Power converter and control method therefor

Abstract

Provided in the present application are a power converter and a control method therefor. The power converter may comprise a first power conversion module, a transformer, a second power conversion module and a controller, wherein an input end of the first power conversion module is connected to a photovoltaic port, and an output end of the first power conversion module is connected to a primary winding and an energy storage port of the transformer; an input end of the second power conversion module is connected to a secondary winding of the transformer, and an output end of the second power conversion module is connected to a load port; and when the photovoltaic port is connected to a photovoltaic module and the energy storage port is connected to a battery, the controller controls the first power conversion module to cause the photovoltaic port and the energy storage port to perform power conversion, and when the photovoltaic port is connected to the photovoltaic module and the load port is connected to an alternating-current power grid, the controller controls the first power conversion module and the second power conversion module to cause the photovoltaic port and the load port to perform power conversion. The present application requires the use of a relatively small number of elements, and has the advantages of high efficiency, a small size and a low cost.

Description

Power converter and control method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 6, 2024, with application number 202410171464.2 and application name “Power Converter and Control Method Thereof”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power electronics and new energy power supply technology, and in particular to a power converter and a control method thereof. Background Art

[0003] With the increasing shortage of traditional energy and worsening global pollution, the use of clean, pollution-free energy sources, such as photovoltaic power generation, is increasing. Inverters convert the low-voltage DC voltage of photovoltaic panels into grid-connected AC voltage, and microinverters are becoming increasingly widely used in the new energy sector. Currently, microinverters used with photovoltaic panels and inverters used with energy storage are two separate systems. Integrated photovoltaic and energy storage systems, consisting of multiple discrete inverters, require a large number of inverters, resulting in high cost, bulk, and low efficiency. Summary of the Invention

[0004] The present application provides a power converter and a control method thereof. The power converter of the present application uses a relatively small number of components and has the advantages of high efficiency, small size and low cost.

[0005] A first aspect of the present application provides a power converter, which may include a first power conversion module, a transformer, a second power conversion module, and a controller. The input end of the first power conversion module is connected to a photovoltaic port, and the output end of the first power conversion module is connected to a primary winding of the transformer and an energy storage port. The input end of the second power conversion module is connected to a secondary winding of the transformer, and the output end of the second power conversion module is connected to a load port. The controller is configured to: in response to the photovoltaic port being connected to a photovoltaic module and the energy storage port being connected to a battery, control a switch in the first power conversion module to perform power conversion between the photovoltaic port and the energy storage port; in response to the photovoltaic port being connected to a photovoltaic module and the load port being connected to an AC grid or an AC load, control a switch in the first power conversion module and a switch in the second power conversion module to perform power conversion between the photovoltaic port and the load port; and in response to the energy storage port being connected to a battery and the load port being connected to an AC grid or an AC load, control a switch in the first power conversion module and a switch in the second power conversion module to perform power conversion between the energy storage port and the load port.

[0006] By using the power converter of the present application, power conversion between the three ports can be achieved by configuring the photovoltaic port, energy storage port and load port. The power converter of the present application uses a smaller number of components and has the advantages of high efficiency, small size and low cost.

[0007] As an optional implementation, the first power conversion module may include a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The second power conversion module includes a fifth switching tube, a sixth switching tube, a seventh switching tube, and an eighth switching tube, wherein the first end of the first switching tube is connected to the first end of the photovoltaic port, the second end of the first switching tube is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the second end of the photovoltaic port, the first end of the third switching tube is connected to the first end of the photovoltaic port, the second end of the third switching tube is connected to the first end of the fourth switching tube, the second end of the fourth switching tube is connected to the second end of the photovoltaic port, the first end of the fifth switching tube is connected to the first end of the sixth switching tube, the second end of the fifth switching tube is connected to the first end of the load port, the second end of the sixth switching tube is connected to the second end of the seventh switching tube, the first end of the seventh switching tube is connected to the first end of the eighth switching tube, and the second end of the eighth switching tube is connected to the second end of the load port.

[0008] As an optional implementation, the controller is also used to: in response to the photovoltaic port being connected to the photovoltaic module and the energy storage port being connected to the battery, control the second switch tube and the fourth switch tube to be turned on during a first time period, and control the first switch tube and the third switch tube to be turned on during a second time period; wherein the first time period and the second time period constitute a switching cycle.

[0009] As an optional implementation, in response to the photovoltaic port being connected to the photovoltaic component and the energy storage port being connected to the battery, during the first time period and the second time period, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are all controlled to be turned off.

[0010] As an optional implementation, the controller is used to: in response to the photovoltaic port being connected to the photovoltaic module and the load port being connected to the AC grid or the AC load, control the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube to be turned on, and control the second switch tube, the third switch tube and the sixth switch tube to be turned off during a first time period of the cycle time; control the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube and the seventh switch tube to be turned on, and control the second switch tube, the third switch tube and the eighth switch tube to be turned off during a second time period of the cycle time; control the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube and the seventh switch tube to be turned on, and control the second switch tube, the third switch tube and the eighth switch tube to be turned off during a third time period of the cycle time. The first switch tube, the third switch tube, and the eighth switch tube are all turned off; in a fourth time period of the cycle time, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube, and the eighth switch tube are all controlled to be turned off; in a fifth time period of the cycle time, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube, and the sixth switch tube are all controlled to be turned off; in a sixth time period of the cycle time, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube, and the sixth switch tube are all controlled to be turned off.

[0011] As an optional implementation, the controller is configured to: in response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, control the second switch tube and the fourth switch tube to be turned on and control the fifth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube to be turned off during a first time period of a first cycle time; and control the first switch tube and the third switch tube to be turned on and control the fifth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube to be turned off during a second time period of the first cycle time;

[0012] During a first time period of the second cycle, the first, fourth, eighth, fifth, and seventh switching transistors are controlled to be turned on, and the second, third, and sixth switching transistors are controlled to be turned off. During a second time period of the second cycle, the first, fourth, sixth, fifth, and seventh switching transistors are controlled to be turned on, and the second, third, and eighth switching transistors are controlled to be turned off. During a third time period of the second cycle, the second, fourth, sixth, fifth, and seventh switching transistors are controlled to be turned on, and the first, third, and eighth switching transistors are controlled to be turned off. During a fourth time period of the second cycle, the second, third, sixth, fifth, and seventh switching tubes are controlled to be turned on, and the first, fifth, and eighth switching tubes are controlled to be turned off. During a fifth time period of the second cycle, the second, third, eighth, fifth, and seventh switching tubes are controlled to be turned on, and the first, fourth, and sixth switching tubes are controlled to be turned off. During a sixth time period of the second cycle, the second, fourth, eighth, fifth, and seventh switching tubes are controlled to be turned on, and the first, third, and sixth switching tubes are controlled to be turned off.

