Motor control method and device, motor control chip and intelligent power module

Abstract

The invention discloses a motor control method and device, a motor control chip and an intelligent power module, and the method comprises the steps: determining the duty ratio of a driving signal of each phase in each motor sector, and enabling the driving signal of each phase to be generated by the intelligent power module, and to be used for driving a motor to operate; determining a minimum effective duty ratio according to the duty ratio of each phase of driving signal; and under the condition that the minimum effective duty ratio is smaller than the preset duty ratio, a zero voltage vector insertion mode is adopted, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation mode. According to the method, the problem of motor shaking caused by insufficient conduction time of the switch tube of the intelligent power module can be avoided, and the reliability of motor control is further improved.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a motor control method and device, a motor control chip, and an intelligent power module. Background Art

[0002] In the field of motor control, SVPWM technology (Space Vector Pulse Width Modulation) is a widely used motor control technology. According to the PWM generation method, SVPWM can be divided into five-segment control and seven-segment control. The difference between the two is that the five-segment control adds a zero vector, and the seven-segment control adds two zero vectors. Therefore, the five-segment control has fewer switching times than the seven-segment control, and the switching loss is lower. At present, in low-power applications, it is a trend to integrate MCU (Microcontroller Unit), HVIC (High Voltage Integrated Circuit) and MOSFET into power modules, which has a great restriction on the heat dissipation capacity of the power module. Therefore, the relevant technology usually adopts five-segment control to control the operation of the motor to minimize the heat generated by the switching loss. However, in some power modules, when the five-segment control is adopted, there will be a problem of too small duty cycle, that is, due to the too small duty cycle, the switch tube is closed before it is fully opened, which will cause the current waveform to be severely distorted, and then the motor will shake, which is particularly obvious in the no-load low-speed section, resulting in low reliability of this type of control method. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a motor control method, by first determining the duty cycle of each phase drive signal in each motor sector, and determining the minimum effective duty cycle according to the duty cycle of each phase drive signal; when the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method, thereby extending the on-time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient on-time of the switch tube, and improving the reliability of the intelligent power module.

[0004] A second object of the present invention is to provide a computer-readable storage medium.

[0005] The third objective of the present invention is to provide a motor control chip.

[0006] A fourth objective of the present invention is to provide a motor control device.

[0007] A fifth objective of the present invention is to provide an intelligent power module.

[0008] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a motor control method, which is applied to an intelligent power module, and the method includes: determining the duty cycle of each phase drive signal in each motor sector, wherein each phase drive signal is generated by an intelligent power module and is used to drive the motor to operate; determining the minimum effective duty cycle according to the duty cycle of each phase drive signal; when the minimum effective duty cycle is less than a preset duty cycle, inserting a zero voltage vector so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

[0009] According to the motor control method of the embodiment of the present invention, the duty cycle of each phase drive signal in each motor sector is determined, and the minimum effective duty cycle is determined according to the duty cycle of each phase drive signal. When the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method, thereby extending the conduction time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient conduction time of the switch tube, and improving the reliability of the intelligent power module.

[0010] According to an embodiment of the present invention, the preset duty cycle is determined according to the switching delay time and the dead time of the power switch tube in the intelligent power module.

[0011] According to an embodiment of the present invention, when the intelligent power module controls the motor based on the seven-segment pulse width modulation method, the duty cycle of each phase drive signal is greater than or equal to a preset duty cycle and less than or equal to a maximum duty cycle.

[0012] According to an embodiment of the present invention, the maximum duty cycle is determined according to the period of each phase driving signal and a preset duty cycle.

[0013] According to an embodiment of the present invention, the time for inserting the zero voltage vector is greater than or equal to the high level time of a preset duty cycle.

[0014] According to an embodiment of the present invention, when the minimum effective duty cycle is greater than or equal to the preset duty cycle, the method further includes: controlling the intelligent power module to maintain a five-segment pulse width modulation mode to control the motor.

[0015] According to one embodiment of the present invention, determining the duty cycle of each phase drive signal in each motor sector includes: acquiring the rotor position of the motor; determining the current motor sector according to the rotor position, and determining the action time of the effective voltage vector according to the current motor sector, and determining the duty cycle of each phase drive signal in the current motor sector according to the action time of the effective voltage vector.

