Dead-time compensation method, dead-time compensation device, motor driver, and storage medium

Abstract

This invention discloses a dead-zone compensation method, a dead-zone compensation device, a motor driver, and a storage medium. The dead-zone compensation method includes: acquiring a first voltage component and a second voltage component in a two-phase stationary coordinate system; calculating the phase angle of the target voltage vector synthesized from the first and second voltage components; modulating the first and second voltage components to obtain the three-phase duty cycle before compensation; calculating the compensation amount of the three-phase duty cycle based on the phase angle; and superimposing the compensation amount onto the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation. The embodiments provided by this invention can effectively suppress torque ripple and have a good dead-zone compensation effect.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a dead-zone compensation method, a dead-zone compensation device, a motor driver, and a computer-readable storage medium. Background Technology

[0002] In a three-phase inverter, the switching transistors must operate at a high switching frequency to output a more ideal current waveform. During the commutation process of the two switching transistors on the same bridge arm, a certain dead time needs to be added between the turn-on and turn-off moments to prevent them from shoot-through and burning out. The dead time effect will cause high-order harmonics in the output current, specifically generating torque ripple at 6 times the fundamental frequency, resulting in large motor torque fluctuations and severely affecting control performance.

[0003] Currently, most solutions in related technologies complete dead zone compensation based on current feedback. This solution requires determining the position of the current zero-crossing point. Since the waveform output at the position of current direction change has glitches and clamping, the distortion is severe, resulting in a large error in determining the position of the zero-crossing point, which in turn affects the dead zone compensation effect. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a dead-zone compensation method, a dead-zone compensation device, a motor driver and a computer-readable storage medium, which can effectively suppress torque ripple and have a good dead-zone compensation effect.

[0005] In a first aspect, embodiments of the present invention provide a dead-zone compensation method, comprising: acquiring a first voltage component and a second voltage component in a two-phase stationary coordinate system; calculating the phase angle of a target voltage vector synthesized by the first voltage component and the second voltage component; modulating the first voltage component and the second voltage component to obtain the three-phase duty cycle before compensation; calculating the compensation amount of the three-phase duty cycle based on the phase angle; and superimposing the compensation amount onto the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation.

[0006] The dead-zone compensation method provided by the embodiments of the present invention has at least the following beneficial effects: While calculating the three-phase duty cycle using the first and second voltage components in a two-phase stationary coordinate system, the phase angle of the target voltage vector is calculated using the first and second voltage components. Based on the phase angle of the target voltage vector, the compensation amount of the three-phase duty cycle is calculated and finally superimposed onto the three-phase duty cycle to modulate the target voltage. The dead-zone compensation method used in this scheme does not require the feedback current of the three-phase motor, thus eliminating the problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not require the value of the previous calculation cycle, eliminating compensation lag. Furthermore, through FFT analysis of the torque feedback, torque ripple at 6 times the fundamental frequency can be effectively suppressed, resulting in a good dead-zone compensation effect.

[0007] In one embodiment of the present invention, the compensation amount is calculated by multiplying the sine value of the compensation angle by a preset compensation gain coefficient and then by negative one, and the compensation angle is determined by the phase angle.

[0008] In one embodiment of the present invention, the compensation amount includes phase A compensation amount, phase B compensation amount and phase C compensation amount, the compensation angle corresponding to the phase A compensation amount is equal to the phase angle, the compensation angle corresponding to the phase B compensation amount is obtained by subtracting 2π / 3 from the phase angle, and the compensation angle corresponding to the phase C compensation amount is obtained by adding 2π / 3 to the phase angle.

[0009] In one embodiment of the present invention, the value range of the compensation gain coefficient is greater than or equal to 0.8 and less than or equal to 1.2.

[0010] In one embodiment of the present invention, before adding the compensation amount to the three-phase duty cycle before compensation, the method further includes: limiting the compensation amount.

[0011] In one embodiment of the present invention, the amplitude limiting process includes: when the compensation amount is greater than the upper limit of amplitude limiting, using the upper limit of amplitude limiting as the compensation amount; when the compensation amount is less than the lower limit of amplitude limiting, using the lower limit of amplitude limiting as the compensation amount.

