Inverter circuit, maximum power tracking method thereof and energy storage inverter equipment

Abstract

The invention discloses an inverter circuit, a maximum power tracking method thereof and energy storage inverter equipment, the inverter circuit comprises a full-bridge circuit, a transformer and a half-bridge circuit, the full-bridge circuit is connected to the half-bridge circuit through the transformer, the full-bridge circuit is connected with a photovoltaic module, and the half-bridge circuit is connected with an alternating current side; the maximum power tracking method comprises the following steps: acquiring the input power of the photovoltaic module in the current period and the input power of the photovoltaic module in the previous period, and the reference output voltage of the inverter in the first period; determining a voltage adjustment step length according to the power deviation and the voltage deviation, the power deviation being based on the input power of the current period and the previous period, and the voltage deviation being based on the input voltage of the photovoltaic module of the current period and the previous period; obtaining the reference output voltage of the current period according to the voltage adjustment step length and the reference output voltage of the previous period; and generating a driving signal according to the reference output voltage of the current period so as to control the inverter circuit. According to the invention, the maximum power point of the photovoltaic module can be tracked by the inverter circuit.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion, and in particular to an inverter circuit and a maximum power tracking method thereof and an energy storage inverter device. Background Art

[0002] At present, inverter circuits are widely used in various devices with power conversion functions, such as photovoltaic energy storage devices and photovoltaic inverter devices, to convert the DC power of photovoltaic modules into AC power through the inverter circuit. Existing inverter circuits generally need to be connected to photovoltaic modules through an MPPT circuit to track the maximum power of photovoltaic modules through the MPPT circuit. That is, there is currently a lack of means to directly connect the inverter circuit to the photovoltaic module to track the maximum power of the photovoltaic module through the inverter circuit. Summary of the invention

[0003] In view of this, the present application provides an inverter circuit and a maximum power tracking method thereof and an energy storage inverter device, which are used to track the maximum power point of a photovoltaic module using an inverter circuit. The technical solution of the present application is as follows: In a first aspect, the present application provides a maximum power tracking method for an inverter circuit, wherein the inverter circuit comprises a full-bridge circuit, a transformer and a half-bridge circuit, wherein the full-bridge circuit is connected to the half-bridge circuit via the transformer, wherein the full-bridge circuit is used to connect a photovoltaic module, and wherein the half-bridge circuit is used to connect an AC side; the maximum power tracking method comprises: obtaining an input power of the photovoltaic module in a current cycle and an input power of a previous cycle, and a reference output voltage of the inverter circuit in a previous cycle; determining a voltage adjustment step according to a power deviation and a voltage deviation, wherein the power deviation is based on the input power of the current cycle and the previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic module in the current cycle and the previous cycle; obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle; and generating a drive signal according to the reference output voltage of the current cycle to control the inverter circuit.

[0004] In one embodiment of the present application, obtaining the input power of the photovoltaic component in the current cycle includes: obtaining the input current and input voltage of the photovoltaic component in the current cycle; and obtaining the input power according to the input current and the input voltage.

[0005] In one embodiment of the present application, determining the voltage adjustment step size based on the power deviation and the voltage deviation includes: obtaining the power deviation of the current cycle and the previous cycle; obtaining the voltage disturbance factor based on the operating voltage range of the inverter circuit, the voltage deviation of the current cycle, and the power deviation of the current cycle and the previous cycle; obtaining the voltage adjustment step size based on the voltage disturbance factor, the power deviation of the current cycle, and the voltage deviation.

[0006] In one embodiment of the present application, the step of obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle includes: determining that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and obtaining the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step; determining that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and obtaining the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step; The reference output voltage of the current cycle is obtained by subtracting the voltage adjustment step from the current voltage; determining that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and the reference output voltage of the previous cycle is added to the voltage adjustment step to obtain the reference output voltage of the current cycle; determining that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and the reference output voltage of the previous cycle is subtracted from the voltage adjustment step to obtain the reference output voltage of the current cycle.

[0007] In one embodiment of the present application, the reference output voltage of the current cycle is obtained based on the voltage adjustment step and the reference output voltage of the previous cycle, and also includes: determining that the input power of the current cycle is equal to the input power of the previous cycle, and using the reference output voltage of the previous cycle as the reference output voltage of the current cycle.

