Double-circuit parallel inverter control method, double-circuit parallel inverter circuit and electrical equipment

Abstract

The embodiment of the invention relates to a two-way parallel inverter control method, a two-way parallel inverter circuit and electrical equipment. The method comprises the following steps: acquiring an expected voltage, a droop coefficient, an actually measured current and an actually measured trunk voltage of the two-way parallel inverter circuit; determining an error between the expected voltage and the actually measured trunk voltage; based on the actually measured current, determining an actually measured equivalent voltage of the double-path parallel inverter circuit; determining a correction control voltage based on the error, the actually measured equivalent voltage, the droop coefficient and the actually measured current; generating respective control signals of the first inversion module and the second inversion module based on the correction control voltage; and adjusting the output power of the first inversion module and the second inversion module based on the control signal. According to the embodiment of the invention, the power output is uniformly distributed, the overload of a single inverter module is avoided, the energy loss is reduced, the response speed of the operation of the inverter circuit is improved, and the stability of the output power of the inverter circuit is improved.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, and in particular, to a dual-path parallel inverter control method, a dual-path parallel inverter circuit, and an electrical device. Background Art

[0002] In a traditional inverter-driven motor system, usually a single inverter is used to drive one motor, which results in an excessive output power of the inverter, making it prone to overheating and even damage of the inverter. Moreover, a single inverter cannot perform power distribution on the output power of the load motor, resulting in unstable power output. Therefore, how to reasonably distribute the output power of the inverter and ensure the stability of the output power is an urgent problem to be solved. Summary of the Invention

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

[0004] In a first aspect, embodiments of this application provide a dual-path parallel inverter control method, which includes: obtaining the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current ratio relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; determining the error between the expected voltage and the measured main circuit voltage; determining the measured equivalent voltage of the dual-path parallel inverter circuit based on the measured current; determining the correction control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current; generating respective control signals for the first inverter module and the second inverter module based on the correction control voltage; and adjusting the output powers of the first inverter module and the second inverter module based on the control signals.

[0005] In a possible implementation manner, generating respective control signals for the first inverter module and the second inverter module based on the correction control voltage includes: determining a reference voltage based on the expected voltage, correction control voltage, droop coefficient, and measured current; using a preset voltage loop to perform an operation on the measured main circuit voltage and the reference voltage to obtain a reference current; and using a preset current loop to perform an operation on the measured current and the reference current to obtain respective control signals for the first inverter module and the second inverter module.

[0006] In a possible implementation manner, determining the correction control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current includes: multiplying the droop coefficient and the measured current to obtain a droop equivalent voltage; calculating the error based on preset control parameters, and summing the obtained calculation result with the measured equivalent voltage and the droop equivalent voltage to obtain the correction control voltage.

[0007] In a possible implementation, the method further includes: alternately controlling the states of the driving switches of the two DC boost units included in the first inverter module according to a preset switching driving period; alternately controlling the states of the driving switches of the two DC boost units included in the second inverter module according to the switching driving period.

[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 with each other.

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

[0010] In a possible implementation, the first inverter module includes a first rectification 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 rectification 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 rectification 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 terminal 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 rectification 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 terminal of the second inverter unit is connected to the controller.

[0011] In a possible implementation, 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; both ends of the first inductor are respectively connected to the first rectification unit and the anode of the first diode, both ends of the second inductor are respectively connected to the first rectification unit and the anode of the second diode, the two current transmission ends of the first controlled switch are respectively connected to the anode of the first diode and the ground terminal, the two current transmission ends of the second controlled switch are respectively connected to the anode of the second diode and the ground terminal, and the 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; both ends of the third inductor are respectively connected to the second rectification unit and the anode of the third diode, both ends of the fourth inductor are respectively connected to the second rectification 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 terminal, the two current transmission ends of the fourth controlled switch are respectively connected to the anode of the fourth diode and the ground terminal, and the cathodes of the third diode and the fourth diode are both connected to the second charging capacitor.

[0012] In a third aspect, an embodiment of the present application provides a dual-path parallel inverter control device, which includes: an acquisition module, configured to acquire the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; a first determination module, configured to determine the error between the expected voltage and the measured main circuit voltage; a second determination module, configured to determine the measured equivalent voltage of the dual-path parallel inverter circuit based on the measured current; a third determination module, configured to determine a corrected control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current; a generation module, configured to generate respective control signals for the first inverter module and the second inverter module based on the corrected control voltage; and an adjustment module, configured to adjust the output power of the first inverter module and the second inverter module based on the control signals.

