Inverter circuit control method and power conversion equipment

Abstract

The invention provides an inverter circuit control method and power conversion equipment. The method comprises the following steps: acquiring an actual direct-current component of an output voltage of an inverter circuit; a compensation coefficient is determined according to the actual direct-current component, and the compensation coefficient and the absolute value of the actual direct-current component are in positive correlation; determining a reference modulation parameter according to the output voltage, a voltage given parameter of the inverter circuit and a preset control loop; compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensation modulation parameter; and performing modulation according to the compensation modulation parameter to obtain a driving signal, and sending the driving signal to an inverter circuit. According to the inverter circuit control method provided by the invention, the overproof direct current component in the output voltage of the inverter circuit can be quickly suppressed, and the probability of overvoltage of the output voltage during sudden loading or sudden unloading of the inverter circuit is reduced.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular, to an inverter circuit control method and a power conversion device. Background Art

[0002] When an inverter operates in off-grid mode, the problem of excessive DC component in the output voltage is likely to occur, and this problem is particularly prominent when driving a half-wave RCD load. However, in the related art, the DC component control method has poor optimization effect on the harmonics in the output voltage on the one hand, and on the other hand, due to the slow response speed, it is easy to have an overvoltage situation in the instantaneous value of the voltage during sudden load addition or sudden load removal. Therefore, there is an urgent need for an inverter circuit control method to solve the above problems. Summary of the Invention

[0003] In view of this, this application provides an inverter circuit control method and a power conversion device, which can quickly and effectively control the DC component in the output voltage of the inverter circuit, and reduce the probability of overvoltage of the output voltage of the inverter circuit during sudden load addition or sudden load removal.

[0004] The first aspect of this application provides an inverter circuit control method, including: obtaining the actual DC component of the output voltage of the inverter circuit; determining a compensation coefficient according to the actual DC component, where the compensation coefficient has a positive correlation with the absolute value of the actual DC component; determining a reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop; compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter; modulating according to the compensated modulation parameter to obtain a drive signal, and sending the drive signal to the inverter circuit.

[0005] In an embodiment, after determining the reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop, the method further includes: determining a compensation amount according to the given DC component, the actual DC component, and a preset compensation loop; superimposing the compensation amount on the reference modulation parameter to update the reference modulation parameter.

[0006] In an embodiment, after compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter, the method further includes: determining a compensation amount according to the given DC component, the actual DC component, and a preset compensation loop; superimposing the compensation amount on the compensated modulation parameter to update the compensated modulation parameter.

[0007] In an embodiment, compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter includes: determining a duty cycle compensation coefficient according to the compensation coefficient and the actual DC component; determining the compensated modulation parameter according to the duty cycle compensation coefficient and the reference modulation parameter.

[0008] In one embodiment, determining the duty cycle compensation coefficient according to the compensation coefficient and the actual DC component includes: obtaining an adjustment coefficient based on the compensation coefficient and the actual DC component; when the reference modulation parameter is greater than 0, using the value obtained by subtracting the adjustment coefficient from 1 as the duty cycle compensation coefficient; when the reference modulation parameter is less than 0, using the value obtained by adding the adjustment coefficient to 1 as the duty cycle compensation coefficient.

[0009] In one embodiment, determining the compensation coefficient according to the actual DC component includes: when the absolute value of the actual DC component is less than or equal to the first threshold, the compensation coefficient is equal to 0; when the absolute value of the actual DC component is greater than the first threshold and less than the second threshold, determining the compensation coefficient according to a preset functional relationship, wherein in the functional relationship, the compensation coefficient is proportional to the absolute value of the actual DC component and the compensation coefficient is less than the first coefficient threshold; when the absolute value of the actual DC component is greater than or equal to the second threshold, the compensation coefficient is equal to the first coefficient threshold.

[0010] In one embodiment, the voltage given parameters include the given d-axis voltage and the given q-axis voltage. Determining the reference modulation parameter according to the output voltage, the voltage given parameters of the inverter circuit, and a preset control loop includes: obtaining the output current of the inverter circuit; respectively performing matrix transformation on the output voltage and the output current to obtain the d-axis voltage, the q-axis voltage, the d-axis current, and the q-axis current; based on deviation adjustment, determining the reference modulation parameter according to the given d-axis voltage, the given q-axis voltage, the d-axis voltage, the q-axis voltage, the d-axis current, and the q-axis current.

[0011] In one embodiment, the voltage given parameter includes the given output voltage. Determining the reference modulation parameter according to the output voltage, the voltage given parameters of the inverter circuit, and a preset control loop includes: obtaining the output current of the inverter circuit; determining the reference output current according to the deviation between the given output voltage and the output voltage; determining the reference modulation parameter according to the deviation between the reference output current and the output current.

[0012] In one embodiment, determining the compensation amount according to the given DC component, the actual DC component, and a preset compensation loop includes: determining the DC component difference between the given DC component and the actual DC component; performing deviation adjustment on the DC component difference to obtain the compensation amount.

[0013] The second aspect of the present application provides a power conversion device, including an inverter circuit and a controller. The controller is configured to execute the inverter circuit control method described in any one of the above.

[0014] In summary, for the inverter circuit control method provided in this application, first, a compensation coefficient is determined according to the actual DC component of the output voltage. Among them, the compensation coefficient has a positive correlation with the absolute value of the actual DC component. In this way, the compensation coefficient can change with the degree of exceeding the standard of the actual DC component. Then, the reference modulation parameter is determined according to the output voltage, the voltage given parameter of the inverter circuit, and the preset control loop, and the reference modulation parameter is compensated according to the compensation coefficient and the actual DC component to obtain the compensated modulation parameter. In this way, the compensation coefficient can flexibly compensate the reference modulation parameter according to the degree of exceeding the standard of the actual DC component. Finally, modulation is performed according to the compensated modulation parameter to obtain the drive signal, and the drive signal is sent to the inverter circuit. In this way, the solution provided in this application is equivalent to directly adjusting the duty cycle of the drive signal of the inverter circuit according to the compensation coefficient and the actual DC component, and the execution frequency is higher, for example, it can reach the kilohertz level. It can be understood that in the related art, the output voltage DC component control loop is usually at the ten-hertz level, such as 50 Hz, in order to adapt to the sampling delay of the actual DC component and avoid overshoot, and cannot respond quickly when the output voltage changes. However, the inverter circuit control method provided in this application can directly adjust the duty cycle of the drive signal of the inverter circuit according to the actual DC component to achieve rapid adjustment of the output voltage. Compared with the DC component control method in the related art, the response is faster, and the excessive DC component in the output voltage of the inverter circuit can be quickly suppressed, reducing the probability of overvoltage of the output voltage of the inverter circuit during sudden load or sudden load unloading. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of this application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as limiting the protection scope of this application. In each drawing, similar components are numbered similarly.

