Dual-path parallel inverter control method, dual-path parallel inverter circuit and electrical equipment

Abstract

The embodiments of the present application relate to a dual-parallel inverter control method, a dual-parallel inverter circuit, and an electrical device. The method includes: obtaining a desired voltage, a droop coefficient, a measured current, and a measured mains voltage of the dual-parallel inverter circuit; determining an error between the desired voltage and the measured mains voltage; determining a measured equivalent voltage of the dual-parallel inverter circuit based on the measured current; determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; generating control signals for a first inverter module and a second inverter module based on the correction control voltage; and adjusting the output power of the first inverter module and the second inverter module based on the control signals. The embodiments of the present application achieve uniform power output distribution, avoid overloading of a single inverter module, reduce energy loss, improve the response speed of the inverter circuit operation, and improve the stability of the inverter circuit output power.

Description

Technical Field

[0001] The present application relates to the field of automation control technology, and in particular to a dual-parallel inverter control method, a dual-parallel inverter circuit, and electrical equipment. Background Art

[0002] Traditional inverter-driven motor systems typically use a single inverter to drive one motor. This results in excessive inverter output power, which can easily cause overheating or even damage. Furthermore, a single inverter cannot distribute the output power of the load motor, resulting in unstable power output. Therefore, how to reasonably distribute the inverter's output power and ensure output stability has become a pressing issue. Summary of the Invention

[0003] In view of this, in order to solve some or all of the above technical problems, the embodiments of the present application provide a dual-parallel inverter control method, a dual-parallel inverter circuit and an electrical device.

[0004] In a first aspect, an embodiment of the present application provides a dual-parallel inverter control method, the method comprising: obtaining an expected voltage, a droop coefficient, a measured current and a measured main circuit voltage of the dual-parallel inverter circuit, wherein the droop coefficient is used to characterize the proportional relationship between the output currents of the first inverter module and the second inverter module included in the dual-parallel inverter circuit; determining an error between the expected voltage and the measured main circuit voltage; determining the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current; determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient and the measured current; generating respective control signals of the first inverter module and the second inverter module based on the correction control voltage; and adjusting the output power of the first inverter module and the second inverter module based on the control signal.

[0005] In one possible embodiment, based on the correction control voltage, control signals for the first inverter module and the second inverter module are generated, including: determining a reference voltage based on the expected voltage, the correction control voltage, the droop coefficient and the measured current; using a preset voltage loop, operating the measured mains voltage and the reference voltage to obtain a reference current; using a preset current loop, operating the measured current and the reference current to obtain control signals for the first inverter module and the second inverter module.

[0006] In one possible embodiment, a correction control voltage is determined based on the error, the measured equivalent voltage, the droop coefficient, and the measured current, including: multiplying the droop coefficient and the measured current to obtain the droop equivalent voltage; calculating the error based on preset control parameters, and summing the calculated result with the measured equivalent voltage and the droop equivalent voltage to obtain the correction control voltage.

[0007] In one possible embodiment, the method further includes: alternately controlling the states of the driving switches of the two groups of DC boost units included in the first inverter module according to a preset switch driving cycle; and alternately controlling the states of the driving switches of the two groups of DC boost units included in the second inverter module according to the switch driving cycle.

[0008] In a possible implementation, the method further includes: in response to the current moment reaching a preset droop coefficient rotation moment, swapping the droop coefficients corresponding to the first inverter module and the second inverter module.

[0009] In a second aspect, an embodiment of the present application provides a dual-parallel inverter circuit, which includes: a first inverter module, a second inverter module, a controller, a main circuit voltage sampling module, a first current sampling module, and a second current sampling module; the current output end of the first inverter module and the current output end of the second inverter module are both connected to the load device; the control signal input end of the first inverter module and the control signal input end of the second inverter module are both connected to the controller; the main circuit voltage sampling module is connected to the current input end of the load device and is connected to the controller; the first current sampling module and the second current sampling module are respectively connected to the current output end of the first inverter module and the current output end of the second inverter module, and are respectively connected to the controller; the controller is used to execute the above-mentioned dual-parallel inverter control method.

[0010] In one possible embodiment, the first inverter module includes a first rectifier unit, a first DC boost unit, a second DC boost unit, a first charging capacitor and a first inverter unit; the second inverter module includes a second rectifier unit, a third DC boost unit, a fourth DC boost unit, a second charging capacitor and a second inverter unit; the voltage input ends of the first DC boost unit and the second DC boost unit are both connected to the first rectifier unit, the voltage output ends of the first DC boost unit and the second DC boost unit are both connected to the first inverter unit and the first charging capacitor, and the control ends of the first DC boost unit and the second DC boost unit are both connected to the controller; the control end of the first inverter unit is connected to the controller; the voltage input ends of the third DC boost unit and the fourth DC boost unit are both connected to the second rectifier unit, the voltage output ends of the third DC boost unit and the fourth DC boost unit are both connected to the second inverter unit and the second charging capacitor, and the control ends of the third DC boost unit and the fourth DC boost unit are both connected to the controller; the control end of the second inverter unit is connected to the controller.