[0013] In a second aspect, the present application also provides a control method for a power converter, which is applied to a power converter, wherein the power converter includes a first power conversion module, a transformer, and a second power conversion module, wherein the input end of the first power conversion module is used to connect to a photovoltaic port, the output end of the first power conversion module is connected to the primary winding and the energy storage port of the transformer, the input end of the second power conversion module is connected to the secondary winding of the transformer, and the output end of the second power conversion module is used to connect to the load port; the control method includes:

[0014] In response to the photovoltaic port being connected to the photovoltaic module and the energy storage port being connected to the battery, controlling the switch tube in the first power conversion module to perform power conversion between the photovoltaic port and the energy storage port;

[0015] In response to the photovoltaic port being connected to the photovoltaic assembly and the load port being connected to the AC grid or the AC load, controlling the switch tube in the first power conversion module and the switch tube in the second power conversion module to perform power conversion between the photovoltaic port and the load port;

[0016] In response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, the switch tube in the first power conversion module and the switch tube in the second power conversion module are controlled to perform power conversion between the energy storage port and the load port.

[0017] In an optional implementation, the first power conversion module may include a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube. The second power conversion module includes a fifth switch tube, a sixth switch tube, a seventh switch tube, and an eighth switch tube, wherein the first end of the first switch tube is connected to the first end of the photovoltaic port, 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 connected to the second end of the photovoltaic port, the first end of the third switch tube is connected to the first end of the photovoltaic port, 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 photovoltaic port, the first end of the fifth switch tube is connected to the first end of the sixth switch tube, the second end of the fifth switch tube is connected to the first end of the load port, the second end of the sixth switch tube is connected to the second end of the seventh switch tube, the first end of the seventh switch tube is connected to the first end of the eighth switch tube, and the second end of the eighth switch tube is connected to the second end of the load port; the control method further includes:

[0018] In response to the photovoltaic port being connected to the photovoltaic component and the energy storage port being connected to the battery, within a first time period, the second switch tube and the fourth switch tube are controlled to be turned on, and the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are controlled; within a second time period, the first switch tube and the third switch tube are controlled to be turned on, and the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube are controlled; wherein the first time period and the second time period constitute a switching cycle.

[0019] As an optional implementation, the control method further includes: in response to the photovoltaic port being connected to the photovoltaic module and the load port being connected to the AC grid or the AC load, in a first time period of the cycle time, controlling the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the second switch tube, the third switch tube, and the sixth switch tube to be turned off; in a second time period of the cycle time, controlling the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the second switch tube, the third switch tube, and the eighth switch tube to be turned off; in a third time period of the cycle time, controlling the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the first switch tube, the third switch tube, and the eighth switch tube to be turned off; in a fourth time period of the cycle time, controlling the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the first switch tube, the fifth switch tube, and the eighth switch tube to be turned off; in a fifth time period of the cycle time, controlling the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the first switch tube, the fourth switch tube, and the sixth switch tube to be turned off; in a sixth time period of the cycle time, controlling the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube to be turned on, and controlling the first switch tube, the third switch tube, and the sixth switch tube to be turned off.

[0020] As an optional implementation, the control method further includes: in response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, in a first time period of the first cycle time, controlling the second switch tube and the fourth switch tube to be turned on, and controlling the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off; in a second time period of the first cycle time, controlling the first switch tube and the third switch tube to be turned on, and controlling the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off; in a first time period of the second cycle time, controlling the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube to be turned on, and controlling the second switch tube, the third switch tube and the sixth switch tube to be turned off; in a second time period of the second cycle time, controlling the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube and the seventh switch tube to be turned on, and controlling the second switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off. The third switch tube and the eighth switch tube are all turned off; in the third time period of the second cycle time, the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube and the eighth switch tube are all controlled to be turned off; in the fourth time period of the second cycle time, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube and the eighth switch tube are all controlled to be turned off; in the fifth time period of the second cycle time, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube and the sixth switch tube are all controlled to be turned off; in the sixth time period of the second cycle time, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube and the sixth switch tube are all controlled to be turned off.

[0021] It should be understood that the control methods described in the second aspect provided above correspond to the power converters of the first aspect provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding power converters provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a diagram showing an application scenario of a power converter provided in an embodiment of the present application.

[0023] FIG2 is another application scenario diagram of a power converter provided in an embodiment of the present application.

[0024] FIG3 is another application scenario diagram of a power converter provided in an embodiment of the present application.

[0025] FIG4 is a schematic diagram of a power converter provided in an embodiment of the present application.

[0026] FIG5 is a schematic diagram of a power converter in a first working mode according to an embodiment of the present application.

[0027] FIG6 is a current path diagram of the power converter according to an embodiment of the present application in the first operating mode.

[0028] FIG. 7 is another current path diagram of the power converter according to an embodiment of the present application in the first operating mode.

[0029] FIG8 is a schematic diagram of a power converter in a second working mode according to an embodiment of the present application.

[0030] FIG9 is a switching timing diagram of the power converter according to an embodiment of the present application in the second working mode.

[0031] FIG10 is a current path diagram of the power converter according to an embodiment of the present application in the second operating mode.

[0032] FIG. 11 is another current path diagram of the power converter according to an embodiment of the present application in the second operating mode.

[0033] FIG12 is another current path diagram of the power converter according to an embodiment of the present application in the second operating mode.

[0034] FIG13 is a diagram showing the working principle of the inductor of the power converter in an embodiment of the present application.

[0035] FIG14 is a schematic diagram of the power converter according to an embodiment of the present application in the third working mode.

[0036] FIG15 is a flow chart of a method for controlling a power converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0037] In the embodiments of this application, terms such as "first" and "second" are used solely to distinguish between different objects and should not be construed as indicating or implying relative importance or order. For example, terms such as "first application" and "second application" are used to distinguish between different applications, not to describe a specific order of applications. Features defined as "first" or "second" may explicitly or implicitly include one or more of these features.

[0038] With the increasing shortage of traditional energy and worsening global pollution, the use of clean, pollution-free energy sources, such as photovoltaic power generation, is increasing. Inverters convert the low-voltage DC voltage of photovoltaic panels into grid-connected AC voltage, and microinverters are becoming increasingly widely used in the new energy sector. Currently, microinverters used with photovoltaic panels and inverters used with energy storage are two separate systems. Integrated photovoltaic and energy storage systems, consisting of multiple discrete inverters, require a large number of inverters, resulting in high cost, bulk, and low efficiency.

[0039] In order to address the above-mentioned problems, the present application provides a power converter and a control method thereof. The power converter of the present application can realize power conversion between three ports by configuring a photovoltaic port, an energy storage port and a load port. The power converter of the present application uses a smaller number of components and has the advantages of high efficiency, small size and low cost, which can solve the technical problems in traditional solutions.

[0040] Please refer to FIG1 , which is a diagram of an application scenario of a power converter 100 provided in one embodiment of the present application.

[0041] As shown in Figure 1, in one possible application scenario, the power converter 100 may be connected between the photovoltaic module 200 and the AC grid 300. In other application scenarios, the power converter 100 may also be connected between the photovoltaic module 200 and the AC load.

[0042] In one working mode, the power converter 100 can realize mutual conversion of energy between the photovoltaic assembly 200 and the AC power grid 300, that is, realize mutual conversion of DC and AC energy.

[0043] Please refer to FIG. 2 , which is another application scenario diagram of the power converter 100 provided in one embodiment of the present application.