[0016] Figure 1 FIG. is a schematic diagram of the application scenario of an inverter provided by an embodiment of this application.

[0017] Figure 2 FIG. is a block diagram of the structure of an inverter provided by an embodiment of this application.

[0018] Figure 3 FIG. is a schematic flowchart of the inverter circuit control method provided by an embodiment of this application.

[0019] Figure 4 FIG. is a partial flowchart of an embodiment of this application after step S303 is executed.

[0020] Figure 5 FIG. is a partial flowchart of an embodiment of this application after step S304 is executed.

[0021] Figure 6 It is a schematic diagram of the sub-step process of step S304 in an embodiment of the present application.

[0022] Figure 7 It is a schematic diagram of the sub-step process of step S601 in an embodiment of the present application.

[0023] Figure 8 It is a schematic diagram of the actual DC component-compensation coefficient curve for determining the compensation coefficient provided in an embodiment of the present application.

[0024] Figure 9 It is a schematic diagram of the sub-step process of step S303 in an embodiment of the present application.

[0025] Figure 10 It is a schematic diagram of the sub-step process of step S303 in another embodiment of the present application.

[0026] Figure 11 It is a schematic diagram of the sub-step process of step S401 or step S501 in an embodiment of the present application.

[0027] Figure 12 It is a specific control block diagram of the inverter circuit control method provided in an embodiment of the present application.

[0028] Figure 13 It is a specific control block diagram of the inverter circuit control method provided in another embodiment of the present application.

[0029] Figure 14A It is the waveform diagram of the output voltage and output current of the inverter circuit when controlling the inverter circuit using the DC component control method in the related art.

[0030] Figure 14B For Figure 14A Under the same conditions, but when controlling the inverter circuit using the inverter circuit control method provided in an embodiment of the present application, it is the waveform diagram of the output voltage and output current of the inverter circuit.

[0031] Figure 15 It is a structural block diagram of the power conversion device provided in an embodiment of the present application.

[0032] Figure 16 It is a functional block diagram of the electronic device provided in an embodiment of the present application.

[0033] Figure 17 It is a functional block diagram of the control device provided in an embodiment of the present application.

[0034] Figure 18 It is a functional block diagram of the computer storage medium provided in an embodiment of the present application. Detailed implementation manners

[0035] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0036] It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be an intermediate component at the same time. When a component is considered to be "disposed on" another component, it may be directly disposed on the other component or there may be an intermediate component at the same time. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "rear", and similar expressions used herein are only for the purpose of illustration.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality" means one or more than one, unless otherwise specifically defined.

[0039] Some embodiments will be described below with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments may be combined with each other.

[0040] Please refer Figure 1 , Figure 1 to the schematic diagram of the application environment of the inverter 10 involved in the embodiments of the present application. The inverter 10 is connected between the DC power supply 20 and the load 30, and is used to convert the direct current output by the DC power supply 20 into alternating current to supply power to the load 30. Among them, the DC power supply 20 may be a photovoltaic module, a battery module, an energy storage device or other electronic devices for outputting direct current, and this application does not limit the DC power supply. The load 30 may be an AC load such as a motor or a transformer having an exciting coil or winding.

[0041] In some embodiments, the inverter 10 can also supply power to a load after passing through a transformer, and the present application does not limit this. In some embodiments, the DC power source 20 can be an energy storage unit. The inverter 10 and the DC power source 20 can be integrated into the same device to form an energy storage converter. At this time, the inverter circuit in the inverter 10 is a bidirectional inverter circuit. In other embodiments, the inverter 10 can be integrated with other voltage conversion circuits (such as a DC conversion circuit, etc.) in a device to form a power conversion device. The DC power source 20 can be connected to the DC bus through the DC interface of the power conversion device, and the load 30 can be connected to the output interface of the inverter 10 through the AC output interface of the power conversion device.

[0042] In some embodiments, the side of the inverter 10 connected to the load 30 can also be connected to the power grid to feed power into the power grid or receive power as a power grid load.

[0043] Please refer to Figure 2 , Figure 2 which is a structural block diagram of the inverter 10 in an embodiment of the present application. The inverter 10 can include a controller 11, a memory 12, and an inverter circuit 13. Among them, the controller 11, the memory 12, and the inverter circuit 13 can be connected through a bus, and this bus can be any applicable bus such as an Inter-integrated Circuit (I2C) bus.

[0044] Among them, the memory 12 can store an operating system and a computer program. This computer program includes program instructions. When these program instructions are executed, the controller 11 can be made to execute the control method of the inverter. The inverter circuit 13 is used to convert direct current into alternating current. Among them, the inverter circuit 13 can be a single-phase or polyphase circuit, and the present application does not limit this. The controller 11 is used to provide computing and control capabilities to support the operation of the entire inverter 10.

[0045] It can be understood that when the inverter 10 is an energy storage converter, the inverter circuit 13 can be a bidirectional inverter circuit, which is used to convert direct current into alternating current or convert alternating current into direct current.

[0046] When the inverter 10 operates off-grid, the problem of excessive DC component in the output voltage is likely to occur, and this problem is particularly prominent when driving a half-wave RCD load. However, for the DC component control method adopted in the related art, on the one hand, the optimization effect on the harmonics in the output voltage is poor, and on the other hand, due to the slow response speed, when suddenly loading or unloading, the situation of overvoltage of the instantaneous voltage value is likely to occur. Therefore, there is an urgent need for an inverter circuit control method to solve the above problems.

[0047] Please continue to refer to Figure 3 , Figure 3Schematic diagram of the control method for an inverter circuit provided by an embodiment of the present application. Understandably, in one embodiment, the controller 11 is used to run a computer program stored in the memory 12 to implement as Figure 3 shown in the steps:

[0048] Step S301: Obtain the actual DC component of the output voltage of the inverter circuit.

[0049] Among them, the output voltage refers to the voltage at the AC output terminal of the inverter circuit 13. In some embodiments, voltage sampling can be performed at the AC output terminal of the inverter circuit 13 through a voltage sensor or a voltage sampling circuit, and then the sampled signal is input to an analog-to-digital converter (ADC) for conversion to obtain the actual DC component of the output voltage. The present application does not limit the method for obtaining the actual DC component. For example, in other embodiments, the actual DC component can also be calculated based on the sampled actual output voltage.

