Dual-stage matrix converter energy information synchronous transmission method based on common-mode current modulation

Abstract

The application provides a double-stage matrix converter energy information synchronous transmission method based on common-mode current modulation. The method takes the common-mode current generated in the operation process of the double-stage matrix converter as an information carrier, selects a corresponding modulation mode according to the binary information to be transmitted through the sending end of the controller, wherein the traditional space vector modulation mode and the low common-mode current space vector modulation mode adopt different zero vector action modes on the basis that the effective vectors and the effective vector action time are consistent, so that the double-stage matrix converter generates distinguishable common-mode current amplitude states. The receiving end of the controller collects three-phase currents and synthesizes the common-mode current, and after amplitude processing, filtering processing and threshold judgment, the original binary information is recovered. The application can complete the information synchronous transmission while ensuring the normal energy conversion of the double-stage matrix converter without additionally laying special communication lines, and reduces the equipment hardware cost and wiring complexity.

Description

Technical Field

[0001] This invention relates to the field of power electronic converter control and communication technology, and more specifically, to a modulation method in a two-stage matrix converter that utilizes the difference in common-mode current amplitude to achieve synchronous energy conversion and information transmission. Background Technology

[0002] With the development of distributed energy, smart microgrids, motor drives, and power electronic equipment, power electronic converters not only need to perform power conversion but also need to undertake functions such as status monitoring, control command transmission, and operational information exchange. Traditional methods typically design energy transmission channels and information transmission channels separately, using RS485, CAN bus, fiber optics, or wireless communication modules for data exchange. However, in applications involving high-frequency switching, high voltage, and high current, additional communication links increase system wiring complexity, hardware costs, and the difficulty of anti-interference design, while also reducing equipment integration and operational reliability.

[0003] A two-stage matrix converter is a type of power electronic device that can directly perform AC-AC conversion. It consists of a rectifier stage and an inverter stage, eliminating the need for the large-capacity DC energy storage capacitor found in traditional AC-DC-AC converters. It offers advantages such as high power density, bidirectional energy flow, and good input / output waveform quality. Two-stage matrix converters typically employ space vector modulation strategies for energy conversion; different combinations of switching vectors and zero-vector operation modes can affect the converter's common-mode characteristics.

[0004] During the operation of a two-stage matrix converter, the high-frequency switching of power switching devices generates common-mode voltage, which in turn forms common-mode current through parasitic capacitance, load, and grounding path. Existing technologies typically treat common-mode current as a source of electromagnetic interference and suppress it through common-mode filters, shielded grounding, or optimized modulation strategies. However, most of these methods only focus on attenuating the common-mode current and do not utilize the information-carrying capacity of the differences in common-mode current amplitude under different modulation modes.

[0005] Therefore, this invention proposes a method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation. While ensuring normal energy conversion of the two-stage matrix converter, it utilizes the difference in common-mode current amplitude generated by different modulation modes to achieve information transmission, thereby reducing independent communication links and improving equipment integration and reliability. Summary of the Invention

[0006] The purpose of this invention is to address the problems of independent energy transmission and information transmission, high complexity of additional communication links, and insufficient anti-interference capability in existing two-stage matrix converters. This invention proposes a method for synchronous energy and information transmission in two-stage matrix converters based on common-mode current modulation. This method utilizes the difference in common-mode current amplitude between traditional space vector modulation and low common-mode current space vector modulation modes to map the binary information to be transmitted into different modulation modes, and completes information transmission through the common-mode current amplitude state.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation includes the following steps:

[0009] S1: The controller collects the input voltage information and output voltage reference information of the two-stage matrix converter to determine the rectifier stage sector and the inverter stage sector, and calculates the duty cycle of adjacent effective vectors of the rectifier stage, the duty cycle of adjacent effective vectors of the inverter stage, and the zero vector duty cycle.

