Method and device for determining dead time compensation value of inverter

Abstract

The invention relates to the field of servo control, and provides a method and a device for determining a dead time compensation value of an inverter. The method comprises the following steps: determining a three-phase current instruction in a current control loop of the servo system and an actually measured dead zone characteristic curve corresponding to an inverter in the servo system; determining a dead-zone time compensation value of the inverter based on the three-phase current instruction and the actually measured dead-zone characteristic curve; and determining a dead-zone compensation coefficient, and determining a final dead-zone time compensation value based on the dead-zone compensation coefficient and the dead-zone time compensation value. According to the method and the device, the error compensation phenomenon can be avoided to the greatest extent, and the accuracy of dead time compensation is effectively improved.

Description

Technical Field

[0001] This application relates to the field of servo control, and more particularly to a method and apparatus for determining the dead time compensation value of an inverter. Background Technology

[0002] In related technologies, the main method for inverter dead time compensation is the current feedback method. This method samples the three-phase feedback current, determines the sector by the polarity of the three-phase current, and compensates a fixed voltage value or duty cycle time in the corresponding sector according to the dead time setting.

[0003] The above method has two significant drawbacks: First, under static enable or low-speed operation conditions, the three-phase currents are small and near zero, which can easily lead to incorrect polarity judgment of the three-phase currents, resulting in miscompensation of the dead zone. This may ultimately exacerbate current waveform distortion or even cause slight vibration of the motor. Second, while a fixed voltage value or duty cycle time is used to compensate for the dead zone effect in each sector, the dead zone effect of a voltage source inverter varies non-linearly with the current magnitude. Compensating with only a fixed value across the entire operating range will result in insufficient accuracy in dead zone compensation, thus affecting the compensation effect and consequently impacting motor performance, especially low-speed performance.

[0004] Therefore, there is an urgent need to further optimize and improve the traditional inverter dead time compensation method. Summary of the Invention

[0005] In view of this, embodiments of this application provide a method and apparatus for determining the dead time compensation value of an inverter, so as to solve the problems of miscompensation and low compensation accuracy in existing inverter dead time compensation methods.

[0006] A first aspect of this application provides a method for determining the dead time compensation value of an inverter, comprising: Determine the three-phase current command in the current control loop of the servo system, and the measured dead-zone characteristic curve of the inverter in the servo system. The dead time compensation value of the inverter is determined based on the three-phase current command and the measured dead time characteristic curve. Determine the dead zone compensation coefficient, and based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

[0007] A second aspect of this application provides an apparatus for determining the dead time compensation value of an inverter, comprising: The first determining module is configured to determine the three-phase current command in the current control loop of the servo system, and the measured dead-zone characteristic curve of the inverter in the servo system. The second determining module is configured to determine the dead time compensation value of the inverter based on the three-phase current command and the measured dead time characteristic curve. The third determining module is configured to determine the dead zone compensation coefficient and, based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

[0008] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0009] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0010] Compared with the prior art, the beneficial effects of this application's embodiments include at least the following: Determining the inverter's dead-time compensation value based on the three-phase current command in the servo system's current control loop and the measured dead-time characteristic curve of the inverter in the servo system not only avoids the detection delay when using feedback current but also avoids noise interference during feedback current sampling. The acquired current command is smoother, avoiding oscillation problems at current zero-crossing points, thereby effectively reducing the occurrence of miscompensation and improving the accuracy of inverter dead-time compensation. Furthermore, the dead-time compensation value obtained by the above method can be adjusted by a dead-time compensation coefficient, further improving the accuracy of inverter dead-time compensation. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the system structure of a servo system provided in an embodiment of this application; Figure 2 This is a flowchart illustrating a method for determining the dead time compensation value of an inverter according to an embodiment of this application; Figure 3 This is a measured dead-zone characteristic curve of a 750W servo system provided in one embodiment of this application; Figure 4 This is a measured current waveform before dead-time compensation was performed on the 750W servo system. Figure 5This is a measured current waveform diagram after dead-time compensation of a 750W servo system using the method provided in the embodiments of this application; Figure 6 This is a schematic diagram of a device for determining the dead time compensation value of an inverter, provided in an embodiment of this application. Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0013] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0014] The following describes in detail, with reference to the accompanying drawings, a method and apparatus for determining the dead time compensation value of an inverter according to an embodiment of this application.