[0012] In the above technical solution, by performing amplitude limiting processing on the calculated compensation amount, the value of the compensation amount is restricted to the range determined by the upper and lower amplitude limiting values, so as to ensure that an appropriate compensation amount is obtained, which is conducive to achieving a reliable and better dead zone compensation effect.

[0013] In one embodiment of the present invention, the phase angle of the target voltage vector is obtained by calculating the ratio of the second voltage component to the first voltage component using the arctangent function.

[0014] In one embodiment of the present invention, the first voltage component and the second voltage component are calculated by inverse Park transformation of the direct-axis voltage and quadrature-axis voltage obtained in the field-oriented control (FOC).

[0015] Secondly, embodiments of the present invention provide a dead-zone compensation device, comprising: a phase angle calculation module, used to acquire a first voltage component and a second voltage component in a two-phase stationary coordinate system, and calculate the phase angle of a target voltage vector synthesized by the first voltage component and the second voltage component; a modulation module, used to modulate the first voltage component and the second voltage component to obtain the three-phase duty cycle before compensation; a compensation amount calculation module, used to calculate the compensation amount of the three-phase duty cycle according to the phase angle; and a compensation superposition module, used to superimpose the compensation amount onto the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation.

[0016] The dead-zone compensation device provided according to the second aspect of the present invention has at least the following beneficial effects: the dead-zone compensation device calculates the three-phase duty cycle by using the first voltage component and the second voltage component in a two-phase stationary coordinate system, and calculates the phase angle of the target voltage vector using the first voltage component and the second voltage component, and calculates the compensation amount of the three-phase duty cycle based on the phase angle of the target voltage vector, and finally superimposes it into the three-phase duty cycle to modulate the target voltage; the dead-zone compensation device used in this scheme does not need to use the feedback current of the three-phase motor, and there is no problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not need to use the value of the previous calculation cycle, and there is no compensation lag. Furthermore, through torque feedback FFT analysis, it can effectively suppress torque ripple of 6 times the fundamental frequency, and has a good dead-zone compensation effect.

[0017] Thirdly, embodiments of the present invention provide a motor driver, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the dead-zone compensation method as described in the first aspect.

[0018] The motor driver provided according to the third aspect of the present invention has at least the following beneficial effects: the motor driver calculates the three-phase duty cycle by using the first voltage component and the second voltage component in a two-phase stationary coordinate system, and calculates the phase angle of the target voltage vector using the first voltage component and the second voltage component. Based on the phase angle of the target voltage vector, the compensation amount of the three-phase duty cycle is calculated and finally superimposed on the three-phase duty cycle to modulate the target voltage. The motor driver used in this scheme does not need to use the feedback current of the three-phase motor, and there is no problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not need to use the value of the previous calculation cycle, and there is no compensation lag. Furthermore, through torque feedback FFT analysis, torque ripple of 6 times the fundamental frequency can be effectively suppressed, and it has a good dead-zone compensation effect.

[0019] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the dead-zone compensation method as described in the first aspect.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0021] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0023] Figure 1 This is a schematic diagram of the structure of a three-phase inverter provided in an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of dead time insertion in a three-phase inverter provided in an embodiment of the present invention;

[0025] Figure 3 This is a flowchart illustrating the dead zone compensation method provided in an embodiment of the present invention;

[0026] Figure 4 This is a flowchart illustrating a dead zone compensation method provided in another embodiment of the present invention;

[0027] Figure 5 This is a loop control block diagram with dead-time compensation provided in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the torque feedback FFT analysis results without using the dead-zone compensation method at a fundamental frequency of 60Hz.

[0029] Figure 7 This is a schematic diagram of the torque feedback FFT analysis results using the dead-zone compensation method at a fundamental frequency of 60Hz.

[0030] Figure 8 This is a schematic diagram of the structure of the motor driver provided in an embodiment of the present invention. Detailed Implementation

[0031] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0032] In the description of this invention, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0033] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0034] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of a three-phase inverter provided in an embodiment of this application. The three-phase inverter includes a DC power supply U. dc The system consists of three inverter arms and a permanent magnet synchronous motor (PMSM), with each inverter arm including two switching devices. The DC power supply is U. dc The output DC current is inverted into a three-phase current i after passing through the three inverter bridge arms. a i b and i c The output is sent to the permanent magnet synchronous motor (PMSM).