[0011] In one possible embodiment, the first DC boost unit includes a first inductor, a first diode and a first controlled switch, and the second DC boost unit includes a second inductor, a second diode and a second controlled switch; the two ends of the first inductor are respectively connected to the anode of the first rectifier unit and the first diode, the two ends of the second inductor are respectively connected to the anode of the first rectifier unit and the second diode, the two current transmission ends of the first controlled switch are respectively connected to the anode and the ground of the first diode, the two current transmission ends of the second controlled switch are respectively connected to the anode and the ground of the second diode, and the cathodes of the first diode and the second diode are both connected to the first charging The first and second rectifier units are connected to the second rectifier unit and the anode of the third diode, and the second and second rectifier units are connected to the ground terminal. The second and second rectifier units are connected to the anode of the third diode and the ground terminal, respectively. The second and second rectifier units are connected to the anode of the fourth diode and the ground terminal, respectively. The second and second rectifier units are connected to the anode of the third diode and the ground terminal, respectively. The second and second rectifier units are connected to the anode of the fourth diode and the ground terminal, respectively. The cathodes of the third and fourth diodes are both connected to the second charging capacitor.

[0012] In a third aspect, an embodiment of the present application provides a dual-parallel inverter control device, which includes: an acquisition module for acquiring the expected voltage, droop coefficient, measured current and measured main circuit voltage of the dual-parallel inverter circuit, wherein the droop coefficient is used to characterize the proportional relationship between the output currents of the first inverter module and the second inverter module included in the dual-parallel inverter circuit; a first determination module for determining the error between the expected voltage and the measured main circuit voltage; a second determination module for determining the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current; a third determination module for determining the correction control voltage based on the error, measured equivalent voltage, droop coefficient and measured current; a generation module for generating control signals for the first inverter module and the second inverter module respectively based on the correction control voltage; and an adjustment module for adjusting the output power of the first inverter module and the second inverter module based on the control signal.

[0013] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising: the above-mentioned dual-parallel inverter circuit and a motor.

[0014] In a fifth aspect, an embodiment of the present application provides an electronic device, comprising: a memory for storing a computer program; a processor for executing the computer program stored in the memory, and when the computer program is executed, it implements the method of any embodiment of the dual-path parallel inverter control method of the first aspect of the present application.

[0015] In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, a method of any embodiment of the dual-path parallel inverter control method of the first aspect described above is implemented.

[0016] In the seventh aspect, an embodiment of the present application provides a computer program, which includes a computer-readable code. When the computer-readable code runs on a device, the processor in the device implements a method as in any embodiment of the dual-parallel inverter control method of the first aspect mentioned above.

[0017] The dual-parallel inverter control method, dual-parallel inverter circuit and electrical equipment provided in the embodiments of the present application obtain the expected voltage, droop coefficient, measured current and measured main circuit voltage of the dual-parallel inverter circuit, then determine the error between the expected voltage and the measured main circuit voltage, determine the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current, and then determine the correction control voltage based on the error, measured equivalent voltage, droop coefficient and measured current, and then generate control signals for the first inverter module and the second inverter module based on the correction control voltage. Finally, based on the control signals, adjust the output power of the first inverter module and the second inverter module. The embodiment of the present application realizes the application of a dual-parallel inverter circuit to the drive of a load device, and uses a droop control method to control the dual-parallel inverter circuit, and sets the droop coefficients of the first inverter module and the second inverter module of the circuit. By setting the droop control, the output power of the first inverter module and the second inverter module can be reasonably distributed, the power output is evenly distributed, the overload of a single inverter module is avoided, the energy loss is reduced, the response speed of the inverter circuit operation is improved, and the stability of the output power of the inverter circuit is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0021] Figure 1A schematic flow chart of a dual-parallel inverter control method provided in an embodiment of the present application;

[0022] Figure 2A A schematic diagram of the connection method of two inverter modules provided in an embodiment of the present application;

[0023] Figure 2B This is an equivalent principle diagram of the droop control provided in the embodiment of the present application;

[0024] Figure 3 A schematic flow chart of another dual-parallel inverter control method provided in an embodiment of the present application;

[0025] Figure 4 A schematic flow chart of another dual-parallel inverter control method provided in an embodiment of the present application;

[0026] Figure 5A This is a schematic diagram of the current change of the traditional single-group boost unit output;

[0027] Figure 5B A schematic diagram of current changes when two groups of boost units are output according to an embodiment of the present application;

[0028] Figure 6 A schematic diagram of the droop correction control provided in an embodiment of the present application;

[0029] Figure 7 A schematic structural diagram of a dual-parallel inverter control device provided in an embodiment of the present application;

[0030] Figure 8 A schematic structural diagram of a dual-parallel inverter circuit provided in an embodiment of the present application;

[0031] Figure 9 A schematic structural diagram of another dual-parallel inverter circuit provided in an embodiment of the present application;

[0032] Figure 10 A schematic structural diagram of another dual-parallel inverter circuit provided in an embodiment of the present application;

[0033] Figure 11 A schematic diagram of the structure of an electrical device provided in an embodiment of the present application;

[0034] Figure 12 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It is apparent that the described embodiments are only a portion of the embodiments of the present application, rather than all of the embodiments. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and numerical values ​​described in these embodiments do not limit the scope of the present application.

[0036] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present application are only used to distinguish between different steps, devices, modules and other objects, and neither represent any specific technical meaning nor indicate the logical order between them.

