A power converter and system

Abstract

A power converter and system, the power converter comprises at least one direct-direct conversion circuit board, a bus circuit board and at least one direct- alternating conversion circuit board; the direct-direct conversion circuit board comprises a first connection terminal, a direct-direct conversion circuit and a second connection terminal; the first connection terminal is electrically connected to a first direct current side of the direct-direct conversion circuit, and the second connection terminal is electrically connected to a second direct current side of the direct-direct conversion circuit; the bus circuit board comprises a third connection terminal, a positive direct current bus, a negative direct current bus, a fourth connection terminal, a first bus capacitor and a second bus capacitor; the direct-alternating conversion circuit board comprises a fifth connection terminal, a direct-alternating conversion circuit and a sixth connection terminal; the fifth connection terminal and the sixth connection terminal are electrically connected to a third direct current side and an alternating current side of the direct-alternating conversion circuit respectively; the first connection terminal is used for electrically connecting a direct current power supply, each second connection terminal is connected in parallel and electrically connected to the third connection terminal; and the fourth connection terminal is electrically connected to the fifth connection terminal. The scheme can reduce maintenance cost.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a power converter and system. Background Technology

[0002] The core of power converters such as inverters lies in the design of the power topology, namely the design of the main power circuit. Since the main power circuit usually operates in high-voltage, high-current scenarios, it is the most vulnerable part of the power converter.

[0003] In current designs, in order to improve the integration level and reduce the size of the power converter, the main power circuit is usually designed on a printed circuit board (PCB). However, if the components on the main power circuit are damaged, the entire PCB usually needs to be replaced, which increases maintenance costs. Utility Model Content

[0004] To address the above issues, this application provides a power converter and system that can reduce maintenance costs and make it easier to expand or upgrade the power converter in the future.

[0005] In a first aspect, this application provides a power converter, which includes at least one DC-DC conversion circuit board, a bus circuit board, and at least one DC-AC conversion circuit board. The DC-DC conversion circuit board includes a first terminal, a DC-DC conversion circuit, and a second terminal; the first terminal is electrically connected to a first DC side of the DC-DC conversion circuit, and the second terminal is electrically connected to a second DC side of the DC-DC conversion circuit. The bus circuit board includes a third terminal, a positive DC bus, a negative DC bus, a fourth terminal, a first bus capacitor, and a second bus capacitor. One end of the positive DC bus is electrically connected to the positive terminal of the third terminal, and the other end is electrically connected to the positive terminal of the fourth terminal. The midpoint of the DC bus is connected to the midpoint terminal of the fourth terminal. One end of the negative DC bus is electrically connected to the negative terminal of the third terminal, and the other end is electrically connected to the negative terminal of the fourth terminal. The first bus capacitor is electrically connected between the positive DC bus and the midpoint of the DC bus, and the second bus capacitor is electrically connected between the negative DC bus and the midpoint of the DC bus. The DC-AC converter circuit board includes a fifth terminal, a DC-AC converter circuit, and a sixth terminal. The fifth terminal is electrically connected to the third DC side of the DC-AC converter circuit, and the sixth terminal is electrically connected to the AC side of the DC-AC converter circuit. The first terminal is used to electrically connect to the DC power supply, all second terminals are connected in parallel and electrically connected to the third terminal, the fourth terminal is electrically connected to the fifth terminal, and the sixth terminal is used to electrically connect to the AC network.

[0006] In this design, the main power circuit components of the power converter, such as the DC-DC conversion circuit, DC bus and bus capacitors, and DC-AC conversion circuit, are not all integrated onto a single circuit board. Instead, they are located on separate circuit boards, which are electrically connected via terminals to achieve power transfer. This modular design simplifies maintenance, reducing time and labor costs. For example, in the event of a partial component failure, only the circuit board containing the faulty component needs to be replaced, eliminating the need to replace the rest of the circuit boards. Furthermore, the modular design facilitates future expansion or upgrades of the power converter, allowing more circuit boards to be connected in parallel as needed without replacing the entire main power circuit.

[0007] In one possible implementation, the power converter provided in this application embodiment can be a photovoltaic inverter or an energy storage converter.

