Output harmonic suppression method, device and equipment of inverter and readable storage medium

Abstract

The invention discloses an output harmonic suppression method, device and equipment of an inverter and a readable storage medium, and relates to the technical field of power electronics. Comprising the steps of performing mathematical modeling on an output side circuit of a target inverter based on a three-phase power grid voltage of the target inverter at a current moment to obtain a mathematical model of the output side; establishing a cost function of the target inverter based on the mathematical model and a current-voltage relationship between the upper capacitance and the lower capacitance of the direct current side of the target inverter at the current moment; calculating cost values of the target inverter in different candidate switching states according to the cost function, and selecting the candidate switching state corresponding to the lowest cost value as a target switching state; the cost value is in positive correlation with the output harmonic wave of the target inverter; and controlling the inverter to output voltage based on the target switching state. According to the method, the output harmonic waves of the inverter are effectively suppressed.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and more particularly to a method, device, equipment and readable storage medium for suppressing output harmonics of an inverter. Background Art

[0002] With the improvement of people's environmental awareness and the depletion of traditional energy sources, renewable energy is becoming an efficient alternative to traditional energy. For example, solar photovoltaic (SPV) systems, which have the advantages of sustainability, cleanliness and no pollution, are of great significance in renewable energy. The inverter is an indispensable part of the SPV system. In high-voltage application scenarios, the inverter has received wide attention in the industry due to its low voltage stress, better output waveform quality, low electromagnetic interference and other advantages.

[0003] However, the control complexity of the inverter is relatively significant, involving key challenges such as multi-objective optimization, dynamic response balance and system stability guarantee, resulting in the inability to effectively suppress the harmonics output by the inverter, which will cause immeasurable damage to the entire system. In order to control the output harmonics of the inverter, the proportional-integral control method is usually adopted in this field. Its principle is to quickly respond to the error change through the proportional link and eliminate the steady-state error through the integral link according to the error between the actual output of the system and the target value, so as to achieve precise control of the inverter output. However, the proportional-integral control method only supports harmonic suppression for a single target, and its parameters highly depend on manually set experience. In the event of sudden situations in the power grid (such as voltage dips, high-frequency noise), it cannot achieve effective adjustment and has poor anti-interference ability.

[0004] Therefore, there is an urgent need for a method for suppressing output harmonics of an inverter that can suppress harmonics for multiple targets and has strong anti-interference ability. Summary of the Invention

[0005] The object of the present invention is to provide a method, device, equipment and readable storage medium for suppressing the output harmonics of an inverter. By mathematically modeling the output measurement circuit of the target inverter, a cost function of the target inverter can be constructed, and then the cost values of the target inverter under different candidate switching states can be obtained. Since the cost value is positively correlated with the output harmonics of the target inverter, that is, the smaller the cost value, the smaller the output harmonics. Therefore, the candidate switching state corresponding to the minimum cost value is the target switching state with the smallest output harmonics. Subsequently, when controlling the target inverter to output voltage based on this target switching state, the harmonics are also the least. Since the cost function is constructed according to the three-phase grid voltage at the current moment and the current-voltage relationship of the upper and lower capacitors on the DC side at the current moment, even if the grid undergoes a mutation, the cost function will be dynamically adjusted accordingly, enabling the target transformer to always be in the optimal switching state, effectively suppressing the output harmonics. Since the harmonic control of the three-phase output of the inverter can be carried out simultaneously, compared with the traditional technology, the harmonic suppression of multiple targets is also achieved.

[0006] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a method for suppressing the output harmonics of an inverter, and the method includes: Based on the three-phase grid voltage of the target inverter at the current moment, mathematically model the output side circuit of the target inverter to obtain a mathematical model of the output side; Based on the mathematical model and the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, establish a cost function of the target inverter; According to the cost function, calculate the cost values of the target inverter under different candidate switching states, and select the candidate switching state corresponding to the lowest cost value as the target switching state; the cost value is positively correlated with the output harmonics of the target inverter; Based on the target switching state, control the inverter to output voltage.

[0007] In some embodiments, establishing a cost function of the target inverter based on the mathematical model and the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter includes: Predict the flux linkage component and torque component of the target inverter at a future moment based on the mathematical model; the future moment is the next moment of the current moment; Predict the voltage difference between the upper and lower capacitors on the DC side of the target inverter at a future moment based on the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment; Based on the flux linkage component, torque component and voltage difference, establish a cost function of the target inverter.