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

[0014] In a fifth aspect, an embodiment of the present application provides an electronic device, including: a memory, configured to store a computer program; and a processor, configured to execute the computer program stored in the memory, and when the computer program is executed, implement the method of any one of the embodiments of the dual-path parallel inverter control method in 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, the method of any one of the dual-path parallel inverter control methods in the first aspect described above is implemented.

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

[0017] The dual-path parallel inverter control method, dual-path parallel inverter circuit and electrical equipment provided by the embodiments of the present application obtain the expected voltage, droop coefficient, measured current and measured main circuit voltage of the dual-path 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-path parallel inverter circuit based on the measured current, and then determine the corrected control voltage based on the error, measured equivalent voltage, droop coefficient and measured current. Then, based on the corrected control voltage, control signals for the first inverter module and the second inverter module are generated respectively. Finally, based on the control signals, the output powers of the first inverter module and the second inverter module are adjusted. The embodiments of the present application realize the application of the dual-path parallel inverter circuit to drive a load device, use the droop control method to control the dual-path parallel inverter circuit, and set the droop coefficients of the first inverter module and the second inverter module of the circuit. By setting the droop control, the output powers 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. Description of the Drawings

[0018] The drawings here are incorporated into the specification and constitute a part of this specification, showing the embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

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

[0021] Figure 1Schematic flowchart of a dual - path parallel inverter control method provided by an embodiment of the present application; Figure 2A Schematic diagram of the connection mode of two inverter modules provided by an embodiment of the present application; Figure 2B Equivalent schematic diagram of droop control provided by an embodiment of the present application; Figure 3 Schematic flowchart of another dual - path parallel inverter control method provided by an embodiment of the present application; Figure 4 Schematic flowchart of yet another dual - path parallel inverter control method provided by an embodiment of the present application; Figure 5A Schematic diagram of the current change of the traditional single - group boost unit output; Figure 5B Schematic diagram of the current change of the two - group boost unit output provided by an embodiment of the present application; Figure 6 Schematic diagram of the droop correction control provided by an embodiment of the present application; Figure 7 Schematic diagram of the structure of a dual - path parallel inverter control device provided by an embodiment of the present application; Figure 8 Schematic diagram of the structure of a dual - path parallel inverter circuit provided by an embodiment of the present application; Figure 9 Schematic diagram of the structure of another dual - path parallel inverter circuit provided by an embodiment of the present application; Figure 10 Schematic diagram of the structure of yet another dual - path parallel inverter circuit provided by an embodiment of the present application; Figure 11 Schematic diagram of the structure of an electrical device provided by an embodiment of the present application; Figure 12 Schematic diagram of the structure of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0022] Now, various exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present application.

[0023] Those skilled in the art can understand that terms such as "first", "second", etc. in the embodiments of the present application are only used to distinguish different steps, devices or modules, etc., and do not represent any specific technical meaning, nor do they represent the logical order between them.

[0024] It should also be understood that in this embodiment, "a plurality of" may mean two or more, and "at least one" may mean one, two or more.

[0025] It should also be understood that for any component, data or structure mentioned in the embodiments of the present application, in the case of no clear limitation or contrary revelation in the context, it can generally be understood as one or more.

[0026] In addition, the term "and / or" in the present application is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the associated objects before and after.

[0027] It should also be understood that the description of each embodiment of the present application emphasizes the differences between the embodiments, and their similarities or similarities can be referred to each other. For the sake of brevity, they will not be elaborated one by one.

[0028] The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present application and its application or use.

[0029] Technologies, circuits and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the above technologies, circuits and devices should be regarded as part of the specification.

[0030] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0031] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. For the convenience of understanding the embodiments of the present application, the present application will be described in detail below with reference to the drawings and in combination with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0032] In order to solve the technical problem that the output power is unstable when the inverter circuit in the prior art operates, the present application provides a dual-path parallel inverter control method, which can reasonably distribute the output power of each inverter module and improve the stability of power output.

[0033] Figure 1Schematic flow chart of a dual - path parallel inverter control method provided by an embodiment of this application. This method can be applied to various electrical appliances that need to drive motors, such as 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 can be implemented as a single software or software module. No specific limitation is made here.