[0010] S2: Obtain the binary information to be transmitted. The controller selects the traditional space vector modulation mode or the low common-mode current space vector modulation mode according to the binary information. The traditional space vector modulation mode and the low common-mode current space vector modulation mode generate common-mode currents with different amplitude levels during the operation of the two-stage matrix converter.

[0011] S3: Based on the rectifier sector, inverter sector, adjacent effective vector duty cycle, zero vector duty cycle, and the selected modulation mode, generate switching drive signals for the rectifier and inverter stages, so that the two-stage matrix converter modulates the binary information into the common-mode current while completing energy conversion;

[0012] S4: Acquire the common-mode current during the operation of the two-stage matrix converter, extract the amplitude representation of the common-mode current, and recover the binary information to be transmitted based on the amplitude representation.

[0013] As a preferred technical solution of the present invention, step S1 specifically includes:

[0014] S11: The rectifier stage sector and inverter stage sector are determined as follows:

[0015] The controller collects the input voltage information of the two-stage matrix converter, determines the sector where the rectifier stage is located based on the phase of the input voltage, and simultaneously collects the output voltage reference information of the two-stage matrix converter, determines the sector where the inverter stage is located based on the phase of the output voltage reference vector.

[0016] S12: The specific calculations for the duty cycles of adjacent effective vectors in the rectifier stage, adjacent effective vectors in the inverter stage, and the zero vector duty cycle are as follows:

[0017] Dividing the rectifier stage space vector plane into six sectors, and the inverter stage space vector plane into six sectors as well, then within any switching cycle, the rectifier stage reference current vector is synthesized from the two adjacent effective vectors corresponding to its rectifier sector, and the inverter stage reference voltage vector is synthesized from the two adjacent effective vectors and the zero vector corresponding to its inverter sector. Therefore:

[0018] The duty cycles of two adjacent effective vectors in the rectifier stage are as follows:

[0019] (1);

[0020] (2);

[0021] The duty cycles of two adjacent effective vectors in the inverter stage are as follows:

[0022] (3);

[0023] (4);

[0024] Where, d i1 and d i2 d represents the duty cycle of two adjacent effective vectors in the rectifier stage. v1 and d v2 The duty cycles of two adjacent effective vectors in the inverter stage are m, respectively. i m is the modulation coefficient of the rectifier stage. v φ is the modulation coefficient of the inverter stage. i θ0 is the relative angle of the input voltage phase angle within the corresponding rectifier sector, and θ0 is the relative angle of the output voltage reference vector within the corresponding inverter sector.

[0025] Based on the duty cycle mentioned above, the zero vector duty cycle can be obtained:

[0026] (5);

[0027] Where, d i1 d v1 d i1 d v2 d i2 d v1 d i2 d v2 d1 and d2 respectively represent the ratio of the effective time of adjacent effective vectors in the rectifier stage and the effective time of adjacent effective vectors in the inverter stage, and d0 represents the ratio of the total effective time of the zero vector within one switching cycle.

[0028] As a preferred technical solution of the present invention: in step S1, the input side of the two-stage matrix converter is connected to a three-phase AC power supply, and the output side is connected to a three-phase resistive-inductive load or a motor.

[0029] As a preferred technical solution of the present invention, step S2 specifically includes:

[0030] The controller selects and switches between traditional space vector modulation mode and low common-mode current space vector modulation mode based on the logic state of the binary information to be transmitted. Specifically:

[0031] When the information to be transmitted is binary "0", the traditional space vector modulation mode is selected;

[0032] When the information to be transmitted is binary "1", select the low common-mode current space vector modulation mode.

[0033] As a preferred technical solution of the present invention: the common-mode current amplitude representation of the conventional space vector modulation mode is greater than the common-mode current amplitude representation of the low common-mode current space vector modulation mode, and the amplitude difference between the two is used as the basis for the transmission and decision of binary information.

