Dead zone compensation method and device, medium, inverter and servo driver

Abstract

The invention provides a dead-zone compensation method and device, a medium, an inverter and a servo driver, and the method comprises the steps: obtaining preset dead-zone time and the current direction of a drive bridge arm, the current direction of current flowing out of the drive bridge arm being positive, and the current direction of current flowing into the drive bridge arm being negative; obtaining conduction delay time and turn-off delay time of the bridge arm upper tube and the bridge arm lower tube; acquiring a preset counting threshold value of the modulated wave; on the basis of the current direction, the waveform of the carrier wave and the rising and falling trend of the carrier wave count value, compensating a preset count threshold value of the modulated wave according to the current direction, the conduction delay time, the turn-off delay time and a preset dead zone time to obtain a target count threshold value of the modulated wave; wherein the target counting threshold value of the modulation wave is used for generating pulse width modulation signals for switching on and switching off the bridge arm upper tube and the bridge arm lower tube.

Description

Technical Field

[0001] The present invention relates to the field of control technology, and in particular to a dead zone compensation method, device, medium, inverter and servo driver. Background Art

[0002] Inverters usually use pulse width modulation (PWM) technology.

[0003] During the inverter control process, the upper and lower switch tubes located in the same driving bridge arm are turned on complementary to each other. The purpose is to prevent the upper and lower switch tubes from being turned on at the same time, causing the driving bridge arm to be directly turned on. A certain dead time will be artificially added to the upper and lower tube opening control process.

[0004] Among them, the addition of dead time can effectively prevent the upper and lower tubes in the same phase drive bridge arm from being directly connected. However, the addition of dead time will cause the voltage output by the inverter to be inconsistent with its expected voltage, resulting in current distortion. Current distortion will cause unnecessary losses and may cause torque pulsation, vibration, noise, and even oscillation. When the motor is at low speed and light load, the performance degradation caused by dead time is more obvious.

[0005] There are two main types of compensation strategies in the related technical solutions. One is based on the average error voltage compensation method, which has the advantage of being easy to implement. The other method is to change the duty cycle of the output pulse, but it increases the complexity of implementation.

[0006] like Figure 1 and Figure 2 It can be seen that no matter which method is used in the above two solutions, the PWM comparison value is updated at the peak or trough of the carrier, that is, the voltage output is updated once a PWM carrier cycle, and the voltage output by the inverter is still inconsistent with its expected voltage. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0008] To this end, a first aspect of the present invention is to provide a dead zone compensation method.

[0009] A second aspect of the present invention is to provide a dead zone compensation device.

[0010] A third aspect of the present invention is to provide another dead zone compensation device.

[0011] A fourth aspect of the present invention provides a readable storage medium.

[0012] A fifth aspect of the present invention provides an inverter.

[0013] A sixth aspect of the present invention provides a servo drive.

[0014] In view of this, according to a first aspect of the present invention, the present invention provides a dead zone compensation method for an inverter, the inverter comprising a three-phase driving bridge arm, each phase driving bridge arm comprising a bridge arm upper tube and a bridge arm lower tube connected in series, the dead zone compensation method comprising: obtaining a preset dead zone time and a current direction of the driving bridge arm; obtaining a turn-on delay time and a turn-off delay time of the bridge arm upper tube and the bridge arm lower tube; obtaining a preset counting threshold of a modulation wave; based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset counting threshold of the modulation wave is compensated according to the turn-on delay time, the turn-off delay time and the preset dead zone time to obtain a target counting threshold of the modulation wave; wherein the target counting threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the bridge arm upper tube and the bridge arm lower tube.

[0015] According to a second aspect of the present invention, the present invention provides a dead zone compensation device for an inverter, the inverter comprising a three-phase driving bridge arm, each phase driving bridge arm comprising a bridge arm upper tube and a bridge arm lower tube connected in series, the dead zone compensation device comprising: a first acquisition unit, used to obtain a preset dead zone time and a current direction of the driving bridge arm; a second acquisition unit, used to obtain a turn-on delay time and a turn-off delay time of the bridge arm upper tube and the bridge arm lower tube; a third acquisition unit, used to obtain a preset counting threshold of a modulation wave; a processing unit, used to compensate for the preset counting threshold of the modulation wave according to the turn-on delay time, the turn-off delay time and the preset dead zone time based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, to obtain a target counting threshold of the modulation wave; wherein the target counting threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the bridge arm upper tube and the bridge arm lower tube.

[0016] According to the third aspect of the present invention, the present invention provides a dead zone compensation device, including a processor and a memory, the memory storing a program or instruction that can be executed on the processor, and when the program or instruction is executed by the processor, the steps of any method in the first aspect are implemented.

[0017] According to a fourth aspect of the present invention, the present invention provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of any method in the first aspect are implemented.

[0018] According to a fifth aspect of the present invention, the present invention provides an inverter, comprising: any one of the dead zone compensation devices described above; and / or the readable storage medium described above.

[0019] According to a sixth aspect of the present invention, the present invention provides a servo drive, comprising: the inverter as described above.

[0020] In some technical solutions, optionally, the electrical equipment using the above-mentioned servo drive includes one of the following: a robot, household appliances, and a machine tool.

