Dead-time compensation method and device for inverter

Abstract

The embodiment of the invention discloses a dead-time compensation method and device for an inverter. The dead-zone compensation method of the inverter comprises the following steps: acquiring an inductance value of an inductor of the inverter, a power supply voltage, an output voltage, a dead-zone duty ratio and a power frequency current, wherein the current flowing through the inductor is the sum of the power frequency current and a high-frequency triangular wave current; determining a high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period; determining a dead-zone compensation voltage according to the power frequency current, the high-frequency triangular wave current, the dead-zone duty ratio and the power supply voltage; and adjusting the duty ratio of a switching tube of the inverter according to the dead-zone compensation voltage, the power supply voltage and the output voltage so as to carry out dead-zone compensation on the inverter. According to the dead-time compensation method and device of the inverter provided by the embodiment of the invention, the reliability of dead-time compensation can be ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to inverter technology, and in particular to a dead zone compensation method and device for an inverter. Background Art

[0002] Inverters such as bipolar controlled full-bridge inverters need to add a dead zone to the control signal to ensure that the upper and lower switches of the same bridge arm of the inverter are not turned on at the same time. The dead zone will cause a certain difference between the ideal output duty cycle of the switch tube and the actual output duty cycle, which will lead to large output voltage and current harmonics and poor waveform quality. Therefore, the dead zone needs to be compensated to reduce the impact caused by the dead zone.

[0003] At present, the existing dead time compensation method of the inverter is usually a method of compensating a fixed dead time in the entire power frequency cycle. This compensation method has the problem of low reliability. Summary of the invention

[0004] The embodiments of the present invention provide a dead zone compensation method and device for an inverter to ensure the reliability of the dead zone compensation.

[0005] In a first aspect, an embodiment of the present invention provides a dead zone compensation method for an inverter, comprising:

[0006] Obtaining the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, wherein the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current;

[0007] Determining the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period;

[0008] Determining a dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage;

[0009] According to the dead zone compensation voltage, the power supply voltage and the output voltage, the switch duty cycle of the inverter is adjusted to perform dead zone compensation on the inverter.

[0010] Optionally, determining the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period includes:

[0011] According to the inductance L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts, the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L) is determined; wherein Tonl is the duty cycle calculated in the previous period.

[0012] Optionally, the obtaining of the inductance value, power supply voltage, output voltage, dead-zone duty cycle, and power frequency current of the inverter includes:

[0013] Collecting the initial value of the power frequency current;

[0014] A first-order low-pass filter is performed on the initial value of the power frequency current to obtain a filtered power frequency current.

[0015] Optionally, determining the dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage, and determining the dead zone compensation voltage includes:

[0016] According to the filtered industrial frequency current iinv, the high-frequency triangular wave current itri, the dead zone duty cycle Td and the power supply voltage Vbus, the dead zone compensation voltage Verr=k*sign(iinv, itri)*2*Vbus*Td is determined; wherein k is the compensation coefficient, when iinv is greater than itri+Δi, sign(iinv, itri) is 1, when iinv is less than itri+Δi and greater than -itri+Δi, sign(iinv, itri) is 0, when iinv is less than -itri+Δi, sign(iinv, itri) is -1, and Δi is the preset margin.

[0017] Optionally, adjusting the switch duty cycle of the inverter according to the dead zone compensation voltage, the power supply voltage and the output voltage includes:

[0018] The duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 is adjusted according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

[0019] Optionally, the filtered power frequency current iinv=(1-λ)*iinvl+λ*iinvo, λ is the filter coefficient, iinvl is the power frequency current calculated in the previous cycle, and iinvo is the initial value sampled in the current cycle.

[0020] Optionally, the preset margin is 0 or greater than 0 or less than 0.

[0021] In a second aspect, an embodiment of the present invention provides a dead zone compensation device for an inverter, comprising:

[0022] A current acquisition module, used to acquire the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, wherein the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current;

[0023] A current determination module, used to determine the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period;

[0024] A voltage determination module, used to determine a dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage;

[0025] The dead zone compensation module is used to adjust the switch duty cycle of the inverter according to the dead zone compensation voltage, the power supply voltage and the output voltage to perform dead zone compensation on the inverter.

[0026] Optionally, the current determination module is specifically used to determine the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L) according to the inductance L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts; wherein Tonl is the duty cycle calculated in the previous period.