[0008] In one embodiment of the present application, the driving signal is generated according to the reference output voltage of the current cycle, including: based on proportional control adjustment, obtaining a reference output current peak value according to the reference output voltage; obtaining a reference output current according to the reference output current peak value and a given phase, and the given phase is based on the voltage phase-locked loop of the inverter circuit; and generating the driving signal according to the reference output current.

[0009] The second aspect of the present application provides an inverter circuit, including a full-bridge circuit, a transformer, a half-bridge circuit and a controller, wherein the full-bridge circuit is connected to the half-bridge circuit through the transformer, the full-bridge circuit is used to connect a photovoltaic module, the half-bridge circuit is used to connect an AC side, and the controller connects the photovoltaic module, the full-bridge circuit and the half-bridge circuit; the controller is used to: obtain the input power of the photovoltaic module in the current cycle and the input power in the previous cycle, and the reference output voltage of the inverter circuit in the previous cycle; determine the voltage adjustment step according to the power deviation and the voltage deviation, the power deviation is based on the input power of the current cycle and the previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic module in the current cycle and the previous cycle; obtain the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle; generate a drive signal according to the reference output voltage of the current cycle to control the inverter circuit.

[0010] In one embodiment of the present application, the full-bridge circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a primary inductor and a primary capacitor; the first end of the first switch tube is used to connect to the positive electrode of the DC side, and the second end of the first switch tube is connected to the first end of the second switch tube; the second end of the second switch tube is used to connect to the negative electrode of the DC side; the first end of the third switch tube is connected to the first end of the first switch tube, and the second end of the third switch tube is connected to the first end of the fourth switch tube; the second end of the fourth switch tube is connected to the second end of the second switch tube; the first input end of the transformer is connected to the second end of the first switch tube, and the second input end of the transformer is connected to the second end of the third switch tube; the primary inductor is connected in parallel with the input end of the transformer; and the primary capacitor is connected in parallel with the DC side.

[0011] In one embodiment of the present application, the half-bridge circuit includes a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the resonant capacitor includes a first capacitor and a second capacitor; the fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube, the second capacitor and the first capacitor are connected in series in sequence; the first output end of the transformer is connected between the sixth switch tube and the seventh switch tube through the transformer, and the second output end of the transformer is connected between the first capacitor and the second capacitor.

[0012] A third aspect of the present application provides an energy storage inverter device, including the inverter circuit.

[0013] The present application determines the power deviation and voltage deviation by obtaining the input power and input voltage of the current cycle and the previous cycle of the photovoltaic component, and then obtains a voltage adjustment step according to the power deviation and the voltage deviation, so as to adjust the reference output voltage through the voltage adjustment step in the current cycle. Since the voltage adjustment step is based on the power deviation and the voltage deviation, that is, the voltage adjustment step is relatively adjusted with the change in the input power and the input voltage of the photovoltaic component, when the power point of the inverter circuit is far away from the maximum power point, the reference output voltage of the current cycle adjusted by a larger voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can speed up the tracking speed of the maximum power point of the current cycle. When the power point of the inverter circuit is close to the maximum power point, the reference output voltage of the current cycle adjusted by a smaller voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can improve the tracking accuracy of the maximum power point of the previous cycle, and finally realize the tracking of the maximum power point of the photovoltaic component by the inverter circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an equivalent schematic block diagram of an inverter circuit provided in an embodiment of the present application.

[0015] Figure 2 It is a flow chart of a maximum power tracking method for an inverter circuit provided in an embodiment of the present application.

[0016] Figure 3 It is a flow chart of a method for obtaining input power provided in an embodiment of the present application.

[0017] Figure 4 It is a schematic diagram of a process for determining a voltage adjustment step size provided in an embodiment of the present application.

[0018] Figure 5 It is a schematic diagram of a process for generating a driving signal provided in an embodiment of the present application.

[0019] Figure 6 It is a schematic block diagram of an inverter circuit provided in an embodiment of the present application.

[0020] Figure 7 It is a circuit diagram of an inverter circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0022] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0023] At present, inverter circuits are widely used in various devices with power conversion functions, such as photovoltaic energy storage devices and photovoltaic inverter devices, to convert the DC power of photovoltaic modules into AC power through the inverter circuit. Existing inverter circuits generally need to be connected to photovoltaic modules through an MPPT circuit to track the maximum power of photovoltaic modules through the MPPT circuit. That is, there is currently a lack of means to directly connect the inverter circuit to the photovoltaic module to track the maximum power of the photovoltaic module through the inverter circuit.