[0021] 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

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0023] Figure 1 A schematic diagram showing a method of updating a PWM comparison value at a peak or trough of a carrier wave in a related technical solution is shown;

[0024] Figure 2 Another schematic diagram of updating at the peak or trough of the carrier wave based on the PWM comparison value in the related technical solution is shown;

[0025] Figure 3 A schematic diagram of the structure of an inverter in an embodiment of the present invention is shown;

[0026] Figure 4 A schematic flow chart of a dead zone compensation method in an embodiment of the present invention is shown;

[0027] Figure 5 A schematic diagram showing an update at the peak and trough of a carrier wave based on a PWM comparison value in an embodiment of the present invention is shown;

[0028] Figure 6 Another schematic diagram of updating at the peak and trough of the carrier wave based on the PWM comparison value in an embodiment of the present invention is shown;

[0029] Figure 7 One of the schematic diagrams of dead zone compensation in an embodiment of the present invention is shown;

[0030] Figure 8 FIG2 shows a second schematic diagram of dead zone compensation in an embodiment of the present invention;

[0031] Fig. 9 A third schematic diagram showing dead zone compensation in an embodiment of the present invention is shown;

[0032] Fig.10 A fourth schematic diagram showing dead zone compensation in an embodiment of the present invention is shown;

[0033] Fig.11One of the schematic diagrams of the process of the dead zone compensation of the three-phase drive bridge arm in the embodiment of the present invention is shown;

[0034] Fig.12 The second schematic diagram of the process of the dead zone compensation of the three-phase drive bridge arm in the embodiment of the present invention is shown;

[0035] Fig.13 The third schematic diagram of the process of the dead zone compensation of the three-phase drive bridge arm in the embodiment of the present invention is shown;

[0036] Fig.14 A schematic diagram showing a current waveform output by an inverter before applying the technical solution of the present application;

[0037] Fig.15 A schematic diagram showing a current waveform output by an inverter after applying the technical solution of the present application;

[0038] Fig.16 A schematic block diagram of a dead zone compensation device in an embodiment of the present invention is shown;

[0039] Fig.17 A schematic block diagram of another dead zone compensation device in an embodiment of the present invention is shown.

[0040] in, Figure 3 The corresponding relationship between the reference numerals and the component names is as follows:

[0041] 302U phase driving bridge arm, 304V phase driving bridge arm, 306W phase driving bridge arm, S1 bridge arm upper tube, S2 bridge arm lower tube, P positive bus, N negative bus. DETAILED DESCRIPTION

[0042] In order to more clearly understand the above aspects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0043] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0044] In one embodiment of the present application, Figure 3 and Figure 4 As shown, a dead zone compensation method is provided for an inverter, the inverter includes a three-phase driving bridge arm, each phase driving bridge arm includes a bridge arm upper tube S1 and a bridge arm lower tube S2 connected in series, and the dead zone compensation method includes:

[0045] Step 402, obtaining a preset dead time and a current direction of a driving bridge arm;

[0046] Step 404, obtaining the turn-on delay time and turn-off delay time of the upper tube of the bridge arm and the lower tube of the bridge arm;

[0047] Step 406, obtaining a preset counting threshold of the modulation wave;

[0048] Step 408 , based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset count threshold of the modulation wave is compensated according to the turn-on delay time, the turn-off delay time and the preset dead time to obtain the target count threshold of the modulation wave.

[0049] The target count threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the upper tube of the bridge arm and the lower tube of the bridge arm.

[0050] The embodiment of the present application proposes a dead zone compensation method. By running the above dead zone compensation method, a preset counting threshold can be compensated to obtain a target counting threshold, so as to control the inverter according to the target counting threshold.

[0051] In this process, by updating the preset counting threshold, the pulse width modulation signal used to control the switch tube (i.e., the upper tube and the lower tube of the bridge arm) to turn on and off is consistent with the pulse width modulation signal in the ideal state, thereby reducing the impact of the dead time on the output voltage of the inverter. In this process, the degree of current distortion on the driving bridge arm of the inverter is reduced, the loss caused by current distortion is reduced, and the torque pulsation, vibration, noise and even oscillation are eliminated, so that the performance deterioration caused by the dead time tends to be weakened when the motor is at low speed and light load.

[0052] like Figure 5 and Figure 6 As shown, in the above dead zone compensation process, the rising and falling trends of the carrier count value are combined, so that the peak and trough double updates can be achieved, so as to minimize the impact of the dead zone time on the inverter output voltage.

[0053] In the above embodiment, the turn-on delay time and the turn-off delay time can be used to characterize the property information of the switching tube. By obtaining the turn-on delay time and the turn-off delay time and using them as reference factors for the preset counting threshold of the compensation modulation wave, it is ensured to the greatest extent that the actual pulse width modulation signal obtained based on the target counting threshold can be the same as the theoretical pulse width modulation signal, thereby reducing the influence of the dead time on the output voltage of the inverter.

[0054] In the above embodiment, the target count threshold is specifically used to form a level flip of the pulse width modulation signal when the carrier count value is greater than the target count threshold or less than the target count threshold.

[0055] Specifically, for example, when the carrier count value is greater than the target count threshold, the level flips from a low level to a high level, and if the switch tube is at a high level and effective, the switch tube is turned on. Similarly, when the carrier count value is less than the target count threshold, the level flips from a high level to a low level, and the switch tube is turned off, thereby forming a pulse width modulation signal.

