Control method, control device, motor driving circuit and motor controller

Abstract

The invention relates to a control method, a control device, a motor driving circuit and a motor controller in the technical field of power driving. According to the control method, in the working voltage range of the power unit, different switching speeds are configured under different working voltages, a low switching speed is configured under a high working voltage, so that the peak value of the turn-off voltage is reduced, the high switching speed is configured under the low working voltage, the switching loss is reduced, and the switching efficiency is improved. The turn-off voltage is controlled to be within a voltage stress range allowed by the power unit, and meanwhile, the potential of the power unit under different working voltages is exerted to the maximum extent, so that the efficiency of the motor controller is improved; under the condition that the switching speed of the power unit is increased, the induced voltage generated when the same working voltage is turned off is larger, and the opportunity of overvoltage detection is advanced by reducing the reference voltage of overvoltage detection, so that the power unit can be protected in time when a fault occurs, and the power unit is prevented from being damaged by the turn-off voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of power drive technology, and in particular to a control method, a control device, a motor drive circuit and a motor controller. Background Art

[0002] Due to the presence of parasitic inductance on the line, an induced voltage will be generated at the moment of shutting down the power unit. The induced voltage is positively correlated with the switching speed of the power unit. The higher the switching speed, the greater the induced voltage. In extreme cases, the peak voltage may even exceed the allowable voltage stress range of the power unit, thereby causing damage to the power unit. In related technologies, in order to ensure that the voltage spike value is within the allowable voltage stress range of the power unit, the power unit is usually switched at a lower switching speed. However, the operating voltage range of the motor controller is relatively large, and the high voltage and low voltage use the same switching speed, which limits the switching speed under low voltage conditions, resulting in the motor controller The efficiency cannot be fully further improved. Summary of the invention

[0003] In order to solve the above technical problems, the present disclosure provides a control method, a control device, a motor drive circuit and a motor controller.

[0004] In a first aspect, the present disclosure provides a control method of a motor controller, comprising:

[0005] Obtain the operating voltage of the power unit;

[0006] Based on the operating voltage and the first association relationship, determining and outputting a reference voltage for overvoltage detection;

[0007] as well as,

[0008] Based on the operating voltage and the second association relationship, determining and outputting a speed control signal, wherein the speed control signal is used to control a switching speed of the power unit;

[0009] Among them, the first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; the second association relationship includes a mapping relationship between the operating voltage and the switching speed, and the operating voltage is negatively correlated with the switching speed.

[0010] Optionally, determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship includes:

[0011] Determining the reference voltage based on the operating voltage and the first association relationship;

[0012] Determining a target duty cycle based on the correlation between the reference voltage and the output duty cycle;

[0013] A pulse width modulation signal corresponding to the target duty cycle is output to achieve output of the reference voltage.

[0014] Optionally, the control method further includes:

[0015] If the result of the overvoltage detection is determined to be overvoltage, a protection control signal is generated and output to control the power unit to enter a safe state;

[0016] The overvoltage detection result is determined based on a comparison result between the reference voltage and the voltage to be detected.

[0017] In a second aspect, the present disclosure further provides a control device of a motor controller, comprising:

[0018] An acquisition module, used for acquiring the operating voltage of the power unit;

[0019] An output module, used for determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship;

[0020] as well as,

[0021] It is also used to determine and output a speed control signal based on the working voltage and the second association relationship, wherein the speed control signal is used to control the switching speed of the power unit;

[0022] Among them, the first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; the second association relationship includes a mapping relationship between the operating voltage and the switching speed, and the operating voltage is negatively correlated with the switching speed.

[0023] In a third aspect, the present disclosure further provides a motor drive circuit, comprising: a power unit, a collection unit and a control unit;

[0024] The input end of the acquisition unit is connected to a power supply that supplies power to the power unit, and the output end of the acquisition unit is connected to a first input end of the control unit;

[0025] The acquisition unit is used to acquire the working voltage of the power unit and transmit it to the control unit; the control unit is used to execute any one of the above-mentioned control methods to determine and output a reference voltage and a speed control signal for overvoltage detection, and the speed control signal is used to control the switching speed of the power unit.

[0026] Optionally, the motor driving circuit further comprises: a comparison unit;

[0027] The first input terminal of the comparison unit is connected to the first output terminal of the control unit, the output terminal of the comparison unit is connected to the second input terminal of the control unit, and the second input terminal of the comparison unit is connected to the voltage to be detected;

[0028] The comparison unit is used to compare the reference voltage with the voltage to be detected, and output a feedback signal to the control unit; the control unit determines the result of the overvoltage detection based on the feedback signal, determines that the result of the overvoltage detection is overvoltage, and generates and outputs a protection control signal.