[0015] Voltage source inverters (VSIs) are widely used in general-purpose servo systems. The dedicated pulse width modulation (PWM) generation circuit of the digital signal processor (DSP) provides the material basis for the digital calculation of PWM and the generation of inverter trigger signals.

[0016] In practical applications, due to the inherent storage time of the VSI switching devices, the turn-on time is shorter than the turn-off time, which can easily lead to short-circuit faults in the two complementary switching transistors of the same-phase bridge arm. To avoid this phenomenon, a certain delay time must be inserted between the turn-on and turn-off of the switching devices; this delay time is called the dead time. During the dead time, both switching transistors are in the off state, the load current freewheels through the anti-parallel diode, and the load voltage is not controlled by the switching transistors. This causes nonlinear distortion in the actual output voltage waveform of the switching devices compared to the ideal voltage waveform, resulting in a decrease in the average output voltage. It can also cause dead-time effects such as motor current waveform distortion and torque ripple, thereby affecting motor performance, especially low-speed performance.

[0017] The inverter dead time compensation method in related technologies mainly adopts the current feedback method. This method is prone to miscompensation under static enable or low-speed operation conditions. In addition, this method compensates for the dead time effect of a fixed voltage value or duty cycle time in each sector, resulting in low compensation accuracy.

[0018] In view of this, embodiments of this application provide a method and apparatus for determining the dead time compensation value of an inverter. The method determines the dead time compensation value based on the three-phase current command in the current control loop of the servo system and the measured dead time characteristic curve of the inverter in the servo system. This not only avoids the detection delay when using feedback current but also avoids noise interference during feedback current sampling. The acquired current command is smoother, avoiding oscillation problems at the current zero-crossing point, thereby effectively reducing the occurrence of miscompensation and improving the accuracy of inverter dead time compensation. Furthermore, the dead time compensation value obtained by the above method can be adjusted by a dead time compensation coefficient to further improve the accuracy of inverter dead time compensation.

[0019] Figure 1 This is a schematic diagram of the system architecture of a servo system provided in an embodiment of this application. Please refer to [link / reference]. Figure 1 The servo system includes a controller 101, a servo driver 102, a servo motor 103, and a mechanical load 104 connected in sequence. The controller 101 and the servo driver 102 can establish a communication connection via a communication cable, etc.; the servo driver 102 and the servo motor 103 can establish a power connection via a cable (such as a three-phase power cable or a DC bus cable); the servo motor 103 and the mechanical load 104 can establish a mechanical power connection via a coupling, reducer, synchronous pulley, etc. The servo driver 102 includes an inverter. The servo three loops of the servo driver 102 from the outer loop to the inner loop are: position control loop → speed control loop → current control loop.

[0020] Torque actually corresponds to the acceleration of the servo motor, therefore the current control loop is essentially an acceleration control loop. Following the order from the inner loop to the outer loop, the control flow of the servo driver 102 is as follows: the q-axis current (i.e., electromagnetic torque) can be adjusted through the current control loop to achieve acceleration control of the servo motor 103; the acceleration of the servo motor 103 can be adjusted through the speed control loop to achieve speed control of the servo motor 103; and the speed of the servo motor 103 can be adjusted through the position control loop to achieve position control of the servo motor 103.

[0021] Figure 2 This is a flowchart illustrating a method for determining the dead time compensation value of an inverter, as provided in an embodiment of this application. Figure 2 The method for determining the inverter dead time compensation value can be derived from... Figure 1 The servo driver 102 in the servo system performs the execution. For example... Figure 2 As shown, the method for determining the inverter dead time compensation value includes the following steps: Step S201: Determine the three-phase current command in the current control loop of the servo system, and the measured dead-zone characteristic curve of the inverter in the servo system.