[0056] In the above embodiment, the carrier count value may be understood as a numerical value, which may gradually change with time, and then a carrier is formed according to the count value.

[0057] Specifically, taking the positive triangle wave as an example, the carrier count value increases continuously until it reaches the maximum value, then gradually decreases until it reaches the minimum value, and then gradually increases, repeating the above steps, wherein the maximum value corresponds to the peak of the positive triangle wave, and the minimum value corresponds to the trough of the positive triangle wave.

[0058] In some embodiments, optionally, the carrier count value increases by 1 every 10 nanoseconds, the maximum value is 10, and the minimum value is 1. The target count threshold can be selected as 4 or 5 according to actual use needs, thereby obtaining a corresponding pulse width modulation signal.

[0059] In the above embodiment, the turn-on delay time, that is, the turn-on delay time, takes IGBT (Insulate-Gate Bipolar Transistor) as an example, which represents the time from 10% of the gate voltage to the collector current rising to 10% of the turn-on value when turned on.

[0060] Similarly, the turn-off delay time, also known as the turn-off delay time, represents the time from when the gate voltage drops to 90% of its turn-on value to when the collector current drops to 90% of the turn-on value when the device is turned off.

[0061] In some embodiments, optionally, based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset count threshold of the modulation wave is compensated according to the turn-on delay time, the turn-off delay time and the preset dead time to obtain the target count threshold of the modulation wave, including: calculating the equivalent dead time according to the turn-on delay time, the turn-off delay time and the preset dead time; based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, increasing or decreasing the carrier count value corresponding to the equivalent dead time for the preset count threshold of the modulation wave to obtain the target count threshold of the modulation wave.

[0062] In this embodiment, by calculating the equivalent dead time, in order to determine the actual scenario according to the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the carrier count value corresponding to the equivalent dead time is increased or decreased based on the preset count threshold of the modulation wave, thereby realizing the calculation of the target count threshold.

[0063] In this embodiment, by obtaining the preset dead time, turn-on delay time and turn-off delay time, the dead time is re-quantized based on the above three parameters, and the preset dead time, turn-on delay time and turn-off delay time are combined, and the corresponding carrier count value of the equivalent dead time obtained by re-quantization is used as the compensation value of the preset count threshold of the modulation wave, and it is compensated to obtain the target count threshold of the modulation wave.

[0064] In this process, the carrier count value is used to quantify the value that needs to be compensated for the preset count threshold, so that compensation can be achieved by compensating the preset count threshold, thereby making the pulse width modulation signal used to control the on and off of the switch tube consistent with the pulse width modulation signal in the ideal state, thereby reducing the impact of the dead time on the output voltage of the inverter. In this process, the degree of current distortion on the driving bridge arm of the inverter is reduced, the loss caused by current distortion is reduced, and the torque pulsation, vibration, noise and even oscillation are eliminated, so that the performance deterioration caused by the dead time tends to be weakened when the motor is at low speed and light load.

[0065] In the above embodiment, after the equivalent dead time is calculated, the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value are used as screening conditions to select the corresponding scene, and then the preset count threshold is corrected and compensated to obtain the target count threshold.

[0066] In this process, a reasonable compensation value can be selected according to the current direction, the waveform of the carrier, and the corresponding band of the pulse width modulation signal to be generated and the carrier, so as to ensure the accuracy of the target counting threshold.

[0067] In some embodiments, optionally, the equivalent dead time includes a first equivalent dead time and a second equivalent dead time, the first equivalent dead time is the sum of the preset dead time and the turn-on delay time, and the second equivalent dead time is the turn-off delay time.

[0068] The preset dead time corresponds to the first count value, the turn-on delay time corresponds to the second count value, and the turn-off delay time corresponds to the third count value.

[0069] In the above embodiment, the first value is the sum of the first count value and the second count value.

[0070] In the above solution, the preset dead time is a time period, and the first count value can be understood as a change value of a carrier count value.

[0071] Specifically, for example, the carrier count value changes from 0 to 10. If the carrier count value changes from 0 to 10 in 100 microseconds, and the preset dead time is 3 microseconds, then the first count value corresponding to the preset dead time is 3, and the first count value corresponding to the preset dead time can be the corresponding carrier count value from 1 to 4, or 7 to 10.

[0072] Similarly, the second count value and the third count value have the same meaning as the first count value, that is, they can be understood as a change value of a carrier count value, and will not be described in detail here.

[0073] In some embodiments, optionally, the driving bridge arm of the inverter is connected between the positive bus and the negative bus, and each phase driving bridge arm is composed of two switching tubes connected in series, the switching tube connected to the positive bus is the upper tube of the bridge arm, and the switching tube connected to the negative bus is the lower tube of the bridge arm.

[0074] In some embodiments, optionally, the preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to open and close, and the second counting threshold is used to drive the lower tube of the bridge arm to open and close, and based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset counting threshold of the modulation wave is increased or decreased by the carrier count value corresponding to the equivalent dead time to obtain the target counting threshold of the modulation wave, including: when the current is less than 0, the waveform of the carrier is a regular triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, based on the first counting threshold and the second counting threshold, increase the first value; when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, When the waveform of the wave is an equilateral triangle and the rising and falling trend of the carrier count value is an upward trend, the first value is reduced based on the first counting threshold and the second counting threshold; when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, the second value is reduced based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, the second value is increased based on the first counting threshold and the second counting threshold; wherein the first value is the carrier count value corresponding to the first equivalent dead time, and the second value is the carrier count value corresponding to the second equivalent dead time.