[0044] As shown in FIG. 2 , in another possible application scenario, the power converter 100 may be connected between the photovoltaic assembly 200 and the battery 400 .

[0045] In another working mode, the power converter 100 can realize mutual conversion of energy between the photovoltaic assembly 200 and the battery 400, that is, realize mutual conversion of DC and DC energy.

[0046] Please refer to FIG. 3 , which is another application scenario diagram of the power converter 100 provided in one embodiment of the present application.

[0047] As shown in FIG. 3 , in another possible application scenario, the power converter 100 may be connected between an AC grid 300 and a battery 400 .

[0048] In another working mode, the power converter 100 can realize mutual conversion of energy between the AC grid 300 and the battery 400, that is, realize mutual conversion of AC and DC energy.

[0049] It is understood that in other possible application scenarios, the power converter 100 can also be connected to the photovoltaic module 200, the AC grid 300 and the battery 400. In other words, the power converter 100 of the present application can realize mutual energy conversion between the photovoltaic module 200, the AC grid 300 and the battery 400.

[0050] The internal structure of the power converter 100 will be described in detail below.

[0051] Please refer to FIG. 4 , which is a schematic diagram of a power converter 100 provided in accordance with an embodiment of the present application.

[0052] The power converter 100 of the present application is a converter based on a dual active bridge (DAB) topology. As shown in FIG4 , the power converter 100 may include a power conversion circuit 101 and a controller 40. The controller 40 is electrically connected to the power conversion circuit 101. The controller 40 may control the operating state of the power conversion circuit 101.

[0053] The power conversion circuit 101 includes a first power conversion module 10, a second power conversion module 20, a transformer 30, a photovoltaic port 50, an energy storage port 60, and a load port 70. It will be appreciated that in this embodiment, the photovoltaic port 50 can be used to connect to the photovoltaic module 200. The energy storage port 60 can be used to connect to the battery 400. The load port 70 can be used to connect to the AC grid 300 or an AC load.

[0054] The transformer 30 may include a primary winding 32 , a secondary winding 34 , and a magnetic core 36 .

[0055] The input of the first power conversion module 10 is connected to the photovoltaic port 50, and the output of the first power conversion module 10 is connected to the primary winding 32 of the transformer 30. The input of the second power conversion module 20 is connected to the secondary winding 34 of the transformer 30, and the output of the second power conversion module 20 is connected to a load.

[0056] In this embodiment, the first power conversion module 10 may include a switch tube Q1 , a switch tube Q2 , a switch tube Q3 and a switch tube Q4 .

[0057] A first terminal of the switch Q1 is electrically connected to a first terminal of the capacitor C1 and a first terminal of the photovoltaic port 50. A second terminal of the switch Q1 is electrically connected to a first terminal of the switch Q2. A third terminal of the switch Q1 is connected to the controller 40. The third terminal of the switch Q1 can serve as a control terminal of the switch Q1. That is, the controller 40 can output a drive signal to the third terminal of the switch Q1 to control the on / off state of the switch Q1.

[0058] A first terminal of the switch Q2 is electrically connected to the second terminal of the capacitor C1 and the second terminal of the photovoltaic port 50. A third terminal of the switch Q2 is connected to the controller 40. The third terminal of the switch Q2 can serve as a control terminal of the switch Q2. That is, the controller 40 can output a drive signal to the first terminal of the switch Q2 to control the on / off state of the switch Q2.

[0059] A first end of the switch Q3 is electrically connected to the first end of the capacitor C1 and the first end of the photovoltaic port 50. A second end of the switch Q3 is electrically connected to the first end of the switch Q4. The first end of the switch Q3 is connected to the controller 40. The third end of the switch Q3 can serve as a control end of the switch Q3. That is, the controller 40 can output a drive signal to the third end of the switch Q3 to control the on / off state of the switch Q3.

[0060] The second end of the switch Q4 is electrically connected to the second end of the capacitor C1 and the second end of the photovoltaic port 50. The third end of the switch Q4 is connected to the controller 40. The third end of the switch Q4 can serve as a control end of the switch Q4. That is, the controller 40 can output a drive signal to the third end of the switch Q4 to control the on / off state of the switch Q4.

[0061] In this embodiment, the capacitor C1 is connected in parallel at both ends of the photovoltaic port 50 to filter out high-frequency current components flowing through the photovoltaic port 50 , thereby ensuring the stability of the voltage on the photovoltaic port 50 .

[0062] It can be understood that the switch tubes Q1-Q4 in this embodiment can be any one of a metal oxide semiconductor field effect transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), a bipolar power transistor (Bipolar Power Transistor, BPT) or a wide bandgap semiconductor field effect transistor.

[0063] The first power conversion module 10 can provide an output voltage to the primary winding 32 of the transformer 30. The secondary winding 34 of the transformer 30 is coupled to the primary winding 32 via a magnetic core 36. The primary winding 32 of the transformer 30 is used to receive the output voltage of the first power conversion module 10 and can generate a primary winding voltage. The secondary winding 34 of the transformer 30 is coupled to the primary winding 32, and a secondary winding voltage can be generated on the secondary winding 34. It can be understood that the primary winding can refer to the winding placed on the primary side of the transformer. The secondary winding can refer to the winding placed on the secondary side of the transformer.

[0064] The first end of the primary winding 32 is electrically connected to a connection point P1 between the second end of the switch tube Q1 and the first end of the switch tube Q2 . The second end of the primary winding 32 is electrically connected to a connection point P2 between the second end of the switch tube Q3 and the first end of the switch tube Q4 .

[0065] It will be appreciated that, in some optional embodiments, the power converter 100 may further include an inductor circuit 90. The inductor circuit 90 includes an inductor L1 and an inductor L2. The first end of the inductor L1 is electrically connected to the connection point P1, the second end of the inductor L1 is electrically connected to the first end of the capacitor C2 and the first end of the energy storage port 60, the first end of the inductor L2 is electrically connected to the connection point P2, and the second end of the inductor L2 is electrically connected to the first end of the capacitor C2 and the first end of the energy storage port 60. The second end of the energy storage port 60 is electrically connected to the second end of the capacitor C2, the second end of the capacitor C1, and the second end of the photovoltaic port 50.

[0066] In this embodiment, the capacitor C2 is a filter capacitor. In other words, the capacitor C2 can be used to filter out high-frequency current components flowing through the energy storage port 60 , thereby ensuring the stability of the voltage on the energy storage port 60 .

[0067] The transformer 30 may further include an inductor L m Inductor L m The two ends of the primary winding 32 are connected in parallel.

[0068] The power converter 100 may further include a filter circuit 80 . The filter circuit 80 is connected between the output terminal of the second power conversion module 20 and the load port 70 .

[0069] The second power conversion module 20 can be used to receive the secondary winding voltage on the secondary winding 34 and convert it into an output voltage for the filter circuit 80. The filter circuit 80 can be used to filter the output voltage of the second power conversion module 20 and provide the filtered voltage to the load port 70.

