Inverter control method and related device

Abstract

The application relates to an inverter control method and related equipment. The inverter control method comprises the following steps: S1, triggering FOC calculation corresponding to the inverter based on a preset instruction, so as to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation; S2, confirming the maximum value of the duty cycle of the effective vectors; S3, when the maximum value of the duty cycle of the effective vectors is greater than a preset value, controlling the inverter through a DPWM vector control method; and S4, when the maximum value of the duty cycle of the effective vectors is less than or equal to the preset value, controlling the inverter through an SVPWM vector control method. The application can avoid noise deterioration of the inverter under a light load working condition and reduce the power device loss of the inverter under a large current working condition.

Description

Technical Field

[0001] This invention relates to the field of inverter technology, and more specifically, to an inverter control method and related equipment. Background Technology

[0002] In the field of variable frequency compressor control, the temperature rise and losses of the drive circuit board are receiving increasing attention. Typical variable frequency drive control systems generate alternating voltage to drive the motor by controlling the high-frequency switching of power semiconductor devices (such as IGBTs or MOSFETs). The losses and heat generated by the switching can lead to excessive temperature rise of the drive circuit board. Therefore, the drive method of the switch is particularly important. Specifically, when the drive method is SVPWM, it results in frequent switching and excessive heat generation under heavy loads. When the drive method is DPWM, it generates large current ripples during light load or no-load operation, causing significant electromagnetic noise and mechanical vibration, resulting in a poor user experience. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an inverter control method and related equipment, addressing the aforementioned technical deficiencies of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: to construct an inverter control method, the method comprising the following steps: S1. Based on a preset instruction, trigger the FOC calculation corresponding to the inverter to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation; S2. Confirm the maximum value of the duty cycle of the effective vector; S3. When the maximum value of the duty cycle of the effective vector is greater than the preset value, the inverter is controlled by the DPWM vector control method. S4. When the maximum value of the duty cycle of the effective vector is less than or equal to the preset value, the inverter is controlled by the SVPWM vector control method.

[0005] Preferably, in one embodiment of the inverter control method of the present invention, the preset value is 0.5.

[0006] Preferably, in one embodiment of the inverter control method of the present invention, in step S1, obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM period corresponding to the inverter; ; in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

[0007] Preferably, in one embodiment of the inverter control method of the present invention, in step S1, triggering the FOC calculation corresponding to the inverter based on a preset command includes: The preset command is generated based on the target bus voltage, so that during the FOC calculation process, the command is generated according to the target bus voltage. and .

[0008] The present invention also provides a controller connected to the inverter, the controller being configured to perform the following steps: Based on a preset instruction, the FOC calculation corresponding to the inverter is triggered so as to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation. Confirm the maximum value of the duty cycle of the effective vector; When the maximum value of the duty cycle of the effective vector is greater than the preset value, the inverter is controlled by the DPWM vector control method; When the maximum value of the duty cycle of the effective vector is less than or equal to the preset value, the inverter is controlled by the SVPWM vector control method.

[0009] Preferably, in one embodiment of the controller of the present invention, the preset value is 0.5.

[0010] Preferably, in one embodiment of the controller of the present invention, obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM period corresponding to the inverter; ; in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

[0011] Preferably, in one embodiment of the controller of the present invention, the step of triggering the FOC calculation corresponding to the inverter based on a preset instruction includes: The preset command is generated based on the target bus voltage, so that during the FOC calculation process, the command is generated according to the target bus voltage. and .

[0012] The present invention also provides an electronic device, including a memory and a processor; The memory is used to store computer programs; The processor is used to execute the computer program to implement the method described above.

[0013] The present invention also provides a computer storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method described above.

