Motor control method, device, control circuit and PG motor

Abstract

The application relates to a motor control method, a motor control device, a control circuit and a PG motor. The motor control method comprises the following steps: in the case that a preset conduction angle adjustment period arrives, obtaining a current motor speed; obtaining a speed increment value according to a last motor speed, a target motor speed and the current motor speed, and determining a first conduction angle of a first half cycle of an alternating-current power supply based on the speed increment value; in the case that a feedback signal transmitted by a zero-crossing detection circuit is received, controlling a motor drive circuit by using the first conduction angle; the feedback signal is obtained by zero-crossing point collection of a live wire or a zero line through the zero-crossing detection circuit; in the case that the motor drive circuit is controlled by using the first conduction angle, controlling the motor drive circuit by using a second conduction angle; the second conduction angle is a conduction angle of a second half cycle of the alternating-current power supply, which is determined according to a frequency of the alternating-current power supply. The application can reduce the circuit cost and the noise of the fan.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a motor control method, device, control circuit, and PG motor. Background Technology

[0002] A PG motor (single-phase asynchronous motor) is an AC motor with speed feedback, essentially a single-phase AC motor with a Hall effect sensor. When the AC power is switched on, a current phase difference exists between the main winding and the auxiliary winding, creating a two-phase current that causes the stator magnetic field to rotate. For a PG motor, the speed depends on the voltage at which the thyristor is turned on; a higher voltage results in a higher speed, and a lower voltage results in a lower speed.

[0003] During the implementation process, the inventors discovered at least the following problems in traditional technologies: traditional motor control schemes suffer from cost waste. Summary of the Invention

[0004] Therefore, it is necessary to provide a motor control method, device, control circuit, and PG motor that can reduce costs in response to the above-mentioned technical problems.

[0005] To achieve the above objectives, one embodiment of this application provides a motor control method, including:

[0006] When the preset conduction angle adjustment period arrives, the motor speed is obtained.

[0007] Based on the previous motor speed, the target motor speed, and the current motor speed, the speed increment value is obtained, and the first conduction angle of the first half-cycle of the AC power supply is determined based on the speed increment value.

[0008] Upon receiving the feedback signal transmitted by the zero-crossing detection circuit, the motor drive circuit is controlled using the first conduction angle; the feedback signal is obtained by collecting the zero-crossing point of the live wire or neutral wire through the zero-crossing detection circuit.

[0009] When the motor drive circuit is controlled by the first conduction angle, the motor drive circuit is controlled by the second conduction angle; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply, which is determined according to the frequency of the AC power supply.

[0010] In one embodiment, the speed increment is the difference between a first variable and a second variable; the first variable is the difference between the current motor speed and the previous motor speed; the second variable is the difference between the current motor speed and the target motor speed.

[0011] In one embodiment, before obtaining the current motor speed when the preset conduction angle adjustment period arrives, the following steps are included:

[0012] Obtain the target motor speed and determine the initial conduction angle based on the AC power supply voltage of a preset multiple;

[0013] The conduction angle adjustment mode is determined based on the crystal oscillator frequency of the clock source and the preset conduction angle adjustment period; the conduction angle adjustment mode includes PID adjustment.

[0014] In one embodiment, the feedback signal is a falling edge signal;

[0015] When the feedback signal is obtained by zero-crossing acquisition through the zero detection circuit of the live wire, the first half-cycle of the AC power supply is the positive half-cycle of the AC power supply, and the second half-cycle of the AC power supply is the negative half-cycle of the AC power supply.

[0016] A motor control device, comprising:

[0017] The speed acquisition module is used to acquire the current motor speed when the preset conduction angle adjustment cycle arrives;

[0018] The incremental value acquisition module is used to obtain the speed increment value based on the previous motor speed, the target motor speed, and the current motor speed;

[0019] The drive control module is used to determine the first conduction angle of the first half-cycle of the AC power supply based on the speed increment value, and to control the motor drive circuit using the first conduction angle when a feedback signal is received from the zero-crossing detection circuit; the feedback signal is obtained by collecting the zero-crossing point of the live wire or neutral wire through the zero-crossing detection circuit; and to control the motor drive circuit using a second conduction angle when the first conduction angle control is completed; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the AC power supply frequency.