[0022] The inverter (specifically a voltage source inverter) is the core power conversion unit for the servo driver 102 to drive the servo motor 103.

[0023] An inverter is a three-phase bridge circuit composed of power devices such as IGBTs and MOSFETs. Its core function is to convert the input DC power (such as the DC bus voltage after three-phase 380V rectification) into adjustable three-phase AC power to directly drive the servo motor.

[0024] The measured dead-time characteristic curve can be a graph used to characterize the effect of dead time on the output voltage / current of the inverter.

[0025] Figure 3 This is a measured dead-zone characteristic curve of a 750W servo system provided in one embodiment of this application. Figure 3 As shown, the horizontal axis represents the magnitude of the current command (usually a percentage of the rated current), and the vertical axis represents the magnitude of the dead time compensation value. This dead time compensation value is calculated by combining the main frequency of the chip used, and it is the compensation time. Generally, the value 100 on the vertical axis corresponds to 1ms (microseconds). Figure 3 The dead time compensation value of the 750W servo system is a value obtained by actual measurement with the dead time set to 200 (i.e., 2ms).

[0026] from Figure 3 It can be seen that the dead time compensation value of the 750W servo system changes non-linearly with the magnitude of the current command, and is not a fixed value.

[0027] The technical solution provided in this application determines the dead time compensation value of the inverter based on the three-phase current command in the current control loop of the servo system and the measured dead time characteristic curve of the inverter in the servo system. This can obtain a more accurate dead time compensation value, thereby minimizing the occurrence of miscompensation.

[0028] Step S202: Determine the dead time compensation value of the inverter based on the three-phase current command and the measured dead time characteristic curve.

[0029] Step S203: Determine the dead zone compensation coefficient, and based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

[0030] The dead time compensation coefficient is a modifiable function code value. Its function is to amplify or reduce the dead time compensation value to flexibly adjust the size of the dead time compensation value, thereby further improving the accuracy of the inverter's dead time compensation.

[0031] The technical solution provided in this application determines the dead-time compensation value of the inverter based on the three-phase current command in the current control loop of the servo system and the measured dead-time characteristic curve of the inverter in the servo system. This not only avoids the detection delay when using feedback current, but also avoids noise interference during feedback current sampling. The acquired current command is smoother, avoiding oscillation problems at the current zero-crossing point, thereby effectively reducing the occurrence of miscompensation and improving the accuracy of inverter dead-time compensation. Furthermore, the dead-time compensation value obtained by the above method can be adjusted by a dead-time compensation coefficient to further improve the accuracy of inverter dead-time compensation.

[0032] The technical solutions provided in this application embodiment do not increase hardware costs and are implemented solely through software programming, making them economical, simple, and efficient.

[0033] The technical solutions provided in this application have significant advantages in terms of real-time performance, noise immunity, and logical simplicity, and are especially suitable for high dynamic and high switching frequency applications.

[0034] In some embodiments, determining the three-phase current command in the current control loop of the servo system includes: Obtain the first and second current commands from the current control loop of the servo system. The first current command and the second current command are low-pass filtered to obtain the first filtered current and the second filtered current. The first and second filter currents are subjected to coordinate transformation to obtain the three-phase current command.

[0035] As an example, the servo driver 102 can acquire the d-axis current command (i.e., the first current command) and the q-axis current command (i.e., the second current command) in the current control loop through a current acquisition device. Then, the acquired first current command and second current command are respectively input into a pre-set low-pass filter (such as a Butterworth filter, Chebyshev filter, etc.) for filtering processing to obtain the first filtered current and the second filtered current.

[0036] The transfer function of the first-order low-pass filter is shown in equation (1): (1); After discretization using first-order backward difference, equation (2) is obtained: (2); In equations (1) and (2), Indicates the filter time constant. This indicates the system sampling period, where S represents the frequency of the input signal (first current command or second current command). This represents the filtered output (first filtered current or second filtered current) at time n. This represents the filtered output at time n-1. This represents the original input (first current command or second current command) at time n.