[0070] In this embodiment, the second power conversion module 20 includes a switch tube Q5, a switch tube Q6, a switch tube Q7 and a switch tube Q8. The filter circuit 80 includes a capacitor C3, a capacitor C4 and an inductor L f .

[0071] The first end of the switch tube Q5 is electrically connected to the first end of the switch tube Q6, and the second end of the switch tube Q5 is electrically connected to the first end of the switch tube Q6 through the inductor L. f The first terminal of the switch Q5 is electrically connected to the load port 70. The third terminal of the switch Q5 is connected to the controller 40. The third terminal of the switch Q5 can serve as the control terminal of the switch Q5, that is, the controller 40 can output a driving signal to the third terminal of the switch Q5 to control the conduction or shutdown of the switch Q5.

[0072] The second terminal of the switch Q6 is electrically connected to the second terminal of the switch Q7. The third terminal of the switch Q6 is connected to the controller 40. The third terminal of the switch Q6 can serve as the control terminal of the switch Q6. That is, the controller 40 can output a drive signal to the third terminal of the switch Q6 to control the conduction or shutdown of the switch Q6.

[0073] The first terminal of the switch Q7 is electrically connected to the first terminal of the switch Q8. The first terminal of the switch Q7 is connected to the controller 40, and the third terminal of the switch Q7 can serve as the control terminal of the switch Q7. That is, the controller 40 can output a drive signal to the third terminal of the switch Q7 to control the conduction or shutdown of the switch Q7.

[0074] The third terminal of the switch Q8 is electrically connected to the second terminal of the load port 70. The third terminal of the switch Q8 is connected to the controller 40. The third terminal of the switch Q8 can serve as a control terminal of the switch Q8. That is, the controller 40 can output a driving signal to the third terminal of the switch Q8 to control the on / off state of the switch Q8.

[0075] The first end of the capacitor C3 is electrically connected to the second end of the switch Q5 and the inductor L f The second end of the capacitor C3 is electrically connected to the first end of the capacitor C4 , and the second end of the capacitor C4 is electrically connected to the second end of the switch tube Q8 and the second end of the load port 70 .

[0076] In this embodiment, the first end of the secondary winding 34 is connected to the inductor L s The second end of the secondary winding 34 is electrically connected to the connection point P3 between the second end of the switch tube Q6 and the second end of the switch tube Q7, and the second end of the secondary winding 34 is electrically connected to the connection point P4 between the second end of the capacitor C3 and the first end of the capacitor C4. It can be understood that the inductor L s is the energy storage inductor. s It can be an external independent inductor or a leakage inductor in the transformer 30. The power converter of the present application can be connected to the inductor L s The charge and discharge characteristics of the battery are used to adjust the power conversion size and direction.

[0077] It is understood that the power converter 100 of the present application is configured with a photovoltaic port, an energy storage port, and a load port, and can achieve power conversion between the three ports. For example, in different application scenarios, power conversion can be performed between the photovoltaic port 50 and the energy storage port 60 to achieve DC-to-DC power conversion, power conversion can be performed between the photovoltaic port 50 and the load port 70 to achieve DC-to-AC power conversion, and power conversion can be performed between the energy storage port 60 and the load port 70 to achieve DC-to-AC power conversion.

[0078] The power conversion between the three ports of the power converter 100 of the present application will be specifically described below using different application scenarios.

[0079] Please refer to FIG. 5 , which is a schematic diagram of the power conversion circuit 101 in the first working mode.

[0080] In this embodiment, in the first operating mode of the power conversion circuit 101, the photovoltaic port 50 is connected to the photovoltaic module 200, and the energy storage port 60 is connected to the battery 400. Power conversion occurs between the photovoltaic port 50 and the energy storage port 60, and the load port 70 does not participate in power conversion with other ports. The controller 40 controls the switches Q5, Q6, Q7, and Q8 to remain in the off state.

[0081] It can be understood that the voltage of the photovoltaic port 50 is recorded as U PV , the voltage of the energy storage port 60 is recorded as U bat The first branch (i.e., consisting of inductor L1, switch Q1, and switch Q2) and the second branch (i.e., consisting of inductor L2, switch Q3, and switch Q4) respectively form two staggered parallel Boost circuits, thereby achieving the voltage U of the energy storage port 60. bat Voltage U to PV port 50 PV of boost.

[0082] It can be understood that the voltage U of the energy storage port 60 bat The voltage U of the photovoltaic port 50 PV The relationship can satisfy the following formula (1).

[0083] Among them, the duty cycle of the switch tube Q2 and the switch tube Q4 is D1, U bat is the voltage of the energy storage port 60, U PV is the voltage of the photovoltaic port 50.

[0084] It can be seen from the above formula (1) that the controller 40 can realize mutual power conversion between the energy storage port 60 and the photovoltaic port 50 by adjusting the duty cycle D1 of the switch tube Q1 and the switch tube Q3.

[0085] As shown in FIG6 , the power conversion circuit 101 operates in a first operating mode. During a first time period, the controller 40 can control both the switch Q2 and the switch Q4 to be in an on state. The energy storage port 60 will charge the inductor L1 through the switch Q2. During this time period, the current in the inductor L1 increases. That is, the current output from the first end of the energy storage port 60 flows sequentially through the inductor L1 and the switch Q2 before returning to the second end of the energy storage port 60. The energy storage port 60 will charge the inductor L2 through the switch Q4. During this time period, the current in the inductor L2 increases. That is, the current output from the first end of the energy storage port 60 will also flow sequentially through the inductor L2 and the switch Q4 before returning to the second end of the energy storage port 60. The current path is shown as line S61 in FIG6 .

[0086] As shown in FIG7 , when the power conversion circuit 101 is in the first operating mode, during the second time period, the controller 40 can control the switch tubes Q1 and Q3 to be in the on state. The energy storage port 60 and the charged inductor L1 supply power to the photovoltaic port 50 via the switch tube Q1. That is, the current output from the first end of the energy storage port 60 will sequentially flow through the inductor L1, the switch tube Q1, and the photovoltaic port 50. Before flowing back to the second end of the energy storage port 60, the energy storage port 60 and the charged inductor L2 will also supply power to the photovoltaic port 50 via the switch tube Q3. That is, the current output from the first end of the energy storage port 60 will sequentially flow through the inductor L2, the switch tube Q3, and the photovoltaic port 50. Before flowing back to the second end of the energy storage port 60, its current path is shown as line S71 in FIG7 , thereby achieving a boosting effect.

[0087] The first time period and the second time period constitute a switching cycle.

[0088] Please refer to FIG. 8 , which is a schematic diagram of the power conversion circuit 101 in the second working mode.

[0089] In this embodiment, in the second working mode of the power conversion circuit 101, the photovoltaic port 50 is connected to the photovoltaic component 200, and the load port 70 is connected to the AC power grid 300 or the AC load. Power conversion is performed between the photovoltaic port 50 and the load port 70, and the energy storage port 60 will not participate in the power conversion with other ports.

[0090] The power converter 100 can convert the DC voltage on the DC side and the AC voltage on the AC side into high-frequency square wave signals. It is understood that the DC side herein refers to the circuit portion between the transformer 30 and the photovoltaic port 50 or the energy storage port 60. The AC side refers to the circuit portion between the transformer 30 and the load port 70.