[0020] A motor control circuit, comprising:

[0021] The zero-crossing detection circuit has its input terminal connected to either the live wire or the neutral wire; it is used to collect the zero-crossing point of the live wire or the neutral wire.

[0022] Controller; one end of the controller is connected to the output of the zero-crossing detection circuit, and the other end is used to connect to the motor drive circuit;

[0023] The controller is used to execute the steps of the motor control method described above.

[0024] In one embodiment, the zero-crossing detection circuit includes a sampling module, an optocoupler, and a shaping circuit connected in sequence;

[0025] The sampling module includes a first resistor, a second resistor, a third resistor, and a fourth resistor connected in sequence; one end of the first resistor is used to connect to the live wire or the neutral wire, and the other end is connected to one end of the fourth resistor in sequence through the second resistor and the third resistor; the other end of the fourth resistor is connected to the anode of the optocoupler; the cathode of the optocoupler is used for grounding.

[0026] The collector of the optocoupler is connected to an external power supply, and the emitter is connected to one end of the shaping circuit. The shaping circuit includes a transistor, a fifth resistor, a sixth resistor, and a first capacitor. The base of the transistor is connected to the emitter of the optocoupler, and the collector of the transistor is connected to one end of the fifth resistor and one end of the sixth resistor, respectively. The other end of the fifth resistor is connected to an external power supply, and the other end of the sixth resistor is connected to the controller and one end of the first capacitor, respectively. The other end of the first capacitor and the emitter of the transistor are both grounded.

[0027] The zero-crossing detection circuit also includes a seventh resistor, an eighth resistor, a ninth resistor, and a second capacitor; one end of the seventh resistor is connected between the other end of the fourth resistor and the anode of the optocoupler, and the other end is used for grounding; the eighth resistor is connected between the base of the transistor and the emitter of the optocoupler; one end of the ninth resistor is connected between the eighth resistor and the emitter of the optocoupler, and the other end is used for grounding; one end of the second capacitor is connected between the eighth resistor and the emitter of the optocoupler, and the other end is used for grounding.

[0028] A PG motor includes a motor drive circuit and a motor control circuit as described above connected to the motor drive circuit.

[0029] In one embodiment, the motor drive circuit is an air conditioner indoor unit motor drive circuit.

[0030] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0031] One of the above technical solutions has the following advantages and beneficial effects:

[0032] This application proposes to control the motor drive circuit using a first conduction angle upon receiving a feedback signal from the zero-crossing detection circuit. This feedback signal is obtained by sampling the zero-crossing point of the live wire or neutral wire through the zero-crossing detection circuit. In other words, this application proposes to use single-sided sampling to collect the zero-crossing point of the L or N wire in the circuit, which can enable the motor to operate normally under various working conditions, reducing circuit components and lowering circuit costs. At the same time, this application proposes to immediately use a second conduction angle for direct control after the first conduction angle control is completed. That is, the fan conduction angle is controlled by estimating the time of the next zero-crossing point, which can better avoid control differences caused by interference and hardware delay, and reduce fan noise. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is an application environment diagram of the motor control method in one embodiment;

[0035] Figure 2 This is a flowchart illustrating a motor control method in one embodiment;

[0036] Figure 3 This is a flowchart illustrating the motor control method in another embodiment;

[0037] Figure 4 This is a structural block diagram of the motor control device in one embodiment;

[0038] Figure 5 This is a schematic diagram of the circuit structure of the motor control circuit in one embodiment;

[0039] Figure 6 This is a schematic diagram of the circuit structure of a zero-crossing detection circuit in one embodiment. Detailed Implementation

[0040] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0042] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

[0043] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0044] It should be noted that when one element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediary element. Furthermore, in the following embodiments, "connection" should be understood as "electrical connection," "communication connection," etc., if there is transmission of electrical signals or data between the connected objects.

[0045] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0046] To control the voltage level of a thyristor during conduction, it's necessary to detect the power supply frequency and its zero-crossing point. However, traditional solutions primarily use two resistors to acquire the AC voltage's zero-crossing point, which leads to cost waste in the circuit design.

