Modulation wave generation method, device, system, apparatus, medium and product

Abstract

Embodiments of the present application provide a modulation wave generation method, device, system, equipment, medium and product. The method comprises: receiving an intermediate voltage under three phases output by a three-phase rectifier; if the input source is a three-phase four-wire system, taking the intermediate voltage under each phase as the modulation wave of the phase; if the input source is a three-phase three-wire system, determining a harmonic component according to the intermediate voltage under three phases, and determining the modulation wave of the phase based on the harmonic component and the intermediate voltage under each phase. When the three-phase four-wire system input source is converted, the sinusoidal pulse width modulation can be directly based on the intermediate voltage under each phase. When the three-phase three-wire system input source is converted, the modulation wave equivalent to the space vector pulse width modulation can be obtained after the harmonic component injection on the intermediate voltage under each phase, and the pulse width modulation can also be realized, thereby improving the compatibility of the rectifier.

Description

Technical Field

[0001] This application relates to the field of rectifiers, and more particularly to a method, apparatus, system, device, medium, and product for generating modulated waves. Background Technology

[0002] A rectifier is a power electronic device that converts alternating current (AC) to direct current (DC). It is widely used in power supplies, chargers, motor drives, and other applications. The basic function of a rectifier is to convert the positive and negative half-cycles of alternating current into a single-direction current output through a rectification process.

[0003] In related technologies, three-phase three-wire rectifiers typically employ space vector pulse width modulation (SVM), while three-phase four-wire rectifiers mostly use sinusoidal pulse width modulation (SVM). However, the control and modulation methods of these rectifiers are not compatible with both three-phase three-wire and three-phase four-wire inputs and cannot perform the corresponding DC-DC conversion. Therefore, the current problem to be solved is how to improve the compatibility of rectifiers. Summary of the Invention

[0004] This application provides a modulation wave generation method, apparatus, system, device, medium, and product to improve the compatibility of rectifiers.

[0005] In a first aspect, embodiments of this application provide a modulation wave generation method, comprising: receiving the intermediate voltage of the three phases output by a three-phase rectifier; and determining the input source of the three-phase rectifier; if the input source is a three-phase four-wire system, then using the intermediate voltage of each phase as the modulation wave of that phase; if the input source is a three-phase three-wire system, then determining the harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase.

[0006] In one possible implementation, determining harmonic components based on the intermediate voltages of the three phases, and determining the modulation wave of each phase based on the harmonic components and the intermediate voltage of each phase, includes: determining the maximum and minimum intermediate voltages among the intermediate voltages of the three phases; determining the harmonic components based on the maximum and minimum intermediate voltages; detecting the signal polarity of the intermediate voltage of each phase; if the intermediate voltage of the phase is in the positive half-cycle, then the sum of the intermediate voltage of the phase and the harmonic components is taken as the modulation wave of the phase; if the intermediate voltage of the phase is in the negative half-cycle, then the difference between the intermediate voltage of the phase and the harmonic components is taken as the modulation wave of the phase.

[0007] In one possible implementation, determining the maximum and minimum intermediate voltages among the three-phase intermediate voltages includes: determining a voltage vector based on the three-phase intermediate voltages; detecting the sector in which the voltage vector is located, wherein the sector represents the magnitude relationship between the three-phase intermediate voltages; and determining the maximum and minimum intermediate voltages among the three-phase intermediate voltages according to the magnitude relationship between the three-phase intermediate voltages represented by the sector.

[0008] In one possible implementation, determining harmonic components based on the intermediate voltages under the three phases, and determining the modulation wave of the phase based on the harmonic components and the intermediate voltage under each phase, includes: determining the maximum and minimum intermediate voltages among the intermediate voltages under the three phases; determining the harmonic components based on the maximum and minimum intermediate voltages; and using the sum of the harmonic components and the intermediate voltage under each phase as the modulation wave of the phase.

[0009] In one possible implementation, the method further includes sending a three-phase modulation wave to a three-phase rectifier so that the three-phase rectifier determines a pulse width modulation signal based on the three-phase modulation wave.

[0010] Secondly, embodiments of this application provide a modulation wave generation device, comprising: a receiving module for receiving the intermediate voltage of the three phases output by a three-phase rectifier; and determining the input source of the three-phase rectifier; and a determining module for, if the input source is a three-phase four-wire system, using the intermediate voltage of each phase as the modulation wave of that phase; and if the input source is a three-phase three-wire system, determining harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase.

