment and a storage medium. According to the scheme, the conduction state of the driving circuit can be adjusted through the control signal generated by the MCU, the first phase current and the second phase current in the driving circuit are collected, and the first voltage value, the second voltage value and the third voltage value in the three-phase motor are calculated according to the first phase current and the second phase current. And calculating motor state values corresponding to the first voltage value, the second voltage value and the third voltage value, determining a rotor position and a rotation direction in the three-phase motor according to the motor state values, and calculating a rotation speed of the three-phase motor. The state value of the motor is calculated by detecting the phase current in the driving circuit, so that various state parameters of the motor are determined, additional circuits or hardware do not need to be added, the cost can be effectively reduced, and the integration degree can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of drive motors, and in particular to a method, device, equipment and storage medium for detecting a motor state based on current. Background Art

[0002] When the motor is not driven, the motor may continue to rotate its rotor due to external force or inertia, which may be reverse or forward. When the driver wants to drive the motor, it needs to know the current motor status, such as forward or reverse, current speed and current position of the motor rotor, in order to achieve smooth connection and drive. The running status of the brushless DC motor can usually be detected by several methods: 1. Detect the magnetic field state of the motor through the hall sensor, 2. Calculate using the encoder and optical and mechanical principles, 3. Use the circuit to capture the back electromotive force voltage. The above methods can be used to obtain whether the motor is currently forward or reverse, the current speed, and the current position of the motor rotor.

[0003] However, the applicant found that the disadvantages of the Hall sensor and encoder optical encoder are that they require additional costs and are subject to installation field restrictions. The circuit method also requires additional circuits. The above three methods all require the use of additional I / O pins of the single chip (MCU), which will cause certain limitations for MCUs with low pin counts. Summary of the invention

[0004] The present application provides a current-based motor state detection method, device, equipment and storage medium, which can calculate the motor state value by detecting the phase current in the drive circuit, thereby determining various state parameters of the motor without adding additional circuits or hardware, which can effectively reduce costs and improve the degree of integration.

[0005] The present application provides a current-based motor state detection method, which is applied to a three-phase motor, wherein the three-phase motor includes an MCU and a drive circuit, including: Adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current; Calculating motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value; The rotor position and rotation direction of the three-phase motor are determined according to the motor state value, and the rotation speed of the three-phase motor is calculated.

[0006] Optionally, the driving circuit includes 6 electronic switches, namely 3 upper bridge arm electronic switches and 3 lower bridge arm electronic switches, and the control signal generated by the MCU adjusts the conduction state of the driving circuit, including: Controlling the MCU to generate a PWM signal with a preset duty cycle; The PWM signal is sent to three lower bridge arm electronic switches to turn on the three lower bridge arms in the driving circuit.

[0007] Optionally, after calculating the first voltage value, the second voltage value, and the third voltage value in the three-phase motor, the method further includes: Setting a preset value according to the acquisition range of the ADC in the driving circuit; Determining whether the first voltage value, the second voltage value or the third voltage value exceeds the preset value; If it does not exceed, the MCU is controlled to generate a PWM signal with a preset duty cycle, and the PWM signal is sent to all electronic switches to make the three upper bridge arms and the three lower bridge arms in the drive circuit complementary to each other.

[0008] Optionally, the calculating the motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value includes: Determine a first state value according to the first voltage value, determine a second state value according to the second voltage value, and determine a third state value according to the third voltage value; The sum of the first state value, the second state value and the third state value is calculated as the motor state value.

[0009] Optionally, determining the rotor position and rotation direction of the three-phase motor according to the motor state value includes: Determine the electrical angle interval of the current rotor corresponding to the motor state value; Sequentially acquiring a plurality of motor state values ​​within one rotation cycle of the rotor; The rotation direction of the three-phase motor is determined according to the transformation mode of the multiple motor state values.