[0047] This application employs single-sided sampling (using only one resistor in the circuit to collect data at the zero-crossing point of the L or N line) and estimates the time of the next zero-crossing point to control the fan conduction angle, thereby enabling the PG motor to operate normally under various working conditions and reducing fan noise. To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description, in conjunction with the accompanying drawings and embodiments, further illustrates this application. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0048] The motor control method provided in this application can be applied to indoor units of air conditioners, specifically to applications such as... Figure 1 In the application environment shown, the controller 102 uses a zero-crossing detection circuit 104 to collect the zero-crossing point of the live wire (L line) or neutral wire (N line) through single-sided sampling. When the controller 102 receives the feedback signal output by the zero-crossing detection circuit 104, it obtains the corresponding conduction angle to control the motor of the indoor unit 106. The indoor unit 106 may include a PG motor, and the controller 102 can control the speed of the PG motor by controlling the conduction angle of the thyristor in the motor drive circuit.

[0049] It should be noted that the zero-crossing detection circuit 104 can be used to detect zero crossings of a switching power supply, which can be an AC power supply. The controller 102 can be implemented using an MCU (Microcontroller Unit).

[0050] In one embodiment, such as Figure 2 As shown, a motor control method is provided, which is applied to... Figure 1 Taking the controller in the example, the following steps are included:

[0051] Step 202: When the preset conduction angle adjustment cycle arrives, obtain the current motor speed.

[0052] The preset conduction angle adjustment period refers to a pre-set time interval at which the motor's conduction angle is controlled. Taking a PG motor as an example, the speed of a PG motor can change under different conditions. Therefore, this application proposes to control the motor's conduction angle at certain intervals. In some embodiments, the value of the preset conduction angle adjustment period can be adjusted, for example, based on experience or obtained experimentally. In one embodiment, the preset conduction angle adjustment period can be 200ms, meaning that the conduction angle is adjusted after 200ms.

[0053] Furthermore, in the adjustment of the conduction angle by the controller of this application, PID (Proportion-Integration-Derivative) regulation can be adopted.

[0054] Specifically, when the preset conduction angle adjustment cycle arrives, the controller can obtain the current motor speed and determine the conduction angle based on the current motor speed.

[0055] Step 204: Based on the previous motor speed, the target motor speed, and the current motor speed, obtain the speed increment value, and determine the first conduction angle of the first half-cycle of the AC power supply based on the speed increment value.

[0056] Specifically, after obtaining the current motor speed, the controller can obtain the previous motor speed and the target motor speed. The target motor speed can be set before the preset conduction angle adjustment cycle arrives. In some embodiments, the target motor speed can be determined based on the target wind speed, which can be set by the user and is generally 500-1500 RPM (revolutions per minute).

[0057] Furthermore, the controller can obtain the speed increment value based on the previous motor speed, the target motor speed, and the current motor speed. That is, using the current speed (i.e., the current motor speed), the previous speed (i.e., the previous motor speed), and the set speed (i.e., the target motor speed) for calculation, using PID control (the final formula can be PD adjustment), the two sets of variables: the current speed and the previous speed, and the current speed and the set speed, together generate an increment value (i.e., the speed increment value), and calculate the conduction angle 1 (i.e., the first conduction angle).

[0058] In some embodiments, the conduction angle in this application can be obtained using the following formula:

[0059] Conduction angle = (previous wind speed - current wind speed) + (set wind speed - current wind speed) / 2;

[0060] The previous wind speed can be obtained from the previous rotation speed, the current wind speed can be obtained from the current rotation speed, and the set wind speed can be obtained from the set rotation speed (target motor speed).

[0061] In one embodiment, the speed increment is the difference between a first variable and a second variable; the first variable is the difference between the current motor speed and the previous motor speed; the second variable is the difference between the current motor speed and the target motor speed.