[0037] Next, the first and second filtered currents obtained after the above low-pass filtering are subjected to inverse Park transformation to obtain the three-phase current command. The mathematical expressions for the inverse Park transformation are shown in equations (3) to (5): (5); In equation (5), , , These represent the first phase current command, the second phase current command, and the third phase current command, respectively. , These represent the first filter current and the second filter current, respectively. It represents the angle between the rotating coordinate system and the stationary coordinate system (which can be measured by motor position sensors such as encoders and Hall sensors, or estimated by sensorless algorithms).

[0038] The first and second current commands are commands in the current control loop of the servo system. They are easily obtained in the servo control loop without the need for any hardware devices, thus not increasing hardware costs.

[0039] Since the first and second current commands are DC, low-pass filtering of them not only removes white noise but also maintains the current phase, making the command current data more accurate. Furthermore, it does not affect the phase relationship of the currents or the original phase of the subsequently transformed three-phase current commands. The transformed three-phase command currents can then be used to determine the current polarity normally without phase compensation. This also reduces reliance on high-precision sensors and yields more real-time and accurate results.

[0040] The aforementioned first-phase current command, second-phase current command, and third-phase current command are 120° electrical degrees apart in time. The dead-time compensation value includes the first dead-time compensation value, the second dead-time compensation value, and the third dead-time compensation value.

[0041] In some embodiments, the dead time compensation value of the inverter is determined based on the three-phase current command and the measured dead time characteristic curve, including: Based on the first phase current command and the measured dead time characteristic curve of the inverter, the first dead time compensation value is determined. Based on the second phase current command and the measured dead-time characteristic curve of the inverter, the second dead-time compensation value is determined. The third dead time compensation value is determined based on the third phase current command and the measured dead time characteristic curve of the inverter.

[0042] In some embodiments, the first dead time compensation value is determined based on the first phase current command and the measured dead time characteristic curve corresponding to the inverter, including: Query the measured dead-time compensation value corresponding to the first phase current command in the actual dead-time characteristic curve of the inverter; If the polarity of the first phase current command is positive, then the first dead time compensation value is positive. If the polarity of the first phase current command is negative, then the first dead time compensation value is negative.

[0043] As an example, suppose the object requiring dead time compensation is a 750W servo system. Then, it can be done by querying... Figure 3 The measured dead-time characteristic curve of the 750W servo system shown yields the first dead-time compensation value corresponding to the first phase current command. For example, assuming the magnitude of the first phase current command is 21%, the corresponding first dead-time compensation value is approximately 100 (i.e., 1ms).

[0044] Similarly, by referring to the above method, the second dead time compensation value corresponding to the second phase current command and the third dead time compensation value corresponding to the third phase current command can be obtained by querying the measured dead time characteristic curve of the 750W servo system. This will not be elaborated further here.

[0045] For different types of inverters and servo systems, their corresponding measured dead-time characteristic curves are usually different. In practical applications, the measured dead-time characteristic curves of different objects that require dead-time compensation can be tested separately, and the correlation between "compensation object - measured dead-time characteristic curve" can be established and stored for easy retrieval and use later.

[0046] In some embodiments, the above method may further include the following steps: Based on the current polarity of the first phase current command, the second phase current command, and the third phase current command, the target sector that needs to be compensated for dead time is determined. Within the target sector, the output voltage waveform generated by the inverter is compensated based on the first dead time compensation value, the second dead time compensation value, and the third dead time compensation value to obtain the final output voltage waveform.

[0047] As an example, in a stationary coordinate system, the 360° electrical angle is divided into 6 sectors, each 60°, numbered I to VI. Each sector corresponds to a unique combination of three-phase current directions. The specific sector-three-phase current direction correspondence is shown in Table 1. The symbol "+" indicates positive polarity, with current flowing from the inverter to the servo motor, and "-" indicates negative polarity, with current flowing from the servo motor back to the inverter via the freewheeling diode.