[0010] Optionally, calculating the rotational speed of the three-phase motor includes: Obtain the single duration or total duration of the 6 motor state values ​​in sequence through the timer; The rotation speed of the three-phase motor is calculated according to the single duration or the total duration.

[0011] Optionally, the method further includes: Taking the rotor position of the three-phase motor as the initial position, and setting the initial voltage of the three-phase motor according to the rotation speed of the three-phase motor; The three-phase motor is driven to operate according to the rotation direction, initial position and initial voltage.

[0012] The present application also provides a current-based motor state detection device, which is applied to a three-phase motor. The three-phase motor includes an MCU and a drive circuit, including: A collection module, used for adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; A first calculation module, used for calculating a first voltage value, a second voltage value and a third voltage value in the three-phase motor according to the first phase current and the second phase current; A second calculation module, used for calculating the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value; A determination module is used to determine the rotor position and rotation direction of the three-phase motor according to the motor state value, and calculate the rotation speed of the three-phase motor.

[0013] The present application also provides an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of any one of the current-based motor state detection methods provided in the present application by calling the computer program stored in the memory.

[0014] The present application also provides a storage medium storing a computer program, wherein the computer program is suitable for being loaded by a processor to execute the steps in any one of the current-based motor state detection methods provided in the present application.

[0015] The current-based motor state detection method provided in the present application can adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit, calculate the first voltage value, the second voltage value and the third voltage value in the three-phase motor according to the first phase current and the second phase current, calculate the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value, determine the rotor position and rotation direction in the three-phase motor according to the motor state value, and calculate the speed of the three-phase motor. The present application calculates the motor state value by detecting the phase current in the drive circuit, thereby determining various state parameters of the motor, without adding additional circuits or hardware, which can effectively reduce costs and improve the degree of integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution in the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a flow chart of a method for detecting a motor state based on current provided in an embodiment of the present application; Figure 2 is a structural schematic diagram of a driving circuit provided in an embodiment of the present application; Figure 3 is another flow chart of a current-based motor state detection method provided in an embodiment of the present application; Figure 4 It is a waveform diagram of voltage values ​​and state values ​​in a three-phase motor provided in an embodiment of the present application; Figure 5 is a structural schematic diagram of a current-based motor state detection device provided in an embodiment of the present application; Figure 6 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0019] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0020] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are displayed in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and it can be performed in other orders. Moreover, at least a portion of the steps in the figure may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0021] It should be noted that, in this article, step codes such as 101, 102, etc. are used for the purpose of expressing the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the sequence. When implementing the step, those skilled in the art may execute 102 first and then 101, etc., but these should all be within the scope of protection of this application.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] An embodiment of the present application provides a current-based motor state detection method, and the executor of the current-based motor state detection method can be the current-based motor state detection device provided in the embodiment of the present application, or a server integrated with the current-based motor state detection device, wherein the current-based motor state detection device can be implemented in hardware or software.

[0024] like Figure 1 As shown, Figure 1 1 is a schematic diagram of a first process flow of a motor state detection method based on current provided in an embodiment of the present application. The specific process flow of the motor state detection method based on current may be as follows: 101. Adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit.

[0025] In one embodiment, the above-mentioned current-based motor state detection method is applied to a three-phase motor, which includes an MCU and a drive circuit. The structure of the drive circuit is shown in FIG. Figure 2, wherein the drive circuit is a three-phase inverter circuit, which may include a DC power supply to provide DC power for the entire drive circuit. Further, Q1-Q6 is composed of 6 electronic switches, such as MOSFET or IGBT, etc. Taking MOSFET as an example, these 6 MOSFETs are power switch devices in the circuit, which are used to control the on and off and flow direction of the current, thereby realizing the drive and control of the motor. Its working principle is that when the gate (G1-G6) of the MOSFET receives a control signal from the MCU (microcontroller), the MOSFET will be turned on or off. For example, by controlling the conduction timing and combination of Q1-Q3 and Q4-Q6, different current loops can be formed, so that three-phase AC is applied to the motor to drive the motor to rotate. Different conduction modes can realize the functions of forward rotation, reverse rotation, speed regulation, etc. of the motor.