[0091] The voltage of photovoltaic port 50 is recorded as U PV , the voltage at the load port 70 is recorded as UAC.

[0092] In the first power conversion module 10, the bridge arm voltage on the DC side can be recorded as V P1P2 , that is, the voltage between the connection point P1 and the connection point P2 can be recorded as V P1P2 In the second power conversion module 20, the bridge arm voltage on the AC side can be recorded as V P3P4 , that is, the voltage between the connection point P3 and the connection point P4 can be recorded as V P3P4 The phase shift angle between the drive signal on the DC side and the drive signal on the AC side is D2. For example, the phase shift angle between the drive signal for driving the switch tube Q1 and the drive signal for driving the switch tube Q6 is D2, or the phase shift angle between the drive signal for driving the switch tube Q3 and the drive signal for driving the switch tube Q8 is D2.

[0093] It can be understood that in this embodiment, the relationship between the duty cycle D1 and the phase shift angle D2 can satisfy the following formula (2): D2 = k × D1 (2)

[0094] Where D1 is the duty cycle of switches Q2 and Q4, D2 is the phase shift angle between the DC drive signal and the AC drive signal, and k is the coefficient. From formula (2), it can be seen that duty cycle D1 and phase shift angle D2 have a specific proportional relationship.

[0095] FIG9 is a switching timing diagram of the power conversion circuit 101 when the power conversion circuit 101 is in the second working mode.

[0096] When the voltage UAC at the load port 70 is a positive voltage, the controller 40 controls the switch tubes Q5 and Q7 to be normally turned on, and controls the switch tubes Q6 and Q8 to be turned on in a high-frequency complementary manner.

[0097] When the voltage UAC of the load port 70 is a negative voltage, the controller 40 controls the switch tubes Q6 and Q8 to be normally turned on, and controls the switch tubes Q5 and Q7 to be turned on in a high-frequency complementary manner.

[0098] During the time period t0-t1, the controller 40 outputs a high-level signal to the switch tubes Q1, Q4, Q8, Q5, and Q7 to control the switch tubes Q1, Q4, Q8, Q5, and Q7 to be turned on (other switch tubes are turned off). At this time, the capacitor C1 is discharged and the inductor L is s The current starts to rise in a positive direction, and the first end of the photovoltaic port 50 outputs current, which passes through the switch tube Q1, the primary winding 32 and the switch tube Q4 in sequence, and then returns to the second end of the photovoltaic port 50. The current path is shown as line S101 in Figure 10. In addition, the primary winding 32 is coupled with the secondary winding 34, and the first end of the secondary winding 34 outputs current, which passes through the inductor L in sequence. s , switch tube Q7, switch tube Q8, load port 70, inductor L f , capacitor C3, and then returns to the second end of the secondary winding 34, wherein the current path is shown as line S102 in FIG10 .

[0099] During the time period t1-t2, the controller 40 outputs a high-level signal to the switch tubes Q1, Q4, Q6, Q5 and Q7 to control the switch tubes Q1, Q4, Q6, Q5 and Q7 to be turned on (other switch tubes are turned off). At this time, the capacitor C1 is discharged and the inductor L sThe current rises in a positive direction, and the first end of the photovoltaic port 50 outputs current, which passes through the switch tube Q1, the primary winding 32 and the switch tube Q4 in sequence, and then returns to the second end of the photovoltaic port 50. The current path is shown as line S111 in Figure 11. In addition, the primary winding 32 is coupled with the secondary winding 34, and the first end of the secondary winding 34 outputs current, which passes through the inductor L in sequence. s , switch tube Q6, switch tube Q5, inductor L f , load port 70, capacitor C4, and then returns to the second end of the secondary winding 34, where the current path is shown as line S8 in Figure 112.

[0100] During the time period t2-t3, the controller 40 outputs a high-level signal to the switch tubes Q2, Q4, Q6, Q5 and Q7 to control the switch tubes Q2, Q4, Q6, Q5 and Q7 to be turned on (other switch tubes are turned off). At this time, the photovoltaic port 50 no longer outputs current, and the inductor L s Starts to flow, and the inductor L s The current is positive, the inductor L s Output current, and then through the switch tube Q6, switch tube Q5, inductor L f , load port 70, capacitor C4 and secondary winding 34, and then back to inductor L s , where the current path is shown as line S122 in FIG12 . In addition, since the switch tubes Q2 and Q4 are turned on, the primary winding 32 is short-circuited, and V P1P2 The voltage is 0. The current path output by the primary winding 32 is shown as line S121 in FIG12 .

[0101] Among them, the time period t0-t3 is half a switching cycle, the time period t3-t6 is half a switching cycle, and the time period t0-t3 and the time period t3-t6 are one switching cycle.

[0102] During the t3-t4 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q3, Q6, Q5 and Q7 to control the switch tubes Q2, Q3, Q6, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0103] During the t4-t5 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q3, Q8, Q5 and Q7 to control the switch tubes Q2, Q3, Q8, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0104] During the t5-t6 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q4, Q8, Q5 and Q7 to control the switch tubes Q2, Q4, Q8, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0105] Figure 13 shows the inductor L s Working diagram. It can be seen that the bridge arm voltage V P1P2 The bridge arm voltage V P3P4 The difference between the two can act on the inductance L s Both ends.

[0106] It can be understood that based on the schematic diagram of the second working mode shown in FIG8 , the controller 40 can adjust the inductance L by adjusting the size of the duty cycle D1 and the size of the phase shift angle D2. s The voltage at both ends is adjusted to adjust the rate of change of the cavity current, so as to achieve the purpose of regulating the mutual energy conversion between the photovoltaic port 50 and the load port 70.

[0107] Please refer to FIG. 14 , which is a schematic diagram of the power conversion circuit 101 in the third working mode.

[0108] In this embodiment, in the third operating mode of the power conversion circuit 101, the energy storage port 60 is connected to the battery, and the load port 70 can be connected to the AC grid or the AC load. Power conversion is performed between the energy storage port 60 and the load port 70, and the photovoltaic port 50 will not participate in the power conversion with other ports.

[0109] The voltage of the energy storage port 60 can be recorded as U bat , the voltage at the load port 70 can be recorded as UAC.

[0110] In the third working mode, the controller 40 controls the power conversion circuit 101 to enter the first working mode first, so as to reduce the voltage U of the energy storage port 60 to bat The voltage is boosted to U by the first power conversion module 10 PV , and then control the power conversion circuit 101 to enter the second working mode.