[0027] Optionally, the dead zone compensation module is specifically used for:

[0028] The duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 is adjusted according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

[0029] The dead zone compensation method and device of the inverter provided by the embodiment of the present invention include: obtaining the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inductor of the inverter, the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current; determining the high-frequency triangular wave current according to the inductance value, power supply voltage, output voltage and preset switching period; determining the dead zone compensation voltage according to the power frequency current, high-frequency triangular wave current, dead zone duty cycle and power supply voltage; adjusting the switch tube duty cycle of the inverter according to the dead zone compensation voltage, power supply voltage and output voltage to compensate the inverter for the dead zone. The dead zone compensation method and device of the inverter provided by the embodiment of the present invention adjust the switch tube duty cycle of the inverter through the dead zone compensation voltage, power supply voltage and output voltage, the dead zone compensation voltage is determined by the power frequency current, high-frequency triangular wave current, dead zone duty cycle and power supply voltage, and the dead zone compensation is performed in combination with multiple parameters to ensure the reliability of the dead zone compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flow chart of a dead zone compensation method for an inverter provided in Embodiment 1 of the present invention;

[0031] Figure 2 is a structural schematic diagram of an inverter provided in Embodiment 1 of the present invention;

[0032] Figure 3 is a schematic diagram of a duty cycle provided by Embodiment 1 of the present invention;

[0033] Figure 4 is a flow chart of a dead zone compensation method for an inverter provided in Embodiment 2 of the present invention;

[0034] Figure 5 It is a schematic diagram of an industrial frequency current and a high-frequency triangular wave current provided in the second embodiment of the present invention;

[0035] Figure 6 It is a structural block diagram of a dead zone compensation device for an inverter provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0037] Embodiment 1

[0038] Figure 1 1 is a flowchart of a dead zone compensation method for an inverter provided in Embodiment 1 of the present invention. This embodiment is applicable to aspects such as compensating the dead zone of an inverter. The method can be executed by a dead zone compensation device for an inverter. The device can be integrated in a device such as a computer. The device can be implemented in the form of software and / or hardware. The method specifically includes the following steps:

[0039] Step 110: Obtain the inductance value of the inductor, the power supply voltage, the output voltage, the dead zone duty cycle, and the power frequency current of the inverter. The current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current.

[0040] The inverter is a bipolar full-bridge inverter. The inductance value, power supply voltage and dead-time duty cycle of the inductor can be pre-input into the dead-time compensation device of the inverter, and the output voltage of the inverter and the power frequency current can be acquired through voltage and current sensors. The dead-time compensation device of the inverter is provided with a voltage and current sensor to obtain the output voltage and power frequency current of the inverter.

[0041] For example, Figure 2 Schematic diagram of the structure of an inverter provided by Embodiment 1 of the present invention. Figure 2, the inverter includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4 and an inductor L0, the first switch tube Q1 and the third switch tube Q3 are located at the upper and lower bridge arms of one bridge arm, the second switch tube Q2 and the fourth switch tube Q4 are located at the upper and lower bridge arms of another bridge arm, one end of the first switch tube Q1 and the third switch tube Q3 is electrically connected to one end of the inductor, and one end of the second switch tube Q2 and the fourth switch tube Q4 is electrically connected to the other end of the inductor. When the inverter is working, the first switch tube Q1 and the fourth switch tube Q4 are turned on, or the second switch tube Q2 and the third switch tube Q3 are turned on. When the first switch tube Q1 and the fourth switch tube Q4 are turned on, and the second switch tube Q2 and the third switch tube Q3 are turned off, point A is connected to the positive pole of the power supply, point B is connected to the negative pole of the power supply, and the voltage VAB between point A and point B is the power supply voltage +Vbus, the duration ratio, that is, the duty cycle is recorded as Ton, and the duration is ton. When the second switch tube Q2 and the third switch tube Q3 are turned on, and the first switch tube Q1 and the fourth switch tube Q4 are turned off, point A is connected to the negative pole of the power supply, point B is connected to the positive pole of the power supply, and the voltage VAB between points A and B is -Vbus, the duration is recorded as Toff, and the duration is toff. In an ideal state, there is no dead zone, Ton+Toff=1, which is a complete cycle. According to the volt-second balance principle, the output voltage Vinv of the inverter is Vbus*Ton-Vbus*Toff, Ton=(1+Vinv / Vbus) / 2. In actual control, the voltage VAB between points A and B is controlled according to the duty cycle Ton, thereby controlling the output voltage Vinv or the current of the inverter connected to the grid.