[0037] It should also be understood that in this embodiment, “a plurality of” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0038] It should also be understood that any component, data or structure mentioned in the embodiments of the present application can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0039] In addition, the term "and / or" in this application is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0040] It should also be understood that the description of each embodiment in this application focuses on the differences between the embodiments, and the same or similar aspects can be referenced with each other. For the sake of brevity, they will not be described one by one.

[0041] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0042] Technologies, circuits, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the above-mentioned technologies, circuits, and devices should be considered part of the specification.

[0043] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0044] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application can be combined with each other. To facilitate understanding of the embodiments of this application, the application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0045] In order to solve the technical problem of unstable output power when the inverter circuit in the prior art is running, the present application provides a dual-parallel inverter control method, which can reasonably distribute the output power of each inverter module and improve the stability of power output.

[0046] Figure 1 A flow chart of a dual-parallel inverter control method provided in an embodiment of the present application. This method can be applied to various electrical devices that require a drive motor. For example, air conditioners, refrigerators, etc. In addition, the execution subject of this method can be hardware or software. When the above-mentioned execution subject is hardware, the execution subject can be one or more of the above-mentioned electronic devices. For example, a single electronic device can execute this method, or multiple electronic devices can cooperate with each other to execute this method. When the above-mentioned execution subject is software, this method can be implemented as multiple software or software modules, or as a single software or software module. No specific limitation is given here.

[0047] like Figure 1 As shown, the method specifically includes:

[0048] Step 101: Obtain the expected voltage, droop coefficient, measured current, and measured mains voltage of a dual parallel inverter circuit.

[0049] In some embodiments, the droop coefficient is used to characterize the proportional relationship between the output currents of the first inverter module and the second inverter module included in the dual parallel inverter circuit. The droop coefficient can be a preset virtual impedance. In this embodiment, the first inverter module and the second inverter module correspond to different droop coefficients K1 and K2, respectively.

[0050] The expected voltage can be obtained based on the control method of the load device. For example, if the load device is a three-phase AC motor, the expected voltage can be calculated based on the set motor speed using the speed loop included in the motor control algorithm. In this embodiment, the first inverter module and the second inverter module correspond to different expected voltages V1' and V2', respectively.

[0051] The measured current can be obtained by sampling from the current output terminals of the first inverter module and the second inverter module. In this embodiment, the first inverter module and the second inverter module correspond to different measured currents I1 and I2, respectively.

[0052] The measured main circuit voltage V can be obtained by sampling from the current input terminal of the load device.

[0053] like Figure 2A , which shows a schematic diagram of the connection mode of the two inverter modules provided in this embodiment. The positions of I1 and I2 in the figure are the positions corresponding to the two sampled measured currents, and the position of V is the position corresponding to the sampled measured main circuit voltage.

[0054] like Figure 2B As shown in FIG, it shows the equivalent principle diagram of the droop control of the dual parallel inverter circuit provided by this embodiment. Among them, R is the equivalent resistance on the main line, V1' and V2' are the expected voltages of the two inverter modules, K1 and K2 are the droop coefficients (i.e., virtual impedances) of the two inverter modules, and R1 and R2 are the equivalent impedances of the load devices corresponding to the two inverter modules respectively. Equivalent impedance R i As shown in the following formula (1):

[0055] (1)

[0056] Where i=1,2, is the inductive reactance of the load device, corresponding to Figure 2A The inductive reactance of the equivalent inductance ML1, ML2, and ML3. is a virtual capacitive load, corresponding to Figure 2A The capacitive reactance of the virtual capacitors VC1, VC2, and VC3 is used as a power compensation parameter. It is the total winding resistance of the load equipment on the main line.

[0057] Depend on Figure 2B We can get:

[0058] (2)

[0059] (3)

[0060] (4)

[0061] in, is the reference voltage. Substituting equation (4) into equation (3) yields:

[0062] (5)

[0063] Further we can get:

[0064] (6)

[0065] Since R1 and R2 are basically equal, it can be simplified to

[0066] (7)

[0067] Therefore, K1 and K2 can represent the output current ratio relationship between the first inverter module and the second inverter module.

[0068] Step 102: Determine the error between the expected voltage and the measured mains voltage.

[0069] In some embodiments, the error It can be calculated according to the following formula (8):

[0070] (8)

[0071] Step 103: Determine the measured equivalent voltage of the dual parallel inverter circuit based on the measured current.

[0072] In some embodiments, the measured equivalent voltage can be obtained by multiplying the sum of the two measured currents by a preset ratio, as shown in the following formula:

[0073] (9)

[0074] Here, the two measured currents are averaged, and it can be considered that the current is converted into resistance, and the resistance is used as the measured equivalent voltage.

[0075] Step 104 : determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current.

[0076] In some embodiments, an algorithm for correcting the control voltage can be set. The input parameters of the algorithm include error, measured equivalent voltage, droop coefficient, and measured current. After calculation, the output correction control voltage u i .

[0077] For example, the correction control voltage u i It can be calculated according to the following formula:

[0078] (10)

[0079] in, The algorithm used to calculate the error according to actual needs, such as the PID (proportional-integral-derivative) algorithm and the PI (proportional-integral) algorithm.

[0080] Step 105 : generating control signals for the first inverter module and the second inverter module respectively based on the corrected control voltage.