[0034] As Figure 1 shown, the method specifically includes: Step 101, obtain the desired voltage, droop coefficient, measured current, and measured main - circuit voltage of the dual - path parallel inverter circuit.

[0035] In some embodiments, the droop coefficient is used to characterize the output - current proportional relationship between the first inverter module and the second inverter module included in the dual - path parallel inverter circuit. The droop coefficient can be a pre - set virtual impedance. In this embodiment, the first inverter module and the second inverter module respectively correspond to different droop coefficients K1 and K2.

[0036] The above - mentioned desired voltage can be obtained according to the control method of the load device. As an example, if the load device is a three - phase AC motor, it can be calculated according to the set motor speed by using the speed loop included in the motor control algorithm. In this embodiment, the first inverter module and the second inverter module respectively correspond to different desired voltages V1' and V2'.

[0037] The above - mentioned 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 respectively correspond to different measured currents I1 and I2.

[0038] The above - mentioned measured main - circuit voltage V can be obtained by sampling from the current input terminal of the load device.

[0039] As Figure 2A shown, it shows a schematic diagram of the connection method of the two inverter modules provided in this embodiment. The positions where I1 and I2 are located in the figure are the positions corresponding to the two sampled measured currents, and the position where V is located is the position corresponding to the sampled measured main - circuit voltage.

[0040] As Figure 2BAs shown, it shows the equivalent schematic diagram of droop control for the dual - path parallel inverter circuit provided in this embodiment. Among them, R is the equivalent resistance on the main circuit, 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. The equivalent impedance R i is as shown in the following formula (1): (1) where i = 1, 2, is the inductive reactance of the load device, corresponding to Figure 2A the inductive reactances of the equivalent inductors ML1, ML2, and ML3 in is the virtual capacitive load, corresponding to Figure 2A the capacitive reactances of the virtual capacitors VC1, VC2, and VC3 in and is used as a power compensation parameter.

[0041] From Figure 2B it can be obtained that: (2) (3) (4) where, is the reference voltage. Substituting formula (4) into formula (3) gives: (5) Furthermore, it can be obtained that: (6) Since R1 and R2 are basically equal, it can be simplified to (7) Therefore, K1 and K2 can represent the output current ratio relationship of the first inverter module and the second inverter module.

[0042] Step 102, determine the error between the expected voltage and the measured main - circuit voltage.

[0043] In some embodiments, this error can be calculated according to the following formula (8): (8) Step 103, based on the measured current, determine the measured equivalent voltage of the dual - path parallel inverter circuit.

[0044] 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: (9) Here, the average of the two measured currents is taken, and it can be considered that the current is converted into a resistance, and this resistance is used as the measured equivalent voltage.

[0045] Step 104: Determine the correction control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current.

[0046] In some embodiments, an algorithm for the correction control voltage can be set, and the input parameters of this algorithm include the error, the measured equivalent voltage, the droop coefficient, and the measured current. After calculation, the correction control voltage u is output. i 。

[0047] For example, the correction control voltage u i can be calculated according to the following formula: (10) where is an algorithm used to calculate the error according to actual requirements, such as the PID (Proportional-Integral-Derivative) algorithm, the PI (Proportional-Integral) algorithm, etc.

[0048] Step 105: Generate the control signals for the first inverter module and the second inverter module respectively based on the correction control voltage.

[0049] In some embodiments, the correction control voltage can be added to the adjustment amount of the trunk voltage. As shown in the following formula: (11) In the control algorithm for the load, the correction control voltage can be used as a parameter for load control. For example, the correction control voltage is added to the voltage loop and the current loop, and the corresponding control signals are output. The control signals are usually PWM (Pulse Width Modulation) signals to control the IGBT (Insulate-Gate Bipolar Transistor) in the inverter module.

[0050] Step 106: Adjust the output powers of the first inverter module and the second inverter module based on the control signals.

[0051] In some embodiments, the control signals are usually PWM signals. By automatically adjusting the duty cycle of the PWM, the output powers of the first inverter module and the second inverter module can be adjusted.

[0052] The dual - path parallel inverter control method provided by the embodiments of the present application obtains the desired voltage, droop coefficient, measured current, and measured main - circuit voltage of the dual - path 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 - path parallel inverter circuit based on the measured current, determines the corrected control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current, then generates the control signals for the first inverter module and the second inverter module respectively based on the corrected control voltage, and finally adjusts the output power of the first inverter module and the second inverter module based on the control signals. The embodiments of the present application realize the application of the dual - path parallel inverter circuit to drive load devices, use the droop control method to control the dual - path parallel inverter circuit, and set 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 allocated, 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.