[0014] The inverter control method and related equipment of the present invention have the following advantages: they can reduce the power device losses under high current conditions while avoiding the noise degradation of the inverter under light load conditions. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a flowchart of an embodiment of an inverter control method according to the present invention; Figure 2 This is a waveform diagram of an embodiment of SVPWM vector control. Figure 3 This is a waveform diagram of an embodiment of DPWM vector control. Figure 4 This is a complete FOC control block diagram. Detailed Implementation

[0016] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] like Figure 1 The figure shows an embodiment of an inverter control method according to the present invention. Figure 1In an embodiment of the inverter control method of the present invention shown, the method includes the following steps: S1, triggering FOC calculation corresponding to the inverter based on a preset command, so as to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation; S2, confirming the maximum value of the duty cycle of the effective vectors; S3, when the maximum value of the duty cycle of the effective vectors is greater than a preset value, controlling the inverter by a DPWM vector control method; S4, when the maximum value of the duty cycle of the effective vectors is less than or equal to the preset value, controlling the inverter by a SVPWM vector control method.

[0018] Based on step S1, such as Figure 4 The diagram shows the control block diagram for FOC. This embodiment primarily implements the SVPWM control process. During inverter operation, FOC calculation is triggered based on the inverter's operating state. During this calculation, the quadrature-axis current is considered... With direct-axis current The measured value is compared with the target value, and after passing through the PI regulator, the output is a voltage command in a rotating coordinate system. and This voltage is to generate the required quadrature-axis current. With direct-axis current The voltage required to supply current. Through inverse Park transformation, the voltage command in the rotating coordinate system is... and Two-phase voltage signals converted back to stationary coordinates and Then the corresponding effective vector is obtained. and Calculation based on the obtained effective vector and Calculate its corresponding duty cycle.

[0019] Based on steps S2, S3, and S4, the duty cycle of the obtained effective vector is determined. When the duty cycle of the obtained effective vector is greater than the preset value, it can be determined that the inverter may be operating under high load. In this case, to avoid excessive heat generation due to frequent switching under high load, the inverter can be controlled using a low-switching-frequency DPWM vector control method, so that the corresponding switching transistors of the inverter will not overheat due to high-frequency switching. When the duty cycle of the obtained effective vector is less than or equal to the preset value, it can be determined that the inverter may be operating under light load or no load. In this case, to avoid generating large current ripple and causing electromagnetic noise, the inverter can be controlled using a low-cut, high-frequency SVPWM vector control method, so as to reduce the noise of the inverter under light load. The FOC calculation process yields the duty cycles corresponding to the multiphase effective vectors. During the judgment process, the duty cycles of all effective vectors need to be evaluated. An effective vector's duty cycle is considered greater than the preset value if any effective vector's duty cycle is greater than the preset value. Only when all effective vectors' duty cycles are less than or equal to the preset value is the effective vector's duty cycle considered less than or equal to the preset value. This judgment process can be achieved by judging only the maximum value of the effective vector's duty cycle.

[0020] Through the above process, it is possible to ensure that the inverter operates at its optimal state under different working conditions, so as to meet the user's needs and improve the user experience.

[0021] In one embodiment, a preset value of 0.5 can be set. That is, whether the inverter is operating under heavy or light load can be determined by whether the duty cycle of the effective vector exceeds 0.5. In one embodiment, this preset value can be adjusted as needed, for example, taking a value near 0.5, such as 0.4 or 0.6. The actual value can be obtained through testing during the actual operation of the inverter.

[0022] In one embodiment, in step S1, obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM cycle corresponding to the inverter; ; in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

[0023] Specifically, the effective duration of each effective vector can be obtained based on the above formula, and then the duty cycle corresponding to the effective vector of each phase can be obtained.

[0024] In one embodiment, in step S1, the FOC calculation corresponding to the inverter triggered based on a preset command includes: obtaining the FOC from the base PI feedback. and generate and So that during the FOC calculation process, the target bus voltage and and Generate using the above formula and The specific FOC calculation process is as follows: Figure 4 The calculation process shown requires obtaining the target quadrature and direct axis currents based on the commanded rotational speed in each control cycle, and then obtaining the target quadrature and direct axis currents. and Finally, the inverse Park transformation is used to obtain... and The effective vector duration is obtained from the above calculation formula, and thus the effective vector duty cycle is obtained.