[0075] As can be seen from the above, the preset counting threshold is used to form a level flip of the pulse width modulation signal when the carrier counting value is greater than the target counting threshold or less than the target counting threshold.

[0076] Based on this, in this embodiment, the preset counting threshold is divided into a first counting threshold and a second counting threshold, wherein the first counting threshold is used to drive the upper tube of the bridge arm to turn on and off, and the second counting threshold is used to drive the lower tube of the bridge arm to turn on and off. The first value or the second value is selected to compensate the first counting threshold and the second counting threshold in combination with the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, so as to make the pulse width modulation signal used to control the switch tube to turn on and off consistent with the pulse width modulation signal in the ideal state, thereby reducing the influence of the dead time on the output voltage of the inverter. In this process, the degree of current distortion on the driving bridge arm of the inverter is reduced, and the loss caused by current distortion is reduced, thereby eliminating torque pulsation and vibration, noise and even oscillation problems, so that when the motor is at low speed and light load, the performance deterioration caused by the dead time tends to be weakened.

[0077] Specifically, when the waveform of the carrier is an equilateral triangle, the current is greater than 0 and the carrier count value rises and falls in an upward trend, the first counting threshold and the second counting threshold are reduced so that the rising edge of the pulse width modulation signal is triggered in advance, so that the front end of the actually generated pulse width modulation signal is consistent with the front end of the ideal pulse width modulation signal, so as to eliminate the influence of the dead time and the turn-on delay time on the pulse width in the pulse width modulation signal, that is, reduce the loss caused by the dead time to the output voltage of the driving bridge arm.

[0078] When the waveform of the carrier wave is an equilateral triangle, the current is greater than 0, and the rising and falling trend of the carrier count value is a downward trend, the second value is added on the basis of the first counting threshold and the second counting threshold so that the falling edge of the pulse width modulation signal is triggered in advance, so that the rear end of the actually generated pulse width modulation signal is consistent with the rear end of the ideal pulse width modulation signal, so as to eliminate the influence of the dead time and the opening delay time on the pulse width in the pulse width modulation signal, that is, to reduce the loss caused by the dead time to the output voltage of the driving bridge arm.

[0079] When the current is greater than 0, the upper switch tube of the corresponding driving bridge arm is turned on and the lower switch tube is turned off. When the current is less than 0, that is, the upper switch tube of the corresponding driving bridge arm is turned off and the lower switch tube is turned on, in order to ensure that the rising edge of the pulse width modulation signal is triggered in advance and the falling edge of the pulse width modulation signal is triggered in advance, when the rising and falling trend is an upward trend, the first counting threshold and the second counting threshold are reduced, and when the rising and falling trend is a downward trend, the first counting threshold and the second counting threshold are increased.

[0080] Specifically, the preset dead time is t d The corresponding PWM carrier count value (i.e., the first count value) is represented by C td , the turn-on delay time of the switch device (ie, the switch tube) is t on The corresponding PWM carrier count value (i.e., the second count value) is represented by C ton , the turn-off delay time is t off The corresponding PWM carrier count value (i.e., the third count value) is expressed as C toff The equivalent dead time between the ideal output voltage and the actual output voltage is t err The corresponding PWM carrier count value is expressed as C terr The PWM comparison values ​​before compensation on the left and right sides of the carrier are represented as CMP Lcmd (i.e., the first counting threshold), CMP Rcmd (i.e., the second counting threshold), and the comparison values ​​after compensation are respectively expressed as CMP Lact 、CMP Ract .

[0081] like Figure 7 As shown, the corresponding compensation strategy is:

[0082] If the phase current>0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is: t err =t d +t on ;

[0083] Compensation method: Reduce the PWM comparison value of the upper and lower tubes by C at the same time terr =C td +C ton , the comparison value after compensation is CMP Lact =CMP Lcmd -C terr =CMP Lcmd -C td -C ton ;

[0084] If the phase current>0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is: t err =t off ;

[0085] Compensation method: Increase the PWM comparison value of the upper and lower tubes by C at the same time terr =C toff , the comparison value after compensation is CMP Ract =CMP Rcmd +C terr =CMP Rcmd+C toff ;

[0086] If the phase current is <0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is: t err =t off ;

[0087] Compensation method: Reduce the PWM comparison value of the upper and lower tubes by C at the same time terr =C toff , the comparison value after compensation is CMP Lact =CMP Lcmd -C terr =CMP Lcmd -C toff ;

[0088] If the phase current is <0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is: t err =t d +t on ;

[0089] Compensation method: Increase the PWM comparison value of the upper and lower tubes by C at the same time terr =C td +C ton , the comparison value after compensation is CMP Ract =CMP Rcmd +C terr =CMP Rcmd +C td +C ton .

[0090] Among them, when the carrier is an equilateral triangle, the current PWM cycle is on the left side of the carrier, that is, the rising and falling trend is an upward trend, and the current PWM cycle is on the right side of the carrier, and the rising and falling trend is a downward trend.