[0026] In one embodiment, the drive circuit can adopt a three-phase bridge inverter structure, including six power switching devices, forming three bridge arms, each bridge arm having two upper and lower switches. The MCU (microcontroller) is the core of the entire motor control system, which generates corresponding control signals according to a preset algorithm or user input. These control signals are usually PWM (pulse width modulation) signals, which are used to control the on and off of power switching devices (such as MOSFET or IGBT) in the drive circuit. The duty cycle, frequency and phase of the PWM signal can be accurately adjusted according to the operating requirements of the motor. For example, in a three-phase motor drive, the MCU will output three different PWM signals to control the upper and lower bridge arm switches (G4, G5, G6) of the three-phase bridge arm, forming different conduction combinations, and realizing different drive modes for the motor. The above-mentioned step of adjusting the conduction state of the drive circuit by the control signal generated by the MCU may include: controlling the MCU to generate a PWM signal with a duty cycle of 50%, and sending the PWM signal to the three lower bridge arm electronic switches to turn on the three lower bridge arms in the drive circuit.

[0027] Furthermore, Figure 2G1-G6 in it are used to receive control signals from the MCU, which determine the on and off states of the corresponding MOSFET. O1-O3 are inverter output signals, which are used to connect to the motor, so as to output the three-phase AC voltage after inverter inversion to the motor to drive the motor to operate. The parameters such as frequency, amplitude and phase of the output three-phase AC voltage can be adjusted according to the control signal of the MCU, so as to realize flexible control of the operating states such as motor speed and torque. RA and RB are current sampling resistors. Specifically, RA and RB can be connected in series in the lower bridge arm to sample the phase current of the motor. When the motor is running, the phase current will flow through these sampling resistors, and a voltage drop proportional to the current will be generated at both ends of the resistor. By measuring the voltage across the sampling resistor and combining the resistance value of the resistor, the current flowing through the resistor, that is, the phase current of the motor, can be calculated. These sampled current signals (that is Figure 2 The CurrA and CurrB in the current information will be transmitted to the MCU, which will implement closed-loop control, status monitoring and protection of the motor based on this current information. This drive circuit architecture is mainly used to convert DC power into three-phase AC power to drive a three-phase motor.

[0028] 102. Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current.

[0029] In one embodiment, according to the electrical characteristics and circuit principles of the motor, after the collected phase current information represented by CurrA and CurrB is known, the first voltage value, the second voltage value and the third voltage value in the three-phase motor can be calculated by a specific formula. For example, Va=-CurrA, Vb=-CurrB, Vc=-Va-Vb.

[0030] In one embodiment, when calculating the voltage value, the running state of the motor and the nonlinear factors of the circuit need to be considered. For example, when the motor is running at high speed and low speed, the resistance and inductance of its winding may change, which is caused by skin effect and magnetic saturation. Therefore, in the actual algorithm implementation, this embodiment also needs to determine whether the motor is in a high speed state. For example, a preset value can be set according to the acquisition range of the ADC in the drive circuit, and then it is determined whether the first voltage value, the second voltage value or the third voltage value exceeds the preset value. If it exceeds, it is determined that the motor is currently in a high-speed state; if it does not exceed, it is determined that the motor is currently in a low-speed state. At this time, the MCU can be controlled to generate a PWM signal with a 50% duty cycle, and the PWM signal is sent to all electronic switches (G1, G2, G3, G4, G5, G6) to make the three upper bridge arms and the three lower bridge arms in the drive circuit complementary to each other. At this time, the inertial operation of the motor will generate a back electromotive force, and a phase current will be generated through the lower three arms of the electronic switch. The current back electromotive force state is known through the MCU collecting signals CurrA and CurrB. Since the upper and lower three arms are complementary to each other at this time, the back electromotive force at this time will generate a larger phase current, thereby compensating for the low back electromotive force at low speed.