[0011] Thirdly, embodiments of this application provide a modulation wave generation system, including the modulation wave generation device and a three-phase rectifier as described above; wherein, the three-phase rectifier includes a voltage outer loop controller, a current inner loop controller, a feedback controller, and a signal processing module; the signal processing module determines the intermediate voltage under the three phases based on the output signals of the voltage outer loop controller, the current inner loop controller, and the feedback controller, and sends the intermediate voltage under the three phases to the modulation wave generation device; the modulation wave generation device determines the modulation wave under the three phases based on the intermediate voltage under the three phases, and returns the modulation wave under the three phases to the three-phase rectifier, so that the three-phase rectifier determines the pulse width modulation signal based on the modulation wave under the three phases.

[0012] Fourthly, embodiments of this application provide an electronic device, including: a memory and a processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0013] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible implementations of the first aspect.

[0014] In a sixth aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0015] The modulation wave generation method, apparatus, system, device, medium, and product provided in this application include: receiving the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, using the intermediate voltage of each phase as the modulation wave of that phase; if the input source is a three-phase three-wire system, determining harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase. The solution of this application allows for direct sinusoidal pulse width modulation based on the intermediate voltage of each phase when converting a three-phase four-wire input source; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase yields a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] Figure 1 A schematic flowchart of the modulation wave generation method provided in the embodiments of this application;

[0018] Figure 2 A schematic flowchart of the modulation wave generation method provided in the embodiments of this application;

[0019] Figure 3 This is a schematic diagram of the modulation wave provided in an embodiment of this application;

[0020] Figure 4 A schematic flowchart of the modulation wave generation method provided in the embodiments of this application;

[0021] Figure 5 A schematic flowchart of the modulation wave generation method provided in the embodiments of this application;

[0022] Figure 6 This is a schematic diagram of the modulation wave generation device provided in the embodiments of this application;

[0023] Figure 7 A schematic diagram of the structure of the electronic device provided in this application.

[0024] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0026] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to be omnipresent but not exclusive. For example, a product or device that comprises a series of components is not necessarily limited to those components that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such products or devices. The term "module" as used in this application refers to any known or subsequently developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code capable of performing the functions associated with that element.

[0027] A rectifier is a power electronic device that converts alternating current (AC) to direct current (DC), and is widely used in power supplies, chargers, motor drives, and other fields. Its basic function is to convert the positive and negative half-cycles of AC power into a single-direction current output through a rectification process. This process involves not only changing the direction of the current but also minimizing energy loss and improving the stability and efficiency of the current output. With technological advancements and increasing electricity demand, the performance requirements for rectifiers are constantly rising, particularly in terms of efficiency, power density, thermal management, and electromagnetic compatibility.

[0028] In related technologies, three-phase three-wire rectifiers typically employ space vector pulse width modulation (SVM). This technology, through precise control of the voltage vector, effectively improves the rectifier's efficiency and output voltage quality. The advantages of SVM lie in its ability to reduce harmonic distortion, improve power factor, and perform exceptionally well in high power density applications. On the other hand, three-phase four-wire rectifiers often use sinusoidal pulse width modulation (SPWM). SPWM, through precise modulation of the sine wave, provides better current waveform quality and is suitable for applications with high requirements for current harmonics, such as power supplies for audio equipment and precision instruments. However, three-phase three-wire rectifiers cannot directly switch their input to three-phase four-wire, primarily because their design and control strategies do not consider the presence of a neutral line, resulting in a lack of necessary circuit topology and control capabilities when handling unbalanced loads and zero-sequence current. Similarly, three-phase four-wire rectifiers cannot directly switch their input to three-phase three-wire, mainly because their design typically includes mechanisms for handling neutral line current, which can lead to unnecessary complexity and efficiency reduction in a three-phase three-wire system.

[0029] The technical content provided in this application aims to solve the aforementioned technical problems in related technologies. The modulation wave generation method, apparatus, system, device, medium, and product provided in the embodiments of this application include: receiving the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, using the intermediate voltage of each phase as the modulation wave of that phase; if the input source is a three-phase three-wire system, determining harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase. The solution of this application, when converting a three-phase four-wire input source, can directly perform sinusoidal pulse width modulation based on the intermediate voltage of each phase; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase can obtain a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier.

[0030] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic flowchart illustrating the modulation wave generation method provided in an embodiment of this application. In this example, the executing entity can be a modulation wave generation device. Figure 1 As shown, the method includes:

[0032] Step 101: Receive the intermediate voltage of the three phases output from the three-phase rectifier; and determine the input source of the three-phase rectifier.