[0034] As a preferred technical solution of the present invention: the conventional space vector modulation mode and the low common-mode current space vector modulation mode use the same rectifier stage effective vector, the same inverter stage effective vector, and the same effective vector action time in the same switching cycle.

[0035] As a preferred embodiment of the present invention: the total zero-vector action time of the traditional space vector modulation mode and the low common-mode current space vector modulation mode is the same, but the zero-vector action mode used during the zero-vector action time is different, specifically:

[0036] Traditional space vector modulation modes employ the traditional zero-vector action method during the zero-vector action time;

[0037] The low common-mode current space vector modulation mode employs a different zero-vector action mode than the traditional space vector modulation mode during the zero-vector action time.

[0038] This allows the two-stage matrix converter to generate common-mode currents of different amplitude levels.

[0039] As a preferred technical solution of the present invention, step S3 specifically includes:

[0040] In the traditional space vector modulation mode, the sequence of vector action of the inverter stage can be as follows:

[0041] (6);

[0042] Where V0 is the traditional zero vector, Vm and V n These are two adjacent effective vectors of the inverter stage;

[0043] In low common-mode current space vector modulation mode, the sequence of vector action of the inverter stage can be as follows:

[0044] (7);

[0045] Among them, V z The new zero vector is composed of the rectifier stage off-state and the inverter stage effective vector holding state.

[0046] In the above manner, the binary information to be transmitted is mapped into two modulation modes, and further manifested as two different common-mode current amplitude states.

[0047] As a preferred technical solution of the present invention, step S4 specifically includes:

[0048] S41: Collect the three-phase current i on the output side or load side of the two-stage matrix converter. a i b i c And synthesize the common-mode current based on the three-phase current:

[0049] (8);

[0050] S42: Perform amplitude processing on the common-mode current to obtain a common-mode current amplitude signal;

[0051] S43: Perform low-pass filtering on the common-mode current amplitude signal to obtain the common-mode current envelope value I, which characterizes the change in common-mode current amplitude. cm ;

[0052] S44: Set the preset decision threshold I th and the common-mode current envelope value I cm With the preset decision threshold I th To make a comparison, specifically:

[0053] When the common-mode current envelope value I cm Greater than the preset decision threshold I th When the current traditional space vector modulation mode is determined, a binary "0" is output.

[0054] When the common-mode current envelope value I cm Less than or equal to the preset decision threshold I th When the current low common-mode current space vector modulation mode is determined, a binary "1" is output.

[0055] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0056] This invention utilizes the common-mode current amplitude difference generated during the operation of a two-stage matrix converter for information transmission, eliminating the need for additional independent communication lines. By switching between traditional space vector modulation (SVM) and low common-mode current (LCM) space vector modulation (LCM) modes, information injection is achieved while ensuring normal energy conversion of the two-stage matrix converter. The receiving end only needs to sum the three-phase currents, take their absolute values, perform low-pass filtering, and threshold comparison to recover the binary information, resulting in a simple method structure. The control structure of this invention is clear and easily implemented using digital signal processors, field-programmable gate arrays (FPGAs), or other controllers, making it valuable for engineering applications. Attached Figure Description

[0057] Figure 1 This is a flowchart of the energy information synchronization transmission method based on common-mode current modulation in an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the main power circuit topology of the two-stage matrix converter in an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram of the space vector sector division of the rectifier stage and inverter stage in an embodiment of the present invention;

[0060] Figure 4 This is a comparison diagram of the zero-vector action mode of the traditional space vector modulation mode and the low common-mode current space vector modulation mode in the embodiments of the present invention;

[0061] Figure 5 This is a simulation waveform diagram of the energy conversion of a two-stage matrix converter in an embodiment of the present invention;

[0062] Figure 6 This is a simulation waveform diagram of common-mode current modulation and information recovery in an embodiment of the present invention. Detailed Implementation

[0063] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0064] This embodiment provides a method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation. This method utilizes the difference in common-mode current amplitude generated by the two-stage matrix converter under different space vector modulation modes to embed the binary information to be transmitted into the power conversion modulation process, thereby completing information transmission while achieving normal energy conversion.