[0031] 103. Calculate motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value.

[0032] Among them, the motor state value is an indicator that comprehensively reflects the operating status of the motor, and it is closely related to the calculated first voltage value, second voltage value and third voltage value. In this embodiment, the motor state value can be defined according to the positive and negative conditions of the first voltage value, the second voltage value and the third voltage value. In other embodiments, calculations can also be performed based on the power equation and efficiency model of the motor. For example, the input power of the motor can be calculated according to the three-phase power formula P=3VphIphcosφ (where Vph is the phase voltage, Iph is the phase current, and cosφ is the power factor), and then the relationship between the output power and input power of the motor (efficiency η=Pout / Pin) and the torque-speed characteristics of the motor (such as for a brushless DC motor, the electromagnetic torque T=Kt*Ia, where Kt is the torque constant and Ia is the phase current) are combined to comprehensively evaluate the state of the motor. Through these calculations, information such as the load degree of the motor, the efficiency, whether it is in the normal operating range, etc. can be obtained, and this information can be integrated into the motor state value, which will not be further described in this embodiment.

[0033] 104. Determine the rotor position and rotation direction of the three-phase motor according to the motor state value, and calculate the rotation speed of the three-phase motor.

[0034] In one embodiment, the rotor position in the three-phase motor is determined based on the calculated motor state value, and different motor state values ​​correspond to different rotor position intervals, such as when Section=2, the rotor position is between 0-60 degrees; when Section=3, the rotor position is between 60-120 degrees, etc. This determination method based on the relationship between voltage and rotor position utilizes the change law of the back electromotive force during the rotation of the motor and the phase relationship of the three-phase voltage. In practical applications, in order to improve the accuracy of the rotor position, the electromagnetic parameters of the motor can also be accurately calibrated, and dynamic compensation can be performed in combination with the motor speed and load conditions.

[0035] Correspondingly, the rotation direction of the motor can also be determined based on the change rule of the motor state value, and the rotation direction of the motor can be accurately determined by monitoring the continuous change sequence of the Section value. As for the calculation of the rotation speed, this embodiment can calculate the time required for the rotor to rotate one circle by a timing measurement method, and thus calculate the rotation speed of the three-phase motor based on the time.

[0036] In one embodiment, the method may further include: taking the rotor position in the three-phase motor as the initial position, setting the initial voltage of the three-phase motor according to the rotation speed of the three-phase motor, and driving the three-phase motor to operate according to the rotation direction, the initial position and the initial voltage. Specifically, in the driving of the permanent magnet motor, the closed-loop operation requires accurate knowledge of the rotor position, which determines the commutation moment and phase of the current in the motor winding, and thus affects the torque and speed output of the motor. If the rotor position is unknown, the operating state of the motor cannot be accurately controlled. Therefore, this embodiment can also directly cut into the closed-loop operation of the motor when it is known that the motor is rotating forward, and give the measured rotor position as the initial position to the internal algorithm. Thereby achieving smooth switching of the motor, that is, allowing the motor to smoothly transition from the current state to the closed-loop control state, avoiding unstable motor operation due to sudden switching of the control mode, such as jitter, loss of step and other phenomena.

[0037] Furthermore, the above speed can also be given to the phase-locked loop, so that the characteristics of the phase-locked loop can be used to make the speed estimation converge to the actual value more quickly, thereby improving the accuracy and speed of speed estimation. In addition, when switching into closed-loop operation or other operating states, the initial value of the three-phase voltage can also be given according to the speed at this time. This is because the internal electromagnetic relationship and operating characteristics of the motor are different at different speeds. If the initial voltage setting is unreasonable, it may cause the motor to run unsteadily, or even cause faults such as overcurrent and overvoltage.