[0008] In one possible implementation, the power converter includes multiple bus circuit boards and multiple DC-AC conversion circuit boards; the third terminals of each bus circuit board are connected in parallel; the fourth terminal of each bus circuit board is electrically connected to the fifth terminal of a DC-AC conversion circuit board; and the sixth terminal of each DC-AC conversion circuit board is connected to a single phase of AC power.

[0009] In one possible implementation, the power converter includes: multiple bus circuit boards and a DC-AC conversion circuit board; the third terminals of each bus circuit board are connected in parallel; the positive terminals of the fourth terminals of each bus circuit board are connected in parallel and then connected to the positive terminal of the fifth terminal of the DC-AC conversion circuit board; the negative terminals of the fourth terminals of each bus circuit board are connected in parallel and then connected to the negative terminal of the fifth terminal of the DC-AC conversion circuit board; the DC bus midpoint terminals of the fourth terminals of each bus circuit board are connected in parallel and then connected to the DC bus midpoint terminal of the fifth terminal of the DC-AC conversion circuit board; the DC-AC conversion circuit board includes multiple DC-AC conversion circuits, and the AC side of each DC-AC conversion circuit is connected to an AC terminal of the sixth terminal, with each AC terminal corresponding to one phase of AC power.

[0010] In one possible implementation, the power converter includes: a bus circuit board and a plurality of DC-AC conversion circuit boards; the bus circuit board includes a plurality of fourth terminals, each fourth terminal being electrically connected to a fifth terminal of a DC-AC conversion circuit board; and a sixth terminal of each DC-AC conversion circuit board being connected to a single phase of AC power.

[0011] In one possible implementation, the power converter further includes: at least one input circuit board, at least one protection switch circuit board, and at least one AC filter circuit board; the input circuit board includes a DC input interface, a switching circuit, and a seventh terminal; the DC input interface is used to connect to a DC power supply and is electrically connected to a first terminal of the switching circuit, a second terminal of the switching circuit is electrically connected to the seventh terminal, and the seventh terminal is electrically connected to the first terminal; the protection switch circuit board includes an eighth terminal, a protection switch, and a ninth terminal; the eighth terminal is electrically connected to a sixth terminal and the first terminal of the protection switch, and the second terminal of the protection switch is electrically connected to the ninth terminal; the AC filter circuit board includes a tenth terminal, a filter circuit, and an AC output port; the tenth terminal is electrically connected to the ninth terminal and the first terminal of the filter circuit, and the second terminal of the filter circuit is electrically connected to the AC output port.

[0012] In one possible implementation, the power converter includes multiple protection switchboards and multiple AC filterboards; each protection switchboard and its corresponding AC filterboard are used to transmit one phase of AC power.

[0013] In one possible implementation, the power converter further includes a controller board, which includes a controller; the DC-DC conversion circuit board further includes a first sampling signal terminal, the bus circuit board further includes a second sampling signal terminal, the DC-AC conversion circuit board further includes a third sampling signal terminal, the input circuit board further includes a fourth sampling signal terminal, the protection switch circuit board further includes a fifth sampling signal terminal, and the AC filter circuit board further includes a sixth sampling signal terminal; one or more of the first, second, third, fourth, fifth, and sixth sampling signal terminals are electrically connected to the sampling signal receiving terminal on the controller board.

[0014] In one possible implementation, the power converter also includes a power supply system; the power supply system is used to power the controller; the power supply system is located on the controller board; or, the power supply system is located on a separate circuit board.

[0015] In one possible implementation, the DC-DC converter circuit board further includes a first control signal terminal, and the DC-AC converter circuit board further includes a second control signal terminal; the first control signal terminal and the second control signal terminal are electrically connected to a third control signal terminal on the controller board.

[0016] Secondly, this application also provides a power conversion system, which includes the power converter provided in the first aspect and any implementation thereof, and further includes a photovoltaic module. The photovoltaic module can serve as the power source for the power converter, providing DC input. Attached Figure Description

[0017] Figure 1 A schematic diagram of the power converter provided in the embodiments of this application. Figure 1 ;

[0018] Figure 2 A schematic diagram of the power converter provided in the embodiments of this application. Figure 2 ;

[0019] Figure 3 A schematic diagram of the power converter provided in the embodiments of this application. Figure 3 ;

[0020] Figure 4 A schematic diagram of the power converter provided in the embodiments of this application. Figure 4 ;

[0021] Figure 5 A schematic diagram of the power converter provided in the embodiments of this application. Figure 5 ;

[0022] Figure 6 A schematic diagram of the power converter provided in the embodiments of this application. Figure 6 ;

[0023] Figure 7 This is a schematic diagram of a power conversion system provided in an embodiment of this application. Detailed Implementation

[0024] The terms "first" and "second" used in this application description are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0025] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly. For example, "connection" may be a fixed connection, a detachable connection, or an integral part; it may be a direct connection or an indirect connection through an intermediate medium.