[0065] like Figure 1As shown, the energy information synchronous transmission method for a two-stage matrix converter based on common-mode current modulation proposed in this embodiment includes the following steps: modulation parameter calculation, modulation mode selection, switch drive signal generation, common-mode current extraction, and information demodulation and recovery.

[0066] The specific process is as follows:

[0067] S1: The controller collects the input voltage information and output voltage reference information of the two-stage matrix converter, determines the rectifier stage sector and inverter stage sector, and calculates the duty cycle of adjacent effective vectors of the rectifier stage, the duty cycle of adjacent effective vectors of the inverter stage, and the zero vector duty cycle.

[0068] In this embodiment, the input side of the two-stage matrix converter is a three-phase AC power supply, and the output side is connected to a three-phase resistive-inductive load or a motor.

[0069] First, determine the rectifier stage sectors and inverter stage sectors, as follows:

[0070] The controller acquires the input voltage information of the two-stage matrix converter and determines the sector where the rectifier stage is located based on the phase of the input voltage. At the same time, it acquires the output voltage reference information of the two-stage matrix converter and determines the sector where the inverter stage is located based on the phase of the output voltage reference vector.

[0071] like Figure 2 As shown, the main power circuit of the two-stage matrix converter includes a rectifier stage and an inverter stage. The rectifier stage converts the three-phase AC input into a virtual DC-side voltage, and the inverter stage converts the virtual DC-side voltage into the desired three-phase AC output. Both the rectifier stage and the inverter stage are composed of power switching devices, and energy conversion is achieved by controlling the on and off states of each switching device.

[0072] Subsequently, the duty cycles of adjacent effective vectors in the rectifier stage, adjacent effective vectors in the inverter stage, and the zero vector duty cycle are calculated, as follows:

[0073] like Figure 3 As shown, (a) is the rectifier stage space vector, and (b) is the inverter stage space vector. The rectifier stage space vector plane is divided into six sectors, and the inverter stage space vector plane is also divided into six sectors.

[0074] During any switching cycle, the rectifier stage reference current vector is synthesized from the two adjacent effective vectors corresponding to its rectifier sector, and the inverter stage reference voltage vector is synthesized from the two adjacent effective vectors and the zero vector corresponding to its inverter sector.

[0075] The duty cycles of two adjacent effective vectors in the rectifier stage are as follows:

[0076] (1);

[0077] (2);

[0078] The duty cycles of two adjacent effective vectors in the inverter stage are as follows:

[0079] (3);

[0080] (4);

[0081] Where, d i1 and d i2 d represents the duty cycle of two adjacent effective vectors in the rectifier stage. v1 and d v2 The duty cycles of two adjacent effective vectors in the inverter stage are m, respectively. i m is the modulation coefficient of the rectifier stage. v φ is the modulation coefficient of the inverter stage. i θ0 is the relative angle of the input voltage phase angle within the corresponding rectifier sector, and θ0 is the relative angle of the output voltage reference vector within the corresponding inverter sector.

[0082] Based on the duty cycle mentioned above, the zero vector duty cycle can be obtained:

[0083] (5);

[0084] Where, d i1 d v1 d i1 d v2 d i2 d v1 d i2 d v2 d1 and d2 respectively represent the ratio of the effective time of adjacent effective vectors in the rectifier stage and the effective time of adjacent effective vectors in the inverter stage, and d0 represents the ratio of the total effective time of the zero vector within one switching cycle.

[0085] S2: Obtain the binary information to be transmitted. The controller selects the traditional space vector modulation mode or the low common-mode current space vector modulation mode according to the binary information. The traditional space vector modulation mode and the low common-mode current space vector modulation mode generate common-mode currents of different amplitude levels during the operation of the two-stage matrix converter.