[0016] To achieve the above-mentioned purpose, a second aspect of the present invention provides a computer-readable storage medium on which a motor control program is stored. When the motor control program is executed by a processor, the above-mentioned motor control method is implemented.

[0017] According to the computer-readable storage medium of the embodiment of the present invention, the aforementioned motor control method can avoid the problem of motor jitter caused by insufficient conduction time of the switch tube, thereby improving the reliability of the intelligent power module.

[0018] To achieve the above objectives, the third aspect of the present invention proposes a motor control chip, including a memory, a processor, and a motor control program stored in the memory and executable on the processor. When the processor executes the motor control program, the aforementioned motor control method is implemented.

[0019] According to the motor control chip of the embodiment of the present invention, the problem of motor jitter caused by insufficient conduction time of the switch tube can be avoided through the above-mentioned motor control method, thereby improving the reliability of the intelligent power module.

[0020] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a motor control device, which is applied to an intelligent power module. The motor control device includes: a determination module, which is used to determine the duty cycle of each phase drive signal in each motor sector, wherein each phase drive signal is generated by the intelligent power module and is used to drive the motor to operate; the determination module is also used to determine the minimum effective duty cycle according to the duty cycle of each phase drive signal; and a control module, which is used to insert a zero voltage vector when the minimum effective duty cycle is less than a preset duty cycle, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

[0021] According to the motor control device of the embodiment of the present invention, the duty cycle of each phase drive signal in each motor sector is determined by a determination module, and the minimum effective duty cycle is determined according to the duty cycle of each phase drive signal; when the minimum effective duty cycle is less than the preset duty cycle, the control module adopts the method of inserting a zero voltage vector, so that the intelligent power module controls the motor based on the seven-segment pulse width modulation method, thereby extending the conduction time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient conduction time of the switch tube, and improving the reliability of the intelligent power module.

[0022] To achieve the above-mentioned purpose, a fifth aspect of the present invention provides an intelligent power module, including the aforementioned motor control chip or the aforementioned motor control device.

[0023] According to the motor control device of the embodiment of the present invention, through the aforementioned intelligent power module or the aforementioned motor control device, the problem of motor jitter caused by insufficient conduction time of the switch tube can be avoided, thereby improving the reliability of the intelligent power module.

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of a motor control method according to an embodiment of the present invention;

[0026] Figure 2 A schematic diagram of an effective voltage vector and a sector according to an embodiment of the present invention;

[0027] Figure 3 A synthetic schematic diagram of an effective voltage vector according to an embodiment of the present invention;

[0028] Figure 4 A driving signal waveform diagram generated by a five-segment pulse width modulation method according to an embodiment of the present invention;

[0029] Figure 5 A driving signal waveform diagram generated by a seven-segment pulse width modulation method according to an embodiment of the present invention;

[0030] Figure 6a to Figure 6b This is a schematic diagram of the motor phase current and phase voltage waveforms driven by the intelligent power module in a conventional scenario;

[0031] Figure 7a to Figure 7b A schematic diagram of phase current and phase voltage waveforms of a motor driven by an intelligent power module according to an embodiment of the present invention;

[0032] Figure 8 is a schematic diagram of the structure of a motor control chip according to an embodiment of the present invention;

[0033] Fig. 9 is a schematic structural diagram of a motor control device according to an embodiment of the present invention;

[0034] Figure 10a to Figure 10b FIG. 4 is a schematic diagram of the structure of an intelligent power module according to some embodiments of the present invention. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0036] The motor control method and device, computer-readable storage medium, motor control chip, and intelligent power module proposed in the embodiments of the present invention are described below with reference to the accompanying drawings.

[0037] Figure 1 is a flow chart of a motor control method according to an embodiment of the present invention, referring to Figure 1 As shown, the method includes:

[0038] S11, determining the duty cycle of each phase drive signal in each motor sector, wherein each phase drive signal is generated by an intelligent power module and is used to drive the motor to operate.

[0039] Specifically, an intelligent power module (IPM) is a switching device that can generate multi-phase drive signals for multi-phase motors according to user settings to drive the motors. Usually, the intelligent power module generates corresponding drive signals through SVPWM (Space Vector Pulse Width Modulation). Taking the three-phase drive signal as an example, according to the on-off state of the switch tube of the three-phase bridge arm, the intelligent power module can generate eight basic voltage vectors, including 6 effective voltage vectors and two zero voltage vectors. The 6 effective voltage vectors can divide the motor into 6 sectors, such as Figure 2 In the SVPWM control method, in order to obtain the best motor efficiency, different effective voltage vectors can be used to synthesize an ideal control vector to optimize the motor control efficiency. The specific principle of the SVPWM method will not be expanded here.