[0042] Further, Figure 3 is a schematic diagram of a duty cycle provided by the first embodiment of the present invention. Figure 3 , S0 is the level change waveform of the control signal of the first switch tube Q1 and the fourth switch tube Q4 under ideal conditions. In order to ensure that the switches of the same bridge arm are not turned on at the same time, it is necessary to add a dead zone to the control signal of the switch tube. S1 is the level change waveform of the control signal of the first switch tube Q1 and the fourth switch tube Q4 after adding the dead zone, and S2 is the level change waveform of the control signal of the second switch tube Q2 and the third switch tube Q3 after adding the dead zone. 实际 +Toff 实际 +2Td=1, Td is the dead zone duty cycle, and the dead zone time is td. Figure 3As shown, t1 to t5 is a complete switching cycle considering the dead zone. t1 to t2 is the forward conduction time, the time is ton-td, and the voltage VAB is Vbus. t2 to t3 is the dead zone time, and the voltage VAB is determined by the direction of the current flowing through the inductor L0. t3 to t4 is the negative conduction time, the time is toff-td, and the voltage VAB is -Vbus. t4 to t5 is the dead zone time, and the voltage VAB is determined by the direction of the current flowing through the inductor L0. The current flowing through the inductor L0 from left to right is the positive direction (point C is the collection point of the power frequency current). When the current is greater than 0, the second switch tube Q2 and the third switch tube Q3 anti-parallel diodes are used for continuous flow in the dead zone, and the voltage VAB is equivalent to -Vbus. When the current is less than 0, the first switch tube Q1 and the fourth switch tube Q4 anti-parallel diodes are used for continuous flow in the dead zone, and the voltage VAB is equivalent to Vbus. There are two dead zones in one switching cycle: the time period from t2 to t3 and the time period from t4 to t5. Figure 3 As shown, the current IL flowing through the inductor L0 is a triangle wave that rises and falls continuously during the switching cycle, so the currents in the two dead zones may be positive or negative. When the currents in the two dead zones are both positive and the voltage VAB is both negative, the output voltage Vinv of the inverter is Vbus*(Ton-Td)-Vbus*(Toff-Td)-2*Vbus*Td=Vbus*Ton-Vbus*Toff-2*Vbus*Td. At this time, the output voltage of the inverter is 2*Vbus*Td lower than the ideal state. When the currents in the two dead zones are one positive and one negative, and the voltages VAB are one positive and one negative, the output voltage Vinv of the inverter is Vbus*(Ton-Td)-Vbus*(Toff-Td)+Vbus*Td-Vbus*Td=Vbus*Ton-Vbus*Toff. At this time, the output voltage of the inverter is the same as the ideal state. When the currents in the two dead zones are both negative and the voltages VAB are both positive, Vinv = Vbus*(Ton-Td)-Vbus*(Toff-Td)+2*Vbus*Td=Vbus*Ton-Vbus*Toff+2*Vbus*Td. At this time, the output voltage of the inverter is 2*Vbus*Td lower than the ideal state. The dead zone causes a certain difference between the ideal duty cycle and the actual duty cycle of the switching tube, which in turn causes the output voltage and current harmonics of the inverter to be large and the waveform quality to be poor. The voltage difference caused by the above-mentioned dead zone can be compensated to make up for the impact of the dead zone.

[0043] Step 120: Determine the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and the preset switching period.

[0044] Specifically, the high-frequency triangular wave current can be calculated based on the inductance value of the inductor, the power supply voltage, the output voltage and the preset switching period. The high-frequency triangular wave current is positively correlated with the preset switching period. The difference between the power supply voltage and the output voltage is positively correlated with the high-frequency triangular wave current. When other parameters remain unchanged, the high-frequency triangular wave current decreases with the increase of inductance.

[0045] Step 130 : Determine the dead zone compensation voltage according to the power frequency current, the high frequency triangle wave current, the dead zone duty cycle and the power supply voltage.