[0086] In this embodiment, the information to be transmitted is binary information. The controller selects and switches between the traditional space vector modulation mode and the low common-mode current space vector modulation mode according to the logic state of the binary information to be transmitted.

[0087] Specifically, when the information to be transmitted is binary "0", the traditional space vector modulation mode is selected; when the information to be transmitted is binary "1", the low common-mode current space vector modulation mode is selected.

[0088] Both traditional space vector modulation (SVM) and low common-mode current (LCF) space vector modulation (LCM) modes can achieve normal energy conversion in a two-stage matrix converter, but they generate different levels of common-mode current amplitude during operation. Therefore, binary information can be mapped to two different modulation modes, which are further manifested as variations in the common-mode current amplitude.

[0089] like Figure 4 As shown, (a) is the traditional space vector modulation mode, and (b) is the low common-mode current space vector modulation mode.

[0090] Both modes are based on space vector modulation of a two-stage matrix converter. Both modulation modes use the same rectifier-stage effective vector, the same inverter-stage effective vector, and the same effective vector duration within the same switching cycle, thus ensuring that the basic energy conversion function of the two-stage matrix converter is consistent in both modulation modes.

[0091] The difference between the two modulation modes lies in the different switching states during the zero-vector action time. The traditional space vector modulation mode uses a traditional zero-vector action method during the zero-vector action time, while the low common-mode current space vector modulation mode uses a different zero-vector action method. Because the two zero-vector action methods have different effects on the common-mode voltage and common-mode circuit state of the two-stage matrix converter, they will cause the converter to generate common-mode currents of different amplitudes.

[0092] In one alternative implementation, a switching cycle T s The time nodes within can be represented as:

[0093] ;

[0094] ;

[0095] ;

[0096] ;

[0097] ;

[0098] ;

[0099] ;

[0100] ;

[0101] As can be seen from the above action time, the effective vector action time is the same in the traditional space vector modulation mode and the low common-mode current space vector modulation mode. The difference lies only in the specific switching state during the zero vector action time.

[0102] S3: Based on the rectifier sector, inverter sector, adjacent effective vector duty cycle, zero vector duty cycle, and the selected modulation mode, generate switching drive signals for the rectifier and inverter stages, so that the two-stage matrix converter modulates the binary information into the common-mode current while completing energy conversion.

[0103] Specifically as follows:

[0104] In the traditional space vector modulation mode, the sequence of vector action of the inverter stage can be as follows:

[0105] (6);

[0106] Where V0 is the traditional zero vector, V m and V n These are two adjacent effective vectors of the invertor stage.

[0107] In low common-mode current space vector modulation mode, the order of vector action can be as follows:

[0108] (7);

[0109] Among them, V z The new zero vector is formed by the rectifier stage off state and the inverter stage effective vector holding state.

[0110] In the above manner, the binary information to be transmitted is mapped into two modulation modes, and further manifested as two different common-mode current amplitude states.

[0111] S4: Acquire the common-mode current during the operation of the two-stage matrix converter, extract the amplitude representation of the common-mode current, and recover the binary information to be transmitted based on the amplitude representation.

[0112] During the operation of the two-stage matrix converter, the three-phase current i is collected. a i b i c The common-mode current is obtained by directly adding the three-phase currents together.

[0113] (8);

[0114] Subsequently, the common-mode current i cm Amplitude processing is performed to obtain the common-mode current amplitude signal.

[0115] In one specific implementation, the common-mode current i can be... cm Perform absolute value processing:

[0116] ;

[0117] The common-mode current amplitude signal is then subjected to low-pass filtering to remove high-frequency fluctuations, resulting in the common-mode current envelope value I. cm .