[0050] Step S302: Determine a compensation coefficient according to the actual DC component, where the compensation coefficient has a positive correlation with the absolute value of the actual DC component.

[0051] Among them, the compensation coefficient is used to represent the proportional coefficient of the part of the actual DC component that participates in compensating the output voltage in all the actual DC components.

[0052] Understandably, the absolute value of the actual DC component should be less than a DC component threshold. If the absolute value of the actual DC component is greater than the DC component threshold, it means that the actual DC component of the output voltage exceeds the standard. When the absolute value of the actual DC component exceeds the DC component threshold, the larger the absolute value of the actual DC component, the more serious the degree of exceeding the standard of the actual DC component. Thus, in step S302, by making the compensation coefficient have a positive correlation with the absolute value of the actual DC component, the compensation coefficient can follow the degree of exceeding the standard of the actual DC component, making it more flexible to adjust the output voltage according to the actual DC component. In the embodiment of the present application, the DC component threshold is taken as 0 to illustrate the inverter circuit control method.

[0053] In some embodiments, the compensation coefficient can be determined according to a preset functional relationship. Among them, this functional relationship can be obtained based on laboratory test data, and the independent variable and the dependent variable of this functional relationship can be the absolute value of the actual DC component and the compensation coefficient respectively. Exemplarily, this functional relationship can be a proportional function, a piecewise function, a power function, a logarithmic function or other types of functions. The present application does not limit the function type and specific parameters of this functional relationship.

[0054] Step S303: Determine a reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop.

[0055] Among them, the voltage reference parameter represents a reference parameter related to the output voltage. For example, the voltage reference parameter may include at least one of a reference output voltage, a reference output current, a reference output power, or other related reference parameters.

[0056] The reference modulation parameter can be used to represent the reference value of the modulation signal. In practical applications, if the output of the inverter circuit 13 is a sine wave, the reference modulation parameter is also a sine wave. It can be understood that the reference modulation parameter can adjust the output voltage and the DC component in the output voltage by affecting the duty cycle of the drive signal used to control the switching logic of the switching tubes in the inverter circuit 13. It can be understood that when controlling the inverter circuit 13 according to the reference modulation parameter, the output voltage of the inverter circuit 13 can be made to conform to the voltage reference parameter.

[0057] The preset control loop can be an output voltage control loop, which controls the output voltage with the acquired output voltage as the feedback value. Among them, the execution frequency of the preset control loop can reach the kilohertz level, such as 20 kHz. The present application does not limit the specific loop of the preset control loop. For example, the preset control loop may include at least one of a voltage loop, a current loop, a power loop, or other control loops. It can be understood that the voltage reference parameter and the reference modulation parameter can be determined according to the specific loop in the preset control loop.

[0058] Step S304: Compensate the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter.

[0059] It can be understood that if the reference modulation parameter is a sine wave, the compensated modulation parameter is also a sine wave. Among them, when the actual DC component exceeds the standard and is a positive offset, the positive half-wave of the sine wave of the reference modulation parameter is proportionally reduced and the negative half-wave is proportionally amplified according to the compensation coefficient and the actual DC component, so that the compensated modulation parameter is less than the reference modulation parameter. In this way, the positive DC component of the output voltage can be reduced to suppress the positive DC component that exceeds the standard of the output voltage; when the actual DC component exceeds the standard and is a negative offset, the positive half-wave of the sine wave of the reference modulation parameter is proportionally amplified and the negative half-wave is proportionally reduced according to the compensation coefficient and the actual DC component, so that the compensated modulation parameter is greater than the reference modulation parameter. In this way, the negative DC component of the output voltage can be reduced.

[0060] Step S305: Modulate according to the compensated modulation parameter to obtain a drive signal, and send the drive signal to the inverter circuit.

[0061] Among them, the driving signal is used to control the switching logic and duty cycle of the switching tubes in the inverter circuit 13 to adjust the output voltage of the inverter circuit 13. The driving signal can be a PWM (Pulse Width Modulation) signal. Understandably, if the compensation modulation parameter is different, the duty cycle of the driving signal obtained by modulation according to the compensation modulation parameter is also different. Within one cycle, if the duty cycle of the driving signal is different, the conduction duration of the switching tubes in the inverter circuit 13 correspondingly controlled by the driving signal is also different, so that the output voltage is also different. In this way, in step S305, the output voltage of the inverter circuit 13 can be adjusted by the driving signal generated according to the compensation modulation parameter.

[0062] In summary, for the inverter circuit control method provided by this application, first, the compensation coefficient is determined according to the actual DC component of the output voltage. Among them, the compensation coefficient has a positive correlation with the absolute value of the actual DC component. In this way, the compensation coefficient can change with the over-standard degree of the actual DC component. Then, the reference modulation parameter is determined according to the output voltage, the voltage given parameter of the inverter circuit, and the preset control loop, and the reference modulation parameter is compensated according to the compensation coefficient and the actual DC component to obtain the compensation modulation parameter. In this way, the compensation coefficient can flexibly compensate the reference modulation parameter according to the over-standard degree of the actual DC component. Finally, modulation is performed according to the compensation modulation parameter to obtain the driving signal, and the driving signal is sent to the inverter circuit. In this way, the solution provided by this application is equivalent to directly adjusting the duty cycle of the driving signal of the inverter circuit according to the compensation coefficient and the actual DC component, and the execution frequency is higher, for example, it can reach the kilohertz level. Understandably, in the related art, the output voltage DC component control loop is usually at the ten-hertz level, such as 50 Hz, in order to adapt to the sampling delay of the actual DC component and avoid overshoot, and it cannot respond quickly when the output voltage changes. However, the inverter circuit control method provided by this application can directly adjust the duty cycle of the driving signal of the inverter circuit according to the actual DC component to achieve rapid adjustment of the output voltage. Compared with the DC component control method in the related art, the response is faster, the over-standard DC component in the output voltage of the inverter circuit can be quickly suppressed, and the probability of overvoltage of the output voltage when the inverter circuit is suddenly loaded or suddenly unloaded is reduced.

[0063] Please continue to refer to Figure 4 , in some embodiments, after performing step S303, the method further includes:

[0064] Step S401: Determine the compensation amount according to the given DC component, the actual DC component, and the preset compensation loop.