[0008] In some embodiments, predicting the flux linkage component and torque component of the target inverter at a future moment based on the mathematical model includes: Perform Park transformation and Euler discretization on the mathematical model to obtain the flux linkage component and torque component of the target inverter at future moments.

[0009] In some embodiments, based on the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, predict the voltage difference between the upper and lower capacitors on the DC side of the target inverter at future moments, including: Based on the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, calculate the neutral point current of the target inverter; Perform Euler equation discretization on the neutral point current of the target inverter to obtain the voltage difference between the upper and lower capacitors on the DC side of the target inverter at future moments.

[0010] In some embodiments, based on the three-phase grid voltage of the target inverter at the current moment, perform mathematical modeling on the output-side circuit of the target inverter to obtain the mathematical model of the output side, including: Based on the circuit topology of the target inverter, use the three-phase grid voltage of the target inverter at the current moment to represent the output current of the target inverter, and obtain the mathematical model of the output side.

[0011] In some embodiments, based on the target switching state, control the inverter to output voltage, including: Adjust the current switching state of the target inverter to the target switching state; Control the inverter to output voltage.

[0012] In a second aspect, the present invention also provides an output harmonic suppression device for an inverter, and the device includes: A model construction module, configured to perform mathematical modeling on the output-side circuit of the target inverter based on the three-phase grid voltage of the target inverter at the current moment to obtain the mathematical model of the output side; A function construction module, configured to establish a cost function of the target inverter based on the mathematical model and the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment; A state determination module, configured to calculate the cost values of the target inverter in different candidate switching states according to the cost function, and select the candidate switching state corresponding to the lowest cost value as the target switching state; the cost value is positively correlated with the output harmonics of the target inverter; A voltage output module, configured to control the inverter to output voltage based on the target switching state.

[0013] In a third aspect, the present invention further provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the output harmonic suppression method of the inverter provided in the first aspect is implemented.

[0014] In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the output harmonic suppression method of the inverter provided in the first aspect is implemented.

[0015] In a fifth aspect, the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the output harmonic suppression method of the inverter provided in the first aspect is implemented.

[0016] The beneficial effects of the present invention are as follows: The present invention provides an output harmonic suppression method for an inverter. First, based on the three-phase grid voltage of the target inverter at the current moment, a mathematical model of the output-side circuit of the target inverter is established to obtain the mathematical model of the output side. Then, based on the mathematical model and the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, a cost function of the target inverter is established. Then, according to the cost function, the cost values of the target inverter in different candidate switching states are calculated, and the candidate switching state corresponding to the lowest cost value is selected as the target switching state; the cost value is positively correlated with the output harmonics of the target inverter; finally, based on the target switching state, the inverter is controlled to output voltage. By establishing a mathematical model of the output-side circuit of the target inverter, the cost function of the target inverter can be constructed, and then the cost values of the target inverter in different candidate switching states can be obtained. Since the cost value is positively correlated with the output harmonics of the target inverter, that is, the smaller the cost value, the smaller the output harmonics, the candidate switching state corresponding to the minimum cost value is the target switching state with the smallest output harmonics. When the target inverter is subsequently controlled to output voltage based on this target switching state, the harmonics are also the least. Since the cost function is constructed based on the three-phase grid voltage at the current moment and the current-voltage relationship of the upper and lower capacitors on the DC side at the current moment, even if the grid undergoes a mutation, the cost function will be dynamically adjusted accordingly, so that the target transformer can always be in the best switching state, effectively suppressing the output harmonics. Since the harmonic control of the three-phase output of the inverter can be carried out simultaneously, compared with the traditional technology, the harmonic suppression of multiple targets is also realized.