[0111] Specifically, in the first time period of the first switching cycle, the controller 40 can control the switch tubes Q2 and Q4 to be in the on state, and control the switch tubes Q1 and Q3 to be off. In the second time period of the first switching cycle, the controller 40 can control the switch tubes Q1 and Q3 to be in the on state, and control the switch tubes Q2 and Q4 to be off. Based on the control of the switch tubes Q1, Q2, Q3 and Q4, the voltage boost effect is achieved. In the first time period and the second time period, the controller 40 will control the switch tubes Q5, Q6, Q7 and Q8 to be in the off state. Then, at the voltage U bat Boost to U PV As shown in FIG9 , during the time period t0-t1, the controller 40 outputs a high-level signal to the switches Q1, Q4, Q8, Q5, and Q7 to turn on the switches Q1, Q4, Q8, Q5, and Q7 (other switches are turned off). During the time period t1-t2, the controller 40 outputs a high-level signal to the switches Q1, Q4, Q6, Q5, and Q7 to turn on the switches Q1, Q4, Q6, Q5, and Q7 (other switches are turned off). During the time period t2-t3, the controller 40 outputs a high-level signal to the switches Q2, Q4, Q6, Q5, and Q7 to turn on the switches Q2, Q4, Q6, Q5, and Q7 (other switches are turned off). During the time period t3-t4, the controller 40 outputs a high-level signal to the switches Q2, Q3, Q6, Q5, and Q7 to control the switches Q2, Q3, Q6, Q5, and Q7 to be turned on (other switches are turned off). During the time period t4-t5, the controller 40 outputs a high-level signal to the switches Q2, Q3, Q8, Q5, and Q7 to control the switches Q2, Q3, Q8, Q5, and Q7 to be turned on (other switches are turned off). During the time period t5-t6, the controller 40 outputs a high-level signal to the switches Q2, Q4, Q8, Q5, and Q7 to control the switches Q2, Q4, Q8, Q5, and Q7 to be turned on (other switches are turned off). The time period t0-t3 is half a switching cycle, the time period t3-t6 is half a switching cycle, and the time periods t0-t3 and t3-t6 are one switching cycle.

[0112] Therefore, the third operating mode of the power conversion circuit 101 is a combination of the first operating mode and the second operating mode, thereby achieving power conversion between the energy storage port 60 and the load port 70 .

[0113] It is understood that the power conversion circuit 101 of the present application can also operate in a fourth operating mode. Specifically, in this embodiment, in the fourth operating mode of the power conversion circuit 101, the photovoltaic port 50 is connected to the photovoltaic module, the energy storage port 60 is connected to the battery, and the load port 70 can be connected to the AC grid or AC load, and power conversion is performed between the photovoltaic port, the energy storage port, and the load port 70.

[0114] In the fourth operating mode of the power conversion circuit 101, the controller 40 can simultaneously adjust the duty cycle D1 of the switch tube Q2 and the switch tube Q4, as well as the phase shift angle D2 between the drive signal on the DC side and the drive signal on the AC side, thereby realizing power conversion between the photovoltaic port, the energy storage port and the load port 70.

[0115] The power converter 100 of the present application is configured with a photovoltaic port, an energy storage port and a load port, and can realize power conversion between the three ports. The power converter 100 of the present application uses a smaller number of components, and power conversion can be completed between the photovoltaic port, the energy storage port and the load port through a single-pole system, thereby improving the efficiency of the power converter 100.

[0116] Referring to FIG. 15 , an embodiment of the present application provides a method for controlling a power converter. The method for controlling a power converter can be executed by the controller 40 in the power converter 100. The method for controlling a power converter provided by the present application can achieve power conversion between a photovoltaic port, an energy storage port, and a load port, and can specifically include the following steps:

[0117] Step S151 , in response to the photovoltaic port being connected to the photovoltaic module and the energy storage port being connected to the battery, controlling the switch tube in the first power conversion module to perform power conversion between the photovoltaic port and the energy storage port.

[0118] The power converter 100 shown in the embodiment of FIG5 is taken as an example for description.

[0119] When the power conversion circuit 101 operates in the first operating mode, the controller 40 controls the switches in the first power conversion module 10 to perform power conversion between the photovoltaic port 50 and the energy storage port 60. Specifically, the photovoltaic port 50 is connected to the photovoltaic module 200, and the energy storage port 60 is connected to the battery 400. Power conversion occurs between the photovoltaic port 50 and the energy storage port 60, and the load port 70 does not participate in power conversion with other ports. The controller 40 controls the switches Q5, Q6, Q7, and Q8 to remain in the off state.

[0120] The first power conversion module 10 includes two Boost circuits connected in parallel, so that the voltage Ubat Voltage U to PV port 50 PV of boost.

[0121] Please also refer to FIG6 . During a first time period, the controller 40 can control both the switch Q2 and the switch Q4 to be in an on state. The energy storage port 60 will charge the inductor L1 through the switch Q2. During this time period, the current in the inductor L1 increases. That is, the current output from the first end of the energy storage port 60 flows sequentially through the inductor L1 and the switch Q2 before returning to the second end of the energy storage port 60. The energy storage port 60 will charge the inductor L2 through the switch Q4. During this time period, the current in the inductor L2 increases. That is, the current output from the first end of the energy storage port 60 will also flow sequentially through the inductor L2 and the switch Q4 before returning to the second end of the energy storage port 60. The current path is shown as line S61 in FIG6 .

[0122] Referring also to FIG7 , during the second time period, the controller 40 can control both the switch transistors Q1 and Q3 to be in the on state. The energy storage port 60 and the charged inductor L1 supply power to the photovoltaic port 50 via the switch transistor Q1. This means that the current output from the first end of the energy storage port 60 will sequentially flow through the inductor L1, the switch transistor Q1, and the photovoltaic port 50. Before returning to the second end of the energy storage port 60, the energy storage port 60 and the charged inductor L2 will also supply power to the photovoltaic port 50 via the switch transistor Q3. This means that the current output from the first end of the energy storage port 60 will sequentially flow through the inductor L2, the switch transistor Q3, and the photovoltaic port 50. Before returning to the second end of the energy storage port 60, the current path is shown as line S71 in FIG7 , thereby achieving a voltage boost effect. The first and second time periods constitute a switching cycle.

[0123] Based on such a design, power conversion between the photovoltaic port 50 and the energy storage port 60 is achieved in the first working mode of the power conversion circuit 101 .

[0124] Step S152, in response to the photovoltaic port being connected to the photovoltaic component and the load port being connected to the AC grid or AC load, controlling the switch tube in the first power conversion module and the switch tube in the second power conversion module to perform power conversion between the photovoltaic port and the load port.

[0125] The power converter 100 shown in the embodiment of FIG8 is taken as an example for description.

[0126] When the power conversion circuit 101 operates in the second operating mode, the photovoltaic port 50 is connected to the photovoltaic component 200, and the load port 70 is connected to the AC grid 300 or the AC load. Power conversion is performed between the photovoltaic port 50 and the load port 70, and the energy storage port 60 will not participate in power conversion with other ports.

[0127] The controller 40 controls the switch tubes in the first power conversion module and the switch tubes in the second power conversion module to perform power conversion between the photovoltaic port 50 and the load port 70 .