[0025] In the controller of the present invention, the controller is connected to the inverter, and the controller is configured to perform the following steps: triggering FOC calculation corresponding to the inverter based on a preset instruction, so as to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation; confirming the maximum value of the duty cycle of the effective vectors; when the maximum value of the duty cycle of the effective vectors is greater than a preset value, controlling the inverter through a DPWM vector control method; when the maximum value of the duty cycle of the effective vectors is less than or equal to the preset value, controlling the inverter through an SVPWM vector control method.

[0026] Specifically, during the inverter's operation, the controller can perform FOC calculations based on the inverter's operating state according to trigger commands. This calculation includes the quadrature-axis current. With direct-axis current The measured value is compared with the target value, and after passing through the PI regulator, the output is a voltage command in a rotating coordinate system. and This voltage is to generate the required quadrature-axis current. With direct-axis current The voltage required to supply current. Through inverse Park transformation, the voltage command in the rotating coordinate system is... and Two-phase voltage signals converted back to stationary coordinates and Then the corresponding effective vector is obtained. and Calculation based on the obtained effective vector and Calculate its corresponding duty cycle.

[0027] The duty cycle of the obtained effective vector is determined. When the duty cycle of the obtained effective vector is greater than the preset value, it can be determined that the inverter may be operating under high load. In this case, to avoid excessive heat generation due to frequent switching under high load, the inverter can be controlled by a low switching frequency DPWM vector control method, so that the corresponding switching transistors of the inverter will not overheat due to high frequency switching. When the duty cycle of the obtained effective vector is less than or equal to the preset value, it can be determined that the inverter may be operating under light load or no load. In this case, to avoid generating large current ripple and causing electromagnetic noise, the inverter can be controlled by a low-cut high-frequency SVPWM vector control method, so as to reduce the noise of the inverter under light load.

[0028] The SVPWM vector control method can be referenced from [the relevant documentation]. Figure 2 DPWM vector control method (refer to) Figure 3 DPWM requires fewer switching operations and has lower switching losses compared to SVPWM, resulting in less temperature rise. However, in the low-modulus region, the output voltage is smaller, requiring a longer zero-vector duration. SVPWM splits the zero vector in two, resulting in very low ripple. DPWM, on the other hand, forces the use of only one zero vector, leading to significant ripple. In this region, SVPWM's harmonic performance is far superior to DPWM. In the high-modulus region, the effective vector duration is longer, while the zero-vector duration is shorter. The waveforms of SVPWM and DPWM become increasingly similar (because there are fewer zero vectors to begin with). Under high-modulus conditions, DPWM's harmonic performance gradually improves, even becoming comparable to SVPWM.

[0029] The FOC calculation process yields the duty cycles corresponding to the multiphase effective vectors. During the judgment process, the duty cycles of all effective vectors need to be evaluated. An effective vector's duty cycle is considered greater than the preset value if any effective vector's duty cycle is greater than the preset value. Only when all effective vectors' duty cycles are less than or equal to the preset value is the effective vector's duty cycle considered less than or equal to the preset value. This judgment process can be achieved by judging only the maximum value of the effective vector's duty cycle.

[0030] Through the above process, the controller's control process can ensure that the inverter operates in the best possible condition under different working conditions, so as to meet the user's needs and improve the user experience.

[0031] In one embodiment, a preset value of 0.5 can be set. That is, whether the inverter is operating under heavy or light load can be determined by whether the duty cycle of the effective vector exceeds 0.5. In one embodiment, this preset value can be adjusted as needed, for example, taking a value near 0.5, such as 0.4 or 0.6. The actual value can be obtained through testing during the actual operation of the inverter.

[0032] In one embodiment, obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM cycle corresponding to the inverter; ; in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

[0033] Specifically, the controller can obtain the effective duration of each effective vector based on the above formula, and then obtain the duty cycle corresponding to the effective vector of each phase.