[0033] Step 102: If the input source is a three-phase four-wire system, the intermediate voltage of each phase is used as the modulation wave of that phase; if the input source is a three-phase three-wire system, the harmonic components are determined based on the intermediate voltage of the three phases, and the modulation wave of that phase is determined based on the harmonic components and the intermediate voltage of each phase.

[0034] In practical applications, the execution entity of this method can be a modulation wave generating device, which can be implemented in various ways. For example, it can be implemented through a computer program, such as application software; or it can be implemented through a physical device that integrates or installs relevant computer programs, such as a chip. For example, the modulation wave generating device can also be integrated into a three-phase rectifier.

[0035] It should be noted that the control loop of the relevant three-phase rectifier, such as the Vienna rectifier, includes an outer voltage control loop and an inner current control loop. Therefore, the three-phase rectifier in this example can be an improved three-phase rectifier based on a relevant three-phase four-wire Vienna rectifier or a three-phase three-wire Vienna rectifier. For example, the intermediate voltage of the three phases output by the three-phase rectifier in this example is formed by superimposing the output signals of the outer voltage loop and the inner current loop of the three-phase rectifier with the feedforward control quantity after passing through a feedback controller. Optionally, the intermediate voltage of each phase can be converted into a digital signal using an analog-to-digital converter for further processing. For example, the wiring method of the input power supply can be detected to determine whether it is a three-phase four-wire or three-phase three-wire system. For example, a current sensor or voltage sensor can be used to detect the presence or absence of the neutral line. For example, a digital signal processor (DSP) can be used to calculate harmonic components in real time.

[0036] The modulation wave generation method provided in this application includes: receiving the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, using the intermediate voltage of each phase as the modulation wave of that phase; if the input source is a three-phase three-wire system, determining the harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase. The solution of this application allows for direct sinusoidal pulse width modulation based on the intermediate voltage of each phase when converting a three-phase four-wire input source; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase yields a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier.

[0037] Figure 2 This is a schematic flowchart illustrating the modulation wave generation method provided in an embodiment of this application. Figure 2 As shown, in this embodiment... Figure 1Based on the embodiment, step 102 determines the harmonic components according to the intermediate voltage under the three phases, and determines the modulation wave of the phase based on the harmonic components and the intermediate voltage under each phase, including:

[0038] Step 201: Determine the maximum and minimum intermediate voltages among the three-phase intermediate voltages;

[0039] Step 202: Determine the harmonic components based on the maximum and minimum intermediate voltages;

[0040] Step 203: Detect the signal polarity of the intermediate voltage under each phase. If the intermediate voltage under the phase is in the positive half-cycle, the sum of the intermediate voltage under the phase and the harmonic component is taken as the modulation wave of the phase. If the intermediate voltage under the phase is in the negative half-cycle, the difference between the intermediate voltage under the phase and the harmonic component is taken as the modulation wave of the phase.

[0041] For example, the maximum and minimum intermediate voltages can be determined by designing a comparator circuit. For instance, two comparators can be used to compare the intermediate voltage values ​​under three-phase conditions; the first comparator compares V... aAct and V bAct The first comparator outputs the larger value; the second comparator compares the output of the first comparator with V. cAct The comparison outputs the final maximum intermediate voltage; similarly, the minimum intermediate voltage can also be determined. Optionally, an analog-to-digital converter can be used to convert the three-phase intermediate voltage signals into digital signals, and the digital signals can be input into a microcontroller where software algorithms are used to compare the voltage values. For example, harmonic components can be determined according to the following formula:

[0042] V0 = 0.5 - 0.5 * X * [(1 - Y * V max )+Z*V min ]

[0043] X = 0.5 * (Y + Z)

[0044] Where V0 is the harmonic component, V max and V min These represent the maximum and minimum intermediate voltages, respectively. Y and Z are constants and can be adjusted according to requirements in practical applications.