[0029] Optionally, the motor drive circuit further includes: a drive unit;

[0030] The input end of the drive unit is connected to the second output end of the control unit, and the output end of the drive unit is connected to the power unit; the drive unit is used to control the switching speed of the power unit based on the speed control signal transmitted by the control unit, and the drive unit is also used to control the power unit to enter a safe state based on the protection control signal transmitted by the control unit.

[0031] Optionally, the motor drive circuit further includes: an isolator;

[0032] The isolator is located between the control unit and the comparison unit, and is used to isolate a high voltage signal from a low voltage signal.

[0033] Optionally, the motor drive circuit further includes:

[0034] A filter unit, wherein an input end of the filter unit is connected to the isolator, and an output end of the filter unit is connected to the first input end of the comparison unit;

[0035] A voltage divider unit, wherein the first end of the voltage divider unit is connected to a power supply, the second end of the voltage divider unit is grounded, the first output end of the voltage divider unit is connected to the acquisition unit, and the second output end of the voltage divider unit is connected to the second input end of the comparison unit; wherein the voltage divider unit is used to transmit an operating voltage to the acquisition unit, and to transmit a voltage to be detected to the comparison unit.

[0036] Optionally, the driving unit includes an isolated driving chip;

[0037] The first output end of the voltage dividing unit is connected to the isolated driving chip, and the isolated driving chip is connected to the collection unit.

[0038] In a fourth aspect, the present disclosure further provides a motor controller, comprising: any one of the above-mentioned motor drive circuits.

[0039] Compared with the prior art, the technical solution provided by the present invention has the following advantages:

[0040] In the technical solution provided in the present invention, within the operating voltage range of the power unit, different switching speeds are configured under different operating voltages. A lower switching speed is configured under a higher operating voltage to reduce the peak value of the turn-off voltage, and a higher switching speed is configured under a lower operating voltage to reduce switching losses. The turn-off voltage is controlled within the allowable voltage stress range of the power unit, while maximizing the potential of the power unit under different operating voltages, thereby improving the efficiency of the motor controller; when the switching speed of the power unit is increased, the induced voltage generated when the same operating voltage is turned off is larger. By lowering the reference voltage for overvoltage detection, the timing of overvoltage detection is advanced, so that the power unit can be protected in time when a fault occurs, avoiding damage to the power unit by the turn-off voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0043] Figure 1 It is a structural diagram of a motor controller in the related art;

[0044] Figure 2 A schematic flow chart of a control method of a motor controller provided by an embodiment of the present disclosure;

[0045] Figure 3 for Figure 2 A detailed flow chart of "determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship" in the control method of the motor controller shown;

[0046] Figure 4 A schematic diagram of the structure of a control device of a motor controller provided by an embodiment of the present disclosure;

[0047] Figure 5 A schematic diagram of the structure of a motor drive circuit provided in an embodiment of the present disclosure;

[0048] Figure 6 A schematic diagram of the structure of another motor drive circuit provided by an embodiment of the present disclosure;

[0049] Figure 7 A schematic diagram of the structure of another motor drive circuit provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0050] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0052] In the related technology, the commonly used overvoltage detection method is as follows Figure 1 As shown, within the operating voltage range of the motor controller, the overvoltage point Ref is provided by a high-precision reference source chip, and the overvoltage detection of the voltage to be detected Vtest is realized by a comparator, but the overvoltage point Ref is fixed, which limits the switching speed of the driver under low voltage conditions, resulting in the inability to further improve the efficiency of the motor controller. Overvoltage detection can also be realized by sampling the operating voltage inside the micro control unit (MCU), but the overvoltage detection time is long, and the power unit cannot be protected in time under fault conditions such as high-voltage load dumping.