[0091] like Figure 8 As shown, the corresponding compensation strategy is:

[0092] If the phase current>0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is: t err =t d +t on ;

[0093] Compensation method: Increase the PWM comparison value of the upper and lower tubes by C at the same time terr =C td +C ton , the comparison value after compensation is CMP Lact =CMP Lcmd +C terr =CMP Lcmd +C td +C ton ;

[0094] If the phase current>0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is: t err =t off ;

[0095] Compensation method: Reduce the PWM comparison value of the upper and lower tubes by C at the same time terr =C toff , the comparison value after compensation is CMP Ract =CMP Rcmd -C terr =CMP Rcmd -C toff ;

[0096] If the phase current is <0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is: t err =t off ;

[0097] Compensation method: Increase the PWM comparison value of the upper and lower tubes by C at the same time terr =C toff , the comparison value after compensation is CMP Lact =CMP Lcmd +C terr =CMP Lcmd +C toff ;

[0098] If the phase current is <0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is: t err =t d +t on ;

[0099] Compensation method: Reduce the PWM comparison value of the upper and lower tubes by C at the same time terr =C td +C ton , the comparison value after compensation is CMP Ract =CMP Rcmd -C terr =CMP Rcmd -C td -C ton .

[0100] Among them, when the carrier is an equilateral triangle, the current PWM cycle is on the left side of the carrier, that is, the rising and falling trend is an upward trend, and the current PWM cycle is on the right side of the carrier, and the rising and falling trend is a downward trend. When the carrier is an inverted triangle, the judgment logic of the current PWM cycle on the left and right of the carrier is opposite to the case where the carrier is an equilateral triangle, that is, the current PWM cycle is on the left side of the carrier, that is, the rising and falling trend is a downward trend, and the current PWM cycle is on the right side of the carrier, and the rising and falling trend is an upward trend.

[0101] In some embodiments, optionally, the equivalent dead time includes a third equivalent dead time and a fourth equivalent dead time, the third equivalent dead time being the sum of the preset dead time multiplied by the proportional coefficient and the turn-on delay time, and the fourth equivalent dead time being the sum of the preset dead time multiplied by the proportional coefficient and the turn-off delay time.

[0102] In this embodiment, by obtaining the proportional coefficient, the preset dead time, the turn-on delay time and the turn-off delay time, the dead time is re-quantized based on the above three parameters, and the preset dead time, the turn-on delay time and the turn-off delay time are combined, and the equivalent dead time obtained by re-quantization is used as the compensation value of the preset counting threshold, and its corresponding carrier count value is used to compensate it, so as to obtain the target counting threshold.

[0103] In this process, the carrier count value is used to quantify the value that needs to be compensated for the preset count threshold, so that compensation can be achieved by compensating the preset count threshold, thereby making the pulse width modulation signal used to control the on and off of the switch tube consistent with the pulse width modulation signal in the ideal state, thereby reducing the impact of the dead time on the output voltage of the inverter. In this process, the degree of current distortion on the driving bridge arm of the inverter is reduced, the loss caused by current distortion is reduced, and the torque pulsation, vibration, noise and even oscillation are eliminated, so that the performance deterioration caused by the dead time tends to be weakened when the motor is at low speed and light load.

[0104] In the above embodiment, after the equivalent dead time is calculated, the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value are used as screening conditions to select the corresponding scene, and then the preset count threshold is corrected and compensated to obtain the target count threshold.

[0105] In this process, a reasonable compensation value can be selected according to the current direction, the waveform of the carrier, and the corresponding band of the pulse width modulation signal to be generated and the carrier, so as to ensure the accuracy of the target counting threshold.

[0106] In some embodiments, optionally, the proportionality coefficient can be set according to actual needs, such as selecting 1 / 2.

[0107] In some embodiments, optionally, the preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to open and close, and the second counting threshold is used to drive the lower tube of the bridge arm to open and close, and based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset counting threshold of the modulation wave is increased or decreased by the carrier count value corresponding to the equivalent dead time to obtain the target counting threshold of the modulation wave, including: when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, reducing the third value based on the first counting threshold and the second counting threshold; when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is greater than 0 and the carrier is When the waveform of the wave is an inverse triangle and the rising and falling trend of the carrier count value is a downward trend, the third value is increased based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, the fourth value is reduced based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, the fourth value is increased based on the first counting threshold and the second counting threshold; wherein the third value is the carrier count value corresponding to the third equivalent dead time, and the fourth value is the carrier count value corresponding to the fourth equivalent dead time.

[0108] In this embodiment, the preset dead time is t d The corresponding PWM carrier count value (i.e., the first count value) is represented by C td , the turn-on delay time of the switch device (ie, the switch tube) is t on The corresponding PWM carrier count value (i.e., the second count value) is represented by C ton , the turn-off delay time is t off The corresponding PWM carrier count value (i.e., the third count value) is expressed as C toff The equivalent dead time between the ideal output voltage and the actual output voltage is t err The corresponding PWM carrier count value is expressed as C terr The PWM comparison values ​​before compensation on the left and right sides of the carrier are represented as CMP Lcmd (i.e., the first counting threshold), CMP Rcmd (i.e., the second counting threshold), and the comparison values ​​after compensation are respectively expressed as CMP Lact 、CMPRact .