[0040] In the SVPWM control method, the duty cycle of the single-phase bridge arm drive signal may change suddenly in different motor sectors. Therefore, before determining the duty cycle of the drive signal, the motor sector at this time needs to be determined. After determining the motor sector, the duty cycle of each phase drive signal can be obtained to calculate the conduction time of the multi-phase bridge arm switch tube, providing a basis for subsequent motor control.

[0041] In some embodiments, determining the duty cycle of a multi-phase drive signal includes: obtaining the rotor position of the motor; determining the current motor sector based on the rotor position, and determining the action time of the effective voltage vector based on the current motor sector, and determining the duty cycle of each phase drive signal in the current motor sector based on the action time of the effective voltage vector.

[0042] Specifically, when the motor is running, the rotor position of the motor can be first obtained through Hall sensors, position sensors, etc. The specific method is not limited here. After the rotor position of the motor is obtained, the current motor sector and the corresponding ideal control vector can be determined according to the rotor position. Then, the corresponding effective voltage vector and its action time can be determined by vector decomposition. Finally, the duty cycle of each phase drive signal is determined according to the action time of the effective voltage vector. Still taking the three-phase motor as an example, when the ideal control vector is determined by the motor rotor position, Figure 3 As shown in UOUT, the reference Figure 3 As shown, at this time, the motor is in the first sector, which can be synthesized by the effective voltage vector U00 and the effective voltage vector U60. At this time, based on the volt-second balance principle, the action time T1 of the effective voltage vector U00 and the action time T2 of the effective voltage vector U60 can be obtained by the following formula (1):

[0043] UOUT=(T1*U0 / T)+(T2 / T*U60) (1)

[0044] Among them, UOUT is the ideal voltage vector, which can be obtained by combining the rotor position and the preset motor control strategy, U0 is the first effective voltage vector, and the corresponding switch state of the three-phase bridge arm is 001, and U60 is the second basic voltage vector, and the corresponding switch state of the three-phase bridge arm is 011. According to the above formula (1), after the motor rotor position is determined, the corresponding effective voltage vector and its action time can be obtained by vector decomposition. Subsequently, the duty cycle of the multi-phase drive signal can be determined according to the action time T1 and the action time T2 and the PWM period T of the intelligent power module, thereby realizing the function of determining the duty cycle of the multi-phase drive signal.

[0045] S12, determining a minimum effective duty cycle according to the duty cycle of each phase driving signal.

[0046] Specifically, the effective duty cycle refers to the duty cycle that is not 0 or 1, for example, Figure 4 The three-phase drive signal shown in FIG. 1 represents a high level and 0 represents a low level. Figure 4 It can be seen that at this time, the duty cycle of the drive signal of the two-phase bridge arm a and b is the effective duty cycle, and the duty cycle of the phase c bridge arm in the motor sector is 0, so the duty cycle of the phase c is not an effective duty cycle. In a certain motor sector, when the duty cycle of a certain phase drive signal is 1 or 0, it means that in the motor sector, the switch tube of the phase bridge arm has not been activated, so the problem of insufficient switch tube conduction time will not occur. After determining the duty cycle of the multi-phase drive signal, the minimum effective duty cycle can be determined according to the duty cycle of each phase drive signal. The minimum effective duty cycle can reflect whether the problem of insufficient switch tube conduction time will occur in the intelligent power module under the current drive signal.

[0047] S13, when the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

[0048] Specifically, the seven-segment pulse width modulation method is a SVPWM method. The seven-segment pulse width modulation method is characterized in that the seven-segment pulse width modulation method needs to insert two zero voltage vectors (000 and 111 respectively), so the seven-segment pulse width modulation method can simultaneously adjust the conduction time of the upper bridge switch tube (or lower bridge switch tube) of the multi-phase bridge arm. The preset duty cycle refers to the duty cycle corresponding to the conduction time that can ensure the stable switching of the upper bridge switch tube and the lower bridge switch tube of the single-phase bridge arm in the intelligent power module, and the preset duty cycle can be set in advance.