[0017] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it in accordance with the content of the specification, the following describes the preferred embodiments of the present invention in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic flow diagram of a method for suppressing output harmonics of an inverter according to an embodiment of the present invention; Figure 2 Circuit topology diagram of a single-phase seven-level boost active neutral point clamped inverter according to an embodiment of the present invention; Figure 3 Circuit topology diagram of a three-phase seven-level boost active neutral point clamped inverter according to an embodiment of the present invention; Figure 4 Schematic diagram of steady-state experimental waveforms of output current and output voltage of a target inverter according to an embodiment of the present invention; Figure 5 Schematic flow diagram of another method for suppressing output harmonics of an inverter according to an embodiment of the present invention; Figure 6 Schematic structural diagram of a device for suppressing output harmonics of an inverter according to an embodiment of the present invention; Figure 7 Schematic structural diagram of another device for suppressing output harmonics of an inverter according to an embodiment of the present invention; Figure 8 Schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] It should be noted that the references to "one embodiment", "embodiment", "exemplary embodiment", etc. in this specification mean that the described embodiment may include specific features, structures, or characteristics, but not every embodiment must include these specific features, structures, or characteristics. In addition, such expressions do not refer to the same embodiment. Further, when combining specific features, structures, or characteristics with an embodiment, it has been shown that it is within the knowledge of those skilled in the art to combine such features, structures, or characteristics with other embodiments whether or not explicitly described.

[0021] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In some embodiments, as Figure 1 shown, a method for suppressing output harmonics of an inverter is provided, and the specific method includes: S102. Based on the three-phase grid voltages of the target inverter at the current moment, perform mathematical modeling on the output-side circuit of the target inverter to obtain the mathematical model of the output side.

[0023] Among them, the target inverter can be a single-phase seven-level boost active neutral point clamped inverter or a three-phase seven-level boost active neutral point clamped inverter. As Figure 2 shown, Figure 2 is the circuit topology diagram of a single-phase seven-level boost active neutral point clamped inverter. This inverter consists of eight power electronic switches , two DC bus capacitors , a floating capacitor and two diodes. Among them, and are composed of two switch tubes connected in reverse. Among them, is the DC-side voltage; and are the upper capacitor voltage and the lower capacitor voltage respectively; , and are the currents flowing through the upper capacitor and the lower capacitor and the neutral point current respectively. The floating capacitor is charged to . For the power switch tubes of the single-phase seven-level boost active neutral point clamped inverter circuit, "1" represents that the switch tube is on, and "0" represents that the switch tube is off. Table 1 shows all the switch states of the single-phase seven-level boost active neutral point clamped inverter and the corresponding output voltages, where is the output voltage.

[0024]

[0025] As Figure 3 shown, Figure 3 is the circuit topology diagram of a three-phase seven-level boost active neutral point clamped inverter. Among them, , and are the output currents respectively, is the filter inductor, is the output-side resistor, is the neutral point, , and are the three-phase grid voltages. When the target inverter is a three-phase seven-level boost active neutral point clamped inverter, based on the circuit topology of the target inverter, use the three-phase grid voltages of the target inverter at the current moment to represent the output current of the target inverter, and obtain the mathematical model of the output side, as shown in formula (1): ; Among them, , and are the output currents respectively, is the filtering inductor, is the output-side resistor, is the neutral point, , , are the three-phase output voltages, , and are the three-phase grid voltages.

[0026] S102. Based on the mathematical model and the current-voltage relationship of the capacitors on the DC side of the target inverter at the current moment, establish the cost function of the target inverter.

[0027] Optionally, the method for establishing the cost function of the target inverter can be: predicting the flux linkage component and torque component of the target inverter at a future moment based on the mathematical model; the future moment is the next moment of the current moment; predicting the voltage difference of the capacitors on the DC side of the target inverter at the future moment based on the current-voltage relationship of the capacitors on the DC side of the target inverter at the current moment; establishing the cost function of the target inverter based on the flux linkage component, torque component and voltage difference.

[0028] Specifically, perform Park transformation and Euler discretization on the mathematical model to obtain the flux linkage component and torque component of the target inverter at the future moment, and calculate the neutral point current of the target inverter based on the current-voltage relationship of the capacitors on the DC side of the target inverter at the current moment; Perform Euler equation discretization on the neutral point current of the target inverter to obtain the voltage difference of the capacitors on the DC side of the target inverter at the future moment. Finally, establish the cost function of the target inverter based on the flux linkage component, torque component and voltage difference.

[0029] Exemplarily, perform Park transformation (i.e., dq transformation) on formula (1) to obtain formula (2): ; wherein, and are the d-axis component and q-axis component of the output current respectively, and are the d-axis component and q-axis component of the output voltage respectively, and are the d-axis component and q-axis component of the three-phase grid voltage respectively, is the output current angular frequency.

[0030] When the sampling period When it is small enough, the Euler discretization process is performed on formula (2) to obtain the following formula (3): ; The current-voltage relationship of the upper and lower DC capacitors can be expressed as the following formula (4): ; The neutral point current can be expressed as the following formula (5): ; where and are respectively the states of the switches of the three phases respectively and of.