[0045] In this example, the signal polarity of the intermediate voltage under each phase is detected separately. The signal polarity can be indirectly determined by phase detection. For example, phase-locked loop (PLL) technology can be used to track the phase change of the signal. Optionally, the signal can be determined to be in the positive or negative half-cycle by comparing the intermediate voltage signal with the zero level. Optionally, an analog comparator can be used to compare the intermediate voltage signal with the zero level; if the signal voltage is higher than the zero level, a high level is output (indicating that the intermediate voltage is in the positive half-cycle); if it is lower than the zero level, a low level is output (indicating that the intermediate voltage is in the positive half-cycle). For example, the intermediate voltage V under phase a can be calculated according to the following formula. aAct If it is in the positive half-cycle, then the modulation wave in phase a is:

[0046] V azAct =V aAct +V0

[0047] If the intermediate voltage under phase a is in the negative half-cycle, then the modulation wave under phase a is:

[0048] V azAct =V aAct -V0

[0049] Similarly, the modulation waves in phases b and c can be calculated using the same logic. Following the above method, the following can be obtained: Figure 3 The diagram shown is a schematic representation of the modulation wave provided in an embodiment of this application. Figure 3 As shown, the red waveform is the modulation wave under one phase of the three-phase circuit, and the blue waveform is the carrier waveform of the rectifier. The obtained modulation wave is equivalent to the modulation wave obtained through space vector pulse width modulation (SVM).

[0050] The scheme in this example determines the harmonic components based on the maximum and minimum intermediate voltages, and uses the voltage after the intermediate voltage of each phase is injected with the harmonic components as the modulation wave, thereby obtaining an equivalent modulation wave without using space vector pulse width modulation.

[0051] Figure 4 This is a schematic flowchart illustrating the modulation wave generation method provided in an embodiment of this application. Figure 4 As shown, step 201, determining the maximum and minimum intermediate voltages among the three-phase intermediate voltages, includes:

[0052] Step 301: Determine the voltage vector based on the intermediate voltage under three phases;

[0053] Step 302: Detect the sector where the voltage vector is located, where the sector represents the magnitude relationship between the intermediate voltages under the three phases;

[0054] Step 303: Based on the magnitude relationship between the intermediate voltages of the three phases represented by the sector, determine the maximum and minimum intermediate voltages among the intermediate voltages of the three phases.

[0055] In this example, the three-phase voltage signal is converted into a space vector. Exemplarily, this can be achieved using the Clarke transform (α-β transform), which converts the three-phase voltage (V...) into a space vector. aAct V bAct V cAct Convert ) to a vector (V) on a two-dimensional plane α V β In space vector modulation, the entire voltage vector space is divided into multiple sectors (typically six sectors). The sector in which the current voltage vector is located is determined by calculating the angle of the voltage vector or by using a lookup table. Specifically, each sector corresponds to a different combination of voltage vectors, which helps determine the maximum and minimum intermediate voltages. For example, one example of a sector is as follows: Sector 1 represents V... cAct ≥V aAct ≥V bAct Sector 2 is V aAct ≥V cAct ≥V bAct Sector 3 is V aAct ≥V bAct ≥V cAct Sector 4 is V bAct ≥V aAct ≥V aAct Sector 5 is V bAct ≥V cAct ≥V aAct Sector 6 is V cAct ≥V bAct ≥V aAct It should be noted that in practical applications, the maximum and minimum intermediate voltages among the three-phase intermediate voltages can also be obtained without using space vector modulation, such as by using a comparator circuit or converting the intermediate voltages into digital signals. The solution in this example utilizes the characteristics of space vector modulation to achieve efficient voltage control and modulation.

[0056] Figure 5 This is a schematic flowchart illustrating the modulation wave generation method provided in an embodiment of this application. Figure 5 As shown, in this embodiment... Figure 1 Based on the embodiment, step 102 determines the harmonic components according to the intermediate voltage under the three phases, and determines the modulation wave of the phase based on the harmonic components and the intermediate voltage under each phase, including:

[0057] Step 401: Determine the maximum and minimum intermediate voltages among the three-phase intermediate voltages; determine the harmonic components based on the maximum and minimum intermediate voltages;

[0058] Step 402: The sum of the harmonic components and the intermediate voltage under each phase is used as the modulation wave of that phase.

[0059] For example, the maximum and minimum intermediate voltages can be determined by designing a comparator circuit. For instance, two comparators can be used to compare the intermediate voltage values ​​under three-phase conditions; the first comparator compares V... aAct and V bAct The first comparator outputs the larger value; the second comparator compares the output of the first comparator with V. cAct The comparison outputs the final maximum intermediate voltage; similarly, the minimum intermediate voltage can also be determined. Optionally, an analog-to-digital converter can be used to convert the three-phase intermediate voltage signals into digital signals, and the digital signals can be input into a microcontroller where software algorithms are used to compare the voltage values. For example, the intermediate voltage V of phase a can be calculated according to the following formula. aAct The modulated wave is:

[0060] V azAct =-K*(V max +V min )+V aAct

[0061] Among them, -K*(V max +V min ) represents the harmonic components, V aAct Let K be the intermediate voltage under phase a, and K be a constant that can be adjusted according to requirements in practical applications. Similarly, the modulation waves under phases b and c can be calculated using the same logic. The scheme in this example determines the harmonic components based on the maximum and minimum intermediate voltages, and uses the voltage after injecting the harmonic components into the intermediate voltage under each phase as the modulation wave, thus obtaining an equivalent modulation wave without using space vector pulse width modulation.