[0049] When the minimum effective duty cycle is less than the preset duty cycle, it means that during the operation of the motor, the conduction time of the bridge arm switch tube corresponding to the minimum effective duty cycle is insufficient to fully open the switch tube, which will cause serious current distortion, thereby causing the motor to vibrate and affect the stable operation of the motor. In the embodiment of the present invention, when this happens, by inserting a zero voltage vector, the control intelligent power module uses a seven-segment SVPWM generation method to generate a multi-phase drive signal. The seven-segment SVPWM drive signal can be as follows: Figure 5 As shown, since the seven-segment pulse width modulation method inserts two zero voltage vectors, the conduction time of the switch tube of each phase bridge arm can be increased by a part, so that all the switch tubes have enough time to be fully turned on, thereby avoiding possible motor jitter problems and allowing the motor to run smoothly.

[0050] In the above embodiment, the duty cycle of each phase drive signal in each motor sector is first determined, and the minimum effective duty cycle is determined according to the duty cycle of each phase drive signal; when the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method, thereby extending the on-time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient on-time of the switch tube, and improving the reliability of the intelligent power module.

[0051] Furthermore, the preset duty cycle is determined according to the switch delay time and dead time of the power switch tube in the intelligent power module.

[0052] Specifically, the switching delay time of the power switch tube refers to the time required for the power switch tube in the intelligent power module to be fully turned on, which is mainly affected by the conduction mode of the intelligent power module and the type of power switch tube; the dead time refers to the fact that the upper bridge switch tube and the lower bridge switch tube of the single-phase bridge arm cannot be turned on at the same time, so when switching the upper bridge switch tube and the lower bridge switch tube, a period of time needs to be reserved to ensure safety. This time is the dead time, and the dead time is mainly determined by the control strategy of the motor. Since the preset duty cycle needs to ensure that the upper bridge switch tube and the lower bridge switch tube of the single-phase bridge arm in the intelligent power module can switch stably. Therefore, the switch tube conduction time corresponding to the preset duty cycle can be determined to be greater than or equal to the sum of the switching delay time and the dead time of the power switch tube in the intelligent power module, so as to ensure that the switch tubes of the upper and lower bridge arms can switch stably.

[0053] For example, refer to Figure 6a-6b As shown, when the motor control method of the embodiment of the present invention is not adopted, when the effective duty ratio is small, the motor phase current waveform under the control of the intelligent power module is as follows Figure 6a As shown, the phase voltage is Figure 6b As shown in FIG. 1 , the motor current waveform is seriously distorted and the phase voltage is obviously unstable. After the motor control method of the embodiment of the present invention is adopted, the motor phase current waveform is as shown in FIG. Figure 7a As shown in Figure 2, the distortion is significantly reduced; at the same time, Figure 7b As shown, the phase voltage variation of the motor is significantly more stable, so that the motor can run smoothly, thereby effectively improving the reliability of the motor control method.

[0054] In some embodiments, when the intelligent power module controls the motor based on a seven-segment pulse width modulation method, the duty cycle of each phase drive signal is greater than or equal to a preset duty cycle and less than or equal to a maximum duty cycle.

[0055] Furthermore, the maximum duty cycle is determined according to the period of each phase driving signal and a preset duty cycle.

[0056] Specifically, refer to Figure 5As shown, when the intelligent power module controls the motor based on the seven-segment pulse width modulation method, the duty cycle of each phase drive signal needs to be greater than or equal to the preset duty cycle to avoid the problem that the switch tube of the three-phase bridge arm is not turned on for a long time, so that the switch tube cannot be fully turned on and needs to be turned off. At the same time, during the operation of the motor, the upper and lower bridge switches in the single-phase bridge arm are alternately turned on. Therefore, in the drive signal of the phase bridge arm, if the high level is regarded as the turn-on signal of the upper bridge switch tube, the low level can be regarded as the turn-on signal of the lower bridge switch tube; or if the high level can be regarded as the turn-on signal of the lower bridge switch tube, the low level can be regarded as the turn-on signal of the upper bridge switch tube. Therefore, the duty cycle of each phase drive signal also needs to be less than or equal to the maximum duty cycle to ensure that both the upper bridge switch tube and the lower bridge switch tube can be fully turned on. Among them, the maximum duty cycle can be determined according to the period of the multi-phase drive signal and the preset duty cycle. For example, the maximum duty cycle can be the difference between the multi-phase drive signal and the preset duty cycle. When the duty cycle of each phase drive signal is less than or equal to the maximum duty cycle, the upper bridge switch tube and the lower bridge switch tube of the motor can be fully opened, thereby ensuring the stable operation of the motor.