[0062] Specifically, taking the first variable as 'a' and the second variable as 'b' as an example, the difference between the current rotational speed and the previous rotational speed is taken as variable 'a', and the difference between the current rotational speed and the set rotational speed is taken as variable 'b'. The difference between the two variables 'a' and 'b' is an increment value (rotational speed increment). Therefore, the first conduction angle can be calculated based on this rotational speed increment value.

[0063] The power cycle has an upper and lower half-cycle. In this application, one power cycle of the AC power supply can include a first half-cycle and a second half-cycle. For example, a complete power cycle can be divided into two half-cycles, the first being the upper half-cycle and the second the lower half-cycle. Alternatively, if the power cycle is a sine wave, the upper and lower half-cycles refer to the upper and lower halves of the sine wave, respectively. In some embodiments, the AC power cycle of this application can include a positive half-cycle and a negative half-cycle of the AC power supply.

[0064] The first conduction angle is the conduction angle of the first half-cycle of the AC power supply. The first conduction angle can only be used and control can be performed after the controller estimates the conduction angle of the next cycle (the second conduction angle). Specifically, the first conduction angle is applied after the zero point of the first half-cycle.

[0065] It should be noted that this application proposes to use single-sided sampling. Due to hardware (hardware resistor voltage division) limitations, the upper or lower half-cycle may be inaccurate. That is, with single-sided sampling, one zero-crossing point is inaccurate. This application proposes to use software to estimate this. For example, if the zero-crossing point of the L line is sampled, the lower half-cycle will be inaccurate; if the zero-crossing point of the N line is sampled, the upper half-cycle will be inaccurate. Furthermore, if the upper half-cycle is accurate but the lower half-cycle is inaccurate, then conduction angle 1 (first conduction angle) cannot be used for control; it is necessary to estimate the conduction angle 2 (second conduction angle) for the next moment.

[0066] Step 206: Upon receiving the feedback signal transmitted by the zero-crossing detection circuit, the motor drive circuit is controlled using the first conduction angle; the feedback signal is obtained by collecting the zero-crossing point of the live wire or neutral wire through the zero-crossing detection circuit.

[0067] Specifically, this application proposes that during the adjustment of the motor conduction angle, it is necessary to wait for the zero-crossing point; wherein, upon receiving the feedback signal transmitted by the zero-crossing detection circuit, the controller uses the first conduction angle to control the motor drive circuit. This feedback signal is obtained by the zero-crossing detection circuit from the zero-crossing point of the live or neutral wire.

[0068] This application proposes a zero-crossing detection circuit to collect the zero-crossing point of the live or neutral wire. This sampling method is single-sided sampling. Taking the PG motor and the sampling of the L wire as an example, only one resistor is used in the circuit to collect the zero-crossing point of the L wire. Therefore, under normal use, high and low voltage, and / or dirt and blockage, the PG motor will not jam or stall, and can operate normally. Compared with the double-sided sampling scheme, the current waveform of the single-sided sampling in this application is consistent with that of the double-sided sampling, and there is no problem of current imbalance between the upper and lower half cycles. The noise of the PG motor is also reduced.

[0069] Furthermore, in conjunction with this unilateral data acquisition, this application proposes to control the turbine conduction angle by estimating the time of the next zero-crossing. It should be noted that for the time of the next zero-crossing, a complete power cycle can be divided into two half-cycles: the first half-cycle and the second half-cycle. If the second half-cycle is inaccurate, the first half-cycle can be considered as the first zero-crossing, and the second half-cycle as the second zero-crossing.

[0070] In one embodiment, the feedback signal is a falling edge signal.

[0071] In this application, the controller uses the falling edge as the zero-crossing point detection, thereby serving as the reference point for power supply voltage adjustment. Specifically, when the zero-crossing point of the first half-cycle is reached, the controller receives a falling edge feedback signal, at which point the conduction angle 1 (first conduction angle) can be used for control. Furthermore, the conduction angle 1 (first conduction angle) can be assigned to a timer to start the thyristor. When the timer expires, the thyristor is turned on, and the conduction time for the next moment is estimated. The timer is used to simulate PWM (Pulse Width Modulation) drive.

[0072] Step 208: If the motor drive circuit is controlled by the first conduction angle, the motor drive circuit is controlled by the second conduction angle; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the frequency of the AC power supply.