[0062] As yet another example, based on any of these examples, the modulated wave generation methods also include:

[0063] The three-phase modulation wave is sent to the three-phase rectifier so that the three-phase rectifier can determine the pulse width modulation signal based on the three-phase modulation wave.

[0064] It should be noted that the modulated wave signal represents the voltage or current characteristics of the rectifier output. In practical applications, a high-frequency triangular or sawtooth wave carrier signal also needs to be generated. The frequency of the carrier signal is usually much higher than that of the modulated wave to achieve high-resolution pulse width modulation. For example, the modulated wave of each phase is compared point-by-point with the carrier signal. When the amplitude of the modulated wave is higher than that of the carrier signal, a high-level signal (usually represented as logic "1") is output; when the amplitude of the modulated wave is lower than that of the carrier signal, a low-level signal (usually represented as logic "0") is output. Through this comparison process, a corresponding PWM signal is generated for each phase. These PWM signals are used to control the switching devices of the rectifier (such as IGBTs or MOSFETs), thereby regulating the output voltage or current. In this example, the three-phase rectifier can generate an appropriate pulse width signal based on the modulated wave, thereby achieving effective control of the rectifier output.

[0065] The modulation wave generation method provided in this application includes: receiving the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, using the intermediate voltage of each phase as the modulation wave of that phase; if the input source is a three-phase three-wire system, determining the harmonic components based on the intermediate voltage of the three phases, and determining the modulation wave of that phase based on the harmonic components and the intermediate voltage of each phase. The solution of this application allows for direct sinusoidal pulse width modulation based on the intermediate voltage of each phase when converting a three-phase four-wire input source; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase yields a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier.

[0066] Figure 6 This is a schematic diagram of the modulation wave generation device provided in the embodiments of this application, as shown below. Figure 6 As shown, the modulation wave generation device provided in this embodiment includes:

[0067] The receiving module 91 is used to receive the intermediate voltage of the three phases output by the three-phase rectifier; and to determine the input source of the three-phase rectifier.

[0068] The determination module 92 is used to determine the intermediate voltage of each phase as the modulation wave of the phase if the input source is a three-phase four-wire system; and to determine the harmonic components based on the intermediate voltage of the three phases and the modulation wave of the phase based on the harmonic components and the intermediate voltage of each phase if the input source is a three-phase three-wire system.

[0069] In practical applications, there are various ways to implement a modulation wave generation device. For example, it can be implemented through a computer program, such as application software; or it can be implemented through a physical device that integrates or installs relevant computer programs, such as a chip. For example, the modulation wave generation device can also be integrated into a three-phase rectifier.

[0070] It should be noted that the control loop of the relevant three-phase rectifier, such as the Vienna rectifier, includes an outer voltage control loop and an inner current control loop. Therefore, the three-phase rectifier in this example can be an improved three-phase rectifier based on a relevant three-phase four-wire Vienna rectifier or a three-phase three-wire Vienna rectifier. For example, the intermediate voltage of the three phases output by the three-phase rectifier in this example is formed by superimposing the output signals of the outer voltage loop and the inner current loop of the three-phase rectifier with the feedforward control quantity after passing through a feedback controller. Optionally, the intermediate voltage of each phase can be converted into a digital signal using an analog-to-digital converter for further processing. For example, the wiring method of the input power supply can be detected to determine whether it is a three-phase four-wire or three-phase three-wire system. For example, a current sensor or voltage sensor can be used to detect the presence or absence of the neutral line. For example, a digital signal processor (DSP) can be used to calculate harmonic components in real time.

[0071] The modulation wave generation device provided in this application receives the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, the intermediate voltage of each phase is used as the modulation wave of that phase; if the input source is a three-phase three-wire system, harmonic components are determined based on the intermediate voltage of the three phases, and the modulation wave of that phase is determined based on the harmonic components and the intermediate voltage of each phase. In this application, when converting a three-phase four-wire input source, sinusoidal pulse width modulation can be directly performed based on the intermediate voltage of each phase; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase can obtain a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier.