[0035] Reference Figure 2 , Figure 2This is a schematic diagram of dead time insertion in a three-phase inverter provided in an embodiment of the present invention. In a three-phase inverter, the commutation of two switching devices on the same bridge arm is controlled by two switching control signals. To output a more ideal current waveform, the switching devices in the inverter must operate at a higher switching frequency. During the commutation process of the two switching devices on the same bridge arm, to prevent the two switching devices from shoot-through and burning out, a certain dead time needs to be added between the turn-on and turn-off times of the two switching devices. Adding dead time will introduce a dead-time effect. The dead-time effect will cause high-order harmonics in the output current, specifically generating torque ripple at 6 times the fundamental frequency, resulting in large motor torque fluctuations and seriously affecting control performance.

[0036] Currently, most solutions in related technologies complete dead zone compensation based on current feedback. This solution requires determining the position of the current zero-crossing point. Since the waveform output at the position of current direction change has glitches and clamping, the distortion is severe, resulting in a large error in determining the position of the zero-crossing point, which in turn affects the dead zone compensation effect.

[0037] Based on this, embodiments of the present invention provide a dead-zone compensation method, a dead-zone compensation device, a motor driver, and a computer-readable storage medium. In the dead-zone compensation method, the three-phase duty cycle is calculated using the first and second voltage components in a two-phase stationary coordinate system. Simultaneously, the phase angle of the target voltage vector is calculated using the first and second voltage components. The compensation amount of the three-phase duty cycle is calculated based on the phase angle of the target voltage vector, and finally superimposed on the three-phase duty cycle to modulate the target voltage. The dead-zone compensation method used in this scheme does not require the feedback current of the three-phase motor, and there is no problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not require the value of the previous calculation cycle, and there is no compensation lag. Furthermore, through torque feedback FFT analysis, torque ripple at 6 times the fundamental frequency can be effectively suppressed, resulting in a good dead-zone compensation effect.

[0038] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0039] Firstly, referring to Figure 3 , Figure 3 This is a schematic flowchart of the dead zone compensation method provided in an embodiment of the present invention. The dead zone compensation method in this embodiment includes, but is not limited to, steps S110, S120, S130, and S140.

[0040] Step S110: Obtain the first voltage component and the second voltage component in the two-phase stationary coordinate system, and calculate the phase angle of the target voltage vector synthesized by the first voltage component and the second voltage component;

[0041] Step S120: Modulate the three-phase duty cycle before compensation based on the first voltage component and the second voltage component;

[0042] Step S130: Calculate the compensation amount of the three-phase duty cycle based on the phase angle;

[0043] Step S140: Add the compensation amount to the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation.

[0044] According to the dead-zone compensation method shown in steps S110 to S140 of the present invention, the three-phase duty cycle is calculated by using the first voltage component and the second voltage component in the two-phase stationary coordinate system. At the same time, the phase angle of the target voltage vector is calculated using the first voltage component and the second voltage component. The compensation amount of the three-phase duty cycle is calculated based on the phase angle of the target voltage vector. The compensation amount is superimposed on the three-phase duty cycle to obtain the compensated three-phase duty cycle, and the target voltage is modulated. In this process, the feedback current of the three-phase motor is not required, and there is no problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not need to use the value of the previous calculation cycle, and there is no compensation lag. Furthermore, through torque feedback FFT analysis, torque ripple of 6 times the fundamental frequency can be effectively suppressed, and it has a good dead-zone compensation effect.

[0045] It is understood that through step S110, the first voltage component and the second voltage component in the two-phase stationary coordinate system can be obtained, the target voltage vector can be synthesized based on the first voltage component and the second voltage component, and the phase angle of the synthesized target voltage vector can be calculated based on the first voltage component and the second voltage component. Specifically, in one embodiment of the present invention, the first voltage component and the second voltage component are calculated from the direct-axis voltage and the quadrature-axis voltage after inverse Park transformation. The direct-axis voltage and the quadrature-axis voltage are obtained from the field-oriented control (FOC). Specifically, FOC is Field-Oriented Control, and the inverse Park transformation is used to convert the direct-axis voltage and the quadrature-axis voltage in the two-phase rotating coordinate system into the first voltage component and the second voltage component in the two-phase stationary coordinate system.