[0073] Specifically, after the first conduction angle control is completed, the second conduction angle needs to be used for control. That is, after the conduction angle 1 (first conduction angle) control is completed, the conduction angle 2 (second conduction angle) needs to be calculated immediately and controlled directly. Even if the controller receives a zero-crossing signal in the second half of the cycle, it will not be processed and control will be carried out directly through the conduction angle 2 (second conduction angle).

[0074] The second conduction angle is the conduction angle of the second half-cycle of the AC power supply, determined based on the AC power supply frequency. The conduction angle 2 (second conduction angle) is primarily calculated using the power supply frequency. For example, when the AC power supply frequency is 50Hz, the conduction angle for the next cycle is estimated; a similar calculation can be performed when the AC power supply frequency is 60Hz. In one embodiment, when the feedback signal is obtained by zero-crossing acquisition through a zero-detection circuit on the live wire, the first half-cycle of the AC power supply is the positive half-cycle, and the second half-cycle is the negative half-cycle.

[0075] Furthermore, in cases where the second half of the cycle is inaccurate, this application proposes to calculate the conduction angle 2 (second conduction angle) based on the power supply frequency, i.e., to determine the fixed delay duration based on the AC power supply frequency. In some embodiments, when the current AC power supply frequency is 50Hz, the fixed delay can be 10ms; if the current AC power supply frequency is 60Hz, the fixed delay is 8.3ms.

[0076] Based on the motor control method of this application, if the voltage is low, the zero-crossing point delay in the second half of the cycle will be more severe. In this case, this application estimates the data for the next conduction angle in advance, which can better avoid control differences caused by interference and hardware delay. Furthermore, this application uses single-sided sampling, which is cost-effective. It also reduces controller errors / delays in detecting the zero-crossing point due to external interference, thereby ensuring the normal operation and stable speed of the PG motor and reducing fan noise.

[0077] In one embodiment, such as Figure 3 As shown, a motor control method is provided, which is applied to... Figure 1 Taking the controller in the example, the following steps are included:

[0078] Step 302: Obtain the target motor speed and determine the initial conduction angle based on the AC power supply voltage of a preset multiple.

[0079] Specifically, before adjusting the conduction angle, the target speed of the fan and the initial conduction angle need to be set. In some embodiments, different target wind speeds can be set. For example, the target wind speed is set by the user and can be 500 RPM-1500 RPM. Setting the target speed of the fan determines the target motor speed.

[0080] Furthermore, the initial conduction angle can be determined based on a preset multiple of the AC power supply voltage; in some embodiments, the preset multiple can be 60%-70%, that is, the initial conduction angle is 60%-70% of the AC voltage. It should be noted that in setting the initial conduction angle, if the initial voltage is low, the fan may not turn on, which may result in a false fault report; while if the initial voltage is high, it is easy to generate fan noise.

[0081] Step 304: Determine the conduction angle adjustment mode based on the crystal oscillator frequency of the clock source and the preset conduction angle adjustment period; the conduction angle adjustment mode includes PID adjustment.

[0082] Specifically, after determining the preset conduction angle adjustment period, the conduction angle adjustment mode can be determined based on the crystal oscillator frequency of the controller clock source and the preset conduction angle adjustment period. The conduction angle adjustment mode may include the adjustment algorithm and the conduction angle step.

[0083] Taking a PG motor with a preset conduction angle adjustment period of 200ms as an example, the speed of the PG motor can be adjusted via PID control. With a 16MHz crystal oscillator, the conduction angle adjustment step every 200ms can be 200 degrees; with an 8MHz crystal oscillator, the adjustment step every 200ms can be 100 degrees. It should be noted that "crystal oscillator" refers to a crystal oscillator, i.e., the clock source of the microcontroller; and "conduction angle step" refers to adjusting the thyristor voltage.

[0084] Step 306: When the preset conduction angle adjustment cycle arrives, obtain the current motor speed.

[0085] Step 308: Based on the previous motor speed, the target motor speed, and the current motor speed, obtain the speed increment value, and determine the first conduction angle of the first half-cycle of the AC power supply based on the speed increment value.