[0072] In one example, module 92 is identified as being used specifically for:

[0073] Determine the maximum and minimum intermediate voltages among the three-phase intermediate voltages;

[0074] The harmonic components are determined based on the maximum and minimum intermediate voltages;

[0075] The signal polarity of the intermediate voltage under each phase is detected. If the intermediate voltage under that phase is in the positive half-cycle, the sum of the intermediate voltage under that phase and the harmonic component is taken as the modulation wave of that phase. If the intermediate voltage under that phase is in the negative half-cycle, the difference between the intermediate voltage under that phase and the harmonic component is taken as the modulation wave of that phase.

[0076] For example, the maximum and minimum intermediate voltages can be determined by designing a comparator circuit. For instance, two comparators can be used to compare the intermediate voltage values ​​under three-phase conditions; the first comparator compares V... aAct and V bActThe first comparator outputs the larger value; the second comparator compares the output of the first comparator with V. cAct The comparison outputs the final maximum intermediate voltage; similarly, the minimum intermediate voltage can also be determined. Optionally, an analog-to-digital converter can be used to convert the three-phase intermediate voltage signals into digital signals, and the digital signals can be input into a microcontroller where software algorithms are used to compare the voltage values. For example, harmonic components can be determined according to the following formula:

[0077] V0 = 0.5 - 0.5 * X * [(1 - Y * V max )+Z*V min ]

[0078] X = 0.5 * (Y + Z)

[0079] Where V0 is the harmonic component, V max and V min These represent the maximum and minimum intermediate voltages, respectively. Y and Z are constants and can be adjusted according to requirements in practical applications.

[0080] In this example, the signal polarity of the intermediate voltage under each phase is detected separately. The signal polarity can be indirectly determined by phase detection. For example, phase-locked loop (PLL) technology can be used to track the phase change of the signal. Optionally, the signal can be determined to be in the positive or negative half-cycle by comparing the intermediate voltage signal with the zero level. Optionally, an analog comparator can be used to compare the intermediate voltage signal with the zero level; if the signal voltage is higher than the zero level, a high level is output (indicating that the intermediate voltage is in the positive half-cycle); if it is lower than the zero level, a low level is output (indicating that the intermediate voltage is in the positive half-cycle). For example, the intermediate voltage V under phase a can be calculated according to the following formula. aAct If it is in the positive half-cycle, then the modulation wave in phase a is:

[0081] V azAct =V aAct +V0

[0082] If the intermediate voltage under phase a is in the negative half-cycle, then the modulation wave under phase a is:

[0083] V azAct =V aAct -V0

[0084] Similarly, the modulation waves in phases b and c can be calculated using the same logic. Following the above method, the following can be obtained: Figure 3 The modulation wave provided in the embodiment of this application is shown. For example... Figure 3 As shown, the red waveform is the modulation wave under one phase of the three-phase circuit, and the blue waveform is the carrier waveform of the rectifier. The obtained modulation wave is equivalent to the modulation wave obtained through space vector pulse width modulation (SVM).

[0085] The scheme in this example determines the harmonic components based on the maximum and minimum intermediate voltages, and uses the voltage after the intermediate voltage of each phase is injected with the harmonic components as the modulation wave, thereby obtaining an equivalent modulation wave without using space vector pulse width modulation.

[0086] In one example, module 92 is identified as being used specifically for:

[0087] Determine the voltage vector based on the intermediate voltage under three phases;

[0088] The sector containing the detected voltage vector is characterized by the magnitude relationship between the intermediate voltages under three phases.

[0089] Based on the magnitude relationship between the intermediate voltages of the three phases as represented by the sector, determine the maximum and minimum intermediate voltages among the three phase intermediate voltages.

[0090] In this example, the three-phase voltage signal is converted into a space vector. Exemplarily, this can be achieved using the Clarke transform (α-β transform), which converts the three-phase voltage (V...) into a space vector. aAct V bAct V cAct Convert ) to a vector (V) on a two-dimensional plane α V β In space vector modulation, the entire voltage vector space is divided into multiple sectors (typically six sectors). The sector in which the current voltage vector is located is determined by calculating the angle of the voltage vector or by using a lookup table. Specifically, each sector corresponds to a different combination of voltage vectors, which helps determine the maximum and minimum intermediate voltages. For example, one example of a sector is as follows: Sector 1 represents V... cAct ≥V aAct ≥V bAct Sector 2 is V aAct ≥V cAct ≥V bAct Sector 3 is V aAct ≥V bAct ≥V cAct Sector 4 is V bAct ≥V aAct ≥V aAct Sector 5 is V bAct ≥V cAct ≥V aAct Sector 6 is V cAct ≥V bAct ≥V aActIt should be noted that in practical applications, the maximum and minimum intermediate voltages among the three-phase intermediate voltages can also be obtained without using space vector modulation, such as by using a comparator circuit or converting the intermediate voltages into digital signals. The solution in this example utilizes the characteristics of space vector modulation to achieve efficient voltage control and modulation.