[0046] Specifically, the industrial frequency current can be a filtered industrial frequency current obtained by filtering the initial value of the collected industrial frequency current. The magnitude relationship between the filtered industrial frequency current and the high-frequency triangular wave current affects the dead zone compensation voltage. For example, the dead zone compensation voltage is a multiple of the product of the dead zone duty cycle and the power supply voltage, and the size of the multiple is related to the magnitude relationship between the filtered industrial frequency current and the high-frequency triangular wave current.

[0047] Step 140: Adjust the switch duty cycle of the inverter according to the dead zone compensation voltage, the power supply voltage and the output voltage to perform dead zone compensation on the inverter.

[0048] Specifically, the duty cycle of the inverter's switch tube is obtained through a calculation formula for the dead zone compensation voltage, power supply voltage and output voltage. By calculating the duty cycle of the dead zone loss, the actual loss duty cycle is compensated, the waveform distortion caused by the dead zone is minimized, and harmonics are reduced.

[0049] It should be noted that the size of each preset parameter in this embodiment can be determined according to actual compensation requirements and is not limited here.

[0050] The dead zone compensation method of the inverter provided in this embodiment includes: obtaining the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current; determining the high-frequency triangular wave current according to the inductance value, power supply voltage, output voltage and preset switching period of the inductor; determining the dead zone compensation voltage according to the power frequency current, high-frequency triangular wave current, dead zone duty cycle and power supply voltage; adjusting the switch duty cycle of the inverter according to the dead zone compensation voltage, power supply voltage and output voltage to compensate the inverter for the dead zone. The dead zone compensation method of the inverter provided in this embodiment adjusts the switch duty cycle of the inverter through the dead zone compensation voltage, power supply voltage and output voltage, the dead zone compensation voltage is determined by the power frequency current, high-frequency triangular wave current, dead zone duty cycle and power supply voltage, and the dead zone compensation is performed in combination with multiple parameters to ensure the reliability of the dead zone compensation.

[0051] Embodiment 2

[0052] Figure 41 is a flowchart of a dead zone compensation method for an inverter provided in Embodiment 2 of the present invention. This embodiment is applicable to aspects such as compensating the dead zone of an inverter. The method can be executed by a dead zone compensation device for an inverter. The device can be integrated in a device such as a computer. The device can be implemented in the form of software and / or hardware. The method specifically includes the following steps:

[0053] Step 210: Obtain the inductance value of the inverter, the power supply voltage, the output voltage, the dead zone duty cycle, and the filtered power frequency current. The current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current.

[0054] Wherein, the inverter is a bipolar full-bridge inverter. The inductance value, power supply voltage and dead zone duty cycle of the inductor can be pre-input into the dead zone compensation device of the inverter, and the output voltage of the inverter and the initial value of the power frequency current can be acquired by the voltage and current sensor. The dead zone compensation device of the inverter is provided with a voltage and current sensor electrically connected to obtain the output voltage of the inverter and the initial value of the power frequency current, and the initial value of the power frequency current is filtered to obtain the filtered power frequency current. The filtered power frequency current iinv = (1-λ) * iinvl + λ * iinvo, λ is the filter coefficient, illustratively, λ is 0.25, iinvl is the power frequency current calculated in the previous cycle, and iinvo is the initial value obtained by sampling in the current cycle.

[0055] Step 220, according to the inductance value L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts, determine the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L); wherein Tonl is the duty cycle calculated in the previous period.

[0056] Specifically, if the current cycle is the first cycle, Ton1 is 0, and if the current cycle is the second cycle, Ton1 is the ideal output duty cycle.

[0057] For example, Figure 5 Schematic diagram of a power frequency current and a high frequency triangular wave current provided by the second embodiment of the present invention. Figure 5 , the solid line shows the sum of the power frequency current iinv and the high-frequency triangular wave current itri, and the dotted line shows the power frequency current iinv. The high-frequency triangular wave current itri is caused by the switch tube, and the power frequency current iinv is determined by the load of the inverter or the grid-connected power. In order to avoid polarity misjudgment caused by noise, the power frequency current iinv needs to be filtered. The power frequency current iinv can be obtained by sampling and filtering at a sampling frequency of 2 times the switching frequency through a current sensor, using a first-order low-pass filter. The high-frequency triangular wave current itri is close to the control frequency and usually cannot be obtained directly by sampling. It is obtained by the calculation formula in the above step 220.