[0086] Step 310: Upon receiving the feedback signal transmitted by the zero-crossing detection circuit, the motor drive circuit is controlled using the first conduction angle; the feedback signal is obtained by collecting the zero-crossing point of the live wire or neutral wire through the zero-crossing detection circuit.

[0087] Step 312: If the motor drive circuit is controlled by the first conduction angle, the motor drive circuit is controlled by the second conduction angle; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the frequency of the AC power supply.

[0088] For details on the implementation process of steps 306 to 312, please refer to the description of steps 202 to 208 above, which will not be repeated here.

[0089] In summary, this application employs single-sided sampling and estimation of the next zero-crossing point to control the fan conduction angle, enabling the PG motor to operate normally under various conditions and reducing fan noise. Specifically, this application reduces one circuit resistor by using single-sided sampling, thereby lowering circuit costs. Furthermore, using single-sided sampling instead of double-sided sampling reduces the risk of controller errors / delays in detecting the zero-crossing point due to external interference, which could affect the normal operation and speed stability of the PG motor and reduce fan noise.

[0090] It should be understood that, although Figure 2 , 3 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 , 3 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0091] In one embodiment, such as Figure 4 As shown, a motor control device is provided, comprising:

[0092] The speed acquisition module 410 is used to acquire the current motor speed when the preset conduction angle adjustment cycle arrives;

[0093] The incremental value acquisition module 420 is used to obtain the speed increment value based on the previous motor speed, the target motor speed, and the current motor speed;

[0094] The drive control module 430 is used to determine the first conduction angle of the first half-cycle of the AC power supply based on the speed increment value, and to control the motor drive circuit with the first conduction angle when receiving the feedback signal transmitted by the zero-crossing detection circuit; the feedback signal is obtained by the live wire or neutral wire passing through the zero-crossing point of the zero-crossing detection circuit; and to control the motor drive circuit with the first conduction angle when the first conduction angle control is completed; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the AC power supply frequency.

[0095] In one embodiment, the speed increment is the difference between a first variable and a second variable; the first variable is the difference between the current motor speed and the previous motor speed; the second variable is the difference between the current motor speed and the target motor speed.

[0096] In one embodiment, it further includes:

[0097] The configuration module is used to obtain the target motor speed and determine the initial conduction angle based on the AC power supply voltage of a preset multiple;

[0098] The mode setting module is used to determine the conduction angle adjustment mode based on the crystal oscillator frequency of the clock source and the preset conduction angle adjustment period; the conduction angle adjustment mode includes PID adjustment.

[0099] In one embodiment, the feedback signal is a falling edge signal;

[0100] When the feedback signal is obtained by zero-crossing acquisition through the zero detection circuit of the live wire, the first half-cycle of the AC power supply is the positive half-cycle of the AC power supply, and the second half-cycle of the AC power supply is the negative half-cycle of the AC power supply.

[0101] Specific limitations regarding the motor control device can be found in the limitations of the motor control method described above, and will not be repeated here. Each module in the aforementioned motor control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. It should be noted that the module division in this embodiment is illustrative and only represents a logical functional division; other division methods may be used in actual implementation.

[0102] In one embodiment, such as Figure 5 As shown, a motor control circuit is provided, including:

[0103] Zero-crossing detection circuit 510, the input terminal of which is used to connect to the live wire or the neutral wire; zero-crossing detection circuit 510 is used to collect the zero-crossing point of the live wire or the neutral wire;

[0104] Controller 520; one end of the controller is connected to the output of the zero-crossing detection circuit 510, and the other end is used to connect to the motor drive circuit; wherein, the controller 520 is used to execute the steps of the above-described motor control method.

[0105] Specifically, the motor control circuit uses only one resistor to sample the zero-crossing point of either the L or N line. If the zero-crossing detection circuit 510 only samples the L line, then there is no need for a device to sample the N line (reducing the resistor for N line sampling in the bilateral sampling circuit).