[0031] Discretize formula (5) with the Euler equation, and the voltage difference between the upper and lower DC capacitors at the future moment, i.e., at the k+1 moment , can be obtained as formula (6): ; where , is the voltage difference between the upper and lower DC capacitors at the k moment.

[0032] Construct the cost function of the target inverter according to the above formula (3) and formula (6), as formula (7): ; where is the weight factor for NP voltage balance, and represent the reference values of the output current.

[0033] S103. According to the cost function, calculate the cost values of the target inverter under different candidate switch states, and select the candidate switch state corresponding to the lowest cost value as the target switch state.

[0034] Among them, the cost value is positively correlated with the output harmonics of the target inverter.

[0035] Specifically, substitute the attribute values of the target inverter under different candidate switch states into the above formula (7), calculate the cost values of the target inverter under different candidate switch states, and perform numerical comparison on the calculated cost values, and select the candidate switch state corresponding to the smallest cost value as the target switch state.

[0036] S104. Based on the target switch state, control the inverter to output voltage.

[0037] Optionally, adjust the current switching state of the target inverter to the target switching state; control the inverter to output voltage.

[0038] For the output harmonic suppression method of the inverter in the above embodiment, first, based on the three-phase grid voltage of the target inverter at the current moment, a mathematical model of the output side circuit of the target inverter is established to obtain the mathematical model of the output side; then, based on the mathematical model and the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, a cost function of the target inverter is established; then, according to the cost function, the cost values of the target inverter in different candidate switching states are calculated, and the candidate switching state corresponding to the lowest cost value is selected as the target switching state; the cost value is positively correlated with the output harmonics of the target inverter; finally, based on the target switching state, the inverter is controlled to output voltage. By establishing a mathematical model of the output side circuit of the target inverter, the cost function of the target inverter can be constructed, and then the cost values of the target inverter in different candidate switching states can be obtained. Since the cost value is positively correlated with the output harmonics of the target inverter, that is, the smaller the cost value, the smaller the output harmonics. Therefore, the candidate switching state corresponding to the minimum cost value is the target switching state with the smallest output harmonics. When the target inverter is subsequently controlled to output voltage based on this target switching state, the harmonics are also the least. Since the cost function is constructed according to the three-phase grid voltage at the current moment and the current-voltage relationship of the upper and lower capacitors on the DC side at the current moment, even if the grid undergoes a mutation, the cost function will be dynamically adjusted accordingly, so that the target transformer can always be in the best switching state, effectively suppressing the output harmonics. Since the harmonic control of the three-phase output of the inverter can be carried out simultaneously, compared with the traditional technology, the harmonic suppression of multiple targets is also achieved.

[0039] In another embodiment, the effectiveness of the output harmonic suppression method of the inverter in the present application is verified, specifically including: Relevant circuits are built on the Matlab / Simulink platform for simulation experiments. The experimental parameters are shown in Table 2.

[0040]

[0041] As Figure 4 shown, Figure 4 For the output harmonic suppression method of the inverter proposed in the present application, the steady-state experimental waveforms of the output current (I a，b，c ) and output voltage (V a，b，c ) of the three-phase seven-level boost active neutral point clamped inverter are shown. The experimental results show that the output voltage waveform contains 13 levels with different amplitudes, the three-phase output current has good sinusoidality, and the steady-state performance is excellent, proving the effectiveness of the proposed control strategy.

[0042] To more comprehensively demonstrate this solution, this embodiment provides an alternative method for suppressing the output harmonics of an inverter, as Figure 5 shown below: S201. Based on the circuit topology of the target inverter, use the three-phase grid voltage of the target inverter at the current moment to represent the output current of the target inverter, and obtain a mathematical model of the output side.

[0043] S202. Perform Park transformation and Euler discretization on the mathematical model to obtain the flux linkage component and torque component of the target inverter at a future moment.

[0044] Herein, the future moment is the next moment of the current moment.

[0045] S203. Based on the current-voltage relationship of the upper and lower capacitors on the DC side of the target inverter at the current moment, calculate the neutral point current of the target inverter.

[0046] S204. Perform Euler equation discretization on the neutral point current of the target inverter to obtain the voltage difference between the upper and lower capacitors on the DC side of the target inverter at a future moment.