[0081] In some embodiments, the correction control voltage can be added to the adjustment of the mains voltage, as shown in the following formula:

[0082] (11)

[0083] In load control algorithms, the corrected control voltage can be used as a load control parameter. For example, the corrected control voltage can be added to the voltage and current loops to output corresponding control signals. This control signal is typically a PWM (Pulse Width Modulation) signal, used to control the IGBTs (Insulated-Gate Bipolar Transistors) in the inverter module.

[0084] Step 106: Adjust the output power of the first inverter module and the second inverter module based on the control signal.

[0085] In some embodiments, the control signal is generally a PWM signal, and the output power of the first inverter module and the second inverter module can be adjusted by automatically adjusting the duty cycle of the PWM.

[0086] The dual-parallel inverter control method provided in the embodiment of the present application obtains the desired voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-parallel inverter circuit, then determines the error between the desired voltage and the measured main circuit voltage, determines the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current, and then determines a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current. Then, based on the correction control voltage, control signals are generated for the first inverter module and the second inverter module, respectively. Finally, the output power of the first inverter module and the second inverter module is adjusted based on the control signals. The embodiment of the present application realizes the application of the dual-parallel inverter circuit to drive a load device, and uses a droop control method to control the dual-parallel inverter circuit, and sets the droop coefficients of the first inverter module and the second inverter module of the circuit. By setting the droop control, the output power of the first inverter module and the second inverter module can be reasonably distributed, so that the power output is evenly distributed, the overload of a single inverter module is avoided, the energy loss is reduced, the response speed of the inverter circuit operation is improved, and the stability of the output power of the inverter circuit is improved.

[0087] In some optional implementations, such as Figure 3 As shown, step 105 includes:

[0088] Step 1051 : determining a reference voltage based on the desired voltage, the corrected control voltage, the droop coefficient, and the measured current.

[0089] Specifically, the above formula (2) can be substituted into formula (4), and the correction control voltage can be added to calculate the reference voltage. The specific formula is as follows:

[0090] (12)

[0091] in, is the reference voltage of the first inverter module or the second inverter module, is the expected voltage of the first inverter module or the second inverter module, To correct the control voltage, is the droop coefficient, is the measured current.

[0092] Step 1052: Calculate the measured mains voltage and the reference voltage using a preset voltage loop to obtain a reference current.

[0093] Step 1053 : Using a preset current loop, calculate the measured current and the reference current to obtain control signals of the first inverter module and the second inverter module.

[0094] The voltage loop and the current loop can be implemented using algorithms related to controlling load devices such as motors, outputting two sets of control signals (such as PWM signals) to control the switching states of the IGBTs of the first inverter module and the second inverter module respectively.

[0095] This embodiment uses parameters such as the correction control voltage and the droop coefficient to calculate the reference voltage and the reference current, and then obtains the control signal, thereby introducing the droop coefficient and the voltage correction amount in the load control, which helps to perform more accurate control on different inverter modules, and the system has a faster response speed and higher stability.

[0096] In some optional implementations, such as Figure 4 As shown, step 104 includes:

[0097] Step 1041 : multiply the droop coefficient and the measured current to obtain the droop equivalent voltage.

[0098] Step 1042 : Calculate the error based on the preset control parameters, and sum the calculated result with the measured equivalent voltage and the droop equivalent voltage to obtain a correction control voltage.

[0099] The control parameters may be parameters of a preset control algorithm, and the control algorithm may be set as required, for example, a PID algorithm, a PI algorithm, etc.

[0100] As an example, the error is calculated using the PI algorithm and the formula for obtaining the correction control voltage is as follows:

[0101] (13)

[0102] in, 、 are the parameters of the PI control algorithm.

[0103] This embodiment calculates the error using a control algorithm, and can make the measured trunk voltage close to the expected voltage after controlling the inverter module, thereby improving the accuracy of controlling the inverter module and improving the stability of the inverter module output power.

[0104] In some optional implementations, the method further includes:

[0105] According to the preset switch driving cycle, the states of the driving switches of the two groups of DC boost units included in the first inverter module are alternately controlled; according to the switch driving cycle, the states of the driving switches of the two groups of DC boost units included in the second inverter module are alternately controlled.

[0106] Specifically, the first inverter module and the second inverter module may each include two sets of parallel DC boost units, and each set of boost units may include a controlled switch. Usually, the boost units may constitute a PFC (Power Factor Correction) circuit. For details, please refer to the following Figure 9 、 Figure 10 The circuit structure diagram is shown.

[0107] like Figure 5A As shown in FIG, it is a schematic diagram of the output current change after the traditional single-group boost unit is used to control the rectified voltage, wherein the square wave signal represents the state of the drive switch, and i is the current output by the boost unit. Figure 5B As shown in FIG, it is a schematic diagram of the output current change after the rectified voltage is controlled by two sets of boost units, wherein the solid square wave and the dotted square wave represent different driving switch states. Figure 5A and Figure 5B As can be seen, using two boost units and alternating the on and off switching of the two drive switches can reduce the harmonic amplitude of the output current, reduce the fluctuation of the inverter module's output power, meet higher power requirements, and improve the power factor. Furthermore, by connecting the two boost units in parallel, the current can be shared, reducing the specification requirements of components such as inductors and drive switches.