[0024] The present application provides an inverter circuit and a maximum power tracking method thereof, which are used to track the maximum power point of a photovoltaic module using the inverter circuit.

[0025] Please refer to Figure 1 , Figure 1 This is an equivalent schematic block diagram of an inverter circuit provided in an embodiment of the present application, wherein the inverter circuit 100 includes a full-bridge circuit 110 , a half-bridge circuit 120 and a transformer 130 .

[0026] In the embodiment of the present application, the full-bridge circuit 110 is connected to the half-bridge circuit 120 via the transformer 130 . The full-bridge circuit 110 is used to connect the photovoltaic module 101 , and the half-bridge circuit is used to connect the AC side of the inverter circuit 100 .

[0027] It can be understood that when the inverter circuit 100 is working, it receives the DC voltage of the photovoltaic module 101 through the full-bridge circuit 110, and can convert the DC voltage into a primary AC voltage and transmit it to the half-bridge circuit 120 through the transformer 130, and then the half-bridge circuit 120 adjusts the waveform of the primary AC voltage and finally outputs the AC voltage to the AC side. The photovoltaic module 101 includes a photovoltaic panel.

[0028] Next, combine Figure 1This paper introduces a maximum power tracking method for an inverter circuit provided by this application. Please refer to Figure 2 , the maximum power tracking method specifically includes the following steps: Step S21: obtaining the input power of the photovoltaic module in the current cycle and the input power in the previous cycle, and the reference output voltage of the inverter circuit in the previous cycle.

[0029] In an embodiment of the present application, the inverter circuit may also be connected to a controller, which controls the inverter circuit to work and execute the various steps in this embodiment. For example, in an energy storage inverter device provided with an inverter circuit, the full-bridge circuit and the half-bridge circuit of the inverter circuit may be connected to the main controller of the energy storage inverter device, and the main controller of the energy storage inverter device controls the switching parameters of the full-bridge circuit and the half-bridge circuit, thereby controlling the inverter circuit to work, and the main controller also executes the various steps in this embodiment. In some embodiments, the inverter circuit may also include a controller, that is, the inverter circuit includes an independently arranged controller, which is communicatively connected to the main controller of the energy storage inverter device.

[0030] It can be understood that the above-mentioned current cycle and previous cycle are both control cycles in the controller. During the control cycle, the controller obtains various operating parameters of the photovoltaic components and the inverter circuit, and controls and adjusts the inverter circuit according to the operating parameters.

[0031] The controller is also connected to the photovoltaic assembly to obtain the input power of the photovoltaic assembly in the current cycle, and stores the input power of the current cycle in a preset cache so as to be called from the preset cache in the next cycle. In some embodiments, a current sampling circuit and a voltage sampling circuit may be provided in the photovoltaic assembly, the current sampling circuit is used to collect the input current of the photovoltaic assembly to the inverter circuit and transmit it to the controller, the voltage sampling circuit is used to collect the input voltage of the photovoltaic assembly to the inverter circuit and transmit it to the controller, the controller obtains the corresponding input power according to the input current and the input voltage, and stores the input voltage of the current cycle in the preset cache so as to be called from the preset cache in the next cycle.

[0032] Step S22: determining the voltage adjustment step size according to the power deviation and the voltage deviation, wherein the power deviation is based on the input power of the current cycle and the previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic module of the current cycle and the previous cycle.

[0033] In the embodiment of the present application, after obtaining the input power of the photovoltaic module in the current cycle and the input power in the previous cycle, the controller can subtract the input power in the current cycle from the input power in the previous cycle to obtain the above power deviation. In addition, the controller can also obtain the input voltage of the photovoltaic module in the previous cycle, and subtract the input voltage in the current cycle from the input voltage in the previous cycle to obtain the above voltage deviation.

[0034] After obtaining the power deviation and the voltage deviation, the controller can use the power deviation and the voltage deviation to calculate a voltage adjustment step according to a preset algorithm, so as to obtain a better voltage adjustment step in the current cycle to adjust the reference output voltage, wherein the voltage adjustment step is based on the power deviation and the voltage deviation, that is, the voltage adjustment step is relatively adjusted with the change in the input power and input voltage of the photovoltaic module.

[0035] It can be understood that when the power deviation and the voltage deviation are large, the voltage adjustment step is large, and when the power deviation and the voltage deviation are small, the voltage adjustment step is small.