[0057] In some embodiments, the time for inserting the zero voltage vector is greater than or equal to the high level time of a preset duty cycle.

[0058] Specifically, in order to ensure that the duty cycle of each phase drive signal is greater than or equal to the preset duty cycle after the invalid voltage vector is inserted, the time of inserting the zero voltage vector needs to be greater than or equal to the high level time of the preset duty cycle. For example, the time of inserting the invalid voltage vector can be equal to the high level time corresponding to the preset duty cycle, so that the duty cycle of each phase drive signal can be ensured to be greater than or equal to the preset duty cycle in a relatively simple way, thereby ensuring the stable operation of the motor and reducing the difficulty of adjustment.

[0059] It should be noted that, in an embodiment of the present invention, after an invalid voltage vector is inserted, there may be a phase duty cycle in the multi-phase drive signal duty cycle that is greater than the maximum duty cycle. At this time, the duration of inserting the invalid voltage vector can be reduced to ensure that the duty cycle of the multi-phase drive signal is less than or equal to the maximum duty cycle, thereby ensuring the stable operation of the motor.

[0060] In some embodiments, when the minimum effective duty cycle is greater than or equal to a preset duty cycle, the method further includes: controlling the intelligent power module to maintain a five-segment pulse width modulation method to control the motor.

[0061] Specifically, in the driving signal generation method of the intelligent power module, the five-segment pulse width modulation method and the seven-segment pulse width modulation method both have certain advantages. In a single PWM cycle, when the five-segment pulse width modulation method is used to generate the driving signal, the number of switching times of the switch tube in the intelligent power module can be reduced, but it will cause the current harmonics to increase, and it may also cause the aforementioned switch tube to be unable to be fully opened, thereby causing the problem of motor jitter. When the seven-segment pulse width modulation method is used to generate the driving signal, the current harmonics of the intelligent power module can be reduced, but it will also cause the heating of the power module to increase. In addition, generally speaking, the multi-phase driving signal of the motor is related to the input voltage of the motor, and the input voltage is related to the motor load. Generally, the heavier the load of the motor, the greater the input voltage of the motor, and the corresponding duty cycle of the multi-phase driving signal of the motor is greater. Therefore, based on the above characteristics, the embodiment of the present invention uses the preset duty cycle as the switching point of the five-segment pulse width modulation method and the seven-segment pulse width modulation method to combine the advantages of the five-segment pulse width modulation method and the seven-segment pulse width modulation method, and further improves the motor control performance of the intelligent power module.

[0062] For example, when the minimum effective duty cycle is greater than or equal to the preset duty cycle, the load is relatively large, and the multi-phase drive signal will not cause the aforementioned problem that the switch tube cannot be fully opened. At this time, a five-segment pulse width modulation method can be used to generate a multi-phase drive signal to reduce switching losses, lower the temperature rise of the intelligent power module, and provide favorable conditions for the miniaturization of the intelligent power module. At the same time, when the minimum effective duty cycle is less than the preset duty cycle, there is a risk that the switch tube of the motor cannot be fully opened. At the same time, the motor is lightly loaded or unloaded. At this time, a seven-segment pulse width modulation method can be used to generate a multi-phase drive signal to avoid the problem that the switch tube cannot be fully opened, and at the same time, the current harmonics can be reduced.

[0063] It should be noted that, in the embodiment of the present invention, the switching point between the five-segment pulse width modulation mode and the seven-segment pulse width modulation mode can be determined by setting different preset duty cycles. For example, for an intelligent power module with less heat dissipation pressure, a higher preset duty cycle can be set to increase the proportion of the seven-segment pulse width modulation mode in the drive signal generation method, thereby further reducing the harmonic current of the motor; or, for an intelligent power module with greater heat dissipation pressure, a lower preset duty cycle can be set, for example, the preset duty cycle is set to the ratio of the sum of the switching delay time and the dead time of the multi-phase drive signal to the PWM period, so as to minimize the switching loss of the intelligent power module. In this way, the motor control method can adapt to intelligent power modules under different conditions, thereby improving the flexibility of the method.