[0106] In one embodiment, such as Figure 6 As shown, the zero-crossing detection circuit 510 may include a sampling module, an optocoupler (PC700A and PC700B) and a shaping circuit connected in sequence;

[0107] The sampling module includes a first resistor R703, a second resistor R702, a third resistor R705, and a fourth resistor R706 connected in sequence. One end (N_3) of the first resistor R703 is used to connect to the live wire or the neutral wire, and the other end is connected to one end of the fourth resistor R706 in sequence through the second resistor R702 and the third resistor R705. The other end of the fourth resistor R706 is connected to the anode of the optocoupler (PC700A). The cathode of the optocoupler (PC700A) is used for grounding.

[0108] The collector of the optocoupler (PC700B) is connected to an external power supply (+3.3V), and the emitter is connected to one end of the shaping circuit. The shaping circuit includes a transistor Q700, a fifth resistor R704, a sixth resistor R707, and a first capacitor C700. The base of the transistor Q700 is connected to the emitter of the optocoupler (PC700B), and the collector of the transistor Q700 is connected to one end of the fifth resistor R704 and one end of the sixth resistor R707. The other end of the fifth resistor R704 is connected to the external power supply (+3.3V), and the other end (ZERO) of the sixth resistor R707 is connected to the controller and one end of the first capacitor C700. The other end of the first capacitor C700 and the emitter of the transistor Q700 are both grounded.

[0109] The zero-crossing detection circuit also includes a seventh resistor R712, an eighth resistor R710, a ninth resistor R711, and a second capacitor C701. One end of the seventh resistor R712 is connected between the other end of the fourth resistor R706 and the anode of the optocoupler (PC700A), and the other end is grounded. The eighth resistor R710 is connected between the base of the transistor Q700 and the emitter of the optocoupler (PC700B). One end of the ninth resistor R711 is connected between the eighth resistor R710 and the emitter of the optocoupler (PC700B), and the other end is grounded. One end of the second capacitor C701 is connected between the eighth resistor R710 and the emitter of the optocoupler (PC700B), and the other end is grounded.

[0110] Specifically, based on the zero-crossing detection circuit in this application, only one resistor is needed to collect the zero-crossing point of the L line or N line, enabling the motor to operate normally under various working conditions. The circuit cost is low, and it reduces the error / delay in the controller's detection of the zero-crossing point caused by external interference, thereby affecting the normal operation and speed stability of the motor and reducing the noise of the fan.

[0111] In one embodiment, a PG motor is provided, including a motor drive circuit and a motor control circuit as described above connected to the motor drive circuit.

[0112] In one embodiment, the motor drive circuit is an air conditioner indoor unit motor drive circuit.

[0113] Specifically, this application can be applied to indoor air conditioning units. In the circuit, only one resistor is used to collect the zero-crossing point data of the L or N line. Under normal use, high and low voltage conditions, and even with dirt or blockage, the PG motor will not jam or stall, and can operate normally. Compared to a dual-side sampling scheme, the current waveform obtained by single-side sampling in this application is consistent with that of dual-side sampling, eliminating the current imbalance problem between the upper and lower half-cycles, and reducing the noise of the PG motor. Furthermore, based on this application, if the zero-crossing point delay is more severe in the lower half-cycle under low voltage conditions, this application, by pre-estimating the data for the next conduction angle, can better avoid control differences caused by interference and hardware delays.

[0114] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described motor control method.

[0115] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0116] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0117] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the 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 this specification.

[0118] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A motor control method, characterized in that, include: When the preset conduction angle adjustment period arrives, the motor speed is obtained. Based on the previous motor speed, the target motor speed, and the current motor speed, the speed increment value is obtained, and the first conduction angle of the first half-cycle of the AC power supply is determined based on the speed increment value. Upon receiving a feedback signal from the zero-crossing detection circuit, the motor drive circuit is controlled using the first conduction angle; the feedback signal is obtained by collecting data at the zero-crossing point of the live wire through the zero-crossing detection circuit. When the motor drive circuit is controlled by the first conduction angle, the motor drive circuit is controlled by the second conduction angle; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the AC power supply frequency. Wherein, the speed increment value is the difference between the first variable and the second variable; the first variable is the difference between the current motor speed and the previous motor speed; the second variable is the difference between the current motor speed and the target motor speed.