[0038] As described above, the current-based motor state detection method proposed in the embodiment of the present application can adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit, calculate the first voltage value, the second voltage value and the third voltage value in the three-phase motor according to the first phase current and the second phase current, calculate the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value, determine the rotor position and rotation direction in the three-phase motor according to the motor state value, and calculate the speed of the three-phase motor. The present application calculates the motor state value by detecting the phase current in the drive circuit, thereby determining various state parameters of the motor, without adding additional circuits or hardware, which can effectively reduce costs and improve the degree of integration.

[0039] The method described in the above embodiment will be further described below.

[0040] See also Figure 3 , Figure 3 1 is a second flow chart of a current-based motor state detection method provided in an embodiment of the present application. The method comprises: 201. Adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit.

[0041] In one embodiment, the MCU, as the core control unit, generates a specific control signal according to the preset program logic and the motor operation requirements, which may be a PWM signal with a duty cycle of 50%. Figure 2 In the three-phase inverter circuit architecture, the signal is sent to G4 / G5 / G6 (corresponding to the control end of the lower three-arm switch). When these control signals act on the electronic switch (such as MOSFET), the lower three-arm switch will be turned on or off according to a certain timing. This change in conduction state is the basis for realizing motor control. Different conduction combinations can guide the flow of current in the motor winding, thereby generating different magnetic field effects, driving the motor to operate or affecting its electrical state when the motor is inertial operation.

[0042] It should be noted that during the inertial operation of the motor, the electromagnetic induction phenomenon inside the motor will generate a back electromotive force. This back electromotive force will drive the current to flow in the circuit. When the current passes through the series resistor of the lower bridge arm (micro-current sampling resistors RA and RB), a voltage drop will be formed across the resistor. Through the above circuit connection, this voltage drop signal can be converted into CurrA and CurrB signals and transmitted to the MCU. The analog-to-digital conversion module inside the MCU will convert these analog signals into digital quantities, thereby realizing the accurate acquisition of the motor phase current. In this process, factors such as the accuracy of the sampling resistor, the anti-interference ability of the circuit, and the sampling frequency of the MCU will affect the accuracy of the acquisition results. For example, a high-precision sampling resistor can more accurately reflect the current size, while a higher MCU sampling frequency can capture faster current changes, providing a guarantee for subsequent accurate calculations.

[0043] 202. Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current.

[0044] In one embodiment, according to the electrical characteristics and circuit principles of the motor, after the collected phase current information represented by CurrA and CurrB is known, the first voltage value, the second voltage value and the third voltage value in the three-phase motor can be calculated by a specific formula. For example, Va=-CurrA, Vb=-CurrB, Vc=-Va-Vb, and the waveform diagrams of Va, Vb, and Vc obtained can be referred to Figure 4 The calculation principle here is based on the equivalent circuit model of the motor and the law of electromagnetic induction. During the operation of the three-phase motor, there is a close coupling relationship between the phase current and the phase voltage. The corresponding voltage value can be calculated by measuring the current and performing specific mathematical transformations. The accuracy of this calculation method depends on the accuracy of the motor parameters, such as the resistance and inductance of the motor winding. In practical applications, the motor parameters can be identified or empirical values ​​can be used to improve the calculation accuracy.

[0045] 203. Determine a first state value according to the first voltage value, determine a second state value according to the second voltage value, and determine a third state value according to the third voltage value.

[0046] 204. Calculate the sum of the first state value, the second state value, and the third state value as the motor state value.

[0047] Specifically, the specific process of calculating the motor state value according to the first voltage value (Va), the second voltage value (Vb) and the third voltage value (Vc) in this embodiment is as follows: First, the positive and negative conditions of Va, Vb and Vc are judged. If Va>0, let a=4; otherwise, a=0. If Vb>0, then b=2; otherwise, b=0. If Vc>0, then c=1; otherwise, c=0. Then, the motor state value is calculated by the formula Section=a+b+c. For example, when a=0, b=2, c=0, Section=2, this Section value represents the specific operating state information of the motor under the current electrical state, as the above-mentioned values ​​of Va, Vb and Vc change, such as Figure 4 As shown, the motor state value is intrinsically linked to the motor's rotor position, rotation direction, speed and other parameters. Different motor state value combinations correspond to different motor operating conditions. The motor's precise operating state can be further determined based on these motor state values, thereby providing key state feedback information for the entire motor control system and achieving effective control and monitoring of the motor.