[0053] In some alternative implementation manners, as Figure 3 shown, step 105 includes: Step 1051, determine a reference voltage based on the desired voltage, corrected control voltage, droop coefficient, and measured current.

[0054] Specifically, the above formula (2) can be substituted into formula (4), and the corrected control voltage is added to calculate the reference voltage. The specific formula is as follows: (12) Wherein, is the reference voltage of the first inverter module or the second inverter module, is the desired voltage of the first inverter module or the second inverter module, is the corrected control voltage, is the droop coefficient, is the measured current.

[0055] Step 1052, use a preset voltage loop to operate on the measured main - circuit voltage and the reference voltage to obtain a reference current.

[0056] Step 1053, use a preset current loop to operate on the measured current and the reference current to obtain the control signals for the first inverter module and the second inverter module respectively.

[0057] Among them, the voltage loop and the current loop can be implemented by using relevant algorithms for controlling load devices such as motors, and output 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.

[0058] In this embodiment, by using parameters such as a correction control voltage and a droop coefficient, a reference voltage and a reference current are calculated, and then a control signal is obtained, thereby introducing a droop coefficient and a voltage correction amount in the load control, which helps to perform more accurate control for different inverter modules, and the system has a faster response speed and higher stability.

[0059] In some alternative implementation manners, such as Figure 4 shown, step 104 includes: Step 1041: Multiply the droop coefficient by the measured current to obtain a droop equivalent voltage.

[0060] Step 1042: Calculate the error based on preset control parameters, and sum the obtained calculation result with the measured equivalent voltage and the droop equivalent voltage to obtain a correction control voltage.

[0061] The above control parameters can be parameters of a preset control algorithm, and the control algorithm can be set according to requirements. For example, a PID algorithm, a PI algorithm, etc. can be used.

[0062] As an example, when using a PI algorithm to calculate the error, the formula for obtaining the correction control voltage is as follows: (13) Where , are parameters of the PI control algorithm.

[0063] In this embodiment, by using a control algorithm to calculate the error, after controlling the inverter module, the measured main voltage can be close to the desired voltage, thereby improving the control accuracy of the inverter module and the stability of the output power of the inverter module.

[0064] In some alternative implementation manners, the method further includes: Controlling the states of the driving switches of the two groups of DC boost units included in the first inverter module alternately according to a preset switching driving period; controlling the states of the driving switches of the two groups of DC boost units included in the second inverter module alternately according to the switching driving period.

[0065] Specifically, the first inverter module and the second inverter module can each include two groups of parallel DC boost units, and each group of boost units can include a controlled switch. Usually, the boost units can form a PFC (Power Factor Correction) circuit. Specifically, reference can be made to the circuit structure diagrams shown in the following Figure 9 , Figure 10 shown.

[0066] Such as Figure 5AAs shown, it is a schematic diagram of the current variation after controlling the rectified voltage by a traditional single set of boost units. The square wave signal therein represents the state of the drive switch, and i is the current output by the boost unit. As Figure 5B shown, it is a schematic diagram of the current variation after controlling the rectified voltage by two sets of boost units. The solid square wave and the dashed square wave therein are the states of different drive switches. From Figure 5A and Figure 5B it can be seen that by using two sets of boost units and alternately turning on and off two drive switches, the harmonic amplitude of the output current can be reduced, the fluctuation amplitude of the output power of the inverter module can be decreased, and higher power requirements can be met, improving the power factor. Moreover, by paralleling two boost units, the current can be shared, reducing the specification requirements of devices such as inductors and drive switches.

[0067] In some alternative implementation manners, the method further includes: In response to the current moment reaching the preset droop coefficient rotation moment, the droop coefficients respectively corresponding to the first inverter module and the second inverter module are swapped with each other.

[0068] Specifically, a rotation period can be set, and the starting moment of each rotation period is the droop coefficient rotation moment. Or manual operation can be performed for rotation, that is, the moment of manual operation for rotation is the droop coefficient rotation moment. After swapping the droop coefficients respectively corresponding to the first inverter module and the second inverter module with each other, 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.