[0091] In one example, module 92 is identified as being used specifically for:

[0092] Determine the maximum and minimum intermediate voltages in the three-phase system; determine the harmonic components based on the maximum and minimum intermediate voltages.

[0093] The sum of the harmonic components and the intermediate voltage under each phase is used as the modulation wave of that phase.

[0094] For example, the maximum and minimum intermediate voltages can be determined by designing a comparator circuit. For instance, two comparators can be used to compare the intermediate voltage values ​​under three-phase conditions; the first comparator compares V... aAct and V bAct The first comparator outputs the larger value; the second comparator compares the output of the first comparator with V. cAct The comparison outputs the final maximum intermediate voltage; similarly, the minimum intermediate voltage can also be determined. Optionally, an analog-to-digital converter can be used to convert the three-phase intermediate voltage signals into digital signals, and the digital signals can be input into a microcontroller where software algorithms are used to compare the voltage values. For example, the intermediate voltage V of phase a can be calculated according to the following formula. aAct The modulated wave is:

[0095] V azAct =-K*(V max +V min )+V aAct

[0096] Among them, -K*(V max +V min ) represents the harmonic components, V aAct Let K be the intermediate voltage under phase a, and K be a constant that can be adjusted according to requirements in practical applications. Similarly, the modulation waves under phases b and c can be calculated using the same logic. The scheme in this example determines the harmonic components based on the maximum and minimum intermediate voltages, and uses the voltage after injecting the harmonic components into the intermediate voltage under each phase as the modulation wave, thus obtaining an equivalent modulation wave without using space vector pulse width modulation.

[0097] In one example, the modulation wave generating device further includes a transmitting module 93; the transmitting module 93 is specifically used for:

[0098] The three-phase modulation wave is sent to the three-phase rectifier so that the three-phase rectifier can determine the pulse width modulation signal based on the three-phase modulation wave.

[0099] It should be noted that the modulated wave signal represents the voltage or current characteristics of the rectifier output. In practical applications, a high-frequency triangular or sawtooth wave carrier signal also needs to be generated. The frequency of the carrier signal is usually much higher than that of the modulated wave to achieve high-resolution pulse width modulation. For example, the modulated wave of each phase is compared point-by-point with the carrier signal. When the amplitude of the modulated wave is higher than that of the carrier signal, a high-level signal (usually represented as logic "1") is output; when the amplitude of the modulated wave is lower than that of the carrier signal, a low-level signal (usually represented as logic "0") is output. Through this comparison process, a corresponding PWM signal is generated for each phase. These PWM signals are used to control the switching devices of the rectifier (such as IGBTs or MOSFETs), thereby regulating the output voltage or current. In this example, the three-phase rectifier can generate an appropriate pulse width signal based on the modulated wave, thereby achieving effective control of the rectifier output.

[0100] The modulation wave generation device provided in this application receives the intermediate voltage of the three phases output by a three-phase rectifier; and if the input source is a three-phase four-wire system, the intermediate voltage of each phase is used as the modulation wave of that phase; if the input source is a three-phase three-wire system, harmonic components are determined based on the intermediate voltage of the three phases, and the modulation wave of that phase is determined based on the harmonic components and the intermediate voltage of each phase. In this application, when converting a three-phase four-wire input source, sinusoidal pulse width modulation can be directly performed based on the intermediate voltage of each phase; when converting a three-phase three-wire input source, injecting harmonic components into the intermediate voltage of each phase can obtain a modulation wave equivalent to space vector pulse width modulation, thus achieving pulse width modulation and improving the compatibility of the rectifier.

[0101] This application embodiment also provides a modulation wave generation system, which includes a modulation wave generation device and a three-phase rectifier; wherein the three-phase rectifier includes a voltage outer loop controller, a current inner loop controller, a feedback controller and a signal processing module;

[0102] The signal processing module determines the intermediate voltage under three phases based on the output signals of the voltage outer loop controller, the current inner loop controller and the feedback controller, and sends the intermediate voltage under three phases to the modulation wave generation device.