[0064] In summary, according to the motor control method of the embodiment of the present invention, by determining the duty cycle of each phase drive signal in each motor sector, and determining the minimum effective duty cycle according to the duty cycle of each phase drive signal, and when the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted, so that the intelligent power module controls the motor based on the seven-segment pulse width modulation method, thereby extending the conduction time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient conduction time of the switch tube, improving the reliability of the intelligent power module, and reducing the harmonic current of the motor under no-load or light-load conditions; at the same time, by using the five-segment pulse width modulation method to generate the drive signal when the minimum effective duty cycle is greater than or equal to the preset duty cycle, the switching loss of the motor is effectively reduced, thereby reducing the heat generation of the power module; in addition, by setting different preset duty cycles as the switching points between the five-segment and seven-segment modes according to the heat dissipation performance and harmonic performance requirements of the intelligent power module, the motor control method can be applied to different intelligent power modules, thereby effectively improving the reliability and flexibility of the motor control method, and realizing the optimization of the motor control performance of the intelligent power module.

[0065] Corresponding to the above embodiment, an embodiment of the present invention further provides a computer-readable storage medium on which a motor control program is stored. When the motor control program is executed by a processor, the above motor control method is implemented.

[0066] According to the computer-readable storage medium of an embodiment of the present invention, through the aforementioned motor control method, it is possible to avoid the problem of motor jitter caused by insufficient conduction time of the switch tube in the intelligent power module, and to reduce the motor current harmonics when the motor is unloaded or lightly loaded, and to reduce the heat generation of the intelligent power module when the motor load is large, thereby optimizing the motor control performance of the intelligent power module.

[0067] Corresponding to the above embodiment, the embodiment of the present invention further provides a motor control chip, referring to Figure 8 As shown, the motor control chip 100 includes a memory 110, a processor 120, and a motor control program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the motor control program, the aforementioned motor control method is implemented.

[0068] According to the motor control chip of the embodiment of the present invention, through the aforementioned motor control method, it is possible to avoid the problem of motor jitter caused by insufficient conduction time of the switch tube in the intelligent power module, and to reduce the motor current harmonics when the motor is unloaded or lightly loaded, as well as reduce the heat generation of the intelligent power module when the motor load is large, thereby optimizing the motor control performance of the intelligent power module.

[0069] Corresponding to the above embodiment, the embodiment of the present invention further provides a motor control device 200, which is applied to an intelligent power module, referring to Fig. 9 As shown, the motor control device 200 includes: a determination module 210 and a control module 220 .

[0070] Among them, the determination module 210 is used to determine the duty cycle of each phase drive signal in each motor sector, wherein each phase drive signal is generated by an intelligent power module and is used to drive the motor to operate; the determination module 210 is also used to determine the minimum effective duty cycle according to the duty cycle of each phase drive signal; the control module 220 is used to insert a zero voltage vector when the minimum effective duty cycle is less than a preset duty cycle, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

[0071] According to an embodiment of the present invention, the preset duty cycle is determined according to the switching delay time and the dead time of the power switch tube in the intelligent power module.

[0072] According to an embodiment of the present invention, when the intelligent power module controls the motor based on the seven-segment pulse width modulation method, the duty cycle of each phase drive signal is greater than or equal to a preset duty cycle and less than or equal to a maximum duty cycle.

[0073] According to an embodiment of the present invention, the maximum duty cycle is determined according to the period of each phase driving signal and a preset duty cycle.

[0074] According to an embodiment of the present invention, the time for inserting the zero voltage vector is less than or equal to the high level time of a preset duty cycle.

[0075] According to an embodiment of the present invention, the control module 220 is further configured to: when the minimum effective duty cycle is greater than or equal to a preset duty cycle, control the intelligent power module to maintain a five-segment pulse width modulation mode to control the motor.

[0076] According to one embodiment of the present invention, the determination module 210 is also used to: obtain the rotor position of the motor; determine the current motor sector according to the rotor position, and determine the action time of the effective voltage vector according to the current motor sector, and determine the duty cycle of each phase drive signal in the current motor sector according to the action time of the effective voltage vector.

[0077] It should be noted that, for the description of the motor control device in this application, please refer to the above-mentioned description of the motor control method, which will not be repeated here.