[0053] In order to solve the above technical problems, the embodiments of the present disclosure provide a control method, a control device, a motor drive circuit and a motor controller; the control method includes: obtaining the working voltage of the power unit; determining and outputting a reference voltage for overvoltage detection based on the working voltage and a first association relationship; and, based on the working voltage and a second association relationship, determining and outputting a speed control signal, the speed control signal being used to control the switching speed of the switching power unit; wherein the first association relationship includes a mapping relationship between the working voltage and the reference voltage, and the reference voltage is positively correlated with the working voltage; the second association relationship includes a mapping relationship between the working voltage and the switching speed, and the switching speed is negatively correlated with the working voltage. Therefore, within the operating voltage range of the power unit, different switching speeds are configured under different operating voltages. A lower switching speed is configured under a higher operating voltage to reduce the peak value of the turn-off voltage, and a higher switching speed is configured under a lower operating voltage to reduce switching losses. The turn-off voltage is controlled within the allowable voltage stress range of the power unit, while maximizing the potential of the power unit under different operating voltages, thereby improving the efficiency of the motor controller; when the switching speed of the power unit is increased, the induced voltage generated when the same operating voltage is turned off is larger. By reducing the reference voltage for overvoltage detection, the timing of overvoltage detection is advanced, so that the power unit can be protected in time when a fault occurs, avoiding the power unit from being damaged by the turn-off voltage.

[0054] The control method, control device, motor drive circuit and motor controller provided by the embodiments of the present disclosure are exemplarily described below in conjunction with the accompanying drawings.

[0055] For example, Figure 2 FIG. 1 is a flow chart of a control method of a motor controller provided by an embodiment of the present disclosure. Figure 2 , the control method of the motor controller comprises the following steps:

[0056] S210: Obtain the operating voltage of the power unit.

[0057] Among them, combined Figure 5 The power unit 10 is used to convert the power supply voltage into a three-phase AC voltage for driving the motor. The power supply voltage is the working voltage of the power unit 10. The working voltage needs to be controlled within a certain voltage range. If the working voltage exceeds the voltage range, it is easy to cause damage to the power unit 10. Therefore, it is necessary to perform overvoltage detection on the working voltage of the power unit 10. When it is determined that the working voltage is greater than the overvoltage point, the power unit 10 is controlled to enter a safe state to prevent the power unit 10 from overvoltage operation, thereby ensuring the safety of personnel and equipment.

[0058] The acquisition unit 30 may directly acquire the power supply voltage, or acquire the voltage division of the power supply voltage, and obtain the working voltage through calculation. The acquisition unit 30 may include a voltage monitor, or any electronic device with a voltage acquisition function known to those skilled in the art, which is not limited here. For example, Figure 6-7 As shown, the voltage sample collected by the collection unit 30 can be the voltage division of the power supply voltage, and the control unit 40 can obtain the power supply voltage (i.e., the working voltage of the power unit 10) through calculation according to the resistance value of the voltage division unit 80. Figure 6 As shown in FIG. 7 , the voltage dividing unit 80 includes a first resistor R1 and a second resistor R2 . Assuming that the voltage sample collected by the collecting unit is U1 , the power supply voltage U=U1×(R1+R2)÷R2 .

[0059] It should be noted that Figure 6 and Figure 7 It is only shown by way of example that the voltage divider unit 80 includes a first resistor R1 and a second resistor R2, the connection point between the first resistor R1 and the second resistor R2 is connected to the acquisition unit 30, no resistor is set on the connection circuit, and the corresponding power supply voltage calculation formula is U=U1×(R1+R2)÷R2, but it does not constitute a limitation on the control method of the motor controller provided in the embodiment of the present disclosure. In other embodiments, three or more resistors may be connected in series in the circuit between the power supply 20 and the ground, or a resistor may be set on the connection circuit connected to the acquisition unit 30, and the calculation formula of the power supply voltage is determined according to the actual situation of the voltage divider unit 80, which is not limited here.

[0060] S220, determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship; and determining and outputting a speed control signal based on the operating voltage and the second association relationship.

[0061] In this embodiment, the speed control signal is used to control the switching speed of the switching power unit. The first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; the second association relationship includes a mapping relationship between the operating voltage and the switching speed, wherein the operating voltage is negatively correlated with the switching speed. The reference voltage is the overvoltage point of the overvoltage detection. The reference voltage is compared with the voltage to be detected. According to the comparison result, it can be determined whether the operating voltage of the power unit is overvoltage. When it is determined that overvoltage occurs, a protection control signal is generated and output, wherein the protection control signal is used to control the power unit to enter a safe state.

[0062] It should be noted that the control method of the motor controller also includes: determining and outputting a switch control signal, the switch control signal is used to control the working state of the power unit, and the working state of the power unit includes an on state and an off state. The method for determining the switch control signal adopts the existing technical method in the technical field, which will not be repeated here.