[0103] The modulation wave generation device determines the modulation wave under the three phases based on the intermediate voltage under the three phases, and returns the modulation wave under the three phases to the three-phase rectifier so that the three-phase rectifier can determine the pulse width modulation signal based on the modulation wave under the three phases.

[0104] The modulation wave generation system provided in this embodiment is similar in implementation principle and technical effect to the above method and device embodiments, and will not be described in detail here.

[0105] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 7 As shown, the electronic device provided in this embodiment includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can call logical instructions in the memory 292 to execute the method described above.

[0106] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0107] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, that is, it implements the methods in the above method examples.

[0108] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0109] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the methods described in the above embodiments.

[0110] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the method described in the above embodiments.

[0111] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for generating a modulated wave, characterized in that, include: Receive the intermediate voltage of the three phases output from the three-phase rectifier; and determine the input source of the three-phase rectifier; If the input source is a three-phase four-wire system, then the intermediate voltage of each phase is used as the modulation wave of that phase; If the input source is a three-phase three-wire system, then the harmonic components are determined based on the intermediate voltage of the three phases, and the modulation wave of the phase is determined based on the harmonic components and the intermediate voltage of each phase.

2. The method according to claim 1, characterized in that, The harmonic components are determined based on the intermediate voltages of the three phases, and the modulation wave of each phase is determined based on the harmonic components and the intermediate voltage of each phase, including: Determine the maximum and minimum intermediate voltages among the intermediate voltages under the three phases; The harmonic components are determined based on the maximum and minimum intermediate voltages. The signal polarity of the intermediate voltage under each phase is detected. If the intermediate voltage under that phase is in the positive half-cycle, the sum of the intermediate voltage under that phase and the harmonic component is taken as the modulation wave of that phase. If the intermediate voltage under that phase is in the negative half-cycle, the difference between the intermediate voltage under that phase and the harmonic component is taken as the modulation wave of that phase.

3. The method according to claim 2, characterized in that, Determining the maximum and minimum intermediate voltages among the three-phase intermediate voltages includes: Based on the intermediate voltage under the three phases, determine the voltage vector; The sector in which the voltage vector is located is detected, wherein the sector represents the magnitude relationship between the intermediate voltages under the three phases; Based on the magnitude relationship between the intermediate voltages of the three phases as represented by the sector, the maximum and minimum intermediate voltages among the intermediate voltages of the three phases are determined.

4. The method according to claim 1, characterized in that, The harmonic components are determined based on the intermediate voltages of the three phases, and the modulation wave of each phase is determined based on the harmonic components and the intermediate voltage of each phase, including: Determine the maximum and minimum intermediate voltages among the intermediate voltages under the three phases; determine the harmonic components based on the maximum and minimum intermediate voltages; The sum of the harmonic components and the intermediate voltage under each phase is used as the modulation wave of that phase.

5. The method according to any one of claims 1-4, characterized in that, The method further includes: The three-phase modulation wave is sent to the three-phase rectifier so that the three-phase rectifier can determine the pulse width modulation signal based on the three-phase modulation wave.

6. A modulated wave generating device, characterized in that, include: A receiving module is used to receive the intermediate voltage of the three phases output by the three-phase rectifier; and to determine the input source of the three-phase rectifier. The determination module is used to determine the intermediate voltage of each phase as the modulation wave of that phase if the input source is a three-phase four-wire system. If the input source is a three-phase three-wire system, then the harmonic components are determined based on the intermediate voltage of the three phases, and the modulation wave of the phase is determined based on the harmonic components and the intermediate voltage of each phase.

7. A modulation wave generation system, characterized in that, It includes the modulation wave generation device and the three-phase rectifier as described in claim 6; wherein the three-phase rectifier includes a voltage outer loop controller, a current inner loop controller, a feedback controller, and a signal processing module; The signal processing module determines the intermediate voltage under three phases based on the output signals of the voltage outer loop controller, the current inner loop controller, and the feedback controller, and sends the intermediate voltage under three phases to the modulation wave generation device. The modulation wave generation device determines the modulation wave under the three phases based on the intermediate voltage under the three phases, and returns the modulation wave under the three phases to the three-phase rectifier so that the three-phase rectifier determines the pulse width modulation signal based on the modulation wave under the three phases.

8. An electronic device, characterized in that, include: Memory, processor; The memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1-5.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-5.

10. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-5.

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