[0046] In one embodiment of this application, the phase angle of the target voltage vector is calculated using the arctangent function as the ratio of the second voltage component to the first voltage component. It should be noted that after obtaining the first and second voltage components in a two-phase stationary coordinate system, the phase angle of the target voltage vector synthesized from the first and second voltage components can be calculated using the arctangent function. It is understood that the arctangent function returns an arctangent value expressed in radians.

[0047] Specifically, let the first voltage component be U. α The second voltage component is Uβ The phase angle of the synthesized target voltage vector is θ; the phase angle of the synthesized target voltage vector is calculated using the arctangent function atan2: θ = atan2(U β / U α ); where θ is the phase of the modulated target voltage, and -π < θ ≤ π.

[0048] It is understandable that step S120 can obtain the three-phase duty cycle before compensation by modulating the first voltage component and the second voltage component. Specifically, the modulation method used is SVPWM modulation, that is, Space Vector Pulse Width Modulation.

[0049] It is understood that through step S130, the compensation amount of the three-phase duty cycle can be calculated based on the phase angle. Specifically, in one embodiment of the present invention, the compensation amount is calculated by multiplying the sine value of the compensation angle by a preset compensation gain coefficient and then by negative one, where the compensation angle is determined by the phase angle. The compensation gain coefficient has a value range of greater than or equal to 0.8 and less than or equal to 1.2.

[0050] It should be noted that, in one embodiment of the present invention, the compensation amount includes phase A compensation amount, phase B compensation amount and phase C compensation amount. The compensation angle corresponding to phase A compensation amount is equal to the phase angle. The compensation angle corresponding to phase B compensation amount is obtained by subtracting 2π / 3 from the phase angle. The compensation angle corresponding to phase C compensation amount is obtained by adding 2π / 3 to the phase angle.

[0051] It is understandable that, through step S140, the calculated compensation amount and the three-phase duty cycle before compensation are superimposed accordingly to obtain the three-phase duty cycle after compensation.

[0052] It should be noted that, in one embodiment of this application, the compensated three-phase duty cycle is over-modulated to obtain the final three-phase duty cycle acting on the three-phase inverter bridge. The target voltage is then modulated and applied to the permanent magnet synchronous motor.

[0053] Reference Figure 4 , Figure 4 This is a flowchart illustrating a dead-zone compensation method provided in another embodiment of the present invention. Step S140: Before adding the compensation amount to the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation, the method may include, but is not limited to, step S210.

[0054] Step S210: Limit the compensation amount.

[0055] In this step, the compensation amount calculated in step S130 is subjected to amplitude limiting. Specifically, in one embodiment of the present invention, the amplitude limiting process includes: when the compensation amount is greater than the upper limit value, the upper limit value is used as the compensation amount; when the compensation amount is less than the lower limit value, the lower limit value is used as the compensation amount. It should be noted that when the compensation amount is less than the upper limit value but greater than the lower limit value, the calculated compensation amount is determined as the compensation amount used subsequently. Here, the amplitude limiting value is the ratio of the dead time to the PWM period, the upper limit value is a positive value of the amplitude limiting value, and the lower limit value is a negative value of the amplitude limiting value. By limiting the calculated compensation amount, the value of the compensation amount is restricted to the range determined by the upper and lower limits, ensuring that a suitable compensation amount is obtained, which is beneficial for achieving a reliable and better dead time compensation effect.

[0056] Specifically, taking a carrier with an SVPWM modulation frequency of 10kHz as an example, the period of a carrier is 100µs. When the inserted dead time is 3µs, the dead time accounts for 3% of the entire carrier period, which is a limiting value of 3%. Therefore, when determining the dead time compensation amount, the compensation amount needs to be limited so that the compensation amount does not exceed 3%.

[0057] For example, refer to Figure 5 , Figure 5 This is a loop control block diagram with dead-time compensation provided in an embodiment of the present invention. Combined with... Figure 3 The dead-zone control method provided in the embodiments of the present invention will be further explained.