[0047] S205. Based on the flux linkage component, torque component, and voltage difference, establish a cost function for the target inverter.

[0048] S206. According to the cost function, calculate the cost values of the target inverter in different candidate switching states, and select the candidate switching state corresponding to the lowest cost value as the target switching state.

[0049] Herein, the cost value is positively correlated with the output harmonics of the target inverter.

[0050] S207. Adjust the current switching state of the target inverter to the target switching state.

[0051] S208. Control the inverter to perform voltage output.

[0052] For the specific processes of S201 - S208 above, reference can be made to the description of the above method embodiment. Their implementation principles and technical effects are similar, and will not be elaborated here.

[0053] Based on the same inventive concept, this embodiment of the present application also provides an output harmonic suppression device for an inverter for implementing the output harmonic suppression method of the inverter involved above. The solution provided by this device for solving the problem is similar to the solution recorded in the above method. Therefore, the specific limitations in one or more embodiments of the output harmonic suppression device for an inverter provided below can refer to the limitations on the output harmonic suppression method of the inverter in the above text, and will not be elaborated here.

[0054] In one embodiment, asFigure 6 As shown, an output harmonic suppression device for an inverter is provided. The device includes: A model construction module 30, configured to perform mathematical modeling on the output side circuit of the target inverter based on the three-phase grid voltage of the target inverter at the current moment, and obtain a mathematical model of the output side; A function construction module 31, configured to establish a cost function of the target inverter based on the mathematical model and the current-voltage relationship of the upper capacitor and the lower capacitor on the DC side of the target inverter at the current moment; A state determination module 32, configured to calculate the cost values of the target inverter in different candidate switching states according to the cost function, and select the candidate switching state corresponding to the lowest cost value as the target switching state; the cost value is positively correlated with the output harmonics of the target inverter; A voltage output module 33, configured to control the inverter to output voltage based on the target switching state.

[0055] In another embodiment, as Figure 7 shown, the above Figure 6 function construction module 31 includes: A first prediction unit 310, configured to predict the flux linkage component and the torque component of the target inverter at a future moment based on the mathematical model; the future moment is the next moment of the current moment; A second prediction unit 311, configured to predict the voltage difference between the upper capacitor and the lower capacitor on the DC side of the target inverter at a future moment based on the current-voltage relationship of the upper capacitor and the lower capacitor on the DC side of the target inverter at the current moment; A function construction unit 312, configured to establish a cost function of the target inverter based on the flux linkage component, the torque component, and the voltage difference.

[0056] In another embodiment, the above Figure 7 first prediction unit 310 is specifically configured to: perform Park transformation processing and Euler discretization processing on the mathematical model to obtain the flux linkage component and the torque component of the target inverter at a future moment.

[0057] In another embodiment, the above Figure 7 second prediction unit 311 is specifically configured to: calculate the neutral point current of the target inverter based on the current-voltage relationship of the upper capacitor and the lower capacitor on the DC side of the target inverter at the current moment; perform Euler equation discretization processing on the neutral point current of the target inverter to obtain the voltage difference between the upper capacitor and the lower capacitor on the DC side of the target inverter at a future moment.

[0058] In another embodiment, the above Figure 6The model construction module 30 therein is specifically configured to: based on the circuit topology of the target inverter, represent the output current of the target inverter by using the three-phase grid voltage of the target inverter at the current moment, and obtain the mathematical model of the output side.

[0059] In another embodiment, the above Figure 6 The voltage output module 33 therein is specifically configured to: adjust the current switching state of the target inverter to the target switching state; control the inverter to output voltage.

[0060] The embodiment of the present application also provides an electronic device. In some embodiments, referring to Figure 8 As shown, the electronic device 700 includes an input unit 710, a memory 720, a processor 730, and an output unit 740. The memory 720 stores program instructions that can run on the processor 730. The processor 730 can execute the output harmonic suppression method and / or technical solution of the inverter based on the foregoing embodiments by invoking the program instructions. The electronic device 700 can be a mobile terminal device such as a mobile phone or a computer.

[0061] In addition, the embodiment of the present application also provides a computer-readable storage medium for storing a computer program for executing the output harmonic suppression method of the inverter. For example, computer program instructions, when executed by a computer, can call or provide the method and / or technical solution according to the present application through the operation of the computer. The program instructions for calling the method of the present application may be stored in a fixed or removable storage medium, and / or transmitted and / or stored in a storage medium running according to the program instructions through a data stream in a broadcast or other signal-bearing medium.