2. The motor control method according to claim 1, characterized in that, Before obtaining the current motor speed when the preset conduction angle adjustment period arrives, the following steps are included: The target motor speed is obtained, and the initial conduction angle is determined according to the AC power supply voltage of a preset multiple; The conduction angle adjustment mode is determined based on the crystal oscillator frequency of the clock source and the preset conduction angle adjustment period; the conduction angle adjustment mode includes PID adjustment.

3. The motor control method according to claim 1, characterized in that, The feedback signal is a falling edge signal; When the feedback signal is obtained by the zero-crossing detection circuit through the live wire, the first half-cycle of the AC power supply is the positive half-cycle of the AC power supply, and the second half-cycle of the AC power supply is the negative half-cycle of the AC power supply.

4. A motor control device, characterized in that, include: The speed acquisition module is used to acquire the current motor speed when the preset conduction angle adjustment cycle arrives; The incremental value acquisition module is used to obtain the speed increment value based on the previous motor speed, the target motor speed, and the current motor speed; The drive control module is used to determine the first conduction angle of the first half-cycle of the AC power supply based on the speed increment value, and to control the motor drive circuit using the first conduction angle when receiving the feedback signal transmitted by the zero-crossing detection circuit; the feedback signal is obtained by the live wire through the zero-crossing detection circuit to collect the zero-crossing point. And when the motor drive circuit is controlled by the first conduction angle, the motor drive circuit is controlled by the second conduction angle; the second conduction angle is the conduction angle of the second half-cycle of the AC power supply determined according to the AC power supply frequency; Wherein, the speed increment value is the difference between the first variable and the second variable; the first variable is the difference between the current motor speed and the previous motor speed; the second variable is the difference between the current motor speed and the target motor speed.

5. A motor control circuit, characterized in that, include: A zero-crossing detection circuit, wherein the input terminal of the zero-crossing detection circuit is used to connect to the live wire; The zero-crossing detection circuit is used to collect the zero-crossing point of the live wire; Controller; one end of the controller is connected to the output terminal of the zero-crossing detection circuit, and the other end is used to connect to the motor drive circuit; The controller is used to execute the steps of the motor control method according to any one of claims 1 to 3.

6. The motor control circuit according to claim 5, characterized in that, The zero-crossing detection circuit includes a sampling module, an optocoupler, and a shaping circuit connected in sequence. The sampling module includes a first resistor, a second resistor, a third resistor, and a fourth resistor connected in sequence; one end of the first resistor is used to connect to the live wire, and the other end is connected to one end of the fourth resistor in sequence through the second resistor and the third resistor; the other end of the fourth resistor is connected to the anode of the optocoupler; the cathode of the optocoupler is used for grounding. The collector of the optocoupler is connected to an external power supply, and the emitter is connected to one end of the shaping circuit. The shaping circuit includes a transistor, a fifth resistor, a sixth resistor, and a first capacitor. The base of the transistor is connected to the emitter of the optocoupler, and the collector of the transistor is connected to one end of the fifth resistor and one end of the sixth resistor, respectively. The other end of the fifth resistor is connected to an external power supply, and the other end of the sixth resistor is connected to the controller and one end of the first capacitor, respectively. The other end of the first capacitor and the emitter of the transistor are both grounded. The zero-crossing detection circuit further includes a seventh resistor, an eighth resistor, a ninth resistor, and a second capacitor; one end of the seventh resistor is connected between the other end of the fourth resistor and the anode of the optocoupler, and the other end is grounded; the eighth resistor is connected between the base of the transistor and the emitter of the optocoupler; one end of the ninth resistor is connected between the eighth resistor and the base of the transistor, and the other end is grounded; one end of the second capacitor is connected between the eighth resistor and the base of the transistor, and the other end is grounded.

7. A PG motor, characterized in that, It includes a motor drive circuit and a motor control circuit as described in claim 5 or 6 connected to the motor drive circuit.

8. The PG motor according to claim 7, characterized in that, The motor drive circuit is the motor drive circuit for the indoor unit of an air conditioner.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

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