[0069] By rotating the droop coefficients of the two inverter modules, it is possible to avoid excessive load on a certain inverter module, which affects the service life of the inverter module, and ensure the long-term stability of the circuit output power.

[0070] Combining the above embodiments, referring to Figure 6 , it shows the schematic diagram of the droop correction control provided by the embodiments of the present application. The measured currents I1, I2, the trunk voltage V, the desired voltages V1', V2', and the droop coefficients K1, K2 collected are used as parameters of the correction control algorithm. The reference voltages V ref1 , V ref2 are respectively input into the voltage loop to obtain the reference currents I ref1 , I ref2 , and then the current loop is used to output a PWM signal to control the first inverter module and the second inverter module to adjust the output power.

[0071] Figure 7 is a schematic structural diagram of a dual-path parallel inverter control device provided by the embodiments of the present application. Specifically, it includes: An acquisition module 701, configured to acquire the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; A first determination module 702, configured to determine the error between the expected voltage and the measured main circuit voltage; A second determination module 703, configured to determine the measured equivalent voltage of the dual-path parallel inverter circuit based on the measured current; A third determination module 704, configured to determine the corrected control voltage based on the error, the measured equivalent voltage, the droop coefficient, and the measured current; A generation module 705, configured to generate respective control signals for the first inverter module and the second inverter module based on the corrected control voltage; An adjustment module 706, configured to adjust the output powers of the first inverter module and the second inverter module based on the control signals.

[0072] In some alternative implementation manners, the generation module includes: a first determination unit, configured to determine a reference voltage based on the expected voltage, the corrected control voltage, the droop coefficient, and the measured current; a first operation unit, configured to perform an operation on the measured main circuit voltage and the reference voltage by using a preset voltage loop to obtain a reference current; and a second operation unit, configured to perform an operation on the measured current and the reference current by using a preset current loop to obtain respective control signals for the first inverter module and the second inverter module.

[0073] In some alternative implementation manners, the third determination module includes: a first calculation unit, configured to multiply the droop coefficient by the measured current to obtain a droop equivalent voltage; and a second calculation unit, configured to calculate the error based on preset control parameters, and sum the obtained calculation result with the measured equivalent voltage and the droop equivalent voltage to obtain the corrected control voltage.

[0074] In some alternative implementation manners, the device further includes: a first control module, configured to alternately control the states of the drive switches of the two groups of DC boost units included in the first inverter module according to a preset switch drive period; and a second control module, configured to alternately control the states of the drive switches of the two groups of DC boost units included in the second inverter module according to the switch drive period.

[0075] In some alternative implementation manners, the device further includes: a rotation module, configured to, in response to the current moment reaching a preset droop coefficient rotation moment, swap the droop coefficients corresponding to the first inverter module and the second inverter module with each other.

[0076] The dual-path parallel inverter control device provided in this embodiment may be as Figure 7The dual-path parallel inverter control device shown in can execute all steps of the above-mentioned dual-path parallel inverter control methods, and thus achieve the technical effects of the above-mentioned dual-path parallel inverter control methods. For specific details, please refer to the above relevant descriptions. For the sake of brevity, it will not be elaborated here.

[0077] Figure 8 FIG. 4 is a schematic structural diagram of a dual-path parallel inverter circuit provided by an embodiment of the present application. Figure 8 The shown dual-path parallel inverter circuit 800 includes: a first inverter module 801, a second inverter module 802, a controller 803, a main circuit voltage sampling module 804, a first current sampling module 805, and a second current sampling module 806.

[0078] The current output terminals of the first inverter module 801 and the second inverter module 802 are both connected to the load device. This load device is usually a three-phase AC motor.

[0079] The control signal input terminals of the first inverter module 801 and the second inverter module 802 are both connected to the controller 803. As Figure 8 shown, PWM1 and PWM2 are control signals output by the controller 803 to the first inverter module 801 and the second inverter module 802.

[0080] The main circuit voltage sampling module 804 is connected to the current input terminal of the load device and is also connected to the controller 803. The main circuit voltage sampling module 804 can send the collected voltage induction signal to the controller 803, and the controller 803 obtains the measured main circuit voltage V according to the voltage induction signal.

[0081] The first current sampling module 805 and the second current sampling module 806 are respectively connected to the current output terminals of the first inverter module 801 and 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 induction signals to the controller 803, and the controller 803 obtains two measured currents I1 and I2 according to the current induction signals.