[0036] Step S23: Obtaining a reference output voltage of the current cycle according to the voltage adjustment step size and the reference output voltage of the previous cycle.

[0037] In the embodiment of the present application, since the voltage adjustment step is based on the power deviation and the voltage deviation, that is, the voltage adjustment step is relatively adjusted with the change in the input power and the input voltage of the photovoltaic component, so that when the power point of the inverter circuit is far away from the maximum power point, the reference output voltage of the current cycle adjusted by a larger voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can speed up the tracking speed of the maximum power point of the current cycle; and when the power point of the inverter circuit is close to the maximum power point, the reference output voltage of the current cycle adjusted by a smaller voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can improve the tracking accuracy of the maximum power point of the previous cycle.

[0038] When the controller adjusts the reference output voltage of the previous cycle according to the voltage adjustment step, it also determines whether to reduce the reference output voltage according to the voltage adjustment step or to increase the reference output voltage according to the voltage adjustment step, based on the magnitude relationship between the input power of the current cycle of the photovoltaic module and the input power of the previous cycle, and the magnitude relationship between the input voltage of the current cycle of the photovoltaic module and the input voltage of the previous cycle. For example: It is determined that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and the reference output voltage of the previous cycle is added to the voltage adjustment step to obtain the reference output voltage of the current cycle.

[0039] It is determined that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and the reference output voltage of the previous cycle is subtracted from the voltage adjustment step to obtain the reference output voltage of the current cycle.

[0040] Determine that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step.

[0041] Determine that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by subtracting the voltage adjustment step from the reference output voltage of the previous cycle.

[0042] In some embodiments, it is determined that the input power of the current cycle is equal to the input power of the previous cycle, and the reference output voltage of the previous cycle is used as the reference output voltage of the current cycle.

[0043] Step S24: Generate a driving signal according to the reference output voltage of the current cycle to control the inverter circuit.

[0044] In an embodiment of the present application, after obtaining the reference output voltage of the current cycle according to the voltage adjustment step, the controller can generate a drive signal according to the reference output voltage, transmit the drive signal to the switch tubes of the full-bridge circuit and the half-bridge circuit, drive and control the actual output voltage of the inverter circuit to approach the reference output voltage, and thereby enable the inverter circuit to achieve maximum power tracking of the input electrical energy of the photovoltaic module.

[0045] It can be understood that the present application determines the power deviation and voltage deviation by obtaining the input power and input voltage of the current cycle and the previous cycle of the photovoltaic component, and then obtains a voltage adjustment step according to the power deviation and the voltage deviation, so as to adjust the reference output voltage through the voltage adjustment step in the current cycle. Since the voltage adjustment step is based on the power deviation and the voltage deviation, that is, the voltage adjustment step is relatively adjusted with the change in the input power and input voltage of the photovoltaic component, when the power point of the inverter circuit is far away from the maximum power point, the reference output voltage of the current cycle adjusted by a larger voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can speed up the tracking speed of the maximum power point of the current cycle. When the power point of the inverter circuit is close to the maximum power point, the reference output voltage of the current cycle adjusted by a smaller voltage adjustment step is used to control the actual output voltage of the inverter circuit, which can improve the tracking accuracy of the maximum power point of the previous cycle, and finally realize the tracking of the maximum power point of the photovoltaic component by the inverter circuit.

[0046] In some embodiments, Figure 3 As shown, the above step of obtaining the input power of the photovoltaic component in the current cycle may specifically include the following steps: Step S31: obtaining the input current and input voltage of the photovoltaic module in the current cycle.

[0047] Step S32: Obtain input power according to the input current and the input voltage.

[0048] In an embodiment of the present application, a DC voltage sampling circuit may be provided in the photovoltaic module, and an AC voltage sampling circuit may be provided on the AC side. The DC voltage sampling circuit is used to collect the DC voltage of the photovoltaic module and transmit it to the controller, and the AC voltage sampling circuit is used to collect the AC voltage on the AC side and transmit it to the controller.

[0049] In some embodiments, Figure 4 As shown, the step of determining the voltage adjustment step size according to the power deviation and the voltage deviation may specifically include the following steps: Step S41: Obtain the power deviation of the current cycle and the previous cycle.

[0050] Step S422: Obtain a voltage disturbance factor according to the operating voltage range of the inverter circuit, the voltage deviation of the current cycle, and the power deviations of the current cycle and the previous cycle.