[0078] According to the motor control device of the embodiment of the present invention, the duty cycle of each phase drive signal in each motor sector is determined by a determination module, and the minimum effective duty cycle is determined according to the duty cycle of each phase drive signal. When the minimum effective duty cycle is less than the preset duty cycle, the control module adopts the method of inserting a zero voltage vector to enable the intelligent power module to control the motor based on the seven-segment pulse width modulation method, thereby extending the conduction time of the switch tube in the intelligent power module, avoiding the problem of motor jitter caused by insufficient conduction time of the switch tube, improving the reliability of the intelligent power module, and reducing the harmonic current of the motor under no-load or light-load conditions; at the same time, when the minimum effective duty cycle is greater than or equal to the preset duty cycle, the control module uses the five-segment SVPWM method to generate the drive signal, effectively reducing the switching loss of the motor, thereby reducing the heat generation of the power module; in addition, by setting different preset duty cycles as the switching points between the five-segment and seven-segment methods according to the heat dissipation performance and harmonic performance requirements of the intelligent power module, the motor control method can be applicable to different intelligent power modules, thereby effectively improving the reliability and flexibility of the motor control method, and realizing the optimization of the motor control performance of the intelligent power module.

[0079] Corresponding to the above embodiment, the embodiment of the present invention further provides an intelligent power module, referring to Figure 10a to Figure 10b As shown, the intelligent power module 1000 includes the aforementioned motor control chip 100 or the aforementioned motor control device 200 .

[0080] According to the intelligent power module of the embodiment of the present invention, through the aforementioned motor control chip or the aforementioned motor control device, it is possible to avoid the problem of motor jitter caused by insufficient conduction time of the switch tube in the motor controller, and to reduce the motor current harmonics when the motor is unloaded or lightly loaded, and to reduce the heat generation of the intelligent power module when the motor load is heavy, thereby optimizing the motor control performance of the motor controller.

[0081] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0082] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0084] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0085] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0086] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A motor control method, characterized in that: Applied to an intelligent power module, the method comprises: Determining a duty cycle of a per-phase drive signal in each motor sector, wherein the per-phase drive signal is generated by the intelligent power module and is used to drive the motor to operate; Determining a minimum effective duty cycle according to the duty cycle of the driving signal of each phase; When the minimum effective duty cycle is less than the preset duty cycle, a zero voltage vector is inserted so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

2. The method according to claim 1, characterized in that The preset duty cycle is determined according to the switch delay time and dead time of the power switch tube in the intelligent power module.

3. The method according to claim 1 or 2, characterized in that: When the intelligent power module controls the motor based on a seven-segment pulse width modulation method, the duty cycle of each phase drive signal is respectively greater than or equal to the preset duty cycle and less than or equal to the maximum duty cycle.

4. The method according to claim 3, characterized in that The maximum duty cycle is determined according to the period of the per-phase driving signal and the preset duty cycle.

5. The method according to claim 3, characterized in that: The time for inserting the zero voltage vector is greater than or equal to the high level time of the preset duty cycle.

6. The method according to claim 1, characterized in that When the minimum effective duty cycle is greater than or equal to a preset duty cycle, the method further includes: The intelligent power module is controlled to maintain a five-segment pulse width modulation mode to control the motor.

7. The method according to claim 1, characterized in that Determine the duty cycle of each phase drive signal within each motor sector, including: Obtaining a rotor position of the motor; The current motor sector is determined according to the rotor position, the action time of the effective voltage vector is determined according to the current motor sector, and the duty cycle of each phase drive signal in the current motor sector is determined according to the action time of the effective voltage vector.

8. A computer-readable storage medium, characterized in that: A motor control program is stored thereon, and when the motor control program is executed by a processor, the motor control method according to any one of claims 1-7 is implemented.

9. A motor control chip, characterized in that: The method comprises a memory, a processor and a motor control program stored in the memory and executable on the processor. When the processor executes the motor control program, the motor control method according to any one of claims 1 to 7 is implemented.

10. A motor control device, characterized in that: Applied to an intelligent power module, the motor control device comprises: A determination module, used to determine the duty cycle of each phase drive signal in each motor sector, wherein the each phase drive signal is generated by the intelligent power module and is used to drive the motor to operate; the determination module is also used to determine the minimum effective duty cycle according to the duty cycle of the each phase drive signal; The control module is used to insert a zero voltage vector when the minimum effective duty cycle is less than a preset duty cycle, so that the intelligent power module controls the motor based on a seven-segment pulse width modulation method.

11. An intelligent power module, characterized in that: It comprises the motor control chip according to claim 9 or the motor control device according to claim 10.

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