[0048] 205. Determine the electrical angle interval of the current rotor corresponding to the motor state value.

[0049] This embodiment introduces Section as the motor state value, and calculates the Section value by judging the positive and negative conditions of Va, Vb, and Vc. Different Section values ​​correspond to different rotor position intervals. For example, when Section=2, the rotor position is 0-60 degrees; when Section=3, the rotor position is 60-120 degrees, when Section=1, the rotor position is 120-180 degrees, when Section=6, the rotor position is 180-240 degrees, when Section=4, the rotor position is 240-300 degrees, and when Section=5, the rotor position is 200-360 degrees.

[0050] 206. Acquire a plurality of motor state values ​​in sequence within one rotation cycle of the rotor, and determine the rotation direction of the three-phase motor according to a transformation method of the plurality of motor state values.

[0051] Furthermore, the rotation direction of the motor can be determined based on the change rule of Section. For example, when the motor rotates forward, the change mode of Section is 2→3→1→5→4→6→…; when the motor rotates reversely, the change mode of Section is 6→4→5→1→3→2→…. Therefore, this embodiment can accurately determine the rotation direction of the motor by monitoring the continuous change order of Section value.

[0052] 207. Obtain the individual durations and the total durations of the six motor state values ​​in sequence through a timer, and calculate the rotation speed of the three-phase motor according to the individual durations or the total durations.

[0053] Among them, for the calculation of the rotational speed, this embodiment can adopt a timing measurement method. Specifically, when it is determined that the motor is in a high-speed state, the change of six consecutive Sections is used as a sign that the motor has run one circle. Use the timer inside the MCU to record the total time T_total of these six intervals, and then calculate the speed of the motor according to the formula Speed ​​(hz) = 1 / T_total. In addition, only a single duration or multiple single durations (such as 2-5) can be used to deduce the total time T_total required for the motor to run one circle, and then calculate the speed of the motor. This embodiment does not make further limitations on this.

[0054] As described above, the current-based motor state detection method proposed in the embodiment of the present application can adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit, calculate the first voltage value, the second voltage value and the third voltage value in the three-phase motor according to the first phase current and the second phase current, determine the first state value according to the first voltage value, determine the second state value according to the second voltage value, determine the third state value according to the third voltage value, calculate the sum of the first state value, the second state value and the third state value as the motor state value, determine the motor state value corresponding to the electrical angle interval of the current rotor, obtain multiple motor state values ​​in sequence within a rotation cycle of the rotor, determine the rotation direction in the three-phase motor according to the transformation mode of the multiple motor state values, obtain the total duration of the six motor state values ​​in sequence through the timer, and calculate the speed of the three-phase motor according to the total duration. The present application calculates the motor state value by detecting the phase current in the drive circuit, thereby determining the various state parameters of the motor, without adding additional circuits or hardware, which can effectively reduce costs and improve the degree of integration.

[0055] In order to implement the above method, an embodiment of the present application further provides a current-based motor state detection device, which can be specifically integrated into a terminal device such as a mobile phone, a tablet computer, and the like.

[0056] For example, Figure 5 , which is a schematic diagram of a first structure of a current-based motor state detection device provided in an embodiment of the present application. The current-based motor state detection device may include: The acquisition module 301 is used to adjust the conduction state of the drive circuit through the control signal generated by the MCU, and to acquire the first phase current and the second phase current in the drive circuit; A first calculation module 302, configured to calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current; A second calculation module 303, used to calculate the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value; The determination module 304 is used to determine the rotor position and rotation direction of the three-phase motor according to the motor state value, and calculate the rotation speed of the three-phase motor.

