Internal power supply system of energy storage inverter and energy storage inverter

Abstract

The utility model relates to an internal power supply system of an energy storage inverter and the energy storage inverter. The system comprises an isolation type transformer, a control module, a first power supply circuit and a second power supply circuit. Wherein the first power supply circuit is connected with the alternating current input end, and the second power supply circuit is connected with the direct current input end; the isolation type transformer comprises a first coil, a second coil and a third coil; wherein the first coil is connected with a first power supply circuit, the second coil is connected with a second power supply circuit, and the third coil is connected with an internal load of the energy storage inverter; the control module is connected with the first power supply circuit and the second power supply circuit, and the control module is used for controlling the first power supply circuit and the second power supply circuit according to the in-place condition of the alternating current input end so as to supply power to an internal load of the energy storage inverter through the first power supply circuit or the second power supply circuit. According to the invention, the hardware cost of the energy storage inverter is reduced when hybrid power supply of a direct current end or an alternating current end is involved.

Description

Technical Field

[0001] This application relates to the field of inverter circuit technology, and in particular to an internal power supply system for an energy storage inverter and an energy storage inverter. Background Technology

[0002] When an energy storage inverter is connected to a large-scale energy storage system, it is typically connected to both an AC terminal (e.g., the power grid) and a DC terminal (e.g., photovoltaic cells or energy storage batteries). Both the AC and DC terminals can serve as power supply terminals to power the internal loads of the energy storage inverter. In specific control, it is necessary to determine which power supply terminal will supply the internal loads of the energy storage inverter based on the actual situation.

[0003] Reference Figure 1 In existing technologies, both the DC and AC ends have independent power supply paths, and the isolation of these power supply paths is achieved through multiple isolation transformers. For example... Figure 1 As shown, when the internal load is powered through the AC terminal, the energy input from the AC terminal is transferred from one side of T1 to the other side to power the internal load located on the other side of T1; when the internal load is powered through the DC terminal, the energy input from the DC terminal is transferred from one side of T2 to the other side to power the internal load located on the other side of T2.

[0004] It is evident that existing energy storage inverters require at least two isolation transformers to achieve mixed power supply from DC and AC terminals to internal loads, which increases the hardware cost of the energy storage inverter. Utility Model Content

[0005] This application provides an internal power supply system and an energy storage inverter to solve the technical problem of high hardware cost when energy storage inverters involve mixed power supply of DC and AC terminals.

[0006] In a first aspect, this application provides an internal power supply system for an energy storage inverter, comprising:

[0007] The system includes an isolation transformer, a control module, at least one first power supply circuit, and at least one second power supply circuit; wherein the first power supply circuit is connected to an AC input terminal, and the second power supply circuit is connected to a DC input terminal.

[0008] The isolation transformer includes at least one first coil, at least one second coil, and at least one third coil; wherein the first coil is connected to the first power supply circuit, the second coil is connected to the second power supply circuit, and the third coil is connected to the internal load of the energy storage inverter; the first coil is located on the first side of the isolation transformer, and the second coil and the third coil are located on the second side of the isolation transformer.

[0009] The control module is connected to the first power supply circuit and the second power supply circuit respectively. The control module is used to control the first power supply circuit and the second power supply circuit according to the presence of the AC input terminal, so as to supply power to the internal load of the energy storage inverter through the first power supply circuit or the second power supply circuit; wherein, when at least one AC input terminal is present, the AC input terminal supplies power to the internal load of the energy storage inverter through the first power supply circuit; or, when neither AC input terminal is present, the DC input terminal supplies power to the internal load of the energy storage inverter through the second power supply circuit.

[0010] In one feasible embodiment of this application, the first power supply circuit includes a rectifier unit, a first switch unit, a first MOSFET, and a first capacitor. The first terminal of the rectifier unit, the control terminal of the first switch unit, and the gate of the first MOSFET are all connected to the control module.

[0011] The second end of the rectifier unit is connected to the AC input terminal, the third end of the rectifier unit is connected to the first end of the first switching unit, the second end of the first switching unit is connected to one end of the first capacitor and one end of the first coil, the other end of the first capacitor is connected to the source of the first MOS transistor and grounded, and the drain of the first MOS transistor is connected to the other end of the first coil.

[0012] When the first switching unit is open, the AC input terminal supplies power to the internal load of the energy storage inverter through the first power supply circuit.

[0013] In one feasible embodiment of this application, the first switching unit includes a third MOS transistor;

[0014] The source of the third MOS transistor is connected to the rectifier unit as the first terminal of the first switching unit, the drain of the third MOS transistor is connected to the first capacitor and the first coil as the second terminal of the first switching unit, and the gate of the third MOS transistor is connected to the control module as the control terminal of the first switching unit.

[0015] In one feasible embodiment of this application, the second power supply circuit includes a second switching unit, a second MOSFET, and a second capacitor, wherein the control terminal of the second switching unit and the gate of the second MOSFET are both connected to the control module.

[0016] The first end of the second switching unit is connected to the DC input terminal, the second end of the second switching unit is connected to one end of the second capacitor and the drain of the second MOSFET, the source of the second MOSFET is connected to one end of the second coil, and the other end of the second capacitor is connected to the other end of the second coil and grounded.

[0017] When the second switching unit is open, the DC input terminal supplies power to the internal load of the energy storage inverter through the second power supply circuit.