[0063] In the second association, a lower switching speed is configured at a higher operating voltage, the corresponding current change rate is smaller, the generated induced voltage is smaller, the peak value of the turn-off voltage is reduced, and the turn-off voltage is controlled within the voltage stress range allowed by the power unit; a higher switching speed is configured at a lower operating voltage, the switching loss is reduced, thereby improving the efficiency, so that the power unit can maximize its potential at low voltage. In this way, within the entire operating voltage range, the turn-off voltage is controlled within the voltage stress range allowed by the power unit, and at the same time, the potential of the power unit under different operating voltages is maximized, thereby improving the efficiency of the motor controller.

[0064] However, at a lower operating voltage, increasing the switching speed will increase the control efficiency, but will also increase the induced voltage by several times or even hundreds or thousands of times. Although the operating voltage is lower at this time, the induced voltage is very large. If the Figure 1 The fixed overvoltage point Ref shown is used for overvoltage detection. Usually, the overvoltage point Ref is relatively high, and the overvoltage detection is relatively delayed. When a fault condition such as load dumping occurs, the power unit cannot be protected in time. The peak value of the shutdown voltage may exceed the allowable voltage stress range of the power unit, thereby damaging the power unit.

[0065] In order to solve the above technical problems, this embodiment configures different reference voltages (i.e., overvoltage points) for different working voltages. According to the working voltage (or the voltage interval where the working voltage is located) and the first association relationship, the corresponding reference voltage can be determined; in the first association relationship, one working voltage can correspond to one reference voltage, or one voltage interval can correspond to one reference voltage. When a voltage interval corresponds to a reference voltage, in order to accurately determine the corresponding reference voltage, the working voltage of the power unit is first determined, and then the target working voltage interval corresponding to the working voltage is determined, and according to the target working voltage interval and the corresponding relationship between the voltage working interval and the reference voltage, the reference voltage corresponding to the target working voltage interval is determined, and the reference voltage corresponding to the target working voltage interval is determined as the reference voltage corresponding to the working voltage of the power unit. A lower reference voltage is configured at a lower working voltage, and the timing of overvoltage detection is advanced. When it is determined that an overvoltage occurs and the power unit needs to be controlled to enter a safe state, although the induced voltage is large, the working voltage of the power unit is in a lower voltage range at this time, and the peak value of the shutdown voltage can be controlled within the allowable voltage stress range of the power unit, ensuring that the shutdown peak value will not cause damage to the power unit.

[0066] It should be noted that the first association relationship and the second association relationship can be preset and stored in a memory, or can be input through an input unit, which is not limited here. In this embodiment, "determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship" and "determining and outputting a speed control signal based on the operating voltage and the second association relationship" are two independent steps, which can be executed simultaneously or successively, which is not limited here.

[0067] A control method for an electrode controller provided by an embodiment of the present disclosure includes: obtaining an operating voltage of a power unit; determining and outputting a reference voltage for overvoltage detection based on the operating voltage and a first association relationship; and determining and outputting a speed control signal based on the operating voltage and a second association relationship, wherein the switch control signal is used to control turning on or off the power unit, and the speed control signal is used to control the switching speed of the switching power unit; wherein the first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; and the second association relationship includes a mapping relationship between the operating voltage and the switching speed, and the operating voltage is negatively correlated with the switching speed. Therefore, within the operating voltage range of the power unit, different switching speeds are configured under different operating voltages. A lower switching speed is configured under a higher operating voltage to reduce the peak value of the turn-off voltage, and a higher switching speed is configured under a lower operating voltage to reduce switching losses. The turn-off voltage is controlled within the allowable voltage stress range of the power unit, while maximizing the potential of the power unit under different operating voltages, thereby improving the efficiency of the motor controller; when the switching speed of the power unit is increased, the induced voltage generated when the same operating voltage is turned off is larger. By reducing the reference voltage for overvoltage detection, the timing of overvoltage detection is advanced, so that the power unit can be protected in time when a fault occurs, avoiding the power unit from being damaged by the turn-off voltage.

[0068] In some embodiments, Figure 3 As shown, Figure 2 A detailed flow chart of "determining and outputting a reference voltage for overvoltage detection based on the working voltage and the first association relationship" in the control method of the motor controller shown. Figure 3 , “determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship” includes the following detailed steps:

[0069] S321. Determine a reference voltage based on the operating voltage and the first association relationship.

[0070] The first association relationship includes a mapping relationship between a reference voltage and an operating voltage. After the voltage value of the operating voltage of the power unit is acquired through step S210, the voltage value of the reference voltage can be determined according to the first association relationship.

[0071] S322: Determine a target duty cycle based on a correlation between a reference voltage and an output duty cycle.