[0057] As can be seen from the above, the current-based motor state detection device proposed in the embodiment of the present application can adjust the conduction state of the drive circuit through the control signal generated by the MCU, and collect the first phase current and the second phase current in the drive circuit, calculate the first voltage value, the second voltage value and the third voltage value in the three-phase motor according to the first phase current and the second phase current, calculate the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value, determine the rotor position and rotation direction in the three-phase motor according to the motor state value, and calculate the speed of the three-phase motor. The present application calculates the motor state value by detecting the phase current in the drive circuit, thereby determining various state parameters of the motor, without adding additional circuits or hardware, which can effectively reduce costs and improve the degree of integration.

[0058] All of the above technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described in detail here.

[0059] A person of ordinary skill in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0060] To this end, an embodiment of the present application provides a computer-readable storage medium, in which a plurality of computer programs are stored, and the computer program can be loaded by a processor to execute the steps in any current-based motor state detection method provided in the embodiment of the present application. For example, the computer program can execute the following steps: Adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current; Calculating motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value; The rotor position and rotation direction of the three-phase motor are determined according to the motor state value, and the rotation speed of the three-phase motor is calculated.

[0061] The specific implementation of the above operations can be found in the previous embodiments, which will not be described in detail here.

[0062] The storage medium may include: a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0063] Since the computer program stored in the storage medium can execute the steps in any current-based motor state detection method provided in the embodiments of the present application, the beneficial effects that can be achieved by any current-based motor state detection method provided in the embodiments of the present application can be achieved. Please see the previous embodiments for details and will not be repeated here.

[0064] An embodiment of the present application also provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the device equipped with the chip executes the methods in various possible implementation modes as described above.

[0065] For example, the computer device mentioned above may be a terminal device with corresponding functions such as a mobile phone, a tablet computer, a personal computer, a cloud computer, etc. Figure 6 , Figure 6 A schematic diagram of the structure of a computer provided in an embodiment of the present application.

[0066] The computer device 400 may include components such as a memory 401 and a processor 402. Those skilled in the art will appreciate that Figure 6 The computer device structure shown in the figure does not constitute a limitation on the computer device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0067] The memory 401 may be used to store applications and data. The applications stored in the memory 401 include executable codes. The applications may be composed of various functional modules. The processor 402 executes various functional applications and data processing by running the applications stored in the memory 401.

[0068] Processor 402 is the control center of the computer device. It uses various interfaces and lines to connect the various parts of the entire computer device. By running or executing applications stored in memory 401 and calling data stored in memory 401, it executes various functions of the computer device and processes data, thereby monitoring the computer device as a whole.

[0069] In this embodiment, the processor 402 in the computer device will load the executable code corresponding to the process of one or more application programs into the memory 401 according to the following instructions, and the processor 402 will run the application program stored in the memory 401 to execute: Adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current; Calculating motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value; The rotor position and rotation direction of the three-phase motor are determined according to the motor state value, and the rotation speed of the three-phase motor is calculated.

[0070] It is understood that the above scenarios are only examples and do not constitute a limitation on the application scenarios of the technical solutions provided in the embodiments of the present application. The technical solutions of the present application can also be applied to other scenarios. For example, it is known to those skilled in the art that with the evolution of the system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0071] The steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs. The modules in the device of the embodiment of the present application can be combined, divided and deleted according to actual needs.

[0072] In the present application, the same or similar terminology concepts, technical solutions and / or application scenario descriptions are generally described in detail only the first time they appear. When they appear again later, they are generally not repeated for the sake of brevity. When understanding the technical solutions and other contents of the present application, for the same or similar terminology concepts, technical solutions and / or application scenario descriptions that are not described in detail later, reference can be made to the previous related detailed descriptions.

[0073] In the present application, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0074] The various technical features of the technical solution of the present application can be arbitrarily combined. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present application.

[0075] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that can be accessed by the computer or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a storage disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state storage disk Solid State Disk), etc.