[0048] Table 1. Correspondence between sector and three-phase current direction For example, assuming the current polarities of the first-phase current command, the second-phase current command, and the third-phase current command are +, +, and - respectively, according to Table 1 above, the target sector requiring dead-time compensation is sector I. Within sector I, based on the above query... Figure 3 The first dead time compensation value, the second dead time compensation value, and the third dead time compensation value obtained from the measured dead time characteristic curve shown are used to compensate the output voltage waveform generated by the inverter to obtain the final output voltage waveform.

[0049] In some embodiments, the waveform of the PWM control signal generated by the inverter is compensated based on a first dead-time compensation value, a second dead-time compensation value, and a third dead-time compensation value, including: The first phase current command is compensated based on the first dead time compensation value; the second phase current command is compensated based on the second dead time compensation value; and the third phase current command is compensated based on the third dead time compensation value.

[0050] Figure 4 This is a measured current waveform before dead-time compensation was performed on the 750W servo system. Figure 5 This is a measured current waveform diagram after applying the method provided in the embodiments of this application to compensate for the dead time of a 750W servo system. Figure 4 , Figure 5 The horizontal axis represents the time axis, and the vertical axis represents the percentage of the rated current (the internal current of a servo system is generally expressed as a percentage of the motor's rated current).

[0051] from Figure 4 and Figure 5It can be seen that before dead-time compensation was applied to the 750W servo system, the measured output current waveform exhibited numerous glitches and steps, with significant distortion at the zero-crossing point. After applying the dead-time compensation method provided in this embodiment, the measured output current waveform closely approximates an ideal sine wave, with smooth zero-crossing. Therefore, the method provided in this embodiment effectively improves the distortion problem caused by the dead-time effect, ultimately restoring the current waveform from a "distorted non-sine wave" to a "smooth ideal sine wave."

[0052] In some embodiments, determining the dead zone compensation coefficient includes: Determine the degree of waveform deviation between the final output voltage waveform and the ideal voltage waveform; If the waveform deviation is greater than the preset deviation threshold, the dead zone compensation coefficient is configured as the first compensation coefficient, and the value range of the first compensation coefficient is 0~1; If the waveform deviation is less than the preset deviation threshold, the dead zone compensation coefficient is configured as the second compensation coefficient, and the value range of the second compensation coefficient is 1~2. If the waveform deviation is equal to the preset deviation threshold, then the dead zone compensation coefficient is configured to be 1.

[0053] An ideal voltage waveform is a smooth, ideal sine wave.

[0054] The degree of deviation between the final output voltage waveform and the ideal voltage waveform is usually measured by the voltage harmonic distortion rate (THD). Of course, the degree of waveform deviation can also be described from the perspectives of waveform amplitude deviation, phase deviation, and waveform shape difference.

[0055] Voltage harmonic distortion (THD) is the ratio of the sum of the effective values ​​of all harmonic voltages to the effective value of the fundamental voltage.

[0056] The smaller the THD, the closer the output voltage waveform is to the ideal sine wave (or target waveform), and the smaller the deviation; the larger the THD, the more harmonic components are contained in the waveform, and the more serious the deviation from the ideal waveform.

[0057] In the first case, when the waveform deviation is greater than the preset deviation threshold (which can be flexibly set according to the actual situation), it indicates that the dead time compensation value is too large and the dead time compensation value needs to be reduced. At this time, the dead time compensation coefficient can be configured as the first compensation coefficient with a value range of 0 to 1.

[0058] In the second scenario, when the waveform deviation is less than the preset deviation threshold, it indicates that the dead time compensation value is too small and needs to be increased. In this case, the dead time compensation coefficient can be configured as a second compensation coefficient with a value range of 1 to 2.

[0059] In the third case, when the waveform deviation is equal to the preset deviation threshold, it indicates that the current dead time compensation value is the optimal compensation value. In this case, the dead time compensation coefficient can be configured to 1.

[0060] By using the above method, the dead-time compensation coefficient can be flexibly and timely adjusted based on the degree of waveform deviation between the final output voltage waveform and the ideal voltage waveform, so as to further improve the accuracy of inverter dead-time compensation.