[0109] When the proportional coefficient is 1 / 2, Fig. 9 As shown, the corresponding compensation strategy is:

[0110] If the phase current>0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is:

[0111] Compensation method: Reduce the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0112] If the phase current>0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is:

[0113] Compensation method: Reduce the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0114] If the phase current is <0, and if the current PWM cycle is on the left side of the carrier, the equivalent dead time is:

[0115] Compensation method: Increase the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0116] If the phase current is <0, and if the current PWM cycle is on the right side of the carrier, the equivalent dead time is:

[0117] Compensation method: Increase the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0118] Among them, when the carrier is an equilateral triangle, the current PWM cycle is on the left side of the carrier, that is, the rising and falling trend is an upward trend, and the current PWM cycle is on the right side of the carrier, and the rising and falling trend is a downward trend.

[0119] When the proportionality factor is 1 / 2, Fig.10 As shown, the corresponding compensation strategy is:

[0120] If the phase current>0, if the current PWM cycle is on the left side of the carrier, the equivalent dead time is:

[0121] Compensation method: Increase the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0122] If the phase current>0, if the current PWM cycle is on the right side of the carrier, the equivalent dead time is:

[0123] Compensation method: Increase the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0124] If the phase current is <0, and if the current PWM cycle is on the left side of the carrier, the equivalent dead time is:

[0125] Compensation method: Reduce the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0126] If the phase current is <0, and if the current PWM cycle is on the right side of the carrier, the equivalent dead time is:

[0127] Compensation method: Reduce the PWM comparison value of the upper and lower tubes at the same time The comparison value after compensation is

[0128] In the above embodiment, the PWM comparison value is also the preset counting threshold of the modulation wave proposed in the present application, and the comparison value after compensation is also the target counting threshold.

[0129] The above is the compensation logic of one phase bridge arm in the three-phase drive bridge arm, and the inverter includes three-phase drive bridge arms, namely U-phase drive bridge arm 302, V-phase drive bridge arm 304 and W-phase drive bridge arm 306. U-phase drive bridge arm 302, V-phase drive bridge arm 304 and W-phase drive bridge arm 306 are respectively connected to the positive bus P and the negative bus N, and output three-phase currents iu, iv and iw correspondingly. A bus voltage U is formed between the positive bus P and the negative bus N. dc .

[0130] The U-phase driving bridge arm 302, the V-phase driving bridge arm 304 and the W-phase driving bridge arm 306 have two switching tubes connected in series, the upper tube S1 of the bridge arm and the lower tube S2 of the bridge arm, and the V-phase driving bridge arm 304 and the W-phase driving bridge arm 306 are represented by S3, S4, S5 and S6 respectively, and their connection relationship is as follows: Figure 3 As shown, no further description is given here.

[0131] Based on this, the dead zone compensation of the three-phase drive bridge arm in the inverter is implemented in three phases, such as Fig.11 , Fig.12 and Fig.13 As shown, the control logic of each phase is the same and will not be repeated here.

[0132] like Fig.14 and Fig.15 As shown, Fig.14 A schematic diagram showing a current waveform output by the inverter before applying the technical solution of the present application, Fig.15 A schematic diagram showing the current waveform output by the inverter after applying the technical solution of the present application is shown. Fig.14 and Fig.15 It can be seen from the comparison that the waveform of the current before application is not smooth, and the quality of the current output by the inverter can be improved by applying the technical solution of the present application.

[0133] In one embodiment, if Fig.16 As shown, the present invention provides a dead zone compensation device 1600, which is used for an inverter. The inverter includes a three-phase driving bridge arm, and each phase driving bridge arm includes a bridge arm upper tube and a bridge arm lower tube connected in series. The dead zone compensation device 1600 includes: a first acquisition unit 1602, which is used to obtain a preset dead zone time and a current direction of the driving bridge arm; a second acquisition unit 1604, which is used to obtain a turn-on delay time and a turn-off delay time of the bridge arm upper tube and the bridge arm lower tube; a third acquisition unit 1606, which is used to obtain a preset counting threshold of the modulation wave; a processing unit 1608, which is used to compensate the preset counting threshold of the modulation wave according to the turn-on delay time, the turn-off delay time and the preset dead zone time based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, to obtain a target counting threshold of the modulation wave; wherein the target counting threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the bridge arm upper tube and the bridge arm lower tube.

[0134] The embodiment of the present application proposes a dead zone compensation device 1600, which can compensate for a preset counting threshold to obtain a target counting threshold, thereby controlling the inverter according to the target counting threshold.

[0135] In this process, by updating the preset counting threshold, the pulse width modulation signal used to control the switch tube (i.e., the upper tube and the lower tube of the bridge arm) to turn on and off is consistent with the pulse width modulation signal in the ideal state, thereby reducing the impact of the dead time on the output voltage of the inverter. In this process, the degree of current distortion on the driving bridge arm of the inverter is reduced, the loss caused by current distortion is reduced, and the torque pulsation, vibration, noise and even oscillation are eliminated, so that the performance deterioration caused by the dead time tends to be weakened when the motor is at low speed and light load.

[0136] In the above dead zone compensation process, the rising and falling trends of the carrier count value are combined, so that the peak and trough double update can be achieved, so as to minimize the impact of the dead zone time on the inverter output voltage.