[0076] The above is a detailed introduction to the current-based motor state detection method, device, equipment and storage medium provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A motor state detection method based on current, applied to a three-phase motor, wherein the three-phase motor includes an MCU and a drive circuit, characterized in that: include: Adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; Calculate a first voltage value, a second voltage value, and a third voltage value in the three-phase motor according to the first phase current and the second phase current; Calculating motor state values ​​corresponding to the first voltage value, the second voltage value, and the third voltage value; The rotor position and rotation direction of the three-phase motor are determined according to the motor state value, and the rotation speed of the three-phase motor is calculated.

2. The motor state detection method based on current according to claim 1, characterized in that: The driving circuit includes 6 electronic switches, which are 3 upper bridge arm electronic switches and 3 lower bridge arm electronic switches. The control signal generated by the MCU adjusts the conduction state of the driving circuit, including: Controlling the MCU to generate a PWM signal with a preset duty cycle; The PWM signal is sent to three lower bridge arm electronic switches to turn on the three lower bridge arms in the driving circuit.

3. The motor state detection method based on current according to claim 2, characterized in that: After calculating the first voltage value, the second voltage value and the third voltage value in the three-phase motor, the method further includes: Setting a preset value according to the acquisition range of the ADC in the driving circuit; Determining whether the first voltage value, the second voltage value or the third voltage value exceeds the preset value; If it does not exceed, the MCU is controlled to generate a PWM signal with a preset duty cycle, and the PWM signal is sent to all electronic switches to make the three upper bridge arms and the three lower bridge arms in the drive circuit complementary to each other.

4. The motor state detection method based on current according to claim 1, characterized in that: The calculating the motor state value corresponding to the first voltage value, the second voltage value, and the third voltage value includes: Determine a first state value according to the first voltage value, determine a second state value according to the second voltage value, and determine a third state value according to the third voltage value; The sum of the first state value, the second state value and the third state value is calculated as the motor state value.

5. The motor state detection method based on current according to claim 1, characterized in that: Determining the rotor position and rotation direction of the three-phase motor according to the motor state value includes: Determine the electrical angle interval of the current rotor corresponding to the motor state value; Sequentially acquiring a plurality of motor state values ​​within one rotation cycle of the rotor; The rotation direction of the three-phase motor is determined according to the transformation mode of the multiple motor state values.

6. The motor state detection method based on current according to claim 2, characterized in that: The calculating the rotation speed of the three-phase motor comprises: The individual duration and total duration of the six motor status values ​​are obtained in sequence through the timer; The rotation speed of the three-phase motor is calculated according to the single duration or the total duration.

7. The motor state detection method based on current according to any one of claims 1 to 6, characterized in that: The method further comprises: Taking the rotor position of the three-phase motor as the initial position, and setting the initial voltage of the three-phase motor according to the rotation speed of the three-phase motor; The three-phase motor is driven to operate according to the rotation direction, initial position and initial voltage.

8. A current-based motor state detection device, applied to a three-phase motor, wherein the three-phase motor includes an MCU and a drive circuit, characterized in that: include: A collection module, used for adjusting the conduction state of the drive circuit through the control signal generated by the MCU, and collecting the first phase current and the second phase current in the drive circuit; A first calculation module, used for calculating a first voltage value, a second voltage value and a third voltage value in the three-phase motor according to the first phase current and the second phase current; A second calculation module, used for calculating the motor state value corresponding to the first voltage value, the second voltage value and the third voltage value; A determination module is used to determine the rotor position and rotation direction of the three-phase motor according to the motor state value, and calculate the rotation speed of the three-phase motor.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps in the current-based motor state detection method according to any one of claims 1 to 7 by calling the computer program stored in the memory.

10. A storage medium, characterized in that: The storage medium stores a computer program, and the computer program is suitable for being loaded by a processor to execute the steps in the current-based motor state detection method according to any one of claims 1-7.

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