[0051] Step S43: Obtaining a voltage adjustment step length according to the voltage disturbance factor, the power deviation of the current cycle, and the voltage deviation.

[0052] In the embodiment of the present application, the formula for calculating the voltage adjustment step size includes: ; ; In the formula, is the voltage adjustment step size, is the voltage disturbance factor, is the power deviation of the current cycle, is the power deviation of the previous cycle, is the maximum operating voltage of the inverter circuit, It is the minimum starting voltage of the inverter circuit.

[0053] The reference output voltage ,in, is the sign function, is the reference output voltage of the previous cycle.

[0054] In some embodiments, Figure 5 As shown, the above step of generating a driving signal according to the reference output voltage of the current cycle may further include the following steps: Step S51: Based on proportional control regulation, a reference output current peak value is obtained according to a reference output voltage.

[0055] In the embodiment of the present application, after obtaining the reference output voltage, the controller can also adjust the proportional control in the voltage loop of the inverter circuit to obtain the corresponding reference output current peak value according to the reference voltage.

[0056] Step S52: Obtain a reference output current according to a reference output current peak value and a given phase, wherein the given phase is based on a voltage phase-locked loop of an inverter circuit.

[0057] In an embodiment of the present application, after obtaining the reference output current peak value, the controller uses the reference output current peak value and the given phase to synthesize to obtain the reference output current, which is the expected current waveform of the output current on the AC side of the inverter circuit that approaches the maximum power point.

[0058] Step S53: generating a driving signal according to the reference output current.

[0059] In the embodiment of the present application, the controller can obtain the inner phase shift angle of the full-bridge circuit, the outer phase shift angle between the full-bridge circuit and the half-bridge circuit, and the switching frequency according to the waveform of the reference output current, and generate the driving signal corresponding to each switch tube in the inverter circuit according to the inner phase shift angle, the outer phase shift angle, and the switching frequency, so as to drive the actual current output by the inverter circuit to approach the reference output current. The above-mentioned driving signal includes a pulse width modulation signal.

[0060] Please refer to Figure 6 , Figure 6 A schematic block diagram of an inverter circuit provided in an embodiment of the present application, wherein the inverter circuit 600 includes: a full-bridge circuit 610, a half-bridge circuit 620, a transformer 630, a resonant inductor 640, a resonant capacitor 650 and a controller 660.

[0061] In an embodiment of the present application, the full-bridge circuit 610 is connected to the half-bridge circuit 620 via a transformer 630 and a resonant inductor 640. The resonant inductor 640 is connected in series with the half-bridge circuit 620, and the resonant capacitor 650 is connected in parallel with the half-bridge circuit 620. The full-bridge circuit 610 is used to connect the photovoltaic module 601, and the half-bridge circuit 620 is used to connect the AC side.

[0062] The controller 660 is connected to the photovoltaic component 601, the full-bridge circuit 610 and the half-bridge circuit 620. The controller 660 is used to obtain the input power of the photovoltaic component 601 in the current cycle and the input power of the previous cycle, as well as the reference output voltage of the inverter circuit 600 in the previous cycle, and determine the voltage adjustment step according to the power deviation and the voltage deviation. The power deviation is based on the input power of the current cycle and the previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic component 601 in the current cycle and the previous cycle. According to the voltage adjustment step and the reference output voltage of the previous cycle, the reference output voltage of the current cycle is obtained, and a driving signal is generated according to the reference output voltage of the current cycle to control the inverter circuit 600.

[0063] In some embodiments, the controller 660 is further used to: obtain the input current and input voltage of the photovoltaic component 601 in the current cycle, and obtain the input power according to the input current and input voltage.

[0064] In some embodiments, the controller 660 is also used to: obtain the power deviation of the current cycle and the previous cycle, obtain the voltage disturbance factor according to the operating voltage range of the inverter circuit 600, the voltage deviation of the current cycle, and the power deviation of the current cycle and the previous cycle, and obtain the voltage adjustment step according to the voltage disturbance factor, the power deviation of the current cycle, and the voltage deviation.