[0082] The controller 803 is used to execute the above-mentioned dual-path parallel inverter control method. The number of the controllers 803 can be one or more. When there are multiple controllers 803, each controller 803 can control one inverter module respectively. The method executed by the controller 803 can refer to the above method embodiments and will not be elaborated here.

[0083] The dual-path parallel inverter circuit provided by the embodiment of the present application collects the measured current and the measured main circuit voltage. The controller executes the above-mentioned dual-path parallel inverter control method, realizing the application of the dual-path parallel inverter circuit to drive the load device, and using the droop control method to control the dual-path parallel inverter circuit. Moreover, by setting the droop coefficients of the first inverter module and the second inverter module of the circuit, the output power of the first inverter module and the second inverter module can be reasonably allocated through the set droop control, 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.

[0084] In some alternative implementation manners, as Figure 9 shown, the first inverter module 801 includes a first rectification 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 rectification 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).

[0085] Among them, the DC boost unit, that is, the boost unit, can raise the rectified voltage.

[0086] The voltage input ends of the first DC boost unit 8012 and the second DC boost unit 8013 are both connected to the first rectification unit 8011. The voltage output ends 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 ends of the first DC boost unit 8012 and the second DC boost unit 8013 are both connected to the controller 803. The control end of the first inverter unit 8014 is connected to the controller 803. Generally, the inverter unit is composed of six groups of IGBT switches, receives the PWM control signal sent by the controller 803, and outputs three-phase alternating current.

[0087] The voltage input ends of the third DC boost unit 8022 and the fourth DC boost unit 8023 are both connected to the second rectification unit 8021. The voltage output ends 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 ends of the third DC boost unit 8022 and the fourth DC boost unit 8023 are both connected to the controller 803. The control end of the second inverter unit 8024 is connected to the controller 803.

[0088] Correspondingly, the controller 803 can execute the following steps: According to the preset switching driving period, alternately control the states of the driving switches of the first DC boost unit 8012 and the second DC boost unit 8013 respectively; according to the switching driving period, alternately control the states of the driving switches of the third DC boost unit 8022 and the fourth DC boost unit 8023 respectively. Specifically, reference can be made to the description of Figure 5A and Figure 5B in the above method embodiments.

[0089] In this embodiment, two groups of DC boost units work alternately, which can reduce the harmonic amplitude of the output current and the fluctuation amplitude of the output power of the inverter module. Moreover, by paralleling two DC boost units, the current can be shared, and the specification requirements of devices such as inductors and driving switches can be reduced.

[0090] In some alternative implementation manners, as Figure 10 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. Among them, the types of M1 and M2 can be set according to actual requirements. For example, Figure 10 N-type field effect transistors are adopted, and triodes can also be used.

[0091] Both ends of the first inductor L1 are respectively connected to the first rectifier unit 8011 and the anode of the first diode D5. Both 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 terminal. 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 terminal. The cathodes of the first diode D5 and the second diode D6 are both connected to the first charging capacitor C1.

[0092] The third DC boost unit 8022 includes a third inductor L3, a third diode D11, and a third controlled switch M3, and the fourth DC boost unit 8023 includes a fourth inductor L4, a fourth diode D12, and a fourth controlled switch M4.

[0093] Both ends of the third inductor L3 are respectively connected to the second rectifier unit 8021 and the anode of the third diode D11. Both ends of the fourth inductor L4 are respectively connected to the second rectifier unit 8021 and the anode of the fourth diode D12. The two current transmission ends of the third controlled switch M3 are respectively connected to the anode of the third diode D11 and the ground terminal. The two current transmission ends of the fourth controlled switch M4 are respectively connected to the anode of the fourth diode D12 and the ground terminal. The cathodes of the third diode D11 and the fourth diode D12 are both connected to the second charging capacitor C2.

[0094] This embodiment realizes the parallel connection of two PFC circuits and alternately controls the on-off states of the switches, which can meet higher power requirements and improve the power factor.

[0095] Figure 11 FIG. is a schematic structural diagram of an electrical device 1100 provided by an embodiment of the present application. As Figure 11 shown, the electrical device 1100 includes: the above-mentioned dual-path parallel inverter circuit 800 and a motor 1101. The three-phase power input end of the motor 1101 is connected to the three-phase output end of the dual-path parallel inverter circuit 800.

[0096] This electrical device can be various devices that need to drive an AC motor, such as an air conditioner, a refrigerator, etc.