[0072] The target duty cycle is positively correlated with the reference voltage. The larger the reference voltage, the larger the target duty cycle; the smaller the reference voltage, the smaller the target duty cycle.

[0073] S323, outputting a pulse width modulation signal corresponding to the target duty cycle to achieve output of a reference voltage.

[0074] In this step, the reference voltage is output in a pulse width modulation (PWM) manner, and the output of the reference voltage is achieved by outputting a PWM signal corresponding to a target duty cycle.

[0075] It should be noted that the embodiment of the present disclosure only exemplarily shows the output of the reference voltage in a PWM manner, but does not constitute a limitation on the control method of the motor controller provided by the embodiment of the present disclosure. In other embodiments, the output of the reference voltage can also be achieved by all control methods known to those skilled in the art, such as PID closed-loop control technology, which is not limited here.

[0076] In some embodiments, the control method further comprises the following steps:

[0077] If the result of the overvoltage detection is determined to be overvoltage, a protection control signal is generated and output to control the power unit to enter a safe state;

[0078] The overvoltage detection result is determined based on the comparison result between the reference voltage and the voltage to be detected; when the voltage to be detected is greater than the reference voltage, the overvoltage detection result is determined to be overvoltage; when the voltage to be detected is less than or equal to the reference voltage, the overvoltage detection result is determined to be no overvoltage. Figure 6 or Figure 7 As shown, the comparison unit 50 compares the reference voltage with the voltage to be detected, and outputs a corresponding feedback signal to the control unit 40. The control unit 40 can determine the result of the overvoltage detection according to the feedback signal. For example, if the voltage to be detected is greater than the reference voltage, the feedback signal output by the comparison unit 50 is a high level; if the voltage to be detected is less than or equal to the reference voltage, the feedback signal output by the comparison unit 50 is a low level; the control unit 40 can determine the result of the overvoltage detection according to whether the feedback signal is a low level or a high level.

[0079] Specifically, when the overvoltage detection result is determined to be overvoltage, a protection control signal is generated and transmitted to the power unit; the power unit controls the power unit 10 to enter a corresponding safe state according to the received protection control signal to prevent the power unit 10 from being damaged. The protection measures taken by the power unit 10 to enter a safe state include resetting, reducing power, and shutting down, etc. The protection measures are related to the working conditions of the power unit 10.

[0080] Based on the same inventive concept, an embodiment of the present disclosure also provides a control device for a motor controller, which is used to execute the steps of any of the above-mentioned control methods for the motor controller and has corresponding beneficial effects. The similarities can be understood by referring to the above and will not be repeated in the following text.

[0081] For example, Figure 4 FIG. 1 is a schematic diagram of a control device of a motor controller provided by an embodiment of the present disclosure. Figure 4 The control device 400 includes: an acquisition module 401, used to acquire the working voltage of the power unit; an output module 402, used to determine and output a reference voltage for overvoltage detection based on the working voltage and a first association relationship; and, further used to determine and output a speed control signal based on the working voltage and a second association relationship, the speed control signal being used to control the switching speed of the switching power unit; wherein the first association relationship includes a mapping relationship between the working voltage and the reference voltage, and the reference voltage is positively correlated with the working voltage; and the second association relationship includes a mapping relationship between the working voltage and the switching speed, and the working voltage is negatively correlated with the switching speed.

[0082] In some embodiments, the output module 402 is used to determine and output a reference voltage for overvoltage detection based on the operating voltage and the first association relationship, including: determining the reference voltage based on the operating voltage and the first association relationship; determining the target duty cycle based on the association relationship between the reference voltage and the output duty cycle; and outputting a pulse width modulation signal corresponding to the target duty cycle to achieve the output of the reference voltage.

[0083] In some embodiments, the output module 402 is also used to generate and output a protection signal to control the power unit to enter a safe state if the result of the overvoltage detection is determined to be overvoltage; wherein the result of the overvoltage detection is determined based on the comparison result between the reference voltage and the voltage to be detected.

[0084] The control device can be implemented by software and / or hardware, and can be integrated on any processor or electronic device with computing capability. For contents not described in detail in the device embodiment of the present disclosure, reference can be made to the description in any method embodiment of the present disclosure.

[0085] Based on the above implementation, the present disclosure also provides a motor drive circuit. Figure 5 As shown, the motor drive circuit includes: a power unit 10, a collection unit 30 and a control unit 40; the input end of the collection unit 30 is connected to the power supply 20 that supplies power to the power unit 10, and the output end of the collection unit 30 is connected to the first input end a of the control unit 40; the collection unit 30 is used to collect the working voltage of the power unit 10 and transmit it to the control unit 40; the control unit 40 is used to execute any of the above-mentioned control methods to determine and output a reference voltage for overvoltage detection and a speed control signal, and the speed control signal is used to control the switching speed of the switching power unit; it has corresponding beneficial effects, and in order to avoid repeated description, it will not be repeated here.