[0061] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0062] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0063] Figure 6 This is a schematic diagram of a device for determining the dead time compensation value of an inverter, provided in an embodiment of this application. Figure 6 As shown, the device for determining the inverter dead time compensation value includes: The first determining module 601 is configured to determine the three-phase current command in the current control loop of the servo system, and the measured dead zone characteristic curve corresponding to the inverter in the servo system. The second determining module 602 is configured to determine the dead time compensation value of the inverter based on the three-phase current command and the measured dead time characteristic curve. The third determining module 603 is configured to determine the dead zone compensation coefficient and, based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

[0064] In some embodiments, the first determining module 601 described above includes: The acquisition unit is configured to acquire the first current command and the second current command in the current control loop of the servo system. The filtering unit is configured to perform low-pass filtering on the first current command and the second current command to obtain the first filtered current and the second filtered current. The transformation unit is configured to perform coordinate transformation processing on the first filter current and the second filter current to obtain the three-phase current command.

[0065] In some embodiments, the three-phase current command includes a first-phase current command, a second-phase current command, and a third-phase current command; the dead-time compensation value includes a first dead-time compensation value, a second dead-time compensation value, and a third dead-time compensation value. The second determining module 602 described above includes: The first determining unit is configured to determine the first dead time compensation value based on the first phase current command and the measured dead time characteristic curve corresponding to the inverter. The second determining unit is configured to determine the second dead time compensation value based on the second phase current command and the measured dead time characteristic curve corresponding to the inverter. The third determining unit is configured to determine the third dead time compensation value based on the third phase current command and the measured dead time characteristic curve corresponding to the inverter.

[0066] In some embodiments, the first determining unit described above may be specifically configured as: Query the measured dead-time compensation value corresponding to the first phase current command in the actual dead-time characteristic curve of the inverter; If the polarity of the first phase current command is positive, then the first dead time compensation value is positive. If the polarity of the first phase current command is negative, then the first dead time compensation value is negative.

[0067] In some embodiments, the above-described apparatus may further include: The fourth determination module is configured to determine the target sector that needs dead time compensation based on the current polarity of the first phase current command, the second phase current command, and the third phase current command. The compensation module is configured to compensate the output voltage waveform generated by the inverter within the target sector based on the first dead time compensation value, the second dead time compensation value, and the third dead time compensation value, so as to obtain the final output voltage waveform.

[0068] In some embodiments, the compensation module described above may be specifically configured as follows: The first phase current command is compensated based on the first dead time compensation value; the second phase current command is compensated based on the second dead time compensation value; and the third phase current command is compensated based on the third dead time compensation value.

[0069] In some embodiments, the third determining module 603 described above further includes: The deviation determination unit is configured to determine the degree of waveform deviation between the final output voltage waveform and the ideal voltage waveform. The first configuration unit is configured to configure the dead zone compensation coefficient as the first compensation coefficient if the waveform deviation is greater than the preset deviation threshold. The value range of the first compensation coefficient is 0~1. The second configuration unit is configured to configure the dead zone compensation coefficient as the second compensation coefficient if the waveform deviation is less than the preset deviation threshold. The value range of the second compensation coefficient is 1 to 2. The third configuration unit is configured to set the dead zone compensation coefficient to 1 if the waveform deviation is equal to a preset deviation threshold.

[0070] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0071] Figure 7 This is a schematic diagram of the electronic device 700 provided in an embodiment of this application. For example... Figure 7 As shown, the electronic device 700 of this embodiment includes a processor 701, a memory 702, and a computer program 703 stored in the memory 702 and executable on the processor 701. When the processor 701 executes the computer program 703, it implements the steps in the various method embodiments described above. Alternatively, when the processor 701 executes the computer program 703, it implements the functions of each module / unit in the various device embodiments described above.

[0072] Electronic device 700 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 700 may include, but is not limited to, a processor 701 and a memory 702. Those skilled in the art will understand that... Figure 7 This is merely an example of electronic device 700 and does not constitute a limitation on electronic device 700. It may include more or fewer parts than shown, or different parts.