[0108] In some optional implementations, the method further includes:

[0109] In response to the current moment reaching the preset droop coefficient rotation moment, the droop coefficients corresponding to the first inverter module and the second inverter module are swapped with each other.

[0110] Specifically, a rotation cycle can be set, with the start of each rotation cycle coinciding with the droop coefficient rotation time. Alternatively, the rotation can be performed manually, with the manual rotation time coinciding with the droop coefficient rotation time. After swapping the droop coefficients corresponding to the first inverter module and the second inverter module, the droop coefficient K1 corresponding to the first inverter module is changed to K2, and the droop coefficient K2 of the second inverter module is changed to K1.

[0111] By rotating the droop coefficients of the two inverter modules, it is possible to avoid excessive load on one inverter module, which would affect the service life of the inverter module, and ensure the long-term stability of the circuit output power.

[0112] In combination with the above embodiments, refer to Figure 6 , which shows the principle diagram of the droop correction control provided by the embodiment of the present application. The collected measured currents I1, I2, main circuit voltage V, expected voltages V1', V2', and droop coefficients K1, K2 are used as parameters of the correction control algorithm, and the reference voltage V ref1 、V ref2 Input the voltage loop respectively to get the reference current I ref1 , I ref2 , and then use the current loop to output a PWM signal to control the first inverter module and the second inverter module to adjust the output power.

[0113] Figure 7 This is a schematic diagram of the structure of a dual-parallel inverter control device provided in an embodiment of the present application. Specifically comprising:

[0114] An acquisition module 701 is configured to acquire a desired voltage, a droop coefficient, a measured current, and a measured mains voltage of a dual-parallel inverter circuit, wherein the droop coefficient is used to characterize a proportional relationship between the output currents of a first inverter module and a second inverter module included in the dual-parallel inverter circuit;

[0115] A first determining module 702 is configured to determine an error between an expected voltage and a measured mains voltage;

[0116] A second determining module 703 is configured to determine a measured equivalent voltage of the dual parallel inverter circuit based on the measured current;

[0117] A third determination module 704 is configured to determine a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current;

[0118] A generating module 705 is configured to generate control signals for the first inverter module and the second inverter module based on the corrected control voltage;

[0119] The adjustment module 706 is configured to adjust the output power of the first inverter module and the second inverter module based on the control signal.

[0120] In some optional implementations, the generation module includes: a first determination unit, used to determine the reference voltage based on the expected voltage, the corrected control voltage, the droop coefficient and the measured current; a first operation unit, used to use a preset voltage loop to operate on the measured mains voltage and the reference voltage to obtain a reference current; a second operation unit, used to use a preset current loop to operate on the measured current and the reference current to obtain the control signals of the first inverter module and the second inverter module respectively.

[0121] In some optional implementations, the third determination module includes: a first calculation unit, used to multiply the droop coefficient and the measured current to obtain a droop equivalent voltage; a second calculation unit, used to calculate the error based on preset control parameters, and sum the calculation result with the measured equivalent voltage and the droop equivalent voltage to obtain a correction control voltage.

[0122] In some optional implementations, the device also includes: a first control module, used to alternately control the state of the driving switches of the two groups of DC boost units included in the first inverter module according to a preset switch drive cycle; and a second control module, used to alternately control the state of the driving switches of the two groups of DC boost units included in the second inverter module according to the switch drive cycle.

[0123] In some optional implementations, the device further includes: a rotation module, configured to interchange the droop coefficients corresponding to the first inverter module and the second inverter module in response to reaching a preset droop coefficient rotation moment at the current moment.

[0124] The dual-parallel inverter control device provided in this embodiment can be as follows Figure 7 The dual-path parallel inverter control device shown in the figure can execute all the steps of the above dual-path parallel inverter control methods, thereby achieving the technical effects of the above dual-path parallel inverter control methods. For details, please refer to the above related description. For the sake of brevity, it will not be repeated here.

[0125] Figure 8 This is a schematic diagram of the structure of a dual-parallel inverter circuit provided in an embodiment of the present application. Figure 8 The dual parallel inverter circuit 800 shown includes: a first inverter module 801 , a second inverter module 802 , a controller 803 , a mains voltage sampling module 804 , a first current sampling module 805 and a second current sampling module 806 .

[0126] The current output end of the first inverter module 801 and the current output end of the second inverter module 802 are both connected to a load device, which is usually a three-phase AC motor.

[0127] The control signal input end of the first inverter module 801 and the control signal input end of the second inverter module 802 are both connected to the controller 803. Figure 8 As shown, PWM1 and PWM2 are control signals output by the controller 803 to the first inverter module 801 and the second inverter module 802 .

[0128] The main circuit voltage sampling module 804 is connected to the current input terminal of the load device and to the controller 803. The main circuit voltage sampling module 804 can send the collected voltage sensing signal to the controller 803, and the controller 803 obtains the measured main circuit voltage V according to the voltage sensing signal.

[0129] The first current sampling module 805 and the second current sampling module 806 are respectively connected to the current output terminal of the first inverter module 801 and the current output terminal of the second inverter module 802, and are also respectively connected to the controller 803. The first current sampling module 805 and the second current sampling module 806 can respectively send the collected current sensing signals to the controller 803, and the controller 803 obtains two measured currents I1 and I2 based on the current sensing signals.