[0118] Next, set the preset decision threshold I. th and the common-mode current envelope value I cm With the preset decision threshold I th To make a comparison, specifically:

[0119] When I cm >I th When I is in the traditional space vector modulation mode, determine the current mode and restore the output binary "0"; when I cm ≤I th When the current low common-mode current space vector modulation mode is determined, the binary "1" is restored to the output.

[0120] like Figure 5 and Figure 6 As shown, Figure 5 (a) shows the output current waveform of the two-stage matrix converter, and (b) shows the virtual DC-side voltage u. pn Waveform, Figure 6 In the diagram, (a) represents the common-mode current amplitude, (b) represents the original binary information to be transmitted, and (c) represents the binary information recovered after demodulation.

[0121] Depend on Figure 5 It can be seen that during the switching process between the traditional space vector modulation mode and the low common-mode current space vector modulation mode, the two-stage matrix converter can still maintain normal output current and virtual DC side voltage, indicating that the modulation switching does not destroy the basic energy conversion function of the converter.

[0122] Depend on Figure 6 It can be seen that the recovered binary information after demodulation is consistent with the original binary information to be transmitted, indicating that information recovery can be effectively completed through common-mode current extraction, amplitude processing, filtering, and threshold decision. This verifies that the method of the present invention can achieve synchronous information transmission while ensuring normal energy conversion of the two-stage matrix converter.

[0123] This invention achieves synchronous transmission of binary information by switching between traditional space vector modulation (SVM) mode and low common-mode current (LCM) SVM mode, enabling the common-mode current to form distinguishable amplitude states. Compared with traditional independent communication links, this invention eliminates the need for additional communication lines, reducing hardware complexity and improving the integration and reliability of the two-stage matrix converter.

[0124] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation, characterized in that, Includes the following steps: S1: The controller collects the input voltage information and output voltage reference information of the two-stage matrix converter to determine the rectifier stage sector and the inverter stage sector, and calculates the duty cycle of adjacent effective vectors of the rectifier stage, the duty cycle of adjacent effective vectors of the inverter stage, and the zero vector duty cycle. S2: Obtain the binary information to be transmitted. The controller selects the traditional space vector modulation mode or the low common-mode current space vector modulation mode according to the binary information. The traditional space vector modulation mode and the low common-mode current space vector modulation mode generate common-mode currents with different amplitude levels during the operation of the two-stage matrix converter. S3: Based on the rectifier sector, inverter sector, adjacent effective vector duty cycle, zero vector duty cycle, and the selected modulation mode, generate switching drive signals for the rectifier and inverter stages, so that the two-stage matrix converter modulates the binary information into the common-mode current while completing energy conversion; S4: Acquire the common-mode current during the operation of the two-stage matrix converter, extract the amplitude representation of the common-mode current, and recover the binary information to be transmitted based on the amplitude representation.

2. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 1, characterized in that, Step S1 specifically includes: S11: The rectifier stage sector and inverter stage sector are determined as follows: The controller collects the input voltage information of the two-stage matrix converter, determines the sector where the rectifier stage is located based on the phase of the input voltage, and simultaneously collects the output voltage reference information of the two-stage matrix converter, determines the sector where the inverter stage is located based on the phase of the output voltage reference vector. S12: The specific calculations for the duty cycles of adjacent effective vectors in the rectifier stage, adjacent effective vectors in the inverter stage, and the zero vector duty cycle are as follows: Dividing the rectifier stage space vector plane into six sectors, and the inverter stage space vector plane into six sectors as well, then within any switching cycle, the rectifier stage reference current vector is synthesized from the two adjacent effective vectors corresponding to its rectifier sector, and the inverter stage reference voltage vector is synthesized from the two adjacent effective vectors and the zero vector corresponding to its inverter sector. Therefore: The duty cycles of two adjacent effective vectors in the rectifier stage are as follows: （1）； （2）； The duty cycles of two adjacent effective vectors in the inverter stage are as follows: （3）； （4）； Where, d i1 and d i2 The duty cycles of two adjacent effective vectors in the rectifier stage are d, respectively. v1 and d v2 The duty cycles of two adjacent effective vectors in the inverter stage are m, respectively. i m is the modulation coefficient of the rectifier stage. v φ is the modulation coefficient of the inverter stage. i θ0 is the relative angle of the input voltage phase angle within the corresponding rectifier sector, and θ0 is the relative angle of the output voltage reference vector within the corresponding inverter sector. Based on the duty cycle mentioned above, the zero vector duty cycle can be obtained: （5）； Where, d i1 d v1 d i1 d v2 d i2 d v1 d i2 d v2 d1 and d2 respectively represent the ratio of the effective time of adjacent effective vectors in the rectifier stage and the effective time of adjacent effective vectors in the inverter stage, and d0 represents the ratio of the total effective time of the zero vector within one switching cycle.

3. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 1, characterized in that, In step S1, the input side of the two-stage matrix converter is connected to a three-phase AC power supply, and the output side is connected to a three-phase resistive-inductive load or a motor.

4. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 1, characterized in that, Step S2 specifically includes: The controller selects and switches between traditional space vector modulation mode and low common-mode current space vector modulation mode based on the logic state of the binary information to be transmitted. Specifically: When the information to be transmitted is binary "0", the traditional space vector modulation mode is selected; When the information to be transmitted is binary "1", select the low common-mode current space vector modulation mode.

5. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 4, characterized in that, The common-mode current amplitude representation generated by the conventional space vector modulation mode is greater than that generated by the low common-mode current space vector modulation mode, and the difference in amplitude between the two is used as the basis for the transmission and decision of binary information.

6. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 4, characterized in that, The conventional space vector modulation mode and the low common-mode current space vector modulation mode use the same rectifier stage effective vector, the same inverter stage effective vector, and the same effective vector application time within the same switching cycle.

7. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 4, characterized in that, The total zero-vector action time is the same for both the traditional space vector modulation mode and the low common-mode current space vector modulation mode, but the zero-vector action method used within the zero-vector action time is different. Specifically: Traditional space vector modulation modes employ the traditional zero-vector action method during the zero-vector action time; The low common-mode current space vector modulation mode employs a different zero-vector action mode than the traditional space vector modulation mode during the zero-vector action time. This allows the two-stage matrix converter to generate common-mode currents of different amplitude levels.

8. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 1, characterized in that, Step S3 specifically includes: In the traditional space vector modulation mode, the sequence of vector action of the inverter stage can be as follows: （6）； Where V0 is the traditional zero vector, V m and V n These are two adjacent effective vectors of the invertor stage; In low common-mode current space vector modulation mode, the sequence of vector action of the inverter stage can be as follows: （7）； Among them, V z The new zero vector is composed of the rectifier stage off-state and the inverter stage effective vector holding state. In the above manner, the binary information to be transmitted is mapped into two modulation modes, and further manifested as two different common-mode current amplitude states.

9. The method for synchronous transmission of energy information in a two-stage matrix converter based on common-mode current modulation according to claim 1, characterized in that, Step S4 specifically includes: S41: Collect the three-phase current i on the output side or load side of the two-stage matrix converter. a i b i c And synthesize the common-mode current based on the three-phase current: （8）； S42: Perform amplitude processing on the common-mode current to obtain a common-mode current amplitude signal; S43: Perform low-pass filtering on the common-mode current amplitude signal to obtain the common-mode current envelope value I, which characterizes the change in common-mode current amplitude. cm ; S44: Set the preset decision threshold I th and the common-mode current envelope value I cm With the preset decision threshold I th To make a comparison, specifically: When the common-mode current envelope value I cm Greater than the preset decision threshold I th When the current traditional space vector modulation mode is determined, a binary "0" is output. When the common-mode current envelope value I cm Less than or equal to the preset decision threshold I th When the current low common-mode current space vector modulation mode is determined, a binary "1" is output.

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