[0086] The power unit 10 is used to convert the power supply voltage into a three-phase AC voltage for driving the motor. The power supply voltage is the working voltage of the power unit 10. The acquisition unit 30 includes a voltage monitor, or any electronic device with a voltage acquisition function known to those skilled in the art, which is not limited here. The acquisition unit 30 directly acquires the power supply voltage, or Figure 6 or Figure 7 As shown, the voltage division of the power supply voltage is collected and the power supply voltage is obtained by calculation. The control unit 40 is used to execute any of the above-mentioned control methods of the motor controller, and according to the working voltage of the power unit 10, a reference voltage and a speed control signal are determined and output, the reference voltage is positively correlated with the working voltage, and the speed control signal is used to control the switching speed of the switching power unit, and the switching speed is negatively correlated with the working voltage; the control unit 40 may include a microcontroller unit, and may also include all electronic devices with computing and processing capabilities known to those skilled in the art, which are not limited here.

[0087] It should be noted that the control unit 40 is also used to determine and output a switch control signal, which is used to control the working state of the power unit, and the working state of the power unit includes an on state and an off state. The method for determining the switch control signal adopts the existing technical method in the technical field, which will not be repeated here.

[0088] It should be noted that the embodiment of the present disclosure does not limit the type of the power supply 20, and includes all types of power supplies known to those skilled in the art, such as a DC power supply module or a grid power supply.

[0089] In some embodiments, Figure 6 FIG. 1 is a schematic diagram of another electrode driving circuit provided by an embodiment of the present disclosure. Figure 6The motor drive circuit also includes: a comparison unit 50; a first input terminal e of the comparison unit 50 is connected to a first output terminal b of the control unit 40, an output terminal g of the comparison unit 50 is connected to a second input terminal d of the control unit, and a second input terminal f of the comparison unit 50 is connected to the voltage to be detected; the comparison unit 50 is used to compare the reference voltage with the voltage to be detected, and output a feedback signal to the control unit 40; the control unit 40 determines the result of the overvoltage detection based on the feedback signal, and if it is determined that the result of the overvoltage detection is overvoltage, a protection control signal is generated and output.

[0090] Among them, the first input terminal e of the comparison unit 50 is used to receive the reference voltage output by the control unit 40, and the second input terminal f is used to receive the voltage to be detected. According to the comparison result of the reference voltage and the voltage to be detected, a feedback signal is transmitted to the control unit 40 through the output terminal g; after receiving the feedback signal, the control unit 40 determines the result of the overvoltage detection based on the level of the feedback signal, and generates and outputs a protection control signal when it is determined that the overvoltage detection result is overvoltage. The protection control signal is used to control the power unit 10 to enter the corresponding safe state to avoid damage to the power unit 10. The protection measures taken by the power unit 10 to enter the safe state include resetting, reducing power, and shutting down, etc., and the protection measures are related to the working conditions of the power unit 10. Exemplarily, the comparison unit 50 includes a comparator.

[0091] In some embodiments, Figure 6 As shown, the motor drive circuit also includes: a drive unit 60; an input end of the drive unit 60 is connected to the second output end c of the control unit 40, and an output end of the drive unit 60 is connected to the power unit 10; the drive unit 60 is used to switch the power unit 10 at a switching speed corresponding to the working voltage based on a speed control signal transmitted by the control unit 40, and the drive unit 60 is also used to control the power unit 10 to enter a safe state based on a drive control signal transmitted by the control unit 40.

[0092] Among them, the driving unit 60 is used to drive the power unit 10 to control the working state of the power unit, and to allow or prohibit the power unit 10 from working; the switch control signal is used to control the opening or closing of the power unit 10, and pulse width modulation (PWM) can be used to control the opening or closing of the power unit; the speed control signal is used to control the switching speed of opening or closing the power unit 10. Based on the received switch control signal and speed control signal, the driving unit 60 opens or closes the power unit 10 at the switching speed corresponding to the working voltage, specifically: under a higher working voltage, the power unit 10 is opened or closed at a lower switching speed; under a lower working voltage, the power unit 10 is opened or closed at a higher switching speed; it is ensured that the peak value of the shutdown voltage will not exceed the voltage stress range allowed by the power unit 10, thereby avoiding the power unit 10 from being damaged by the shutdown voltage. The switching speed is controlled by controlling the driving current value or driving voltage value output by the driving unit to the power unit.