[0018] In one feasible embodiment of this application, the second switching unit includes a fourth MOS transistor;

[0019] The drain of the fourth MOS transistor serves as the first terminal of the second switching unit and is connected to the DC input terminal. The source of the fourth MOS transistor serves as the second terminal of the second switching unit and is connected to the second capacitor and the second MOS transistor respectively. The gate of the fourth MOS transistor serves as the control terminal of the second switching unit and is connected to the control module.

[0020] In one feasible embodiment of this application, the control module includes a detection unit, a control unit, and a first drive unit;

[0021] The detection unit is connected to the AC input terminal and the control unit respectively. The detection unit is used to determine the presence of the AC input terminal and output a first control signal to the control unit according to the presence of the AC input terminal.

[0022] The control unit is connected to the first drive unit, and the control unit is used to control the first drive unit to output a first drive signal and a second drive signal according to the first control signal.

[0023] The first driving unit is connected to the first switching unit and the second switching unit respectively. The first driving unit outputs the first driving signal to the first switching unit and the second driving signal to the second switching unit. The first driving signal is used to control the switching state of the first switching unit, and the second driving signal is used to control the switching state of the second switching unit.

[0024] In one feasible embodiment of this application, the control module further includes a sampling unit and a second driving unit;

[0025] The sampling unit is connected to the AC input terminal, the DC input terminal, the internal load, and the control unit respectively. The sampling unit is used to acquire the sampling voltage of the AC input terminal, the DC input terminal, and the internal load, and output a second control signal to the control unit according to the sampling voltage.

[0026] The control unit is further configured to control the second drive unit to output a third drive signal and a fourth drive signal according to the second control signal;

[0027] The second driving unit is connected to the first MOSFET and the second MOSFET respectively. The second driving unit outputs the third driving signal to the first MOSFET and the fourth driving signal to the second MOSFET. The third driving signal is used to perform high-frequency control on the first MOSFET, and the fourth driving signal is used to perform high-frequency control on the second MOSFET.

[0028] In one feasible embodiment of this application, the detection unit includes a detection circuit, the input terminal of the detection circuit is connected to an AC input terminal, and the output terminal of the detection circuit is connected to the control unit;

[0029] The detection circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a third capacitor, and a fourth capacitor;

[0030] One end of the first resistor is connected to the AC input terminal as the input terminal of the detection circuit, and the other end of the first resistor is connected to the inverting input terminal of the first operational amplifier and one end of the third capacitor, and the other end of the third capacitor is grounded.

[0031] The non-inverting input terminal of the first operational amplifier is connected to one end of the fourth capacitor, one end of the second resistor, and one end of the third resistor, respectively. The other end of the fourth capacitor and the other end of the second resistor are connected to the first reference voltage source. The other end of the third resistor is connected to the output terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the control unit as the output terminal of the detection circuit.

[0032] In one feasible embodiment of this application, the detection unit further includes an amplifier circuit, the first input terminal of the amplifier circuit is connected to the live wire of the AC input terminal, the second input terminal of the amplifier circuit is connected to the neutral wire of the AC input terminal, and the output terminal of the amplifier circuit is connected to the input terminal of the detection circuit.

[0033] The amplifier circuit includes a second operational amplifier, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a fifth capacitor, and a sixth capacitor;

[0034] One end of the fourth resistor is connected to the live wire of the AC input terminal as the first input terminal of the amplifier circuit. The other end of the fourth resistor is connected to one end of the fifth capacitor, one end of the fifth resistor, and the non-inverting input terminal of the second operational amplifier. The other end of the fifth capacitor and the other end of the fifth resistor are connected to the second reference voltage source.

[0035] One end of the sixth resistor serves as the second input terminal of the amplifier circuit and is connected to the neutral line of the AC input terminal. The other end of the sixth resistor is connected to one end of the seventh resistor, one end of the sixth capacitor, and the inverting input terminal of the second operational amplifier. The other end of the seventh resistor and the other end of the sixth capacitor are connected to the output terminal of the second operational amplifier.

[0036] The output terminal of the second operational amplifier is connected to the input terminal of the detection circuit as the output terminal of the amplification circuit.

[0037] Secondly, this application provides an energy storage inverter that includes an internal power supply system for an energy storage inverter as described in any of the embodiments of the first aspect above.

[0038] The technical solutions provided in this application have the following advantages compared with the prior art:

[0039] In the technical solution provided in this application, the control module identifies the presence of the AC input terminal and controls the first power supply circuit connected to the AC input terminal and the second power supply circuit connected to the DC input terminal according to the presence of the AC input terminal. This controls the first power supply circuit to supply power to the internal load of the energy storage inverter through the AC input terminal of the energy storage inverter when at least one AC input terminal is present; or, when neither AC input terminal is present, the second power supply circuit to supply power to the internal load of the isolation transformer through the DC input terminal of the energy storage inverter.

[0040] The technical solution provided in this application integrates the DC power supply path and the AC power supply path, requiring only one isolation transformer. Switching between different power supply modes can be achieved through control of the control module. Since the technical solution provided in this application achieves hybrid power supply with just one isolation transformer, the number of isolation transformers required for hybrid power supply in energy storage inverters is reduced, thus lowering the hardware cost of energy storage inverters when hybrid power supply involves both DC and AC terminals. Attached Figure Description

[0041] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0044] Figure 1 This is a schematic diagram of the power supply system when an energy storage inverter provides hybrid power to its internal loads in the existing technology.