[0065] Among them, the given DC component is the target value of the DC component of the output voltage. The preset compensation loop at least includes a DC component control loop of the output voltage. In some embodiments, the DC component control loop may be a proportional-integral (PI) control loop of the DC component, a proportional-integral-derivative (PID) control loop of the DC component, etc., and the present application does not limit this.

[0066] In step S401, the actual DC component can be used as the feedback value of the preset compensation loop, the given DC component can be used as the given value of the preset compensation loop, and the preset compensation loop outputs a compensation amount based on the deviation between the actual DC component and the given DC component. It can be understood that the compensation amount is used to make the actual DC component of the adjusted output voltage close to the given DC component.

[0067] Step S402: Superimpose the compensation amount on the reference modulation parameter to update the reference modulation parameter.

[0068] In some embodiments, the sum of the compensation amount and the reference modulation parameter can be used as the updated reference modulation parameter.

[0069] In this way, after performing steps S401 to S402 and then continuing to perform steps S304 and S305, it can quickly respond when the output of the inverter circuit fluctuates, suppress the DC component of the output voltage of the inverter circuit that exceeds the standard, and make the DC component of the output voltage of the inverter circuit close to the given DC component when the output of the inverter circuit is in a steady state, improving the circuit stability. By combining the duty cycle adjustment of the drive signal of the inverter circuit and the DC component control loop, both the response speed is improved and the circuit stability is ensured.

[0070] Please continue to refer to Figure 5 , in some embodiments, after performing step S304, the method further includes:

[0071] Step S501: Determine the compensation amount according to the given DC component, the actual DC component, and the preset compensation loop.

[0072] It can be understood that step S501 is substantially the same as step S401 and will not be elaborated here.

[0073] Step S502: Superimpose the compensation amount on the compensation modulation parameter to update the compensation modulation parameter.

[0074] In some embodiments, the sum of the compensation amount and the compensation modulation parameter can be used as the updated compensation modulation parameter.

[0075] In some embodiments, the updated compensation modulation parameter can also be subjected to a clipping process to limit the value of the compensation modulation parameter within a preset range to further reduce the probability of overshoot of the output voltage.

[0076] Thus, after performing steps S501 to S502 and then performing step S305, it is also possible to quickly suppress the DC component of the output voltage of the inverter circuit from exceeding the standard while ensuring the circuit stability, which not only improves the response speed but also ensures the circuit stability.

[0077] Understandably, Figure 4 and Figure 5 the embodiments of only differ in whether the compensation amount obtained through the DC component loop is superimposed on the reference modulation parameter or on the compensation modulation parameter.

[0078] Please continue to refer to Figure 6 , in some embodiments, step S304 includes the following sub-steps:

[0079] Step S601: Determine the duty cycle compensation coefficient according to the compensation coefficient and the actual DC component.

[0080] Wherein, when the reference modulation parameter is greater than 0, the duty cycle compensation coefficient and the actual DC component are negatively correlated. When the reference modulation parameter is less than 0, the compensation coefficient and the actual DC component are positively correlated. And the duty cycle compensation coefficient is greater than or equal to 0.

[0081] Understandably, the present application does not limit the specific calculation method for determining the duty cycle compensation coefficient in step S601. In some embodiments, based on a preset formula, the duty cycle compensation coefficient can be calculated according to the compensation coefficient and the actual DC component.

[0082] Step S602: Determine the compensation modulation parameter according to the duty cycle compensation coefficient and the reference modulation parameter.

[0083] Wherein, the compensation modulation parameter and the reference modulation parameter are positively correlated, and the compensation modulation parameter and the duty cycle compensation coefficient are positively correlated. Taking the output of the inverter circuit 13 as a sine wave as an example, if the reference modulation parameter is the first sine wave and the compensation modulation parameter is the second sine wave, then the second sine wave is a sine wave obtained by equally scaling the positive half-wave / negative half-wave of the first sine wave. Also, since when the reference modulation parameter is greater than 0, the duty cycle compensation coefficient and the actual DC component are negatively correlated, and when the reference modulation parameter is less than 0, the compensation coefficient and the duty cycle compensation coefficient are positively correlated, thus, when the reference modulation parameter is greater than 0, the compensation modulation parameter and the actual DC component are negatively correlated; when the reference modulation parameter is less than 0, the compensation modulation parameter and the actual DC component are positively correlated.

[0084] That is to say, when the reference modulation parameter is greater than 0, if the actual DC component is positive, it indicates a positive offset of the output voltage. Then, as the actual DC component increases, the compensation modulation parameter decreases (the shrinking ratio of the positive half-wave of the second sine wave increases) to suppress the positive DC component of the output voltage. If the actual DC component is negative, it indicates a negative offset of the output voltage. Then, as the actual DC component decreases, the compensation modulation parameter increases (the amplification ratio of the positive half-wave of the second sine wave increases) to suppress the negative DC component of the output voltage. Correspondingly, when the reference modulation parameter is less than 0, if the actual DC component is positive, it indicates a positive offset of the output voltage. Then, as the actual DC component increases, the compensation modulation parameter increases (the amplification ratio of the negative half-wave of the second sine wave increases) to suppress the positive DC component of the output voltage. If the actual DC component is negative, it indicates a negative offset of the output voltage. Then, as the actual DC component increases, the compensation modulation parameter decreases (the shrinking ratio of the negative half-wave of the second sine wave increases) to reduce the negative offset voltage of the output voltage, thereby suppressing the negative DC component of the output voltage.

[0085] In some embodiments, the product of the duty cycle compensation coefficient and the reference modulation parameter can be obtained as the compensation modulation parameter.

[0086] In other embodiments, the compensation modulation parameter can be determined according to the following formula (1):

[0087] P a_mod_comp =P a_mod_ref *h + a (1)

[0088] Wherein, P a_mod_comp represents the compensation modulation parameter; P a_mod_ref represents the reference modulation parameter; h represents the duty cycle compensation coefficient; a represents the first adjustment parameter. Among them, the compensation modulation parameter and the reference modulation parameter are both positive or both negative at the same time. The first adjustment parameter a can be a constant. The present application does not limit the specific value of the first adjustment parameter a, as long as the first adjustment parameter a can make the compensation modulation parameter and the reference modulation parameter both positive or both negative at the same time. In some embodiments, a can be 0.

[0089] In this way, by performing step S601 to step S602, the reference modulation parameter can be compensated according to the compensation coefficient and the actual DC component to obtain the compensation modulation parameter, and the obtained compensation modulation parameter after compensation can effectively suppress the DC component that exceeds the standard of the output voltage.