[0093] When it is determined that overvoltage occurs, the control unit 40 sends a protection control signal to the drive unit 60. The transmission path of the protection control signal is the same as the transmission path of the switch control signal. After receiving the protection control signal, the drive unit 60 takes protection measures corresponding to the current operating conditions of the power unit 10 (such as resetting, reducing power, and shutting down, etc.) to put the power unit 10 into a safe state and ensure that the power unit 10 is not damaged.

[0094] In some embodiments, Figure 7 FIG. 1 is a schematic diagram of a structure of another electrode driving circuit provided by an embodiment of the present disclosure. Figure 7 The motor driving circuit further includes: an isolator 90; the isolator 90 is located between the control unit 40 and the comparison unit 50, and the isolator 90 is used to isolate the high voltage signal from the low voltage signal.

[0095] Among them, the comparison unit 50 is used to compare the reference voltage with the voltage to be detected, and the comparison unit 50 obtains the voltage to be detected by connecting to the power supply 20. The voltage of the power supply 20 is very high. In order to ensure the safety of personnel, the control unit 40 is isolated from the comparison unit 50 by using an isolator 90, that is, the high voltage signal and the low voltage signal are isolated.

[0096] In some embodiments, Figure 6-7As shown, the motor drive circuit also includes: a filter unit 70, the input end of the filter unit 70 is connected to the isolator 90, and the output end of the filter unit 70 is connected to the first input end e of the comparison unit 50; a voltage divider unit 80, the first end of the voltage divider unit 80 is connected to the power supply 20, the second end of the voltage divider unit 80 is grounded, the first output end of the voltage divider unit 80 is connected to the acquisition unit 30, and the second output end of the voltage divider unit 80 is connected to the second input end f of the comparison unit 50; wherein the voltage divider unit 80 is used to transmit the working voltage to the acquisition unit 30, and transmit the voltage to be detected to the comparison unit 50.

[0097] The filter unit 70 is used to filter the PWM signal so that the output PWM signal is more stable.

[0098] For example, Figure 6 As shown, the filtering unit 70 is an RC filter, including a resistor and a capacitor, the input end of the resistor is connected to the first output end of the control unit 40, and the output end of the resistor is connected to the first input end e of the comparison unit 50; the input end of the capacitor is connected to the connection line between the resistor and the comparison unit 50, and the output end of the capacitor is grounded.

[0099] In other embodiments, the filtering unit 70 may also be configured as any type of filtering device or filtering circuit known to those skilled in the art, such as a differential filter or a digital filter, which is not limited here.

[0100] The voltage divider unit 80 is used to divide the power supply voltage, converting a higher power supply voltage into a smaller divided voltage, which ensures the safety of personnel and equipment on the one hand, and helps to reduce line energy consumption on the other hand.

[0101] It should be noted that Figure 6 and Figure 7 It is only shown by way of example that the voltage divider unit 80 includes two resistors, and the voltage outputted by the first output terminal is equal to the voltage outputted by the second output terminal, but this does not constitute a limitation on the motor drive circuit provided by the embodiment of the present disclosure. In other embodiments, the number of resistors included in the voltage divider unit 80 can be flexibly set according to the requirements of the motor drive circuit, and the voltage outputted by the first output terminal can be equal to or different from the voltage outputted by the second output terminal, which is not limited here.

[0102] In some embodiments, Figure 7 As shown, the driving unit includes an isolated driving chip 61 ; the first output end of the voltage dividing unit 80 is connected to the isolated driving chip 61 , and the isolated driving chip 61 is connected to the acquisition unit 30 .

[0103] Among them, the driving unit includes an isolated driving chip 61, which obtains a divided voltage (i.e., a voltage sample) of the power supply voltage from the voltage divider unit 80, and transmits the voltage sample to the acquisition unit 30, which is then transmitted to the control unit 40 by the acquisition unit 30. In other embodiments, the isolated driving chip 61 can also transmit the collected voltage samples to the control unit 40, which is not limited here. The isolated driving chip 61 is used to isolate the high voltage side (e.g., the power unit 10, the power supply 20, and the voltage divider unit 80) and the low voltage side (e.g., the acquisition unit 30 and the control unit 40), effectively ensuring the safety of personnel.