[0045] Figure 2 A schematic diagram of the internal power supply system of an energy storage inverter provided in this application embodiment;

[0046] Figure 3 A schematic diagram showing the connection of a first power supply circuit and a second power supply circuit in the internal power supply system of an energy storage inverter provided in an embodiment of this application;

[0047] Figure 4 A connection diagram of a detection unit in the internal power supply system of an energy storage inverter provided in this application embodiment;

[0048] Figure 5 Another connection diagram of the detection unit in the internal power supply system of an energy storage inverter provided in this application embodiment;

[0049] Figure 6 This is a schematic diagram of the structure of an energy storage inverter provided in an embodiment of this application.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1. Control module; 2. First power supply circuit; 21. Rectifier unit; 22. First switching unit; 3. Second power supply circuit; 31. Second switching unit; 41. First coil; 42. Second coil; 43. Third coil; 5. Detection circuit; 6. Amplifier circuit; T. Isolation transformer; Q1. First MOSFET; Q2. Second MOSFET; Q3. Third MOSFET; Q4. Fourth MOSFET; C1. First capacitor; C2. Second capacitor; C3. Third capacitor; C4. Fourth capacitor; C 5. Fifth capacitor; C6. Sixth capacitor; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; R7. Seventh resistor; R8. Eighth resistor; U1. First operational amplifier; U2. Second operational amplifier; AC_IN. AC input terminal; DC_IN. DC input terminal; Vref1. First reference voltage source; Vref2. Second reference voltage source; Vref3. Third reference voltage source. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0054] To address the technical problem of high hardware costs in energy storage inverters when multiple DC or AC terminals are involved in mixed power supply, this application provides an internal power supply system and an energy storage inverter that can reduce hardware costs when multiple DC or AC terminals are involved in mixed power supply.

[0055] Figure 2 This is a schematic diagram of the internal power supply system of an energy storage inverter provided in an embodiment of this application, with reference to... Figure 2 The internal power supply system of an energy storage inverter provided in this application embodiment includes:

[0056] The system includes an isolation transformer T, a control module 1, at least one first power supply circuit 2, and at least one second power supply circuit 3; wherein the first power supply circuit 2 is connected to the AC input terminal AC_IN, and the second power supply circuit 3 is connected to the DC input terminal DC_IN.

[0057] The isolation transformer T includes at least one first coil 41, at least one second coil 42 and at least one third coil 43; wherein, the first coil 41 is connected to the first power supply circuit 2, the second coil 42 is connected to the second power supply circuit 3, and the third coil 43 is connected to the internal load of the energy storage inverter. The first coil 41 is located on the first side of the isolation transformer T, and the second coil 42 and the third coil 43 are located on the second side of the isolation transformer T.

[0058] The control module 1 is connected to the first power supply circuit 2 and the second power supply circuit 3 respectively. The control module 1 is used to control the first power supply circuit 2 and the second power supply circuit 3 according to the presence of the AC input terminal AC_IN, so as to supply power to the internal load of the energy storage inverter through the first power supply circuit 2 or the second power supply circuit 3. Specifically, when at least one AC input terminal AC_IN is present, the AC input terminal AC_IN supplies power to the internal load of the energy storage inverter through the first power supply circuit 2; or, when neither AC input terminal AC_IN is present, the DC input terminal DC_IN supplies power to the internal load of the energy storage inverter through the second power supply circuit 3.

[0059] Specifically, the isolation transformer T is located between the AC input terminal AC_IN, the DC input terminal DC_IN, and the internal load. The AC input terminal AC_IN can be the power grid connected to the energy storage inverter, the DC input terminal DC_IN can be photovoltaic equipment or energy storage batteries connected to the energy storage inverter, and the internal load can be the internal power-consuming unit of the energy storage inverter, such as the display screen, protection circuit, metering circuit, etc. of the energy storage inverter.

[0060] The isolation transformer T includes multiple coils, including at least one first coil 41, at least one second coil 42, and at least one third coil 43. The first coil 41 is connected to a first power supply circuit 2, the second coil 42 is connected to a second power supply circuit 3, and the third coil 43 is connected to an internal load. The first coil 41 is located on a first side of the isolation transformer T, and the second coil 42 and the third coil 43 are located on a second side of the isolation transformer T. That is, the second coil 42 and the third coil 43 are located on the same side of the isolation transformer T, while the first coil 41 and the second coil 42 are located on different sides of the isolation transformer T.

[0061] Control module 1 is connected to both the first power supply circuit 2 and the second power supply circuit 3. Since the first power supply circuit 2 is connected to the AC input terminal AC_IN, control module 1 can detect the presence of the AC input terminal AC_IN. Based on the presence of the AC input terminal AC_IN, control module 1 controls the first power supply circuit 2 and the second power supply circuit 3 to supply power to the internal load, thereby controlling the energy supply to the internal load through the AC input terminal AC_IN or the DC input terminal DC_IN.

[0062] In the technical solution provided in the embodiments of this application, when at least one AC input terminal AC_IN is in place, the internal load of the energy storage inverter is powered by the first power supply circuit 2 through the AC input terminal AC_IN; or, when neither AC input terminal AC_IN is in place, the internal load of the energy storage inverter is powered by the second power supply circuit 3 through the DC input terminal DC_IN.