[0090] Please continue to refer to Figure 7 , in some embodiments, step S601 includes the following sub-steps:

[0091] Step S701: Obtain an adjustment coefficient according to the compensation coefficient and the actual DC component.

[0092] In some embodiments, the adjustment coefficient has a positive correlation with the actual DC component. And the adjustment coefficient is greater than or equal to -1 and less than or equal to 1.

[0093] In some embodiments, the product of the compensation coefficient and the actual DC component can be directly obtained as the adjustment coefficient.

[0094] In some other embodiments, the adjustment coefficient can also be obtained according to the following formula (2):

[0095]

[0096] Wherein, V a_bias_comp represents the adjustment coefficient; V a_bias represents the actual DC component; K represents the compensation coefficient; b represents the second adjustment parameter. Wherein, b can be a constant. The present application does not limit the specific value of b, as long as the adjustment coefficient is greater than -1 and less than 1 according to the above formula. It can be understood that based on the value of V a_bias_comp , the duty cycle compensation coefficient h is greater than 0.

[0097] Step S702: When the reference modulation parameter is greater than 0, the value obtained by subtracting the adjustment coefficient from 1 is used as the duty cycle compensation coefficient.

[0098] Step S703: When the reference modulation parameter is less than 0, the value obtained by adding the adjustment coefficient to 1 is used as the duty cycle compensation coefficient.

[0099] That is, in some embodiments, the duty cycle compensation coefficient can be determined according to the following formula (3):

[0100]

[0101] In formula (3), in different embodiments, the reference modulation parameter P a_mod_ref can be the reference modulation parameter before update or the reference modulation parameter after update. For example, when applied to the embodiment shown in Figure 4 , the reference modulation parameter P a_mod_ref is the reference modulation parameter updated after superimposing the compensation amount. When applied to the embodiment shown in Figure 5 , the reference modulation parameter P a_mod_ref is the reference modulation parameter without superimposing the compensation amount.

[0102] It can be understood that since the adjustment coefficient is greater than -1 and less than 1, thus, based on the above formula and the adjustment coefficient V a_bias_comp calculated, the value range of the duty cycle compensation coefficient is (0, 2).

[0103] In some embodiments, step S302 includes the following steps:

[0104] When the absolute value of the actual DC component is less than or equal to the first threshold, the compensation coefficient is equal to 0; when the absolute value of the actual DC component is greater than the first threshold and less than the second threshold, the compensation coefficient is determined according to a preset functional relationship, where, in the functional relationship, the compensation coefficient is proportional to the absolute value of the actual DC component and the compensation coefficient is less than the first coefficient threshold; when the absolute value of the actual DC component is greater than or equal to the second threshold, the compensation coefficient is equal to the first coefficient threshold.

[0105] Among them, the first threshold can be used to represent the acceptable DC component threshold, that is, when the absolute value of the actual DC component is less than or equal to the first threshold, it means that the current actual DC component is within the acceptable range. At this time, there is no need to compensate the actual DC component or only a small compensation coefficient is required, so the compensation coefficient can be equal to 0. The second threshold can be used as the DC component threshold that will cause waveform distortion of the output waveform. When the absolute value of the actual DC component is greater than the first threshold and less than the second threshold, the compensation coefficient can be determined according to a preset functional relationship to limit the compensation coefficient below the first coefficient threshold. When the absolute value of the actual DC component is greater than or equal to the second threshold, if the compensation coefficient is still determined according to the preset functional relationship at this time, the compensation coefficient may exceed the first coefficient threshold. Therefore, the compensation coefficient is directly made equal to the first coefficient threshold to reduce the probability of overshoot.

[0106] For example, in some embodiments, the compensation coefficient can be determined according to the actual DC component based on the following formula (4).

[0107]

[0108] Among them, K represents the compensation coefficient; V a_bias represents the actual DC component; d / 10 represents the first threshold; c / 10 represents the second threshold. (e*c - f) represents the first coefficient threshold. c, d, e, f can all be constants. In this embodiment, since the sampling range of the actual DC component of the output voltage is small, V a_bias *10 is used for calculation to reduce the computational complexity. In other embodiments, the compensation coefficient can also be determined according to the range in which the absolute value of V a_bias is located, or according to the range in which the operation result of the absolute value of V a_bias and other constants is located.

[0109] In some embodiments, c, d, e, f can all be obtained by fitting multiple groups of data related to the actual DC component, and the specific values of c, d, e, f are not limited in this application.

[0110] For example, when c is 8, d is 2, e is 0.833, and f is -1.6555 in formula (4), the schematic diagram of the actual DC component - compensation coefficient curve as shown in Figure 8 can be obtained. In this curve, the |V a_bias | on the horizontal axis represents the absolute value of the actual DC component, and K on the vertical axis represents the compensation coefficient.

[0111] In summary, in this embodiment, when the absolute value of the actual DC component is small, by selecting a smaller compensation coefficient to participate in controlling the inverter circuit, the control accuracy of the inverter circuit can be guaranteed. When the absolute value of the actual DC component is large, by selecting a larger compensation coefficient to participate in controlling the inverter circuit, the rapid control of the output voltage of the inverter circuit can be achieved.

[0112] Please continue to refer to Figure 9 , in some embodiments, when the inverter circuit 13 is a three - phase inverter circuit and the voltage - given parameters include the given d - axis voltage and the given q - axis voltage, step S303 includes the following sub - steps:

[0113] Step S901: Obtain the output current of the inverter circuit.

[0114] In some embodiments, the controller 11 can obtain the output current of each phase of the alternating current output by the inverter circuit 13 through an internal detection circuit or an external detection circuit, such as an ammeter, a power meter, a power analyzer, etc. Correspondingly, in step S301, the controller 11 also obtains the output voltage of each phase of the alternating current output by the inverter circuit 13 and obtains the actual DC component of the corresponding output voltage of each phase.

[0115] Step S902: Perform matrix transformation on the output voltage and output current respectively to obtain the d - axis voltage, q - axis voltage, d - axis current, and q - axis current.

[0116] In step S902, the controller 11 can convert the three - phase output voltage and three - phase output current to the two - phase rotating coordinate system (i.e., the dq coordinate system) through matrix transformation to obtain the d - axis voltage, q - axis voltage, d - axis current, and q - axis current.

[0117] Step S903: Based on deviation regulation, determine the reference modulation parameters according to the given d - axis voltage, given q - axis voltage, d - axis voltage, q - axis voltage, d - axis current, and q - axis current.

[0118] Among them, the deviation regulation can be proportional - integral regulation or proportional regulation, etc., and the present application does not limit this. For example, step S903 can be implemented through a current loop with a proportional - integral regulator or a proportional regulator.