[0128] Specifically, please refer to FIG9 . During the time period t0-t1, the controller 40 outputs a high-level signal to the switch tubes Q1, Q4, Q8, Q5, and Q7 to control the switch tubes Q1, Q4, Q8, Q5, and Q7 to be turned on (the other switch tubes are turned off). At this time, the capacitor C1 is discharged and the inductor L s The current starts to rise in a positive direction, and the first end of the photovoltaic port 50 outputs current, which passes through the switch tube Q1, the primary winding 32 and the switch tube Q4 in sequence, and then returns to the second end of the photovoltaic port 50. The current path is shown as line S101 in Figure 10. In addition, the primary winding 32 is coupled with the secondary winding 34, and the first end of the secondary winding 34 outputs current, which passes through the inductor L in sequence. s , switch tube Q7, switch tube Q8, load port 70, inductor L f , capacitor C3, and then returns to the second end of the secondary winding 34, wherein the current path is shown as line S102 in FIG10 .

[0129] During the time period t1-t2, the controller 40 outputs a high-level signal to the switch tubes Q1, Q4, Q6, Q5 and Q7 to control the switch tubes Q1, Q4, Q6, Q5 and Q7 to be turned on (other switch tubes are turned off). At this time, the capacitor C1 is discharged and the inductor L s The current rises in a positive direction, and the first end of the photovoltaic port 50 outputs current, which passes through the switch tube Q1, the primary winding 32 and the switch tube Q4 in sequence, and then returns to the second end of the photovoltaic port 50. The current path is shown as line S111 in Figure 11. In addition, the primary winding 32 is coupled with the secondary winding 34, and the first end of the secondary winding 34 outputs current, which passes through the inductor L in sequence. s , switch tube Q6, switch tube Q5, inductor L f , load port 70, capacitor C4, and then returns to the second end of the secondary winding 34, where the current path is shown as line S8 in Figure 112.

[0130] During the time period t2-t3, the controller 40 outputs a high-level signal to the switch tubes Q2, Q4, Q6, Q5 and Q7 to control the switch tubes Q2, Q4, Q6, Q5 and Q7 to be turned on (other switch tubes are turned off). At this time, the photovoltaic port 50 no longer outputs current, and the inductor L s Starts to flow, and the inductor L sThe current is positive, the inductor L s Output current, and then through the switch tube Q6, switch tube Q5, inductor L f , load port 70, capacitor C4 and secondary winding 34, and then back to inductor L s , where the current path is shown as line S122 in FIG12 . In addition, since the switch tubes Q2 and Q4 are turned on, the primary winding 32 is short-circuited, and V P1P2 The voltage is 0. The current path output by the primary winding 32 is shown as line S121 in FIG12 .

[0131] Among them, the time period t0-t3 is half a switching cycle, the time period t3-t6 is half a switching cycle, and the time period t0-t3 and the time period t3-t6 are one switching cycle.

[0132] During the t3-t4 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q3, Q6, Q5 and Q7 to control the switch tubes Q2, Q3, Q6, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0133] During the t4-t5 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q3, Q8, Q5 and Q7 to control the switch tubes Q2, Q3, Q8, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0134] During the t5-t6 time period, the controller 40 outputs a high-level signal to the switch tubes Q2, Q4, Q8, Q5 and Q7 to control the switch tubes Q2, Q4, Q8, Q5 and Q7 to be turned on (the other switch tubes are turned off).

[0135] Step S153, in response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, controlling the switch tube in the first power conversion module and the switch tube in the second power conversion module to perform power conversion between the energy storage port and the load port.

[0136] The power converter 100 shown in the embodiment of FIG14 is taken as an example for description.

[0137] When the power conversion circuit 101 operates in the third operating mode, the energy storage port 60 is connected to the battery, and the load port 70 can be connected to the AC grid or the AC load. Power conversion is performed between the energy storage port 60 and the load port 70, and the photovoltaic port 50 will not participate in the power conversion with other ports.

[0138] In the third working mode, the controller 40 controls the switch tube in the first power conversion module 10 and the switch tube in the second power conversion module 20 to perform power conversion between the energy storage port 60 and the load port 70. Specifically, the controller 40 controls the power conversion circuit 101 to enter the first working mode first, so as to reduce the voltage U of the energy storage port 60 to bat The voltage is boosted to U by the first power conversion module 10 PV , and then controls the power conversion circuit 101 to enter the second working mode. Therefore, the third working mode of the power conversion circuit 101 is a combination of the first working mode and the second working mode, thereby achieving power conversion between the energy storage port 60 and the load port 70.

Claims

1. A power converter, characterized in that: The power converter includes a first power conversion module, a transformer, a second power conversion module and a controller. The input end of the first power conversion module is used to connect to the photovoltaic port, and the output end of the first power conversion module is connected to the primary winding of the transformer and the energy storage port; The input end of the second power conversion module is connected to the secondary winding of the transformer, and the output end of the second power conversion module is used to connect to the load port; The controller is used to: In response to the photovoltaic port being connected to a photovoltaic module and the energy storage port being connected to a battery, controlling a switch tube in the first power conversion module to perform power conversion between the photovoltaic port and the energy storage port; In response to the photovoltaic port being connected to the photovoltaic assembly and the load port being connected to an AC grid or an AC load, controlling a switch tube in the first power conversion module and a switch tube in the second power conversion module to perform power conversion between the photovoltaic port and the load port; In response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, power conversion is performed between the energy storage port and the load port by controlling the switch tube in the first power conversion module and the switch tube in the second power conversion module.

2. The power converter according to claim 1, wherein The first power conversion module includes a first switching tube, a second switching tube, a third switching tube and a fourth switching tube, and the second power conversion module includes a fifth switching tube, a sixth switching tube, a seventh switching tube and an eighth switching tube. The first end of the first switching tube is connected to the first end of the photovoltaic port, the second end of the first switching tube is connected to the first end of the second switching tube, and the second end of the second switching tube is connected to the second end of the photovoltaic port. The first end of the third switching tube is connected to the first end of the photovoltaic port, the second end of the third switching tube is connected to the first end of the fourth switching tube, and the second end of the fourth switching tube is connected to the second end of the photovoltaic port. The first end of the fifth switching tube is connected to the first end of the sixth switching tube, and the second end of the fifth switching tube is connected to the first end of the load port. The second end of the sixth switching tube is connected to the second end of the seventh switching tube, the first end of the seventh switching tube is connected to the first end of the eighth switching tube, and the second end of the eighth switching tube is connected to the second end of the load port.

3. The power converter according to claim 2, wherein: The controller is used to: In response to the photovoltaic port being connected to the photovoltaic assembly and the energy storage port being connected to the battery, the second switch tube and the fourth switch tube are controlled to be turned on during a first time period, and the first switch tube and the third switch tube are controlled to be turned on during a second time period; The first time period and the second time period constitute a switching cycle.

4. The power converter according to claim 3, wherein: The controller is used to: In response to the photovoltaic port being connected to the photovoltaic assembly and the energy storage port being connected to the battery, the fifth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube are all controlled to be turned off during the first time period and the second time period.

5. The power converter according to claim 2, wherein: The controller is used to: In response to the photovoltaic port being connected to the photovoltaic component and the load port being connected to the AC grid or the AC load, In a first time period of a cycle, the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the sixth switch tube are all controlled to be turned off; In a second time period of the cycle time, the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a third time period of the cycle time, the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a fourth time period of the cycle time, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube, and the eighth switch tube are all controlled to be turned off; In a fifth time period of the cycle time, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube, and the sixth switch tube are all controlled to be turned off; In a sixth time period of the cycle time, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are controlled to be turned on, and the first switch tube, the third switch tube and the sixth switch tube are controlled to be turned off.