[0063] In one feasible embodiment of this application, the control module 1 controls whether the internal load can be powered through the first power supply circuit 2 via the AC input terminal AC_IN based on the control of the switching state of the first power supply circuit 2; the control module 1 controls whether the internal load can be powered through the second power supply circuit 3 via the DC input terminal DC_IN based on the control of the switching state of the second power supply circuit 3.

[0064] Figure 3 A schematic diagram of the connection between the first power supply circuit 2 and the second power supply circuit 3 in the internal power supply system of an energy storage inverter provided in this application embodiment, referring to... Figure 3 In one feasible embodiment of this application, the first power supply circuit 2 is specifically connected as follows:

[0065] The first power supply circuit 2 includes a rectifier unit 21, a first switch unit 22, a first MOSFET Q1, and a first capacitor C1. The first terminal of the rectifier unit 21, the control terminal of the first switch unit 22, and the gate of the first MOSFET Q1 are all connected to the control module 1.

[0066] The second end of the rectifier unit 21 is connected to the AC input terminal AC_IN, the third end of the rectifier unit 21 is connected to the first end of the first switch unit 22, the second end of the first switch unit 22 is connected to one end of the first capacitor C1 and one end of the first coil 41 respectively, the other end of the first capacitor C1 is connected to the source of the first MOS transistor Q1 and grounded, and the drain of the first MOS transistor Q1 is connected to the other end of the first coil 41.

[0067] When the first switch unit 22 is open, the AC input terminal AC_IN supplies power to the internal load of the energy storage inverter through the first power supply circuit 2.

[0068] Specifically, the rectifier unit 21 is used to rectify the AC voltage input at the AC input terminal AC_IN, converting the AC voltage into a DC voltage for input. In one feasible embodiment of this application, the rectifier unit 21 includes a rectifier circuit, which can be an uncontrolled rectifier circuit, a semi-controlled rectifier circuit, or a fully controlled rectifier circuit, and no limitation is made here.

[0069] The first MOSFET Q1 and the first capacitor C1 work together to generate a magnetic field at the core of the isolation transformer T. The control module 1 controls the switching state of the first MOSFET Q1 to continuously change, thereby causing the current through the first coil 41 to continuously change, thus generating a magnetic field at the core of the isolation transformer T. The first MOSFET Q1 can be an NMOS transistor or a PMOS transistor, and there is no restriction here.

[0070] The first switching unit 22 is controlled by the control module 1. The control module 1 controls the switching state of the first power supply circuit 2 by controlling the switching state of the first switching unit 22. In a feasible embodiment of this application, the first switching unit 22 includes a third MOS transistor Q3.

[0071] The source of the third MOSFET Q3 is connected to the rectifier unit 21 as the first terminal of the first switching unit 22, the drain of the third MOSFET Q3 is connected to the first capacitor C1 and the first coil 41 as the second terminal of the first switching unit 22, and the gate of the third MOSFET Q3 is connected to the control module 1 as the control terminal of the first switching unit 22.

[0072] Specifically, the third MOSFET Q3 can be either an NMOS transistor or a PMOS transistor, such as... Figure 3 As shown, the third MOSFET Q3 is an NMOS transistor. When the control module 1 inputs a high-level signal to the gate of the third MOSFET Q3, the third MOSFET Q3 is turned on.

[0073] It is understood that the first switching unit 22 plays the role of controlling the switching state of the first power supply circuit 2 based on its own switching state. Therefore, the first switching unit 22 only needs to be able to change its own switching state based on the control of the control module 1. In other embodiments of this application, the first switching unit 22 may also be a relay, a switching circuit, a switching transistor, etc., and there is no limitation here.

[0074] Continue to refer to Figure 3 In one feasible embodiment of this application, the second power supply circuit 3 is specifically connected as follows:

[0075] The second power supply circuit 3 includes a second switching unit 31, a second MOSFET Q2, and a second capacitor C2. The control terminal of the second switching unit 31 and the gate of the second MOSFET Q2 are both connected to the control module 1.

[0076] The first end of the second switching unit 31 is connected to the DC input terminal DC_IN. The second end of the second switching unit 31 is connected to one end of the second capacitor C2 and the drain of the second MOSFET Q2. The source of the second MOSFET Q2 is connected to one end of the second coil 42. The other end of the second capacitor C2 is connected to the other end of the second coil 42 and grounded.

[0077] When the second switch unit 31 is open, the DC input terminal DC_IN supplies power to the internal load of the energy storage inverter through the second power supply circuit 3.

[0078] The second MOSFET Q2 and the second capacitor C2 work together to generate a magnetic field at the core of the isolation transformer T. The control module 1 controls the switching state of the second MOSFET Q2 to continuously change, thereby causing the current through the second coil 42 to continuously change, thus generating a magnetic field at the core of the isolation transformer T. The second MOSFET Q2 can be an NMOS transistor or a PMOS transistor, and there is no restriction here.

[0079] The second switching unit 31 is controlled by the control module 1. The control module 1 controls the switching state of the second power supply circuit 3 by controlling the switching state of the second switching unit 31. In one feasible embodiment of this application, the second switching unit 31 includes a fourth MOS transistor Q4.

[0080] The drain of the fourth MOSFET Q4 serves as the first terminal of the second switching unit 31 and is connected to the DC input terminal DC_IN. The source of the fourth MOSFET Q4 serves as the second terminal of the second switching unit 31 and is connected to the second capacitor C2 and the second MOSFET Q2 respectively. The gate of the fourth MOSFET Q4 serves as the control terminal of the second switching unit 31 and is connected to the control module 1.