[0130] Controller 803 is used to execute the above-mentioned dual-parallel inverter control method. The number of controllers 803 can be one or more. When there are multiple controllers, each controller 803 can control an inverter module. The method executed by controller 803 can refer to the above-mentioned method embodiment and will not be repeated here.

[0131] The dual-parallel inverter circuit provided in the embodiment of the present application collects the measured current and the measured main circuit voltage, and the controller executes the above-mentioned dual-parallel inverter control method, thereby realizing the application of the dual-parallel inverter circuit to the drive of the load device, and utilizing the droop control method to control the dual-parallel inverter circuit, and setting the droop coefficients of the first inverter module and the second inverter module of the circuit. By setting the droop control, the output power of the first inverter module and the second inverter module can be reasonably distributed, so that the power output is evenly distributed, avoiding overload of a single inverter module, reducing energy loss, improving the response speed of the inverter circuit operation, and improving the stability of the output power of the inverter circuit.

[0132] In some optional implementations, such as Figure 9As shown, the first inverter module 801 includes a first rectifier unit 8011 (including rectifier diodes D1-D4), a first DC boost unit 8012, a second DC boost unit 8013, a first charging capacitor C1 and a first inverter unit 8014 (including Q1-Q6); the second inverter module 802 includes a second rectifier unit 8021 (including rectifier diodes D7-D10), a third DC boost unit 8022, a fourth DC boost unit 8023, a second charging capacitor C2 and a second inverter unit 8024 (including Q7-Q12).

[0133] Among them, the DC boost unit is also called the boost unit, which can increase the rectified voltage.

[0134] The voltage input terminals of the first DC boost unit 8012 and the second DC boost unit 8013 are both connected to the first rectifier unit 8011. The voltage output terminals of the first DC boost unit 8012 and the second DC boost unit 8013 are both connected to the first inverter unit 8014 and the first charging capacitor C1. The control terminals of the first DC boost unit 8012 and the second DC boost unit 8013 are both connected to the controller 803. The control terminal of the first inverter unit 8014 is connected to the controller 803. Typically, the inverter unit consists of six groups of IGBT switches, receives PWM control signals sent by the controller 803, and outputs three-phase AC power.

[0135] The voltage input terminals of the third DC boost unit 8022 and the fourth DC boost unit 8023 are both connected to the second rectifier unit 8021. The voltage output terminals of the third DC boost unit 8022 and the fourth DC boost unit 8023 are both connected to the second inverter unit 8024 and the second charging capacitor C2. The control terminals of the third DC boost unit 8022 and the fourth DC boost unit 8023 are both connected to the controller 803. The control terminal of the second inverter unit 8024 is connected to the controller 803.

[0136] Accordingly, the controller 803 may perform the following steps:

[0137] According to the preset switch driving cycle, the states of the driving switches of the first DC boost unit 8012 and the second DC boost unit 8013 are alternately controlled; according to the switch driving cycle, the states of the driving switches of the third DC boost unit 8022 and the fourth DC boost unit 8023 are alternately controlled. Figure 5A and Figure 5B Description.

[0138] This embodiment employs two sets of DC boost units operating alternately, which can reduce the harmonic amplitude of the output current and minimize fluctuations in the inverter module's output power. Furthermore, by connecting the two DC boost units in parallel, current can be shared, reducing the required specifications for components such as inductors and drive switches.

[0139] In some optional implementations, such as Figure 10 As shown, the first DC boost unit 8012 includes a first inductor L1, a first diode D5 and a first controlled switch M1, and the second DC boost unit 8013 includes a second inductor L2, a second diode D6 and a second controlled switch M2. The types of M1 and M2 can be set according to actual needs, for example Figure 10 N-type field effect transistors are used, but transistors and the like may also be used.

[0140] The two ends of the first inductor L1 are respectively connected to the first rectifier unit 8011 and the anode of the first diode D5. The two ends of the second inductor L2 are respectively connected to the first rectifier unit 8011 and the anode of the second diode D6. The two current transmission ends of the first controlled switch M1 are respectively connected to the anode of the first diode D5 and the ground. The two current transmission ends of the second controlled switch M2 are respectively connected to the anode of the second diode D6 and the ground. The cathodes of the first diode D5 and the second diode D6 are both connected to the first charging capacitor C1.

[0141] The third DC boost unit 8022 includes a third inductor L3, a third diode D11 and a third controlled switch M3. The fourth DC boost unit 8023 includes a fourth inductor L4, a fourth diode D12 and a fourth controlled switch M4.

[0142] The two ends of the third inductor L3 are connected to the second rectifier unit 8021 and the anode of the third diode D11, respectively. The two ends of the fourth inductor L4 are connected to the second rectifier unit 8021 and the anode of the fourth diode D12, respectively. The two current transmission ends of the third controlled switch M3 are connected to the anode of the third diode D11 and the ground, respectively. The two current transmission ends of the fourth controlled switch M4 are connected to the anode of the fourth diode D12 and the ground, respectively. The cathodes of the third diode D11 and the fourth diode D12 are both connected to the second charging capacitor C2.

[0143] This embodiment realizes the parallel connection of two PFC circuits and alternately controls the on and off states of the switches, which can meet higher power requirements and improve the power factor.