[0137] In the above embodiment, the turn-on delay time and the turn-off delay time can be used to characterize the property information of the switching tube. By obtaining the turn-on delay time and the turn-off delay time and using them as reference factors for the preset counting threshold of the compensation modulation wave, it is ensured to the greatest extent that the actual pulse width modulation signal obtained based on the target counting threshold can be the same as the theoretical pulse width modulation signal, thereby reducing the influence of the dead time on the output voltage of the inverter.

[0138] In some of the embodiments, optionally, the processing unit 1608 is used to calculate the equivalent dead time based on the turn-on delay time, the turn-off delay time and the preset dead time; based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset count threshold of the modulation wave is increased or decreased by the carrier count value corresponding to the equivalent dead time to obtain the target count threshold of the modulation wave.

[0139] In some of the embodiments, optionally, the equivalent dead time includes a first equivalent dead time and a second equivalent dead time, the first equivalent dead time is the sum of the preset dead time and the turn-on delay time, and the second equivalent dead time is the turn-off delay time.

[0140] In some of the embodiments, optionally, the preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to open and close, and the second counting threshold is used to drive the lower tube of the bridge arm to open and close, and the processing unit 1608 is used to increase the first value based on the first counting threshold and the second counting threshold when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend; when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, The first value is reduced based on the first counting threshold and the second counting threshold; when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, the second value is reduced based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, the second value is increased based on the first counting threshold and the second counting threshold; wherein the first value is the carrier count value corresponding to the first equivalent dead time, and the second value is the carrier count value corresponding to the second equivalent dead time.

[0141] In some of the embodiments, optionally, the equivalent dead time includes a third equivalent dead time and a fourth equivalent dead time, the third equivalent dead time being the sum of the preset dead time multiplied by the proportional coefficient and the turn-on delay time, and the fourth equivalent dead time being the sum of the preset dead time multiplied by the proportional coefficient and the turn-off delay time.

[0142] In some of the embodiments, optionally, the preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to open and close, and the second counting threshold is used to drive the lower tube of the bridge arm to open and close, and the processing unit 1608 is used to reduce the third value based on the first counting threshold and the second counting threshold when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend; when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, A third value is increased based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, the fourth value is reduced based on the first counting threshold and the second counting threshold; when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is an upward trend, or when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is an upward trend, the fourth value is increased based on the first counting threshold and the second counting threshold; wherein the third value is the carrier count value corresponding to the third equivalent dead time, and the fourth value is the carrier count value corresponding to the fourth equivalent dead time.

[0143] In one embodiment, if Fig.17 As shown, the present invention provides a dead zone compensation device 1700, including a processor 1702 and a memory 1704, the memory 1704 stores a program or instruction that can be executed on the processor 1702, and when the program or instruction is executed by the processor 1702, the steps of any method in the first aspect are implemented.

[0144] In one embodiment, the present invention provides a readable storage medium storing a program or instruction, and when the program or instruction is executed by a processor, the steps of any method in the first aspect are implemented.

[0145] In one of the embodiments, the present invention provides an inverter, comprising: any of the dead zone compensation devices described above; and / or the readable storage medium described above.

[0146] In one embodiment, the present invention provides a servo drive, comprising: the inverter as described above.

[0147] In one embodiment, the electrical equipment using the servo drive includes one of the following: a robot, household appliances, and a machine tool.

[0148] The term "first" or "second" in the specification and claims of the present application may include one or more of the features explicitly or implicitly. In the textual description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0149] In the claims, specification and drawings of the present invention, the term "multiple" refers to two or more than two. Unless otherwise clearly defined, the orientation or position relationship indicated by the terms "upper" and "lower" is based on the orientation or position relationship shown in the drawings, which is only for the purpose of more conveniently describing the present invention and making the description process simpler, rather than indicating or implying that the device or element referred to must have the specific orientation described, be constructed and operated in a specific orientation, so these descriptions cannot be understood as limiting the present invention; the terms "connect", "install", "fix" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection between multiple objects, or a detachable connection between multiple objects, or an integral connection; it can be a direct connection between multiple objects, or an indirect connection between multiple objects through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood based on the specific circumstances of the above data.

[0150] In the claims, specification and drawings of the present invention, the description of the terms "one embodiment", "some embodiments", "specific embodiments" and the like 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 the claims, specification and drawings of the present invention, 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.

[0151] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dead zone compensation method for an inverter, characterized in that: The inverter includes a three-phase driving bridge arm, each phase of the driving bridge arm includes a bridge arm upper tube and a bridge arm lower tube connected in series, and the dead zone compensation method includes: Obtaining a preset dead time and a current direction of the driving bridge arm, wherein the current direction of the current flowing out of the driving bridge arm is positive, and the current direction of the current flowing into the driving bridge arm is negative; Obtaining the turn-on delay time and turn-off delay time of the upper tube of the bridge arm and the lower tube of the bridge arm; Get the preset count threshold of the modulation wave; Based on the current direction, the waveform of the carrier wave and the rising and falling trend of the carrier wave count value, the preset count threshold of the modulation wave is compensated according to the turn-on delay time, the turn-off delay time and the preset dead time to obtain the target count threshold of the modulation wave; The target count threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the upper tube of the bridge arm and the lower tube of the bridge arm.