[0081] Specifically, the fourth MOSFET Q4 can be either an NMOS transistor or a PMOS transistor, such as... Figure 3 As shown, the fourth MOSFET Q4 is an NMOS transistor. When the control module 1 inputs a high-level signal to the gate of the fourth MOSFET Q4, the fourth MOSFET Q4 is turned on.

[0082] It is understood that the second switching unit 31 plays the role of controlling the switching state of the second power supply circuit 3 based on its own switching state. Therefore, the second switching unit 31 only needs to be able to change its own switching state based on the control of the control module 1. In other embodiments of this application, the second switching unit 31 may also be a relay, a switching circuit, a switching transistor, etc., and there is no limitation here.

[0083] Continue to refer to Figure 3 Based on the specific connection method between the first power supply circuit 2 and the second power supply circuit 3, the implementation principle of the technical solution provided in this application is as follows:

[0084] When control module 1 detects that the AC input terminal AC_IN is in position, it controls the first switching unit 22 and the second switching unit 31 to turn on, and simultaneously performs high-frequency control on the first MOSFET Q1 and the second MOSFET Q2. At this time, the AC current input at the AC input terminal AC_IN is converted into DC current after passing through the rectifier unit 21. As the switching state of the first MOSFET Q1 continuously changes, this DC current generates a magnetic field at the core of the isolation transformer T. Energy is transferred from the first coil 41 of the isolation transformer T to the second coil 42 and the third coil 43 of the isolation transformer T, thereby providing energy to the internal load and the energy storage device that may be connected to the DC input terminal DC_IN through the AC input terminal AC_IN.

[0085] When control module 1 detects that the AC input terminal AC_IN is not in position, it controls the first switching unit 22 to turn off and the second switching unit 31 to turn on, while simultaneously performing high-frequency control on the first MOSFET Q1 and the second MOSFET Q2. At this time, the DC current input at the DC input terminal DC_IN, under the continuous change of the switching state of the second MOSFET Q2, generates a magnetic field at the core of the isolation transformer T. The energy is transferred from the second coil 42 of the isolation transformer T to the first coil 41 of the isolation transformer T, and then temporarily stored in the first capacitor C1. The first capacitor C1 releases the energy again, and under the continuous change of the switching state of the first MOSFET Q1, the energy is transferred from the first coil 41 of the isolation transformer T to the third coil 43 of the isolation transformer T, thereby providing energy to the internal load through the DC input terminal DC_IN.

[0086] As can be seen, the DC power supply path and the AC power supply path are integrated through the technical solution provided in this application. Only one isolation transformer T is needed, and the switching between different power supply modes can be achieved based on the control of the control module 1. Since the technical solution provided in this application achieves hybrid power supply by setting up only one isolation transformer T, the number of isolation transformers T required when the energy storage inverter performs hybrid power supply is reduced. Therefore, the hardware cost of the energy storage inverter when it involves hybrid power supply of DC and AC ends is reduced.

[0087] The above implementation principle is based on Figure 3 The description of the case with a single AC input terminal AC_IN and a single DC input terminal DC_IN is as follows. For the case with multiple AC input terminals AC_IN and multiple DC input terminals DC_IN, it is only necessary to add a first power supply circuit 2 and a first coil 41 with the same number of AC input terminals AC_IN, and a second power supply circuit 3 and a second coil 42 with the same number of DC input terminals DC_IN. The overall implementation principle is basically the same as that of the case with a single AC input terminal AC_IN and a single DC input terminal DC_IN, and will not be elaborated here.

[0088] As can be seen, for cases with multiple AC input terminals AC_IN and multiple DC input terminals DC_IN, only one isolation transformer T is needed. This requires only increasing the number of the first coil 41 and the second coil 42. Similarly, switching between different power supply modes can be achieved based on the control module 1. Therefore, the technical solution provided in this application can also reduce the hardware cost of the energy storage inverter when dealing with mixed DC and AC power supply situations, even in more complex power supply scenarios.

[0089] To realize the logic in the above embodiment that the control module 1 controls the first switch unit 22 and the second switch unit 31 to open when the AC input terminal AC_IN is in place, and controls the first switch unit 22 to close and the second switch unit 31 to open when the AC input terminal AC_IN is not in place, in a feasible embodiment of this application, the control module 1 includes a detection unit, a control unit and a first drive unit.

[0090] The detection unit is connected to the AC input terminal AC_IN and the control unit respectively. The detection unit is used to determine the presence of the AC input terminal AC_IN and output a first control signal to the control unit according to the presence of the AC input terminal AC_IN.

[0091] The control unit is connected to the first drive unit, and the control unit is used to control the first drive unit to output a first drive signal and a second drive signal according to the first control signal.

[0092] The first driving unit is connected to the first switching unit 22 and the second switching unit 31 respectively. The first driving unit outputs a first driving signal to the first switching unit 22 and a second driving signal to the second switching unit 31. The first driving signal is used to control the switching state of the first switching unit 22, and the second driving signal is used to control the switching state of the second switching unit 31.

[0093] Specifically, the detection unit is used to determine the presence of the AC input terminal AC_IN, and outputs a first control signal to the control unit based on the presence of the AC input terminal AC_IN. In one feasible embodiment of this application, the detection unit outputs a high-level first control signal to the control unit when the AC input terminal AC_IN is present, and outputs a low-level first control signal to the control unit when the AC input terminal AC_IN is not present.