[0104] On the basis of the above implementation, the embodiment of the present disclosure further provides a motor controller, including: any one of the above motor drive circuits, which has corresponding beneficial effects, and will not be described again here to avoid repeated description.

[0105] In other embodiments, the motor controller further includes all components known to those skilled in the art, such as a temperature acquisition unit and a communication unit, which are not limited here.

[0106] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0107] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a motor controller, characterized in that: include: Obtain the operating voltage of the power unit; Based on the operating voltage and the first association relationship, determining and outputting a reference voltage for overvoltage detection; as well as, Based on the working voltage and the second association relationship, determining and outputting a speed control signal, wherein the speed control signal is used to control a switching speed of the power unit; Among them, the first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; the second association relationship includes a mapping relationship between the operating voltage and the switching speed, and the operating voltage is negatively correlated with the switching speed.

2. The control method according to claim 1, characterized in that: The determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship comprises: Determining the reference voltage based on the operating voltage and the first association relationship; Determining a target duty cycle based on the correlation between the reference voltage and the output duty cycle; A pulse width modulation signal corresponding to the target duty cycle is output to achieve output of the reference voltage.

3. The control method according to claim 1 or 2, characterized in that: Also includes: If the result of the overvoltage detection is determined to be overvoltage, a protection control signal is generated and output to control the power unit to enter a safe state; The overvoltage detection result is determined based on a comparison result between the reference voltage and the voltage to be detected.

4. A control device for a motor controller, characterized in that: include: An acquisition module, used for acquiring the operating voltage of the power unit; An output module, used for determining and outputting a reference voltage for overvoltage detection based on the operating voltage and the first association relationship; as well as, It is also used to determine and output a speed control signal based on the working voltage and the second association relationship, wherein the speed control signal is used to control the switching speed of the power unit; Among them, the first association relationship includes a mapping relationship between the operating voltage and the reference voltage, and the reference voltage is positively correlated with the operating voltage; the second association relationship includes a mapping relationship between the operating voltage and the switching speed, and the operating voltage is negatively correlated with the switching speed.

5. A motor drive circuit, characterized in that: include: Power unit, acquisition unit and control unit; The input end of the acquisition unit is connected to a power supply that supplies power to the power unit, and the output end of the acquisition unit is connected to a first input end of the control unit; The acquisition unit is used to collect the working voltage of the power unit and transmit it to the control unit; the control unit is used to execute the control method as described in any one of claims 1 to 3 to determine and output a reference voltage and speed control signal for overvoltage detection, and the speed control signal is used to control the switching speed of the power unit.

6. The motor drive circuit according to claim 5, characterized in that: Also includes: Comparison unit; The first input terminal of the comparison unit is connected to the first output terminal of the control unit, the output terminal of the comparison unit is connected to the second input terminal of the control unit, and the second input terminal of the comparison unit is connected to the voltage to be detected; The comparison unit is used to compare the reference voltage with the voltage to be detected, and output a feedback signal to the control unit; the control unit determines the result of the overvoltage detection based on the feedback signal, and if the result of the overvoltage detection is determined to be overvoltage, a protection control signal is generated and output.

7. The motor driving circuit according to claim 6, characterized in that: Also includes: Drive unit; The input end of the driving unit is connected to the second output end of the control unit, and the output end of the driving unit is connected to the power unit; The driving unit is used to control the switching speed of the power unit based on the speed control signal transmitted by the control unit, and the driving unit is also used to control the power unit to enter a safe state based on the protection control signal transmitted by the control unit.

8. The motor drive circuit according to claim 7, characterized in that: Also includes: Isolator; The isolator is located between the control unit and the comparison unit, and is used to isolate a high voltage signal from a low voltage signal.

9. The motor driving circuit according to claim 8, characterized in that: Also includes: A filter unit, wherein an input end of the filter unit is connected to the isolator, and an output end of the filter unit is connected to the first input end of the comparison unit; A voltage divider unit, wherein the first end of the voltage divider unit is connected to a power supply, the second end of the voltage divider unit is grounded, the first output end of the voltage divider unit is connected to the acquisition unit, and the second output end of the voltage divider unit is connected to the second input end of the comparison unit; wherein the voltage divider unit is used to transmit an operating voltage to the acquisition unit, and to transmit a voltage to be detected to the comparison unit.

10. The motor driving circuit according to claim 9, characterized in that: The driving unit includes an isolated driving chip; The first output end of the voltage dividing unit is connected to the isolated driving chip, and the isolated driving chip is connected to the collection unit.

11. A motor controller, characterized in that: include: The motor drive circuit as described in claims 5-10.

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