[0144] Figure 11 A schematic diagram of the structure of an electrical device 1100 provided in an embodiment of the present application is shown in FIG. Figure 11As shown, the electrical device 1100 includes: the above-mentioned dual-parallel inverter circuit 800 and a motor 1101 , and the three-phase electrical input end of the motor 1101 is connected to the three-phase output end of the dual-parallel inverter circuit 800 .

[0145] The electrical equipment may be any equipment that needs to drive an AC motor, such as an air conditioner, a refrigerator, etc.

[0146] The electrical equipment provided in the embodiment of the present application can evenly distribute power output by applying the above-mentioned dual-parallel inverter circuit, avoid overload of a single inverter module, reduce energy loss, and improve the stability of the operation of the electrical equipment.

[0147] Figure 12 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 12 The electronic device 1200 shown includes: at least one processor 1201, a memory 1202, at least one network interface 1204 and another user interface 1203. The various components in the electronic device 1200 are coupled together via a bus system 1205. It is understood that the bus system 1205 is used to achieve connection and communication between these components. In addition to including a data bus, the bus system 1205 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, the bus system 1205 is not described in detail. Figure 12 Various buses are labeled as bus system 1205.

[0148] The user interface 1203 may include a display, a keyboard, or a pointing device (eg, a mouse, a trackball, a touchpad, or a touch screen).

[0149] It is understood that the memory 1202 in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDRSDRAM), enhanced synchronous DRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus RAM (DRRAM). Memory 1202 described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0150] In some embodiments, the memory 1202 stores the following elements, executable units, or data structures, or a subset thereof, or an extended set thereof: an operating system 12021 and application programs 12022 .

[0151] The operating system 12021 includes various system programs, such as a framework layer, a core library layer, and a driver layer, for implementing various basic services and handling hardware-based tasks. Application programs 12022 include various application programs, such as a media player and a browser, for implementing various application services. Programs implementing the methods of the embodiments of the present application may be included in application programs 12022.

[0152] In this embodiment, by calling a program or instruction stored in the memory 1202, specifically, a program or instruction stored in the application 12022, the processor 1201 is configured to execute the method steps provided in each method embodiment, for example, including:

[0153] Obtaining the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-parallel inverter circuit, wherein the droop coefficient is used to characterize the proportional relationship between the output currents of the first inverter module and the second inverter module included in the dual-parallel inverter circuit; determining the error between the expected voltage and the measured main circuit voltage; determining the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current; determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; generating control signals for the first inverter module and the second inverter module based on the correction control voltage; and adjusting the output power of the first inverter module and the second inverter module based on the control signals.

[0154] The methods disclosed in the above embodiments of the present application can be applied to or implemented by processor 1201. Processor 1201 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be performed by hardware integrated logic circuits or software instructions in processor 1201. Processor 1201 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of the present application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software units in the decoding processor. The software units can be located in storage media well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other such storage media. The storage medium is located in the memory 1202 , and the processor 1201 reads the information in the memory 1202 and completes the steps of the above method in combination with its hardware.

[0155] It is understood that the embodiments described herein may be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, or other electronic units or combinations thereof for performing the aforementioned functions of the present application.

[0156] For software implementation, the techniques described above can be implemented by a unit that performs the functions described above. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0157] The electronic device provided in this embodiment may be Figure 12 The electronic device shown in can execute all the steps of the above-mentioned dual-path parallel inverter control methods, thereby achieving the technical effects of the above-mentioned dual-path parallel inverter control methods. For details, please refer to the above related description. For the sake of brevity, it will not be repeated here.

[0158] The present application also provides a storage medium (computer-readable storage medium). The storage medium stores one or more programs. The storage medium may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as read-only memory, flash memory, a hard disk, or a solid-state drive; or a combination of the aforementioned types of memory.

[0159] When one or more programs in the storage medium can be executed by one or more processors, the dual-path parallel inverter control method executed on the electronic device side can be implemented.

[0160] The processor is configured to execute a program stored in the memory to implement the following steps of a dual-parallel inverter control method executed on the electronic device side:

[0161] Obtaining the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-parallel inverter circuit, wherein the droop coefficient is used to characterize the proportional relationship between the output currents of the first inverter module and the second inverter module included in the dual-parallel inverter circuit; determining the error between the expected voltage and the measured main circuit voltage; determining the measured equivalent voltage of the dual-parallel inverter circuit based on the measured current; determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; generating control signals for the first inverter module and the second inverter module based on the correction control voltage; and adjusting the output power of the first inverter module and the second inverter module based on the control signals.

[0162] Professionals should also be further aware that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different circuits to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0163] The steps of the circuits or algorithms described in conjunction with the embodiments disclosed herein may be implemented using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0164] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0165] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A dual-parallel inverter control method, characterized in that: The method comprises: Obtaining an expected voltage, a droop coefficient, a measured current, and a measured main circuit voltage of a dual-parallel inverter circuit, wherein the droop coefficient is used to characterize a proportional relationship between output currents of a first inverter module and a second inverter module included in the dual-parallel inverter circuit; determining an error between the expected voltage and the measured mains voltage; determining a measured equivalent voltage of the dual parallel inverter circuit based on the measured current; determining a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; generating respective control signals for the first inverter module and the second inverter module based on the corrected control voltage; adjusting the output power of the first inverter module and the second inverter module based on the control signal; The determining of the correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current includes: Multiplying the droop coefficient and the measured current to obtain a droop equivalent voltage; The error is calculated based on preset control parameters, and the calculated result is summed with the measured equivalent voltage and the droop equivalent voltage to obtain the correction control voltage.