[0094] In one feasible embodiment of this application, to implement the above control logic, the detection unit may specifically include a detection circuit 5, as shown in the following figure. Figure 4 The specific connection method of detection circuit 5 is as follows:

[0095] The input terminal of detection circuit 5 is connected to the AC input terminal AC_IN, and the output terminal of detection circuit 5 is connected to the control unit;

[0096] The detection circuit 5 includes a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a third capacitor C3, and a fourth capacitor C4.

[0097] One end of the first resistor R1 is connected to the AC input terminal AC_IN as the input terminal of the detection circuit 5. The other end of the first resistor R1 is connected to the inverting input terminal of the first operational amplifier U1 and one end of the third capacitor C3. The other end of the third capacitor C3 is grounded.

[0098] The non-inverting input of the first operational amplifier U1 is connected to one end of the fourth capacitor C4, one end of the second resistor R2, and one end of the third resistor R3. The other end of the fourth capacitor C4 and the other end of the second resistor R2 are connected to the first reference voltage source Vref1. The other end of the third resistor R3 is connected to the output of the first operational amplifier U1. The output of the first operational amplifier U1 is connected to the control unit as the output of the detection circuit 5.

[0099] Specifically, one end of the first resistor R1 is connected to the AC input terminal AC_IN as the input terminal of the detection circuit 5. Specifically, one end of the first resistor R1 can be connected to the neutral wire of the AC input terminal AC_IN or the live wire of the AC input terminal AC_IN.

[0100] The input voltage of AC_IN is divided by the first resistor R1 and then input to the inverting input of the first operational amplifier U1. The input voltage is compared with the first reference voltage input to the first reference voltage source Vref1. Based on the comparison result, different high and low level signals are output at the output of the first operational amplifier U1.

[0101] based on Figure 4The connection method is such that when the input voltage of the AC input terminal AC_IN is greater than the first reference voltage, the output terminal of the first operational amplifier U1 outputs a high-level signal; conversely, when the input voltage of the AC input terminal AC_IN is less than the first reference voltage, the output terminal of the first operational amplifier U1 outputs a low-level signal, which is the first control signal.

[0102] The third capacitor C3 is used to filter the input voltage at the AC input terminal AC_IN; the second resistor R2, the third resistor R3, and the fourth capacitor C4 are used to suppress noise in the input voltage at the AC input terminal AC_IN, forming a configuration for gain and stability.

[0103] In one feasible embodiment of this application, in order to ensure that the first control signal output by the first operational amplifier U1 can be recognized by the control unit, an eighth resistor R8 is also provided at the output of the first operational amplifier U1 to connect to the third reference voltage source Vref3. The third reference voltage source Vref3 is used to raise the output first control signal by a certain value to ensure that the first control signal can be recognized by the control unit.

[0104] However, when the AC input terminal AC_IN is detected directly through the detection circuit 5, the input voltage of the AC input terminal AC_IN can only be compared with the first reference voltage source Vref1. For the complex input voltage of the AC input terminal AC_IN, when the input voltage contains noise and small signals, detection by only the detection circuit 5 will lead to a decrease in detection accuracy.

[0105] To achieve accurate detection of whether the AC input terminal AC_IN is in place, refer to Figure 5 In one feasible embodiment of this application, the detection module further includes an amplifier circuit 6. When the detection module includes both the amplifier circuit 6 and the detection circuit 5, the input terminal of the amplifier circuit 6 is connected to the AC input terminal AC_IN, and the output terminal of the amplifier circuit 6 is connected to the detection circuit 5.

[0106] In this embodiment, the first input terminal of the amplifier circuit 6 is connected to the live wire of the AC input terminal AC_IN, the second input terminal of the amplifier circuit 6 is connected to the neutral wire of the AC input terminal AC_IN, and the output terminal of the amplifier circuit 6 is connected to the input terminal of the detection circuit 5.

[0107] The amplifier circuit 6 includes a second operational amplifier U2, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a fifth capacitor C5, and a sixth capacitor C6.

[0108] One end of the fourth resistor R4 is connected to the live wire of the AC input terminal AC_IN as the first input terminal of the amplifier circuit 6. The other end of the fourth resistor R4 is connected to one end of the fifth capacitor C5, one end of the fifth resistor R5 and the non-inverting input terminal of the second operational amplifier U2 respectively. The other end of the fifth capacitor C5 and the other end of the fifth resistor R5 are connected to the second reference voltage source Vref2.

[0109] One end of the sixth resistor R6 is connected to the neutral line of the AC input terminal AC_IN as the second input terminal of the amplifier circuit 6. The other end of the sixth resistor R6 is connected to one end of the seventh resistor R7, one end of the sixth capacitor C6 and the inverting input terminal of the second operational amplifier U2 respectively. The other end of the seventh resistor R7 and the other end of the sixth capacitor C6 are connected to the output terminal of the second operational amplifier U2.

[0110] The output of the second operational amplifier U2 is connected to the input of the detection circuit 5 as the output of the amplifier circuit 6.

[0111] Specifically, based on Figure 5 The connection method of this amplifier circuit 6 essentially constitutes a differential amplifier circuit 6. Through differential amplification, the influence of common-mode noise is reduced, and only the real voltage difference between the live wire and the neutral wire is amplified to improve the signal strength.

[0112] The detection circuit 5 is connected to the amplifier circuit 6, so that the detection circuit 5 does not directly process the input voltage of the AC input terminal AC_IN, but processes the output result of the amplifier circuit 6, suppresses noise in the input voltage, amplifies small signals in the input voltage, and ensures detection accuracy.