[0119] Specifically, in some embodiments, step S903 may include the following sub - steps:

[0120] Determine a reference d-axis current based on the deviation between the given d-axis voltage and the d-axis voltage;

[0121] Determine a reference d-axis voltage based on the deviation between the reference d-axis current and the d-axis current;

[0122] Determine a reference q-axis current based on the deviation between the given q-axis voltage and the q-axis voltage;

[0123] Determine a reference q-axis voltage based on the deviation between the reference q-axis current and the q-axis current;

[0124] Perform a matrix inverse transformation on the reference d-axis voltage and the reference q-axis voltage to obtain reference modulation parameters.

[0125] Among them, the difference obtained by subtracting the d-axis voltage from the given d-axis voltage can be obtained as the first voltage deviation value, and the reference d-axis current is obtained by performing deviation adjustment based on the first voltage deviation value. Furthermore, the difference obtained by subtracting the d-axis current from the reference d-axis current is obtained as the first current deviation value, and the reference d-axis voltage is obtained by performing deviation adjustment based on the first current deviation value. Similarly, the difference obtained by subtracting the q-axis voltage from the given q-axis voltage can be obtained as the second voltage deviation value, and the reference q-axis current is obtained by performing deviation adjustment based on the second voltage deviation value. Furthermore, the difference obtained by subtracting the q-axis current from the reference q-axis current is obtained as the second current deviation value, and the reference q-axis voltage is obtained by performing deviation adjustment based on the second current deviation value. Furthermore, the controller 11 can convert the reference d-axis voltage and the reference q-axis voltage to the three-phase stationary coordinate system through matrix inverse transformation to obtain the reference modulation parameters of each phase of the three-phase alternating current.

[0126] It can be understood that in other embodiments, the reference modulation parameters of each phase of the alternating current can also be calculated according to other control loops, such as a power control loop and / or a feedforward control loop, etc. The present application does not limit the specific control loop.

[0127] In this way, by executing the above steps S901 to step S903, when the inverter circuit 13 is a three-phase inverter circuit, the reference voltage modulation parameters of each phase output voltage can be determined according to the obtained output voltage and output current.

[0128] Please continue to refer to Figure 10 , in some embodiments, when the inverter circuit 13 is a single-phase inverter circuit and the voltage given parameter includes the given output voltage, step S303 includes the following sub-steps:

[0129] Step S101: Obtain the output current of the inverter circuit.

[0130] In some embodiments, the controller 11 can obtain the output current according to a current sensor or a current sampling circuit provided at the output end of the inverter circuit 13.

[0131] Step S102: Determine a reference output current based on the deviation between a given output voltage and the output voltage.

[0132] In step S102, the difference obtained by subtracting the output voltage from the given output voltage can be acquired as a third voltage deviation value, and the third voltage deviation value is subjected to deviation adjustment to obtain the reference output current.

[0133] Step S103: Determine a reference modulation parameter based on the deviation between the reference output current and the output current.

[0134] In step S103, the difference obtained by subtracting the output current from the reference output current can be acquired as a third current deviation value, and the third current deviation value is subjected to deviation adjustment to obtain the reference modulation parameter.

[0135] It can be understood that the deviation adjustment mentioned in step S102 and step S103 can be performed by proportional integral derivative regulation, proportional integral regulation, or proportional regulation. For example, inputting the third voltage deviation value into a proportional integral regulator or a proportional regulator can calculate the reference output current. Specifically, it can be achieved through a current loop having a proportional integral regulator or a proportional regulator.

[0136] In this way, by executing step S101 to step S103, when the inverter circuit 13 is a single-phase inverter circuit, the reference voltage modulation parameters of each phase output voltage can be determined according to the acquired output voltage and output current.

[0137] It can be understood that in other embodiments, the output end of the inverter circuit 13 can also have other phases. Correspondingly, based on the idea of deviation adjustment, the output voltage and output current of each phase of the inverter circuit 13 can be acquired to determine the reference modulation parameters of each phase of the inverter circuit 13. The present application does not limit the number of phases of the inverter circuit 13.

[0138] Please continue to refer to Figure 11 , in some embodiments, step S401 or step S501 includes the following sub-steps:

[0139] Step S111: Determine the DC component difference between a given DC component and an actual DC component.

[0140] In some embodiments, the difference obtained by subtracting the actual DC component from the given DC component can be acquired as the DC component difference.

[0141] Step S112: Perform deviation adjustment on the DC component difference to obtain a compensation amount.

[0142] Among them, deviation adjustment is performed on the DC component difference, that is, according to the DC component difference at the current moment, a compensation amount is obtained by using a deviation adjustment algorithm. The compensation amount is used to make the actual DC component of the output voltage at the next moment closer to the given DC component. In this embodiment, it is to make the actual DC component of the output voltage at the next moment closer to 0, thereby suppressing the over-standard of the DC component of the output voltage.

[0143] It can be understood that the deviation adjustment algorithm can be a proportional control algorithm, a proportional integral control algorithm, or a proportional integral derivative control algorithm, and the present application does not limit this.

[0144] Please continue to refer to Figure 12 , Figure 12 which shows a specific control block diagram for implementing the inverter circuit control method provided in an embodiment of the present application when the inverter circuit 13 is a three-phase inverter circuit. Figure 12 Only the control block diagram for adjusting the output voltage of one of the phases of the inverter circuit 13 is shown. As Figure 12 shown, the control block diagram includes an output voltage control loop 40, a DC component compensation loop 50, and a duty cycle compensation loop 60. The following will explain the specific working process of the inverter circuit control method according to Figure 12 this.