[0065] In some embodiments, the controller 660 is further used to: determine that the power deviation of the current cycle is greater than the power deviation of the previous cycle, and the voltage deviation of the current cycle is greater than the voltage deviation of the previous cycle, and obtain the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step length; determine that the power deviation of the current cycle is greater than the power deviation of the previous cycle, and the voltage deviation of the current cycle is less than the voltage deviation of the previous cycle, and obtain the reference output voltage of the current cycle by subtracting the reference output voltage of the previous cycle from the voltage adjustment step length; determine that the power deviation of the current cycle is less than the power deviation of the previous cycle, and the voltage deviation of the current cycle is less than the voltage deviation of the previous cycle, and obtain the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step length; determine that the power deviation of the current cycle is less than the power deviation of the previous cycle, and the voltage deviation of the current cycle is greater than the voltage deviation of the previous cycle, and obtain the reference output voltage of the current cycle by subtracting the reference output voltage of the previous cycle from the voltage adjustment step length. Determine that the power deviation of the current cycle is equal to the power deviation of the previous cycle, and use the reference output voltage of the previous cycle as the reference output voltage of the current cycle.

[0066] In some embodiments, the controller 660 is also used to: based on proportional control regulation, obtain a reference output current peak value according to a reference output voltage, obtain a reference output current according to the reference output current peak value and a given phase, the given phase is based on the voltage phase-locked loop of the inverter circuit 600, and generate a drive signal according to the reference output current.

[0067] Please refer to Figure 7 , Figure 7 A circuit diagram of an inverter circuit 600 provided in an embodiment of the present application, wherein the full-bridge circuit 610 includes a first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a primary inductor Lm and a primary capacitor Cdc.

[0068] In the embodiment of the present application, the first end of the first switch tube S1 is used to connect to the positive electrode of the photovoltaic component 601, and the second end of the first switch tube S1 is connected to the first end of the second switch tube S2; the second end of the second switch tube S2 is used to connect to the negative electrode of the photovoltaic component 601; the first end of the third switch tube S3 is connected to the first end of the first switch tube S1, and the second end of the third switch tube is connected to the first end of the fourth switch tube S4; the second end of the fourth switch tube S4 is connected to the second end of the second switch tube S2.

[0069] The first input end of the transformer 630 is connected to the second end of the first switch tube S1 , and the second input end of the transformer 630 is connected to the second end of the third switch tube; the primary inductor Lm is connected in parallel with the input end of the transformer 630 ; and the primary capacitor Cdc is connected in parallel with the photovoltaic module 601 .

[0070] Among them, the half-bridge circuit 620 includes a fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7 and an eighth switch tube S8, and the resonant capacitor 650 includes a first capacitor Cr1 and a second capacitor Cr2; the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, the eighth switch tube S8, the second capacitor Cr2 and the first capacitor Cr1 are connected in series in sequence; the first output end of the transformer 630 is connected between the sixth switch tube S6 and the seventh switch tube S7 through the resonant inductor 640, and the second output end of the transformer 630 is connected between the first capacitor Cr1 and the second capacitor Cr2.

[0071] It can be understood that the beneficial effects that can be achieved by the inverter circuit 600 of the embodiment of the present application can refer to the beneficial effects of the maximum power tracking method of any of the aforementioned embodiments, and will not be repeated here.

[0072] The present application also provides an energy storage inverter device, comprising the inverter circuit of any of the above embodiments.

[0073] An embodiment of the present application further provides a computer storage medium, which stores a computer program. When the computer program is executed by a processor, the processor executes the above-mentioned maximum power tracking method.

[0074] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer storage medium or transmitted through a computer storage medium. The computer instructions can be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer storage medium can be any available medium that can be accessed by the computer or a data storage device such as a server or a data center that contains one or more available media integrated. Available media may be magnetic media (eg, floppy disks, hard disks, tapes), optical media (eg, digital versatile discs (DVD)), or semiconductor media (eg, solid state disks (SSD)), etc.

[0075] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes. In the absence of conflict, the technical features in this embodiment and the implementation scheme can be combined arbitrarily.

[0076] The above embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope of the claims of the present application.

Claims

1. A maximum power tracking method for an inverter circuit, characterized in that: The inverter circuit includes a full-bridge circuit, a transformer and a half-bridge circuit, the full-bridge circuit is connected to the half-bridge circuit through the transformer, the full-bridge circuit is used to connect the photovoltaic module, and the half-bridge circuit is used to connect the AC side; The maximum power tracking method comprises: Acquire the input power of the photovoltaic module in the current cycle and the input power in the previous cycle, and the reference output voltage of the inverter circuit in the previous cycle; Determining a voltage adjustment step according to a power deviation and a voltage deviation, wherein the power deviation is based on the input power of a current cycle and a previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic module of the current cycle and the previous cycle; Obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle; A driving signal is generated according to the reference output voltage of the current cycle to control the inverter circuit.