[0058] In the dead-zone compensation method provided in this embodiment of the invention, firstly, the direct-axis voltage U in a two-phase rotating coordinate system is obtained by magnetic field orientation control (FOC). d and quadrature axis voltage U q .

[0059] Then, the direct-axis voltage U d and quadrature axis voltage U q The three-phase duty cycle t is obtained after SVPWM modulation. A t B and t C Meanwhile, the direct-axis voltage U d and quadrature axis voltage U q The first voltage component U in the two-phase stationary coordinate system is obtained after inverse Park transformation. α Second voltage component U β .

[0060] Then, the arctangent function atan2 is used to calculate the voltage component U from the first voltage component. α With the second voltage component U β The phase angle θ of the synthesized target voltage vector is specifically: θ = atan2(U β / U α ); where θ is the phase of the modulated target voltage, and -π < θ ≤ π.

[0061] Next, the compensation amount for the three-phase duty cycle is calculated based on the phase angle of the target voltage vector. The compensation amount includes the A-phase compensation amount t. Acomp Phase B compensation amount t Bcomp and C phase compensation amount t Ccomp ;Specifically: t Acomp = -ksin(θ); t Bcomp = -ksin(θ-2π / 3); t Ccomp = -ksin(θ+2π / 3); where k is the compensation gain coefficient, and the value range of the compensation gain coefficient is 0.8, depending on the actual situation. <k<1.2。

[0062] Subsequently, the compensation amount t of phase A was adjusted by the limiting module. Acomp Phase B compensation amount t Bcomp and C phase compensation amount t Ccomp Amplitude limiting is performed. Specifically, the limiting value t is obtained based on the ratio of the dead time to the PWM period. comp Then the upper limit value is t. comp The lower limit of the amplitude limit is -t comp When the compensation amount is greater than the upper limit value t comp The upper limit value t will be limited. comp As compensation amount; when the compensation amount is less than the lower limit of the amplitude limit -t comp Set the lower limit of the amplitude limit to -t comp As compensation amount; when the compensation amount is less than the upper limit value t comp And greater than the lower limit of the amplitude limit - t comp The calculated compensation amount is determined as the compensation amount used subsequently. By applying amplitude limiting processing to the calculated compensation amount, the compensation amount t for phase A is... Acomp Phase B compensation amount t Bcomp and C phase compensation amount t Ccomp The value of is limited to the upper limit value t. comp and the lower limit of the amplitude -t comp Within the determined range of values, it is possible to obtain an appropriate compensation amount, which is conducive to achieving a reliable and better dead zone compensation effect.

[0063] Then, the compensation values ​​of phase A, phase B, and phase C obtained after amplitude limiting are superimposed onto the three-phase duty cycle t obtained after SVPWM modulation. A t B and t C The above is the three-phase duty cycle after compensation.

[0064] Finally, the compensated three-phase duty cycle is processed through a modulation algorithm to obtain the final three-phase duty cycle acting on the three-phase inverter bridge. The target voltage is then modulated and applied to the permanent magnet synchronous motor.

[0065] In addition, through Figure 6 and Figure 7 This further illustrates the effectiveness of the dead-zone compensation method provided in the embodiments of the present invention. Wherein, Figure 6 This is a schematic diagram of the analysis results obtained by performing torque feedback FFT analysis at a base frequency of 60Hz, for cases where the dead-zone compensation method of this invention is not used; Figure 7 This is a schematic diagram of the analysis results obtained by performing torque feedback FFT analysis at a fundamental frequency of 60Hz, specifically for the case where the dead-time compensation method of this invention is used. Compared to Figure 6 , Figure 7 Torque ripple at six times the fundamental frequency is effectively suppressed.

[0066] As can be understood from the above further explanation, the dead-zone control method provided in the embodiments of the present invention does not require the feedback current of the three-phase motor, and there is no problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not require the value of the previous calculation cycle, and there is no compensation lag. Furthermore, through FFT analysis of torque feedback, torque ripple of 6 times the fundamental frequency can be effectively suppressed, and it has a good dead-zone compensation effect.