6. The power converter according to claim 2, wherein: The controller is used to: In response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, During a first time period of a first cycle, the second and fourth switching transistors are controlled to be turned on, and the fifth, sixth, seventh, and eighth switching transistors are controlled to be turned off. During a second time period of the first cycle, the first and third switching transistors are controlled to be turned on, and the fifth, sixth, seventh, and eighth switching transistors are controlled to be turned off. In a first time period of a second cycle, the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the sixth switch tube are all controlled to be turned off; In a second time period of the second cycle, the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a third time period of the second cycle, the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a fourth time period of the second cycle, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube, and the eighth switch tube are all controlled to be turned off; In a fifth time period of the second cycle, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube, and the sixth switch tube are all controlled to be turned off; In a sixth time period of the second cycle, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are controlled to be turned on, and the first switch tube, the third switch tube and the sixth switch tube are controlled to be turned off.

7. A method for controlling a power converter, characterized in that: The control method is applied to a power converter, which includes a first power conversion module, a transformer, and a second power conversion module. The input end of the first power conversion module is used to connect to a photovoltaic port, the output end of the first power conversion module is connected to the primary winding and energy storage port of the transformer, the input end of the second power conversion module is connected to the secondary winding of the transformer, and the output end of the second power conversion module is used to connect to a load port. The control method includes: In response to the photovoltaic port being connected to a photovoltaic module and the energy storage port being connected to a battery, controlling the switch tube in the first power conversion module to perform power conversion between the photovoltaic port and the energy storage port; In response to the photovoltaic port being connected to the photovoltaic assembly and the load port being connected to an AC grid or an AC load, controlling the switch tube in the first power conversion module and the switch tube in the second power conversion module to perform power conversion between the photovoltaic port and the load port; In response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, the switch tube in the first power conversion module and the switch tube in the second power conversion module are controlled to perform power conversion between the energy storage port and the load port.

8. The control method of the power converter according to claim 7, wherein: The first power conversion module includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube; the second power conversion module includes a fifth switching tube, a sixth switching tube, a seventh switching tube, and an eighth switching tube; the first end of the first switching tube is connected to the first end of the photovoltaic port, the second end of the first switching tube is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the second end of the photovoltaic port, the first end of the third switching tube is connected to the first end of the photovoltaic port, the second end of the third switching tube is connected to the first end of the fourth switching tube, the second end of the fourth switching tube is connected to the second end of the photovoltaic port, the first end of the fifth switching tube is connected to the first end of the sixth switching tube, the second end of the fifth switching tube is connected to the first end of the load port, the second end of the sixth switching tube is connected to the second end of the seventh switching tube, the first end of the seventh switching tube is connected to the first end of the eighth switching tube, and the second end of the eighth switching tube is connected to the second end of the load port; the control method further includes: In response to the photovoltaic port being connected to the photovoltaic assembly and the energy storage port being connected to the battery, in a first time period, the second switch tube and the fourth switch tube are controlled to be turned on, and the fifth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube are controlled; in a second time period, the first switch tube and the third switch tube are controlled to be turned on, and the fifth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube are controlled; The first time period and the second time period constitute a switching cycle.

9. The control method of the power converter according to claim 7, wherein: The first power conversion module includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube; the second power conversion module includes a fifth switching tube, a sixth switching tube, a seventh switching tube, and an eighth switching tube; the first end of the first switching tube is connected to the first end of the photovoltaic port, the second end of the first switching tube is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the second end of the photovoltaic port, the first end of the third switching tube is connected to the first end of the photovoltaic port, the second end of the third switching tube is connected to the first end of the fourth switching tube, the second end of the fourth switching tube is connected to the second end of the photovoltaic port, the first end of the fifth switching tube is connected to the first end of the sixth switching tube, the second end of the fifth switching tube is connected to the first end of the load port, the second end of the sixth switching tube is connected to the second end of the seventh switching tube, the first end of the seventh switching tube is connected to the first end of the eighth switching tube, and the second end of the eighth switching tube is connected to the second end of the load port; the control method further includes: In response to the photovoltaic port being connected to the photovoltaic component and the load port being connected to the AC grid or the AC load, In a first time period of a cycle, the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the sixth switch tube are all controlled to be turned off; In a second time period of the cycle time, the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a third time period of the cycle time, the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a fourth time period of the cycle time, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube, and the eighth switch tube are all controlled to be turned off; In a fifth time period of the cycle time, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube, and the sixth switch tube are all controlled to be turned off; In a sixth time period of the cycle time, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are controlled to be turned on, and the first switch tube, the third switch tube and the sixth switch tube are controlled to be turned off.

10. The control method of the power converter according to claim 7, wherein: The first power conversion module includes a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube; the second power conversion module includes a fifth switching tube, a sixth switching tube, a seventh switching tube, and an eighth switching tube; the first end of the first switching tube is connected to the first end of the photovoltaic port, the second end of the first switching tube is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the second end of the photovoltaic port, the first end of the third switching tube is connected to the first end of the photovoltaic port, the second end of the third switching tube is connected to the first end of the fourth switching tube, the second end of the fourth switching tube is connected to the second end of the photovoltaic port, the first end of the fifth switching tube is connected to the first end of the sixth switching tube, the second end of the fifth switching tube is connected to the first end of the load port, the second end of the sixth switching tube is connected to the second end of the seventh switching tube, the first end of the seventh switching tube is connected to the first end of the eighth switching tube, and the second end of the eighth switching tube is connected to the second end of the load port; the control method further includes: In response to the energy storage port being connected to the battery and the load port being connected to the AC grid or the AC load, During a first time period of a first cycle, the second and fourth switching transistors are controlled to be turned on, and the fifth, sixth, seventh, and eighth switching transistors are controlled to be turned off. During a second time period of the first cycle, the first and third switching transistors are controlled to be turned on, and the fifth, sixth, seventh, and eighth switching transistors are controlled to be turned off. In a first time period of a second cycle, the first switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the sixth switch tube are all controlled to be turned off; In a second time period of the second cycle, the first switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the second switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a third time period of the second cycle, the second switch tube, the fourth switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the third switch tube, and the eighth switch tube are all controlled to be turned off; In a fourth time period of the second cycle, the second switch tube, the third switch tube, the sixth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fifth switch tube, and the eighth switch tube are all controlled to be turned off; In a fifth time period of the second cycle, the second switch tube, the third switch tube, the eighth switch tube, the fifth switch tube, and the seventh switch tube are all controlled to be turned on, and the first switch tube, the fourth switch tube, and the sixth switch tube are all controlled to be turned off; In a sixth time period of the second cycle, the second switch tube, the fourth switch tube, the eighth switch tube, the fifth switch tube and the seventh switch tube are controlled to be turned on, and the first switch tube, the third switch tube and the sixth switch tube are controlled to be turned off.

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