2. The dead zone compensation method according to claim 1, characterized in that: Based on the current direction, the waveform of the carrier wave and the rising and falling trend of the carrier wave count value, the preset count threshold of the modulation wave is compensated according to the turn-on delay time, the turn-off delay time and the preset dead time to obtain the target count threshold of the modulation wave, including: Calculate an equivalent dead time according to the turn-on delay time, the turn-off delay time and the preset dead time; Based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, the preset count threshold of the modulation wave is increased or decreased by the carrier count value corresponding to the equivalent dead time to obtain the target count threshold of the modulation wave.

3. The dead zone compensation method according to claim 2, characterized in that: The equivalent dead time includes a first equivalent dead time and a second equivalent dead time, the first equivalent dead time is the sum of the preset dead time and the turn-on delay time, and the second equivalent dead time is the turn-off delay time.

4. The dead zone compensation method according to claim 3, characterized in that: The preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to be turned on and off, and the second counting threshold is used to drive the lower tube of the bridge arm to be turned on and off, and the preset counting threshold of the modulation wave based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier counting value is increased or reduced by the carrier counting value corresponding to the equivalent dead time to obtain the target counting threshold of the modulation wave, including: When the current is less than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, increase a first value based on the first counting threshold and the second counting threshold; When the current is less than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rises and falls in an upward trend, or when the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rises and falls in an upward trend, reducing the first value based on the first counting threshold and the second counting threshold; When the current is less than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rise and fall trend is an upward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rise and fall trend is an upward trend, reducing the second value based on the first counting threshold and the second counting threshold; When the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rises and falls in a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rises and falls in a downward trend, a second value is increased based on the first counting threshold and the second counting threshold; The first value is a carrier count value corresponding to the first equivalent dead time, and the second value is a carrier count value corresponding to the second equivalent dead time.

5. The dead zone compensation method according to claim 2, characterized in that: The equivalent dead time includes a third equivalent dead time and a fourth equivalent dead time. The third equivalent dead time is the sum of the preset dead time multiplied by the proportional coefficient and the turn-on delay time. The fourth equivalent dead time is the sum of the preset dead time multiplied by the proportional coefficient and the turn-off delay time.

6. The dead zone compensation method according to claim 5, characterized in that: The preset counting threshold includes a first counting threshold and a second counting threshold, the first counting threshold is used to drive the upper tube of the bridge arm to be turned on and off, and the second counting threshold is used to drive the lower tube of the bridge arm to be turned on and off, and the preset counting threshold of the modulation wave based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier counting value is increased or reduced by the carrier counting value corresponding to the equivalent dead time to obtain the target counting threshold of the modulation wave, including: When the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rise and fall trend is an upward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rise and fall trend is an upward trend, reduce the third value based on the first counting threshold and the second counting threshold; When the current is less than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rises and falls in a downward trend, or when the current is greater than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rises and falls in a downward trend, a third value is increased based on the first counting threshold and the second counting threshold; When the current is greater than 0, the waveform of the carrier is an equilateral triangle, and the rising and falling trend of the carrier count value is a downward trend, or when the current is less than 0, the waveform of the carrier is an inverse triangle, and the rising and falling trend of the carrier count value is a downward trend, reducing the fourth value based on the first counting threshold and the second counting threshold; When the current is greater than 0, the waveform of the carrier is an inverse triangle, and the carrier count value rise and fall trend is an upward trend, or when the current is less than 0, the waveform of the carrier is an equilateral triangle, and the carrier count value rise and fall trend is an upward trend, a fourth value is increased based on the first counting threshold and the second counting threshold; The third value is a carrier count value corresponding to the third equivalent dead time, and the fourth value is a carrier count value corresponding to the fourth equivalent dead time.

7. A dead zone compensation device for an inverter, characterized in that: The inverter comprises a three-phase driving bridge arm, each phase of the driving bridge arm comprises a bridge arm upper tube and a bridge arm lower tube connected in series, and the dead zone compensation device comprises: A first acquisition unit, used to acquire a preset dead time and a current direction of the driving bridge arm, wherein the current direction of the current flowing out of the driving bridge arm is positive, and the current direction of the current flowing into the driving bridge arm is negative; A second acquisition unit, used to acquire the turn-on delay time and turn-off delay time of the upper tube of the bridge arm and the lower tube of the bridge arm; A third acquisition unit, used to acquire a preset counting threshold of the modulation wave; A processing unit, configured to compensate the preset counting threshold of the modulation wave according to the turn-on delay time, the turn-off delay time and the preset dead time based on the current direction, the waveform of the carrier and the rising and falling trend of the carrier count value, so as to obtain a target counting threshold of the modulation wave; The target count threshold of the modulation wave is used to generate a pulse width modulation signal for turning on and off the upper tube of the bridge arm and the lower tube of the bridge arm.

8. A dead zone compensation device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A readable storage medium, characterized in that: The readable storage medium stores a program or an instruction, and when the program or the instruction is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. An inverter, characterized in that: include: The dead zone compensation device according to claim 7 or 8; and / or The readable storage medium as claimed in claim 9.

11. A servo driver, characterized in that: include: The inverter as claimed in claim 10.

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