[0113] The control unit may specifically be a receiving chip, which includes at least one input terminal and multiple output terminals. One of the output terminals of the receiving chip is connected to the first driving unit, and the input terminal of the receiving chip is connected to the detection unit. The input terminal of the receiving chip is used to receive a first control signal. Based on the level of the received first control signal, the first driving unit is controlled to output different first driving signals and second driving signals.

[0114] In one feasible embodiment of this application, when the control unit receives a high-level first control signal, the current AC input terminal AC_IN is in position. The control unit controls the first drive unit to output a high-level first drive signal and a high-level second drive signal, thereby controlling both the first switch unit 22 and the second switch unit 31 to open, so as to supply power to the internal load through the AC input terminal AC_IN.

[0115] In one feasible embodiment of this application, when the control unit receives a low-level first control signal, the current AC input terminal AC_IN is not in position. The control unit outputs a low-level first drive signal and a high-level second drive signal, thereby controlling the first switch unit 22 to close and the second switch unit 31 to open, so as to supply power to the internal load through the DC input terminal DC_IN.

[0116] The first drive unit is connected to the first switch unit 22 and the second switch unit 31 respectively. The first drive unit outputs a first drive signal to the first switch unit 22 to control the switching state of the first switch unit 22, and outputs a second drive signal to the second switch unit 31 to control the switching state of the second switch unit 31.

[0117] When power is supplied to the internal load through the AC input terminal AC_IN or the DC input terminal DC_IN, it is desirable to be able to control the power supply to the internal load. Therefore, in one feasible embodiment of this application, the control module 1 further includes a sampling unit and a second driving unit.

[0118] The sampling unit is connected to the AC input terminal AC_IN, the DC input terminal DC_IN, the internal load, and the control unit respectively. The sampling unit is used to acquire the sampling voltage of the AC input terminal AC_IN, the DC input terminal DC_IN, and the internal load, and outputs a second control signal to the control unit according to the sampling voltage.

[0119] The control unit is also used to control the second drive unit to output a third drive signal and a fourth drive signal according to the second control signal;

[0120] The second driving unit is connected to the first MOSFET Q1 and the second MOSFET Q2 respectively. The second driving unit outputs a third driving signal to the first MOSFET Q1 and a fourth driving signal to the second MOSFET Q2. The third driving signal is used to perform high-frequency control on the first MOSFET Q1, and the fourth driving signal is used to perform high-frequency control on the second MOSFET Q2.

[0121] Specifically, the sampling unit samples the AC input terminal AC_IN, the DC input terminal DC_IN, and the internal load to obtain the sampled voltages of the AC input terminal AC_IN, the DC input terminal DC_IN, and the internal load, and outputs a second control signal to the control unit based on the sampled voltages.

[0122] The control unit controls the second drive unit to output a third drive signal to the first MOSFET Q1 based on the second control signal, and controls the second drive unit to output a fourth drive signal to the second MOSFET Q2, thereby controlling the switching frequency of the first MOSFET Q1 and the second MOSFET Q2, changing the operating frequency of the current isolation transformer T, and thus performing closed-loop control of the power supply to the internal load.

[0123] The technical solution provided in this application allows for the switching of different power supply modes based on the control module 1, regardless of the number of AC input terminals AC_IN and DC input terminals DC_IN used to provide mixed power to the internal load. Since only one isolation transformer T is needed to achieve mixed power supply for the energy storage inverter, the number of isolation transformers T required for mixed power supply is reduced, thus lowering the hardware cost of the energy storage inverter when multiple DC or AC input terminals are involved in mixed power supply.

[0124] Figure 6 This is a schematic diagram of the structure of an energy storage inverter provided in an embodiment of this application, with reference to... Figure 6 The energy storage inverter includes an internal power supply system as described in any of the above embodiments.

[0125] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0126] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An internal power supply system for an energy storage inverter, characterized in that, include: The system includes an isolation transformer, a control module, at least one first power supply circuit, and at least one second power supply circuit; wherein the first power supply circuit is connected to an AC input terminal, and the second power supply circuit is connected to a DC input terminal. The isolation transformer includes at least one first coil, at least one second coil, and at least one third coil; wherein the first coil is connected to the first power supply circuit, the second coil is connected to the second power supply circuit, and the third coil is connected to the internal load of the energy storage inverter; the first coil is located on the first side of the isolation transformer, and the second coil and the third coil are located on the second side of the isolation transformer. The control module is connected to the first power supply circuit and the second power supply circuit respectively. The control module is used to control the first power supply circuit and the second power supply circuit according to the presence of the AC input terminal, so as to supply power to the internal load of the energy storage inverter through the first power supply circuit or the second power supply circuit; wherein, when at least one AC input terminal is present, the AC input terminal supplies power to the internal load of the energy storage inverter through the first power supply circuit; or, when neither AC input terminal is present, the DC input terminal supplies power to the internal load of the energy storage inverter through the second power supply circuit.