[0145] Specifically, in the output voltage control loop 40, the first adder 41 calculates the first voltage deviation value U_d_dev based on the d-axis voltage U_d_feed and the given d-axis voltage U_d_ref. The first PI regulator 42 performs deviation adjustment on the first voltage deviation value U_d_dev to obtain the reference d-axis current Idref. Then, the second adder 43 calculates the first current deviation value I_d_dev based on the reference d-axis current I dref and the d-axis current I_d_feed. The second PI regulator 44 performs deviation adjustment on the first current deviation value I_d_dev to obtain the reference d-axis voltage U_d_out. At the same time, the third adder 45 calculates the second voltage deviation value U_q_dev based on the q-axis voltage U_q_feed and the given q-axis voltage U_q_ref. The third PI regulator 46 performs deviation adjustment on the second voltage deviation value U_q_dev to obtain the reference q-axis current I_q_ref. Then, the fourth adder 47 calculates the second current deviation value I_q_dev based on the reference q-axis current I_q_ref and the q-axis current I_q_feed. The fourth PI regulator 48 performs deviation adjustment on the second current deviation value I_q_dev to obtain the reference q-axis voltage U_q_out. Then, the matrix inverse converter 49 calculates the reference modulation parameters for each phase of the inverter circuit 13 based on the reference d-axis voltage U_d_out and the reference q-axis voltage U_q_out respectively, such as the reference modulation parameter Pa mod ref, the reference modulation parameter Pb mod ref, and the reference modulation parameter Pcmod ref. In the embodiment of the present application, the process of adjusting the corresponding phase output voltage of the control block diagram is continued with the reference modulation parameter Pa mod ref as an example. It can be understood that the reference modulation parameter Pb mod ref and the reference modulation parameter Pc mod ref can also obtain the corresponding compensation modulation parameters according to the following corresponding process, so as to adjust the corresponding phase output voltage.

[0146] In the DC component compensation loop 50, the fifth adder 51 calculates the DC component difference U dc dev based on the actual DC component Va bias and the given DC component Va bias ref. The fifth PI regulator 52 performs deviation adjustment on the DC component difference U dcdev to obtain the compensation amount Pa_comp.

[0147] In the duty cycle compensation loop 60, the first calculator 61 calculates a compensation coefficient K according to the magnitude of the absolute value of the input actual DC component Va_bias. Next, the first multiplier 62 calculates an adjustment coefficient Va_bias_comp according to the compensation coefficient K and the actual DC component Va_bias. Then, the second calculator 63 determines a duty cycle compensation coefficient h according to the adjustment coefficient Va_bias_comp and the reference modulation parameter Pa_mod_ref. Alternatively, the second calculator 63 may also determine the duty cycle compensation coefficient h according to the adjustment coefficient Va_bias_comp and the updated reference modulation parameter Pa_mod_refl. Understandably, for the process of the first calculator 61 calculating the compensation coefficient K and the process of the second calculator 63 calculating the duty cycle compensation coefficient h, please refer to the above for details and will not be elaborated here.

[0148] Next, the sixth adder 71 updates the reference modulation parameter Pa_mod_ref output by the DC component compensation loop 50 to calculate an updated reference modulation parameter Pa_mod_ref1. Then, the second multiplier 72 calculates a compensation modulation parameter Pa_mod_comp according to the updated reference modulation parameter Pa_mod_ref1 and the duty cycle compensation coefficient h output by the duty cycle compensation loop 60. Then, the PWM modulator 73 calculates a drive signal PWM according to the compensation modulation parameter Pa_mod_comp and outputs the drive signal PWM to the inverter circuit 13, so as to quickly suppress the excessive DC component in the output voltage of the inverter circuit and reduce the probability of overshoot, thereby reducing the probability of overvoltage of the output voltage of the inverter circuit during sudden load addition or sudden load removal.

[0149] Please continue to refer to Figure 13 , Figure 13 which shows a specific control block diagram for implementing the inverter circuit control method provided by another embodiment of the present application when the inverter circuit 13 is a three-phase inverter circuit. Figure 13 The shown control block diagram is substantially the same as Figure 12 the shown control block diagram, the difference being Figure 13After the output voltage control loop 40 outputs the reference modulation parameter Pa_mod_ref and the duty cycle compensation loop 60 outputs the duty cycle compensation coefficient h, the second multiplier 72 calculates the compensated modulation parameter Pa_mod_comp according to the reference modulation parameter Pa_mod_ref1 and the duty cycle compensation coefficient h. Then, the sixth adder 71 updates the compensated modulation parameter Pa_mod_comp according to the compensation amount Pa_comp output by the DC component compensation loop 50 to obtain the updated compensated modulation parameter Pa_mod_comp1. Then, the PWM modulator 73 calculates the drive signal PWM according to the updated compensated modulation parameter Pa_mod_comp1 and outputs the drive signal PWM to the inverter circuit 13.

[0150] Understandably, the above first PI regulator 42, second PI regulator 44, third PI regulator 46, fourth PI regulator 48, and fifth PI regulator 52 take existing controllers in the related art, such as a PI controller (proportional integral controller), as an example. In other embodiments, other controllers such as a PID controller (proportional integral differentiation controller) etc. can also be used, and the present application does not limit this. Correspondingly, the deviation adjustment algorithm can also be a PID adjustment algorithm (Proportion Integration Differentiation control), a PI adjustment algorithm (proportional integral control), etc. Of course, it can also be other adjustment algorithms.

[0151] Understandably, Figure 12 and Figure 13 The control process of the shown control block diagram can be implemented by the inverter circuit control method provided by the present application, for example, implemented by a computer program stored in the controller 11, and the specific implementation details are not elaborated here.

[0152] It can be understood that Figure 12 and Figure 13 In, the output voltage control loop 40 and the duty cycle compensation loop 60 can have the same execution frequency, such as in the kilohertz level. The execution frequency of the DC component compensation loop 50 is lower than that of the output voltage control loop 40 and the duty cycle compensation loop 60. For example, it is in the ten-hertz level.

[0153] Please refer to Figure 14A and Figure 14B , Figure 14AWhen only the DC component control method in the related art is used to control the inverter circuit 13, the waveforms of the output voltage and output current of the inverter circuit 13 are shown. Among them, Figure 14A The curve 141 in it is a schematic diagram of the output voltage curve of the inverter circuit 13, and the curve 142 is a schematic diagram of the output current curve of the inverter circuit 13. Figure 14B For Figure 14A Under the same conditions, but when the inverter circuit control method provided in an embodiment of the present application is used to control the inverter circuit 13, the waveforms of the output voltage and output current of the inverter circuit 13 are shown. Among them, Figure 14B The curve 143 in it is a schematic diagram of the output voltage curve of the inverter circuit 13, and the curve 144 is a schematic diagram of the output current curve of the inverter circuit 13.

[0154] From Figure 14A and Figure 14B It can be seen that even when the DC component control method in the related art is used, there are still problems of waveform distortion in the output voltage and output current of the inverter circuit 13. When the inverter circuit control method provided in the present application is used, the waveforms of the output voltage and output current of the inverter circuit 13 do not undergo distortion, and the output voltage and output current remain in a relatively stable state, indicating that the inverter circuit control method provided in the present application is conducive to realizing effective control of the output voltage and output current of the inverter circuit.