[0067] Secondly, embodiments of the present invention provide a dead-zone compensation device. The dead-zone compensation device includes: a phase angle calculation module, a modulation module, a compensation amount calculation module, and a compensation superposition module. The phase angle calculation module is used to obtain a first voltage component and a second voltage component in a two-phase stationary coordinate system, and calculate the phase angle of the target voltage vector synthesized from the first voltage component and the second voltage component; the modulation module is used to modulate the first voltage component and the second voltage component to obtain the three-phase duty cycle before compensation; the compensation amount calculation module is used to calculate the compensation amount of the three-phase duty cycle based on the phase angle; and the compensation superposition module is used to superimpose the compensation amount onto the three-phase duty cycle before compensation to obtain the three-phase duty cycle after compensation.

[0068] The dead-zone compensation device provided in this embodiment of the invention can calculate the three-phase duty cycle using the first and second voltage components in a two-phase stationary coordinate system, while simultaneously calculating the phase angle of the target voltage vector using the first and second voltage components. Based on the phase angle of the target voltage vector, the compensation amount of the three-phase duty cycle is calculated and finally superimposed on the three-phase duty cycle to modulate the target voltage. The dead-zone compensation device used in this scheme does not require the feedback current of the three-phase motor, thus eliminating the problem of zero-crossing detection error of the feedback current. The calculation of the compensation amount does not require the value of the previous calculation cycle, eliminating the compensation lag. Furthermore, through FFT analysis of torque feedback, it can effectively suppress torque ripple at 6 times the fundamental frequency, exhibiting a good dead-zone compensation effect.

[0069] In one embodiment of the present invention, the dead-time compensation device further includes a limiting module. The limiting module is used to limit the compensation amount. Specifically, under the limiting effect of the limiting module, when the compensation amount is greater than the upper limit value, the upper limit value is used as the compensation amount; when the compensation amount is less than the lower limit value, the lower limit value is used as the compensation amount. It should be noted that when the compensation amount is less than the upper limit value but greater than the lower limit value, the calculated compensation amount is determined as the compensation amount used subsequently. Here, the limiting value is the ratio of the dead time to the PWM period, the upper limit value is a positive value, and the lower limit value is a negative value. By limiting the calculated compensation amount, the value of the compensation amount is restricted to the range determined by the upper and lower limits, ensuring that a suitable compensation amount is obtained, which is beneficial for achieving a reliable and better dead-time compensation effect.

[0070] Thirdly, referring to Figure 8 , Figure 8 This is a schematic diagram of the structure of a motor driver provided in an embodiment of the present invention. The motor driver 800 includes: a memory 810, a processor 820, and a computer program stored in the memory 810 and executable on the processor 820. When the computer program is executed, it is used to perform the dead-zone compensation method described above.

[0071] The processor 820 and memory 810 can be connected via a bus or other means.

[0072] The memory 810, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs, such as the dead-zone compensation method described in the embodiments of the present invention. The processor 820 implements the aforementioned dead-zone compensation method by running the non-transitory software program and instructions stored in the memory 810. The memory 810 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and application programs required for at least one function; the data storage area may store the execution of the aforementioned dead-zone compensation method. In addition, the memory 810 may include high-speed random access memory and may also include non-transitory memory, such as at least one storage device, flash memory, or other non-transitory solid-state storage device. In some embodiments, the memory 810 may optionally include remotely located memories 810 relative to the processor 820, which can be connected to the motor driver 800 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0073] The non-transient software program and instructions required to implement the dead-zone compensation method described above are stored in memory 810. When executed by one or more processors 820, the dead-zone compensation method described above is performed, for example, the method described above is executed. Figure 3 Method steps S110 to S140 and Figure 4 Method step S210.

[0074] Furthermore, this invention provides a permanent magnet synchronous motor, which includes a motor driver as described in the third aspect. The permanent magnet synchronous motor calculates the three-phase duty cycle using a first voltage component and a second voltage component in a two-phase stationary coordinate system. Simultaneously, it calculates the phase angle of the target voltage vector using the first and second voltage components, and calculates the compensation amount for the three-phase duty cycle based on the phase angle of the target voltage vector. Finally, this compensation is superimposed onto the three-phase duty cycle to modulate the target voltage. The permanent magnet synchronous motor used in this solution does not require the feedback current of the three-phase motor, thus eliminating the problem of zero-crossing detection error in the feedback current. The calculation of the compensation amount does not require the value of the previous calculation cycle, eliminating compensation lag. Furthermore, through torque feedback FFT analysis, it can effectively suppress torque ripple at 6 times the fundamental frequency, exhibiting good dead-zone compensation effect.