[0097] For the electrical device provided by the embodiment of the present application, by applying the above-mentioned dual-path parallel inverter circuit, the power output can be evenly distributed, avoiding overloading of a single inverter module, reducing energy loss, and improving the operating stability of the electrical device.

[0098] Figure 12 FIG. is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Figure 12 As shown, the electronic device 1200 includes: at least one processor 1201, a memory 1202, at least one network interface 1204, and other user interfaces 1203. Each component in the electronic device 1200 is coupled together through a bus system 1205. It can be understood that the bus system 1205 is used to realize the 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 clear illustration, in Figure 12 all kinds of buses are labeled as the bus system 1205.

[0099] Among them, the user interface 1203 may include a display, a keyboard, or a pointing device (such as a mouse, a trackball, a touchpad, or a touch screen, etc.).

[0100] It can be understood that the memory 1202 in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can 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 can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synch link dynamic random access memory (SLDRAM), and direct rambus random access memory (DRRAM). The memory 1202 described herein is intended to include but not be limited to these and any other suitable types of memory.

[0101] In some embodiments, the memory 1202 stores the following elements, executable units, or data structures, or subsets thereof, or extended sets thereof: the operating system 12021 and the application program 12022.

[0102] Among them, the operating system 12021 includes various system programs, such as the framework layer, the core library layer, the driver layer, etc., and is used to implement various basic services and process hardware-based tasks. The application program 12022 includes various application programs, such as a media player and a browser, etc., and is used to implement various application services. The program for implementing the method of the embodiments of the present application can be included in the application program 12022.

[0103] In this embodiment, by calling the program or instruction stored in the memory 1202, specifically, the program or instruction stored in the application program 12022, the processor 1201 is used to execute the method steps provided in each method embodiment, for example, including: Obtain the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; determine the error between the expected voltage and the measured main circuit voltage; determine the measured equivalent voltage of the dual-path parallel inverter circuit based on the measured current; determine the corrected control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current; generate respective control signals for the first inverter module and the second inverter module based on the corrected control voltage; adjust the output power of the first inverter module and the second inverter module based on the control signals.

[0104] The method disclosed in the embodiments of the present application above can be applied to or implemented by the processor 1201. The processor 1201 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor 1201 or the instructions in the form of software. The above 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, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed by the hardware decoding processor, or executed by the combination of the hardware and software units in the decoding processor. The software unit may be located in a mature storage medium in the art such as a random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, register, etc. This storage medium is located in the memory 1202, and the processor 1201 reads the information in the memory 1202 and combines its hardware to complete the steps of the above method.

[0105] It can be understood that the embodiments described herein can be implemented using hardware, software, firmware, middleware, microcode, or any combination thereof. For hardware implementation, the processing unit can 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, other electronic units for performing the above functions of this application, or any combination thereof.

[0106] For software implementation, the above technologies herein can be implemented by units that execute the above functions herein. The software code can be stored in a memory and executed by a processor. The memory can be implemented within the processor or outside the processor.

[0107] The electronic device provided in this embodiment can be an electronic device as shown in Figure 12 which can execute all the steps of the above-described dual-path parallel inverter control method, thereby achieving the technical effects of the above-described dual-path parallel inverter control method. For specific details, please refer to the above relevant descriptions. For the sake of brevity, it will not be elaborated here.

[0108] The embodiments of this application also provide a storage medium (computer-readable storage medium). The storage medium stores one or more programs. Among them, the storage medium can include volatile memory, such as random access memory; the memory can also include non-volatile memory, such as read-only memory, flash memory, hard disk, or solid-state drive; the memory can also include a combination of the above types of memory.

[0109] When one or more programs in the storage medium can be executed by one or more processors to implement the above-described dual-path parallel inverter control method executed on the electronic device side.

[0110] The above processor is used to execute the program stored in the memory to implement the following steps of the dual-path parallel inverter control method executed on the electronic device side: Obtain the expected voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; determine the error between the expected voltage and the measured main circuit voltage; determine the measured equivalent voltage of the dual-path parallel inverter circuit based on the measured current; determine the correction control voltage based on the error, measured equivalent voltage, droop coefficient, and measured current; generate respective control signals for the first inverter module and the second inverter module based on the correction control voltage; and adjust the output power of the first inverter module and the second inverter module based on the control signals.