[0062] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present application can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. Optionally, they can be implemented by program code executable by the computing device. Thus, they can be stored in a storage device and executed by the computing device, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to implement. In this way, the present application is not limited to any specific combination of hardware and software.

[0063] The technical features of the above embodiments can be arbitrarily integrated. For the sake of brevity of description, not all possible integrations of the technical features in the above embodiments are described. However, as long as the integration of these technical features does not conflict, it should be considered to be within the scope described in this specification.

[0064] The above embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for suppressing output harmonics of an inverter, characterized in that: The method comprises: Based on the three-phase grid voltage of the target inverter at the current moment, mathematical modeling is performed on the output side circuit of the target inverter to obtain a mathematical model of the output side; Establishing a cost function of the target inverter based on the mathematical model and the current-voltage relationship between the upper capacitor and the lower capacitor of the DC side of the target inverter at the current moment; According to the cost function, calculating the cost value of the target inverter in different candidate switching states, and selecting the candidate switching state corresponding to the lowest cost value as the target switching state; the cost value is positively correlated with the output harmonic of the target inverter; Based on the target switch state, the inverter is controlled to output voltage.

2. The method for suppressing output harmonics of an inverter according to claim 1, characterized in that: Based on the mathematical model and the current-voltage relationship between the upper capacitor and the lower capacitor on the DC side of the target inverter, a cost function of the target inverter is established, including: Predicting the flux component and torque component of the target inverter at a future moment based on the mathematical model; the future moment is a moment next to the current moment; Based on the current-voltage relationship between the upper capacitor and the lower capacitor on the DC side of the target inverter at the current moment, predicting the voltage difference between the upper capacitor and the lower capacitor on the DC side of the target inverter at a future moment; A cost function of the target inverter is established based on the flux component, the torque component and the voltage difference.

3. The method for suppressing output harmonics of an inverter according to claim 2, characterized in that: Predicting the flux component and torque component of the target inverter at a future time based on the mathematical model includes: The mathematical model is subjected to Park transformation processing and Euler discretization processing to obtain the flux component and torque component of the target inverter at a future moment.

4. The method for suppressing output harmonics of an inverter according to claim 2, characterized in that: Based on the current-voltage relationship between the upper capacitor and the lower capacitor of the DC side of the target inverter at the current moment, predicting the voltage difference between the upper capacitor and the lower capacitor of the DC side of the target inverter at a future moment, including: Calculating the neutral point current of the target inverter based on the current-voltage relationship between the upper capacitor and the lower capacitor of the DC side of the target inverter at the current moment; The neutral point current of the target inverter is discretized using the Euler equation to obtain a voltage difference between an upper capacitor and a lower capacitor on the DC side of the target inverter at a future time.

5. The method for suppressing output harmonics of an inverter according to claim 1, characterized in that: Based on the three-phase grid voltage of the target inverter at the current moment, mathematical modeling is performed on the output side circuit of the target inverter to obtain the mathematical model of the output side, including: Based on the circuit topology of the target inverter, the output current of the target inverter is expressed by utilizing the three-phase grid voltage of the target inverter at the current moment, thereby obtaining a mathematical model of the output side.

6. The method for suppressing output harmonics of an inverter according to any one of claims 1 to 5, characterized in that: Based on the target switch state, controlling the inverter to output voltage includes: adjusting the current switching state of the target inverter to the target switching state; The inverter is controlled to output voltage.

7. An output harmonic suppression device for an inverter, characterized in that: The device comprises: A model building module, used to perform mathematical modeling on the output side circuit of the target inverter based on the three-phase grid voltage of the target inverter at the current moment, so as to obtain a mathematical model of the output side; A function building module, used to establish a cost function of the target inverter based on the mathematical model and the current-voltage relationship between the upper capacitor and the lower capacitor of the DC side of the target inverter at the current moment; a state determination module, configured to calculate, according to the cost function, the cost value of the target inverter in different candidate switching states, and select the candidate switching state corresponding to the lowest cost value as the target switching state; the cost value is positively correlated with the output harmonic of the target inverter; A voltage output module is used to control the inverter to output voltage based on the target switch state.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for suppressing output harmonics of the inverter according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for suppressing output harmonics of an inverter according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the output harmonic suppression method of the inverter according to any one of claims 1 to 6 is implemented.

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