2. The method according to claim 1, characterized in that The generating, based on the correction control voltage, respective control signals of the first inverter module and the second inverter module includes: determining a reference voltage based on the desired voltage, the corrected control voltage, the droop coefficient, and the measured current; Using a preset voltage loop, the measured main circuit voltage and the reference voltage are calculated to obtain a reference current; The measured current and the reference current are calculated using a preset current loop to obtain respective control signals of the first inverter module and the second inverter module.

3. The method according to claim 1, characterized in that The method further comprises: Alternately controlling the states of the driving switches of the two groups of DC boost units included in the first inverter module according to a preset switch driving cycle; According to the switch driving cycle, the states of the driving switches of the two groups of DC boost units included in the second inverter module are alternately controlled.

4. The method according to claim 1, wherein The method further comprises: In response to the current moment reaching a preset droop coefficient rotation moment, the droop coefficients corresponding to the first inverter module and the second inverter module are swapped with each other.

5. A dual parallel inverter circuit, characterized in that: The circuit includes: a first inverter module, a second inverter module, a controller, a main circuit voltage sampling module, a first current sampling module and a second current sampling module; The current output end of the first inverter module and the current output end of the second inverter module are both connected to a load device; The control signal input end of the first inverter module and the control signal input end of the second inverter module are both connected to the controller; The main circuit voltage sampling module is connected to the current input terminal of the load device and is connected to the controller; The first current sampling module and the second current sampling module are connected to the current output end of the first inverter module and the current output end of the second inverter module respectively, and are also connected to the controller respectively; The controller is used to execute the dual-parallel inverter control method according to any one of claims 1 to 4.

6. The circuit according to claim 5, characterized in that The first inverter module includes a first rectifier unit, a first DC boost unit, a second DC boost unit, a first charging capacitor and a first inverter unit; the second inverter module includes a second rectifier unit, a third DC boost unit, a fourth DC boost unit, a second charging capacitor and a second inverter unit; The voltage input terminals of the first DC boost unit and the second DC boost unit are both connected to the first rectifier unit, the voltage output terminals of the first DC boost unit and the second DC boost unit are both connected to the first inverter unit and the first charging capacitor, and the control terminals of the first DC boost unit and the second DC boost unit are both connected to the controller; The control end of the first inverter unit is connected to the controller; The voltage input terminals of the third DC boost unit and the fourth DC boost unit are both connected to the second rectifier unit, the voltage output terminals of the third DC boost unit and the fourth DC boost unit are both connected to the second inverter unit and the second charging capacitor, and the control terminals of the third DC boost unit and the fourth DC boost unit are both connected to the controller; The control end of the second inverter unit is connected to the controller.

7. The circuit according to claim 6, characterized in that The first DC boost unit includes a first inductor, a first diode and a first controlled switch, and the second DC boost unit includes a second inductor, a second diode and a second controlled switch; Two ends of the first inductor are connected to the anode of the first rectifier unit and the first diode, respectively; two ends of the second inductor are connected to the anode of the first rectifier unit and the second diode, respectively; two current transmission ends of the first controlled switch are connected to the anode of the first diode and the ground, respectively; two current transmission ends of the second controlled switch are connected to the anode of the second diode and the ground, respectively; and cathodes of the first diode and the second diode are both connected to the first charging capacitor; The third DC boost unit includes a third inductor, a third diode and a third controlled switch, and the fourth DC boost unit includes a fourth inductor, a fourth diode and a fourth controlled switch; The two ends of the third inductor are respectively connected to the second rectifier unit and the anode of the third diode, the two ends of the fourth inductor are respectively connected to the second rectifier unit and the anode of the fourth diode, the two current transmission ends of the third controlled switch are respectively connected to the anode of the third diode and the ground, the two current transmission ends of the fourth controlled switch are respectively connected to the anode of the fourth diode and the ground, and the cathodes of the third diode and the fourth diode are both connected to the second charging capacitor.

8. A dual-parallel inverter control device, characterized in that: The device comprises: an acquisition module, configured to acquire an expected voltage, a droop coefficient, a measured current, and a measured main circuit voltage of a dual-parallel inverter circuit, wherein the droop coefficient is used to characterize a proportional relationship between output currents of a first inverter module and a second inverter module included in the dual-parallel inverter circuit; A first determining module, configured to determine an error between the expected voltage and the measured mains voltage; A second determining module is configured to determine a measured equivalent voltage of the dual parallel inverter circuit based on the measured current; a third determining module, configured to determine a correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; a generating module, configured to generate control signals for the first inverter module and the second inverter module respectively based on the corrected control voltage; an adjustment module, configured to adjust the output power of the first inverter module and the second inverter module based on the control signal; The third determining module includes: a first calculation unit, configured to multiply the droop coefficient and the measured current to obtain a droop equivalent voltage; The second calculation unit is used to calculate the error based on preset control parameters, and sum the calculated result with the measured equivalent voltage and the droop equivalent voltage to obtain the correction control voltage.

9. An electrical device, characterized in that: include: The dual parallel inverter circuit and motor according to any one of claims 5 to 7.

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