2. The system according to claim 1, characterized in that, The first power supply circuit includes a rectifier unit, a first switch unit, a first MOSFET, and a first capacitor. The first terminal of the rectifier unit, the control terminal of the first switch unit, and the gate of the first MOSFET are all connected to the control module. The second end of the rectifier unit is connected to the AC input terminal, the third end of the rectifier unit is connected to the first end of the first switching unit, the second end of the first switching unit is connected to one end of the first capacitor and one end of the first coil, the other end of the first capacitor is connected to the source of the first MOS transistor and grounded, and the drain of the first MOS transistor is connected to the other end of the first coil. When the first switching unit is open, the AC input terminal supplies power to the internal load of the energy storage inverter through the first power supply circuit.

3. The system according to claim 2, characterized in that, The first switching unit includes a third MOSFET; The source of the third MOS transistor is connected to the rectifier unit as the first terminal of the first switching unit, the drain of the third MOS transistor is connected to the first capacitor and the first coil as the second terminal of the first switching unit, and the gate of the third MOS transistor is connected to the control module as the control terminal of the first switching unit.

4. The system according to claim 3, characterized in that, The second power supply circuit includes a second switching unit, a second MOSFET, and a second capacitor. The control terminal of the second switching unit and the gate of the second MOSFET are both connected to the control module. The first end of the second switching unit is connected to the DC input terminal, the second end of the second switching unit is connected to one end of the second capacitor and the drain of the second MOSFET, the source of the second MOSFET is connected to one end of the second coil, and the other end of the second capacitor is connected to the other end of the second coil and grounded. When the second switching unit is open, the DC input terminal supplies power to the internal load of the energy storage inverter through the second power supply circuit.

5. The system according to claim 4, characterized in that, The second switching unit includes a fourth MOSFET; The drain of the fourth MOS transistor serves as the first terminal of the second switching unit and is connected to the DC input terminal. The source of the fourth MOS transistor serves as the second terminal of the second switching unit and is connected to the second capacitor and the second MOS transistor respectively. The gate of the fourth MOS transistor serves as the control terminal of the second switching unit and is connected to the control module.

6. The system according to claim 5, characterized in that, The control module includes a detection unit, a control unit, and a first drive unit; The detection unit is connected to the AC input terminal and the control unit respectively. The detection unit is used to determine the presence of the AC input terminal and output a first control signal to the control unit according to the presence of the AC input terminal. The control unit is connected to the first drive unit, and the control unit is used to control the first drive unit to output a first drive signal and a second drive signal according to the first control signal; The first driving unit is connected to the first switching unit and the second switching unit respectively. The first driving unit outputs the first driving signal to the first switching unit and the second driving signal to the second switching unit. The first driving signal is used to control the switching state of the first switching unit, and the second driving signal is used to control the switching state of the second switching unit.

7. The system according to claim 6, characterized in that, The control module also includes a sampling unit and a second driving unit; The sampling unit is connected to the AC input terminal, the DC input terminal, the internal load, and the control unit respectively. The sampling unit is used to acquire the sampling voltage of the AC input terminal, the DC input terminal, and the internal load, and output a second control signal to the control unit according to the sampling voltage. The control unit is further configured to control the second drive unit to output a third drive signal and a fourth drive signal according to the second control signal; The second driving unit is connected to the first MOSFET and the second MOSFET respectively. The second driving unit outputs the third driving signal to the first MOSFET and the fourth driving signal to the second MOSFET. The third driving signal is used to perform high-frequency control on the first MOSFET, and the fourth driving signal is used to perform high-frequency control on the second MOSFET.

8. The system according to claim 6, characterized in that, The detection unit includes a detection circuit, the input terminal of which is connected to an AC input terminal, and the output terminal of which is connected to the control unit. The detection circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a third capacitor, and a fourth capacitor; One end of the first resistor is connected to the AC input terminal as the input terminal of the detection circuit, and the other end of the first resistor is connected to the inverting input terminal of the first operational amplifier and one end of the third capacitor, and the other end of the third capacitor is grounded. The non-inverting input terminal of the first operational amplifier is connected to one end of the fourth capacitor, one end of the second resistor, and one end of the third resistor, respectively. The other end of the fourth capacitor and the other end of the second resistor are connected to the first reference voltage source. The other end of the third resistor is connected to the output terminal of the first operational amplifier. The output terminal of the first operational amplifier is connected to the control unit as the output terminal of the detection circuit.

9. The system according to claim 8, characterized in that, The detection unit further includes an amplifier circuit, the first input terminal of which is connected to the live wire of the AC input terminal, the second input terminal of which is connected to the neutral wire of the AC input terminal, and the output terminal of which is connected to the input terminal of the detection circuit. The amplifier circuit includes a second operational amplifier, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a fifth capacitor, and a sixth capacitor; One end of the fourth resistor is connected to the live wire of the AC input terminal as the first input terminal of the amplifier circuit. The other end of the fourth resistor is connected to one end of the fifth capacitor, one end of the fifth resistor, and the non-inverting input terminal of the second operational amplifier. The other end of the fifth capacitor and the other end of the fifth resistor are connected to the second reference voltage source. One end of the sixth resistor serves as the second input terminal of the amplifier circuit and is connected to the neutral line of the AC input terminal. The other end of the sixth resistor is connected to one end of the seventh resistor, one end of the sixth capacitor, and the inverting input terminal of the second operational amplifier. The other end of the seventh resistor and the other end of the sixth capacitor are connected to the output terminal of the second operational amplifier. The output terminal of the second operational amplifier is connected to the input terminal of the detection circuit as the output terminal of the amplification circuit.

10. An energy storage inverter, characterized in that, The energy storage inverter includes the internal power supply system of the energy storage inverter as described in any one of claims 1-9.

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