[0058] Step 230 , determining the dead zone compensation voltage Verr=k*sign(iinv, itri)*2*Vbus*Td according to the filtered power frequency current iinv, the high frequency triangular wave current itri, the dead zone duty cycle Td and the power supply voltage Vbus.

[0059] Wherein, k is the compensation coefficient, 0≤k≤1, exemplarily, k is 1, sign(iinv, itri) is the judgment function of the current direction flowing through the inductor during the dead zone, when iinv is greater than itri+Δi, sign(iinv, itri) is 1, when iinv is less than itri+Δi and greater than -itri+Δi, sign(iinv, itri) is 0, when iinv is less than -itri+Δi, sign(iinv, itri) is -1, and Δi is the preset margin. Specifically, when iinv is greater than itri+Δi, Verr=k*2*Vbus*Td, when iinv is less than itri+Δi and greater than -itri+Δi, Verr is 0, when iinv is less than -itri+Δi, Verr=-k*2*Vbus*Td. In addition, the preset margin is 0 or greater than 0 or less than 0, such as when iinv is greater than itri+0.2, sign(iinv, itri) is 1. The size relationship between iinv and itri is such that if iinv is greater than itri, it will continue for multiple cycles, such as 3 cycles, before switching the value of sign(iinv, itri).

[0060] Step 240 , adjusting the duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

[0061] Specifically, the voltage impact caused by the dead zone can be compensated by adjusting the duty cycle, and the dead zone compensation voltage is calculated and the duty cycle is adjusted once in each control cycle of the switch tube to compensate for the dead zone in real time.

[0062] It should be noted that the size of each preset parameter in this embodiment can be determined according to actual compensation requirements and is not limited here.

[0063] The dead zone compensation method of the inverter provided in this embodiment determines the dead zone compensation voltage Verr=k*sign(iinv, itri)*2*Vbus*Td according to the filtered industrial frequency current iinv, the high-frequency triangular wave current itri, the dead zone duty cycle Td and the power supply voltage Vbus, and adjusts the duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv. The dead zone compensation is performed by combining multiple parameters to ensure the reliability of the dead zone compensation.

[0064] Embodiment 3

[0065] Figure 6 : is a structural block diagram of a dead zone compensation device for an inverter provided by Embodiment 3 of the present invention. Figure 6 The dead zone compensation device of the inverter includes: a current acquisition module 310, a current determination module 320, a voltage determination module 330 and a dead zone compensation module 340. Among them, the current acquisition module 310 is used to obtain the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, and the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current; the current determination module 320 is used to determine the high-frequency triangular wave current according to the inductance value, power supply voltage, output voltage and preset switching period of the inductor; the voltage determination module 330 is used to determine the dead zone compensation voltage according to the power frequency current, high-frequency triangular wave current, dead zone duty cycle and power supply voltage; the dead zone compensation module 340 is used to adjust the switch duty cycle of the inverter according to the dead zone compensation voltage, power supply voltage and output voltage to compensate the inverter for the dead zone.

[0066] Based on the above implementation, the current determination module 320 is specifically used to determine the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L) according to the inductance L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts; wherein Tonl is the duty cycle calculated in the previous period.

[0067] Optionally, the current acquisition module 310 includes a current acquisition unit and a current filtering unit. The current acquisition unit is used to acquire the initial value of the power frequency current; the current filtering unit is used to perform a first-order low-pass filtering on the initial value of the power frequency current to obtain a filtered power frequency current.

[0068] In one embodiment, the voltage determination module 330 is specifically used to determine the dead zone compensation voltage Verr = k*sign(iinv, itri)*2*Vbus*Td according to the filtered industrial frequency current iinv, the high-frequency triangular wave current itri, the dead zone duty cycle Td and the power supply voltage Vbus; wherein k is the compensation coefficient, when iinv is greater than itri+Δi, sign(iinv, itri) is 1, when iinv is less than itri+Δi and greater than -itri+Δi, sign(iinv, itri) is 0, when iinv is less than -itri+Δi, sign(iinv, itri) is -1, and Δi is the preset margin.

[0069] Optionally, the dead zone compensation module 340 is specifically configured to adjust the duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

[0070] The dead zone compensation device of the inverter provided in this embodiment and the dead zone compensation method of the inverter provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the dead zone compensation method of the inverter provided in any embodiment of the present invention.