2. The maximum power tracking method according to claim 1, characterized in that: The obtaining of the input power of the photovoltaic component in the current cycle includes: Obtaining the input current and input voltage of the photovoltaic module in the current cycle; The input power is obtained according to the input current and the input voltage.

3. The maximum power tracking method according to claim 1, characterized in that: The step of determining the voltage adjustment step according to the power deviation and the voltage deviation includes: Obtaining the power deviation of the current cycle and the previous cycle; Obtaining a voltage disturbance factor according to the operating voltage range of the inverter circuit, the voltage deviation of the current cycle, and the power deviations of the current cycle and the previous cycle; The voltage adjustment step is obtained according to the voltage disturbance factor, the power deviation of the current cycle, and the voltage deviation.

4. The maximum power tracking method according to claim 1, characterized in that: The step of obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle includes: Determine that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step; Determine that the input power of the current cycle is greater than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by subtracting the voltage adjustment step from the reference output voltage of the previous cycle; Determine that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is less than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by adding the reference output voltage of the previous cycle to the voltage adjustment step; Determine that the input power of the current cycle is less than the input power of the previous cycle, and the input voltage of the current cycle is greater than the input voltage of the previous cycle, and obtain the reference output voltage of the current cycle by subtracting the voltage adjustment step from the reference output voltage of the previous cycle.

5. The maximum power tracking method according to claim 4, characterized in that: The step of obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle further includes: It is determined that the input power of the current cycle is equal to the input power of the previous cycle, and the reference output voltage of the previous cycle is used as the reference output voltage of the current cycle.

6. The maximum power tracking method according to claim 1, characterized in that: The step of generating a driving signal according to the reference output voltage of the current cycle comprises: Based on proportional control regulation, a reference output current peak value is obtained according to the reference output voltage; Obtaining a reference output current according to the reference output current peak value and a given phase, wherein the given phase is based on a voltage phase-locked loop of the inverter circuit; The driving signal is generated according to the reference output current.

7. An inverter circuit, characterized in that: It includes a full-bridge circuit, a transformer, a half-bridge circuit and a controller, wherein the full-bridge circuit is connected to the half-bridge circuit through the transformer, the full-bridge circuit is used to connect the photovoltaic module, the half-bridge circuit is used to connect the AC side, and the controller connects the photovoltaic module, the full-bridge circuit and the half-bridge circuit; The controller is used to: Acquire the input power of the photovoltaic module in the current cycle and the input power in the previous cycle, and the reference output voltage of the inverter circuit in the previous cycle; Determining a voltage adjustment step according to a power deviation and a voltage deviation, wherein the power deviation is based on the input power of a current cycle and a previous cycle, and the voltage deviation is based on the input voltage of the photovoltaic module of the current cycle and the previous cycle; Obtaining the reference output voltage of the current cycle according to the voltage adjustment step and the reference output voltage of the previous cycle; A driving signal is generated according to the reference output voltage of the current cycle to control the inverter circuit.

8. The inverter circuit according to claim 7, characterized in that: The full-bridge circuit includes a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a primary inductor and a primary capacitor; The first end of the first switch tube is used to connect the positive electrode of the DC side, and the second end of the first switch tube is connected to the first end of the second switch tube; the second end of the second switch tube is used to connect the negative electrode of the DC side; the first end of the third switch tube is connected to the first end of the first switch tube, and the second end of the third switch tube is connected to the first end of the fourth switch tube; the second end of the fourth switch tube is connected to the second end of the second switch tube; The first input end of the transformer is connected to the second end of the first switch tube, and the second input end of the transformer is connected to the second end of the third switch tube; the primary inductor is connected in parallel with the input end of the transformer; and the primary capacitor is connected in parallel with the DC side.

9. The inverter circuit according to claim 7, characterized in that: The half-bridge circuit includes a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, and the resonant capacitor includes a first capacitor and a second capacitor; The fifth switch tube, the sixth switch tube, the seventh switch tube, the eighth switch tube, the second capacitor and the first capacitor are connected in series in sequence; the first output end of the transformer is connected between the sixth switch tube and the seventh switch tube through the transformer, and the second output end of the transformer is connected between the first capacitor and the second capacitor.

10. An energy storage inverter device, characterized in that: The invention comprises the inverter circuit as claimed in any one of claims 7 to 9.

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