[0075] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the dead-zone compensation method as described above, for example, performing the method described above. Figure 3 Method steps S110 to S140 and Figure 4 Method step S210.

[0076] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0077] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which may include computer storage media or non-transitory media and communication media or transient media. As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc DVD or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0078] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A dead-time compensation method characterized by, The method comprises the following steps: obtaining a first voltage component and a second voltage component in a two-phase stationary coordinate system, and calculating a phase angle of a target voltage vector composed of the first voltage component and the second voltage component; modulating the first voltage component and the second voltage component to obtain a three-phase duty cycle before compensation; calculating compensation amounts of the three-phase duty cycle according to the phase angle respectively; superimposing the compensation amounts to the three-phase duty cycle before compensation to obtain a three-phase duty cycle after compensation; wherein the compensation amounts are calculated by multiplying a sine value of a compensation angle by a preset compensation gain coefficient and then by -1, and the compensation angle is determined by the phase angle; the compensation amounts comprise an A-phase compensation amount, a B-phase compensation amount and a C-phase compensation amount, the compensation angle corresponding to the A-phase compensation amount is equal to the phase angle, the compensation angle corresponding to the B-phase compensation amount is obtained by subtracting 2π / 3 from the phase angle, and the compensation angle corresponding to the C-phase compensation amount is obtained by adding 2π / 3 to the phase angle.

2. The dead-time compensation method according to claim 1, characterized by, The compensation gain coefficient is greater than or equal to 0.8 and less than or equal to 1.

2.

3. The dead-time compensation method of claim 1, wherein Before the compensation amounts are superimposed to the three-phase duty cycle before compensation, the compensation amounts are subjected to amplitude limiting processing.

4. The dead-time compensation method according to claim 3, characterized by, The amplitude limiting processing comprises: when the compensation amount is greater than an upper limit value of amplitude limiting, the upper limit value of amplitude limiting is taken as the compensation amount; when the compensation amount is less than a lower limit value of amplitude limiting, the lower limit value of amplitude limiting is taken as the compensation amount.

5. The dead-time compensation method of claim 1, wherein The phase angle of the target voltage vector is calculated by using an inverse tangent function on a ratio of the second voltage component to the first voltage component.

6. The dead-time compensation method of claim 1, wherein The first voltage component and the second voltage component are calculated by inverse Park transformation on a direct-axis voltage and a quadrature-axis voltage obtained in field-oriented control (FOC).

7. A dead time compensation device characterized by comprising: The method comprises the following steps: a phase angle calculation module is configured to obtain a first voltage component and a second voltage component in a two-phase stationary coordinate system, and calculate a phase angle of a target voltage vector composed of the first voltage component and the second voltage component; a modulation module is configured to modulate the first voltage component and the second voltage component to obtain a three-phase duty cycle before compensation; a compensation amount calculation module is configured to calculate compensation amounts of the three-phase duty cycle according to the phase angle respectively; a compensation superimposition module is configured to superimpose the compensation amounts to the three-phase duty cycle before compensation to obtain a three-phase duty cycle after compensation; wherein the compensation amounts are calculated by multiplying a sine value of a compensation angle by a preset compensation gain coefficient and then by -1, and the compensation angle is determined by the phase angle; the compensation amounts comprise an A-phase compensation amount, a B-phase compensation amount and a C-phase compensation amount, the compensation angle corresponding to the A-phase compensation amount is equal to the phase angle, the compensation angle corresponding to the B-phase compensation amount is obtained by subtracting 2π / 3 from the phase angle, and the compensation angle corresponding to the C-phase compensation amount is obtained by adding 2π / 3 to the phase angle.

8. An electric motor drive, characterized by A computer program stored in the memory and executable on the processor is provided, and the processor executes the program to implement the dead zone compensation method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer executable instructions for causing a computer to perform the dead-time compensation method according to any one of claims 1 to 6.

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