[0071] Embodiment 4

[0072] Embodiment 4 of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the dead zone compensation method of the inverter provided in the embodiment of the present invention is implemented, including:

[0073] Obtain the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter. The current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current.

[0074] Determine the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and the preset switching cycle;

[0075] Determine the dead zone compensation voltage according to the power frequency current, the high frequency triangle wave current, the dead zone duty cycle and the power supply voltage;

[0076] According to the dead zone compensation voltage, the power supply voltage and the output voltage, the switch duty cycle of the inverter is adjusted to perform dead zone compensation on the inverter.

[0077] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0078] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0079] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0080] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0081] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, re-modulations, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A dead zone compensation method for an inverter, characterized in that: include: Obtaining the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, wherein the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current; Determining the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period; Determining a dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage; According to the dead zone compensation voltage, the power supply voltage and the output voltage, the switch duty cycle of the inverter is adjusted to perform dead zone compensation on the inverter.

2. The dead zone compensation method of the inverter according to claim 1, characterized in that: The step of determining the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period includes: According to the inductance L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts, the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L) is determined; wherein Tonl is the duty cycle calculated in the previous period.

3. The dead zone compensation method of the inverter according to claim 1, characterized in that: The obtaining of the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter includes: Collecting the initial value of the power frequency current; A first-order low-pass filter is performed on the initial value of the power frequency current to obtain a filtered power frequency current.

4. The dead zone compensation method of the inverter according to claim 3, characterized in that: The step of determining the dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage comprises: According to the filtered industrial frequency current iinv, the high-frequency triangular wave current itri, the dead zone duty cycle Td and the power supply voltage Vbus, the dead zone compensation voltage Verr=k*sign(iinv, itri)*2*Vbus*Td is determined; wherein k is the compensation coefficient, when iinv is greater than itri+Δi, sign(iinv, itri) is 1, when iinv is less than itri+Δi and greater than -itri+Δi, sign(iinv, itri) is 0, when iinv is less than -itri+Δi, sign(iinv, itri) is -1, and Δi is the preset margin.

5. The dead zone compensation method of the inverter according to claim 1, characterized in that: The step of adjusting the switch duty cycle of the inverter according to the dead zone compensation voltage, the power supply voltage and the output voltage comprises: The duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 is adjusted according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

6. The dead zone compensation method of the inverter according to claim 4, characterized in that: The filtered power frequency current iinv=(1-λ)*iinvl+λ*iinvo, λ is the filter coefficient, iinvl is the power frequency current calculated in the previous cycle, and iinvo is the initial value sampled in the current cycle.

7. The dead zone compensation method of the inverter according to claim 4, characterized in that: The preset margin is 0 or greater than 0 or less than 0.

8. A dead zone compensation device for an inverter, characterized in that: include: A current acquisition module, used to acquire the inductance value, power supply voltage, output voltage, dead zone duty cycle and power frequency current of the inverter, wherein the current flowing through the inductor is the sum of the power frequency current and the high-frequency triangular wave current; A current determination module, used to determine the high-frequency triangular wave current according to the inductance value of the inductor, the power supply voltage, the output voltage and a preset switching period; A voltage determination module, used to determine a dead zone compensation voltage according to the power frequency current, the high frequency triangular wave current, the dead zone duty cycle and the power supply voltage; The dead zone compensation module is used to adjust the switch duty cycle of the inverter according to the dead zone compensation voltage, the power supply voltage and the output voltage to perform dead zone compensation on the inverter.

9. The dead zone compensation device of the inverter according to claim 8, characterized in that: The current determination module is specifically used to determine the high-frequency triangular wave current itri=Ts*Tonl*(Vbus-Vinv) / (2*L) according to the inductance L of the inductor, the power supply voltage Vbus, the output voltage Vinv and the preset switching period Ts; wherein Tonl is the duty cycle calculated in the previous period.

10. The dead zone compensation device of the inverter according to claim 8, characterized in that: The dead zone compensation module is specifically used for: The duty cycle Ton=(1+(Vinv+Verr) / Vbus) / 2 is adjusted according to the dead zone compensation voltage Verr, the power supply voltage Vbus and the output voltage Vinv.

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