[0111] Those skilled in the art should also be able to further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different circuits to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0112] The steps of the circuits or algorithms described in combination with the embodiments disclosed in this article can be implemented by hardware, software modules executed by a processor, or a combination of the two. The software modules can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the technical field.

[0113] It should be understood that the terms used in this article are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless otherwise clearly specified in the context, the singular forms "a", "an", and "the" as used in this article may also represent the plural form. The terms "including", "comprising", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The steps, processes, and operations described in this article are not to be construed as necessarily requiring them to be executed in the specific order described or illustrated, unless the execution order is clearly specified. It should also be understood that additional or alternative steps can be used.

[0114] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A dual-path parallel inverter control method, characterized in that The method includes: Obtaining the desired voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; Determining the error between the desired voltage and the measured main circuit voltage; Based on the measured current, determining the measured equivalent voltage of the dual-path parallel inverter circuit; Based on the error, the measured equivalent voltage, the droop coefficient, and the measured current, determining the corrected control voltage; Based on the corrected control voltage, generating respective control signals for the first inverter module and the second inverter module; Based on the control signals, adjusting the output powers of the first inverter module and the second inverter module.

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

3. The method according to claim 1, characterized in that, The determining the corrected 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; Based on preset control parameters, calculating the error, and summing the obtained calculation result with the measured equivalent voltage and the droop equivalent voltage to obtain the corrected control voltage.

4. The method according to claim 1, characterized in that The method further includes: Alternately controlling the states of the drive switches of the two groups of DC boost units included in the first inverter module according to a preset switching drive period; Alternately controlling the states of the drive switches of the two groups of DC boost units included in the second inverter module according to the switching drive period.

5. The method according to claim 1, wherein The method further includes: In response to the current moment reaching a preset droop coefficient rotation moment, mutually swapping the droop coefficients corresponding to the first inverter module and the second inverter module.

6. A dual-path 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 terminals of the first inverter module and the second inverter module are both connected to a load device; The control signal input terminals of the first inverter module and 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 respectively connected to the current output terminals of the first inverter module and the second inverter module and are respectively connected to the controller; The controller is configured to execute the dual-path parallel inverter control method according to any one of claims 1-5.

7. The circuit according to claim 6, characterized in that, The first inverter module includes a first rectification 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 rectification 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 rectification 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. 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 rectification 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. 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.

8. The circuit according to claim 7, wherein The first DC boost unit includes a first inductor, a first diode, and a first controlled switch. The second DC boost unit includes a second inductor, a second diode, and a second controlled switch; Two ends of the first inductor are respectively connected to the first rectification unit and the anode of the first diode. Two ends of the second inductor are respectively connected to the first rectification unit and the anode of the second diode. Two current transmission ends of the first controlled switch are respectively connected to the anode of the first diode and the ground terminal. Two current transmission ends of the second controlled switch are respectively connected to the anode of the second diode and the ground terminal. The 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. The fourth DC boost unit includes a fourth inductor, a fourth diode, and a fourth controlled switch; Two ends of the third inductor are respectively connected to the second rectification unit and the anode of the third diode. Two ends of the fourth inductor are respectively connected to the second rectification unit and the anode of the fourth diode. Two current transmission ends of the third controlled switch are respectively connected to the anode of the third diode and the ground terminal. Two current transmission ends of the fourth controlled switch are respectively connected to the anode of the fourth diode and the ground terminal. The cathodes of the third diode and the fourth diode are both connected to the second charging capacitor.

9. A dual-path parallel inverter control device, characterized in that, The device includes: An acquisition module, configured to acquire the desired voltage, droop coefficient, measured current, and measured main circuit voltage of the dual-path parallel inverter circuit, where the droop coefficient is used to characterize the output current proportional relationship between the first inverter module and the second inverter module included in the dual-path parallel inverter circuit; A first determination module, configured to determine the error between the desired voltage and the measured main circuit voltage; A second determination module, configured to determine an actual equivalent voltage of the dual-path parallel inverter circuit based on the measured current; A third determination module, configured to determine a corrected control voltage based on the error, the actual equivalent voltage, the droop coefficient, and the measured current; A generation module, configured to generate respective control signals for the first inverter module and the second inverter module based on the corrected control voltage; An adjustment module, configured to adjust output powers of the first inverter module and the second inverter module based on the control signals.

10. An electrical device, characterized in that, Comprising: The dual-path parallel inverter circuit and the motor according to any one of claims 6-8.

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