[0073] The processor 701 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0074] The memory 702 can be an internal storage unit of the electronic device 700, such as a hard disk or RAM of the electronic device 700. The memory 702 can also be an external storage device of the electronic device 700, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the electronic device 700. The memory 702 can also include both internal and external storage units of the electronic device 700. The memory 702 is used to store computer programs and other programs and data required by the electronic device.

[0075] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0076] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable medium may include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in a computer-readable medium can be appropriately added to or subtracted according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, a computer-readable medium does not include electrical carrier signals and electrical signals.

[0077] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for determining the dead time compensation value of an inverter, characterized in that, include: Determine the three-phase current command in the current control loop of the servo system, and the measured dead-zone characteristic curve of the inverter in the servo system. Based on the three-phase current command and the measured dead-time characteristic curve, the dead-time compensation value of the inverter is determined. Determine the dead zone compensation coefficient, and based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

2. The method according to claim 1, characterized in that, Determine the three-phase current commands in the current control loop of the servo system, including: Obtain the first and second current commands from the current control loop of the servo system. The first current command and the second current command are low-pass filtered to obtain the first filtered current and the second filtered current. The first and second filtered currents are subjected to coordinate transformation to obtain the three-phase current command.

3. The method according to claim 1 or 2, characterized in that, The three-phase current command includes a first-phase current command, a second-phase current command, and a third-phase current command; the dead-time compensation value includes a first dead-time compensation value, a second dead-time compensation value, and a third dead-time compensation value. Based on the three-phase current command and the measured dead-time characteristic curve, the dead-time compensation value of the inverter is determined, including: Based on the first phase current command and the measured dead-time characteristic curve of the inverter, the first dead-time compensation value is determined. Based on the second phase current command and the measured dead time characteristic curve of the inverter, the second dead time compensation value is determined. Based on the third phase current command and the measured dead-time characteristic curve of the inverter, the third dead-time compensation value is determined.

4. The method according to claim 3, characterized in that, Based on the first phase current command and the measured dead-time characteristic curve of the inverter, the first dead-time compensation value is determined, including: Query the first dead time compensation value corresponding to the first phase current command in the measured dead time characteristic curve of the inverter; If the polarity of the first phase current command is positive, then the first dead time compensation value is positive. If the polarity of the first phase current command is negative, then the first dead time compensation value is negative.

5. The method according to claim 3, characterized in that, The method further includes: Based on the current polarity of the first phase current command, the second phase current command, and the third phase current command, the target sector that needs to be compensated for dead time is determined. Within the target sector, the output voltage waveform generated by the inverter is compensated based on the first dead time compensation value, the second dead time compensation value, and the third dead time compensation value to obtain the final output voltage waveform.

6. The method according to claim 5, characterized in that, Based on the first dead-time compensation value, the second dead-time compensation value, and the third dead-time compensation value, the waveform of the PWM control signal generated by the inverter is compensated, including: The first phase current command is compensated according to the first dead time compensation value; The second phase current command is compensated according to the second dead time compensation value; The third phase current command is compensated based on the third dead time compensation value.

7. The method according to claim 5, characterized in that, Determining the dead zone compensation coefficient includes: Determine the degree of waveform deviation between the final output voltage waveform and the ideal voltage waveform; If the waveform deviation is greater than a preset deviation threshold, the dead zone compensation coefficient is configured as the first compensation coefficient, and the value range of the first compensation coefficient is 0~1. If the waveform deviation is less than a preset deviation threshold, then the dead zone compensation coefficient is configured as the second compensation coefficient, and the value range of the second compensation coefficient is 1 to 2. If the degree of waveform deviation is equal to the preset deviation threshold, then the dead zone compensation coefficient is configured to be 1.

8. A device for determining the dead time compensation value of an inverter, characterized in that, include: The first determining module is configured to determine the three-phase current command in the current control loop of the servo system, and the measured dead-zone characteristic curve corresponding to the inverter in the servo system. The second determining module is configured to determine the dead time compensation value of the inverter based on the three-phase current command and the measured dead time characteristic curve. The third determining module is configured to determine the dead zone compensation coefficient and, based on the dead zone compensation coefficient and the dead zone time compensation value, determine the final dead zone time compensation value.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 7.

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