[0034] In one embodiment, in step S1, the FOC calculation corresponding to the inverter triggered based on a preset command includes: obtaining the FOC from the base PI feedback. and generate and So that during the FOC calculation process, the target bus voltage and and Generate using the above formula and The specific FOC calculation process is as follows: Figure 4 The calculation process shown requires obtaining the target quadrature and direct axis currents based on the commanded rotational speed in each control cycle, and then obtaining the target quadrature and direct axis currents. and Finally, the inverse Park transformation is used to obtain... and The effective vector duration is obtained from the above calculation formula, and thus the effective vector duty cycle is obtained.

[0035] Furthermore, an electronic device of the present invention has the function of implementing the corresponding steps performed in the above-described method. Each function can be implemented by hardware or by hardware executing corresponding software. The corresponding hardware or software includes one or more modules corresponding to the above-described functions. That is, the steps in the above-described method are executed by one or more modules respectively. The specific cooperative operation between the modules can be referred to the specific process of the above-described method, and will not be repeated here.

[0036] Furthermore, an electronic device according to the present invention may further include a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program to implement the above-described method. Specifically, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, when the computer program is downloaded, installed, and executed by an electronic device, it performs the functions defined in the methods of the embodiments of the present invention. The electronic device in the present invention may be a terminal such as a laptop, desktop computer, tablet computer, or smartphone, or it may be a server.

[0037] Furthermore, this invention provides a computer storage medium storing a computer program, which, when executed by a processor, implements any of the methods described above. Specifically, it should be noted that the computer-readable medium described above can be a computer-readable signal medium, a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. The transmitted data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0038] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device.

[0039] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. An inverter control method, characterized in that, The method includes the following steps: S1. Based on a preset instruction, trigger the FOC calculation corresponding to the inverter to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation; S2. Confirm the maximum value of the duty cycle of the effective vector; S3. When the maximum value of the duty cycle of the effective vector is greater than the preset value, the inverter is controlled by the DPWM vector control method. S4. When the maximum value of the duty cycle of the effective vector is less than or equal to the preset value, the inverter is controlled by the SVPWM vector control method.

2. The inverter control method according to claim 1, characterized in that, The preset value is 0.

5.

3. The inverter control method according to claim 1, characterized in that, In step S1, obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM period corresponding to the inverter; ； in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

4. The inverter control method according to claim 3, characterized in that, In step S1, triggering the FOC calculation corresponding to the inverter based on a preset command includes: The preset command is generated based on the target bus voltage, so that during the FOC calculation process, the command is generated according to the target bus voltage. and .

5. A controller, characterized in that, The controller is connected to the inverter, and the controller is used to perform the following steps: Based on a preset instruction, the FOC calculation corresponding to the inverter is triggered so as to obtain the duty cycle of all effective vectors corresponding to the inverter according to the output result of the FOC calculation. Confirm the maximum value of the duty cycle of the effective vector; When the maximum value of the duty cycle of the effective vector is greater than the preset value, the inverter is controlled by the DPWM vector control method; When the maximum value of the duty cycle of the effective vector is less than or equal to the preset value, the inverter is controlled by the SVPWM vector control method.

6. The controller according to claim 5, characterized in that, The preset value is 0.

5.

7. The controller according to claim 5, characterized in that, The step of obtaining the duty cycle of all effective vectors corresponding to the inverter based on the output result calculated by the FOC includes: obtaining the effective duration of the effective vector according to the following formula, and obtaining the duty cycle of the effective vector based on the ratio of the effective duration of the effective vector to the PWM period corresponding to the inverter; ； in, The PWM period corresponding to the inverter. The bus voltage corresponding to the inverter. and The output result of the FOC calculation, The effective duration of the V-phase effective vector. The effective duration of the W effective vector.

8. The controller according to claim 6, characterized in that, The FOC calculation for the inverter triggered by the preset command includes: The preset command is generated based on the target bus voltage, so that during the FOC calculation process, the command is generated according to the target bus voltage. and .

9. An electronic device, characterized in that, Including memory and processor; The memory is used to store computer programs; The processor is used to execute the computer program to implement the method as described in any one of claims 1 to 4.

10. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 4.

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