[0155] Please refer to Figure 15 , the present application also provides a power conversion device 100, including an inverter circuit 13 and a controller 11. The controller 11 is used to execute the inverter circuit control method described in any of the above embodiments. The present application does not limit the specific product form of the power conversion device 100. For example, the power conversion device 100 can be any one of electronic devices integrated with an inverter circuit 13 such as an energy storage device, a self-mobile device, a robot, a refrigerator, an air conditioner, etc. It can be understood that in some embodiments, the power conversion device 100 may further include other power conversion circuits, such as a rectifier circuit, a DC / DC conversion circuit, etc.

[0156] Please refer to Figure 16 , the present application also provides an electronic device 200, including a controller 11 and a memory 12. Among them, the memory 12 is used to store programs, instructions or codes for executing the discharge control method of the above DC converter. The controller 11 is used to execute the programs, instructions or codes stored in the memory 12. The programs, instructions or codes stored in the memory 12 can execute some or all of the steps of the inverter circuit control method in any of the above embodiments.

[0157] An embodiment of the present application also provides a control device 300, which is applied to the inverter circuit 13 or an electronic device integrated with the inverter circuit 13. Figure 17The structural block diagram of the control device 300 provided by the embodiment of the present application is schematically shown. As Figure 17 shown, the control device 300 includes:

[0158] An acquisition module 310, configured to acquire the actual DC component of the output voltage of the inverter circuit.

[0159] A first determination module 320, configured to determine a compensation coefficient according to the actual DC component, where the compensation coefficient has a positive correlation with the absolute value of the actual DC component.

[0160] A second determination module 330, configured to determine a reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop.

[0161] A compensation module 340, configured to compensate the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter.

[0162] A modulation module 350, configured to perform modulation according to the compensated modulation parameter to obtain a drive signal, and send the drive signal to the inverter circuit.

[0163] The specific details of the control device 300 provided by the embodiment of the present application for implementing the inverter circuit control method have been described in detail in the corresponding embodiment of the inverter circuit control method, and will not be elaborated here.

[0164] Please refer to Figure 18 , the present application also provides a computer-readable storage medium 400, on which a computer program 410 is stored. When the computer program 410 is executed by a controller 11, it implements the inverter circuit control method in the above technical solution. The computer-readable storage medium may adopt a portable compact disc read-only memory (CD-ROM) and include program codes, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or in combination with an instruction execution system, apparatus, or device.

[0165] The above program product may employ any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0166] The computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries the readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable signal medium can also be any readable medium other than the readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0167] The program code contained on the readable medium can be transmitted by any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the above.

[0168] The program code for performing the operations of the present invention can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., by using an Internet service provider to connect through the Internet).

[0169] In addition, the above drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present invention, rather than for limiting purposes. It is easy to understand that the processes shown in the above drawings do not indicate or limit the time sequence of these processes. Additionally, it is also easy to understand that these processes can be executed, for example, synchronously or asynchronously in multiple modules.

[0170] The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A control method for an inverter circuit, characterized in that The method includes: Obtaining the actual DC component of the output voltage of the inverter circuit; Determining a compensation coefficient according to the actual DC component, wherein the compensation coefficient has a positive correlation with the absolute value of the actual DC component; Determining a reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop; Compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter; Modulating according to the compensated modulation parameter to obtain a drive signal, and sending the drive signal to the inverter circuit.

2. The method according to claim 1, wherein After determining the reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop, the method further includes: Determining a compensation amount according to a given DC component, the actual DC component, and a preset compensation loop; Superimposing the compensation amount on the reference modulation parameter to update the reference modulation parameter.

3. The method according to claim 1, wherein After compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter, the method further includes: Determining a compensation amount according to a given DC component, the actual DC component, and a preset compensation loop; Superimposing the compensation amount on the compensated modulation parameter to update the compensated modulation parameter.

4. The method according to claim 1, characterized in that Compensating the reference modulation parameter according to the compensation coefficient and the actual DC component to obtain a compensated modulation parameter, including: Determining a duty cycle compensation coefficient according to the compensation coefficient and the actual DC component; Determining the compensated modulation parameter according to the duty cycle compensation coefficient and the reference modulation parameter.

5. The method according to claim 4, wherein Determining the duty cycle compensation coefficient according to the compensation coefficient and the actual DC component, including: Obtaining an adjustment coefficient according to the compensation coefficient and the actual DC component; When the reference modulation parameter is greater than 0, using the value obtained by subtracting the adjustment coefficient from 1 as the duty cycle compensation coefficient; When the reference modulation parameter is less than 0, using the value obtained by adding the adjustment coefficient to 1 as the duty cycle compensation coefficient.

6. The method according to claim 1, characterized in that, Determining the compensation coefficient according to the actual DC component, including: When the absolute value of the actual DC component is less than or equal to a first threshold, the compensation coefficient is equal to 0; When the absolute value of the actual DC component is greater than the first threshold and less than a second threshold, determining the compensation coefficient according to a preset functional relationship, wherein in the functional relationship, the compensation coefficient is proportional to the absolute value of the actual DC component and the compensation coefficient is less than a first coefficient threshold; When the absolute value of the actual DC component is greater than or equal to the second threshold, the compensation coefficient is equal to the first coefficient threshold.

7. The method according to claim 1, characterized in that, The voltage given parameter includes a given d-axis voltage and a given q-axis voltage. Determining the reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit, and a preset control loop includes: Obtaining the output current of the inverter circuit; Performing matrix transformation on the output voltage and the output current respectively to obtain a d-axis voltage, a q-axis voltage, a d-axis current, and a q-axis current; Based on deviation adjustment, determine the reference modulation parameter according to the given d-axis voltage, the given q-axis voltage, the d-axis voltage, the q-axis voltage, the d-axis current and the q-axis current.

8. The method according to claim 1, wherein The voltage given parameter includes the given output voltage, and determining the reference modulation parameter according to the output voltage, the voltage given parameter of the inverter circuit and a preset control loop includes: Obtain the output current of the inverter circuit; Determine the reference output current according to the deviation between the given output voltage and the output voltage; Determine the reference modulation parameter according to the deviation between the reference output current and the output current.

9. The method according to claim 2 or 3, characterized in that, Determining the compensation amount according to the given DC component, the actual DC component and a preset compensation loop includes: Determine the DC component difference between the given DC component and the actual DC component; Perform deviation adjustment on the DC component difference to obtain the compensation amount.

10. A power conversion device, characterized in that, The power conversion device includes an inverter circuit and a controller, and the controller is configured to execute the inverter circuit control method according to any one of claims 1 to 9.

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