[0026] The circuit board mentioned below is short for printed circuit board (PCB).

[0027] This application provides a power converter, which will be described in detail below with reference to the accompanying drawings.

[0028] See Figure 1 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 1 .

[0029] The power converter 10 includes at least one DC-DC conversion circuit board 11, a bus circuit board 12, and at least one DC-AC conversion circuit board 13.

[0030] The DC-DC converter circuit board 11 includes a first terminal 112, a DC-DC converter circuit 111, and a second terminal 113. The first terminal 112 is used to electrically connect to the DC power supply 20.

[0031] The first terminal 112 is electrically connected to the first DC side of the DC-DC converter circuit 111, and the second terminal 113 is electrically connected to the second DC side of the DC-DC converter circuit 111.

[0032] In the case where the power converter 10 includes multiple DC-DC conversion circuit boards 11, the second terminals 113 of the multiple DC-DC conversion circuit boards 11 are connected in parallel and electrically connected to the third terminal 123.

[0033] The bus circuit board 12 includes a third terminal 123, a positive DC bus DC+, a negative DC bus DC-, a fourth terminal 124, a first bus capacitor C1, and a second bus capacitor C2.

[0034] One end of the positive DC bus DC+ is electrically connected to the positive terminal IN+ of the third terminal 123, and the other end is electrically connected to the positive terminal OUT+ of the fourth terminal 124. The midpoint N of the DC bus is connected to the midpoint N of the DC bus of the fourth terminal 124.

[0035] One end of the negative DC bus DC- is electrically connected to the negative terminal IN- of the third terminal 123, and the other end is electrically connected to the negative terminal OUT- of the fourth terminal. The first bus capacitor C1 is electrically connected between the positive DC bus DC+ and the midpoint N of the DC bus, and the second bus capacitor C2 is electrically connected between the negative DC bus DC- and the midpoint N of the DC bus.

[0036] It is understood that in practical applications, the DC bus capacitor can be a single capacitor or multiple capacitors connected in parallel. The DC bus capacitor can be an electrolytic capacitor, a film capacitor, or a combination of both; this application does not specifically limit the types used.

[0037] The DC-AC conversion circuit board 13 includes a fifth terminal 132, a DC-AC conversion circuit 131, and a sixth terminal 133.

[0038] The fifth terminal 132 is electrically connected to the third DC side of the DC-AC converter circuit 131.

[0039] The fifth terminal 132 is also electrically connected to the fourth terminal 124. Specifically, the positive terminal IN+ of the fifth terminal 132 is connected to the positive terminal OUT+ of the fourth terminal 124; the negative terminal IN- of the fifth terminal 132 is connected to the negative terminal OUT- of the fourth terminal 124; and the DC bus midpoint terminal N0 of the fifth terminal 132 is connected to the DC bus midpoint terminal N0 of the fourth terminal 124.

[0040] The sixth terminal 133 is electrically connected to the AC side of the DC-AC converter circuit 131. The sixth terminal 133 is used for electrical connection to the AC network.

[0041] In this application, the main power circuit, including the DC-DC converter 111, the first bus capacitor C1, the second bus capacitor C2, and the DC-AC converter 131, is not integrated on the same circuit board, but is arranged on multiple circuit boards. The multiple circuit boards are electrically connected to achieve normal power transmission.

[0042] In one possible implementation, the power converter 10 is a photovoltaic inverter, and the DC power supply 20 can be a photovoltaic (PV) module. In this case, the DC-DC conversion circuit 111 can perform boost conversion. This application embodiment does not limit the specific topology of the DC-DC conversion circuit 111; for example, it can be a Boost circuit, a flying capacitor boost circuit, or a symmetrical three-level boost circuit, etc. The DC-DC conversion circuit 111 generally includes power switches, energy storage reactors (also called inductors), diodes, capacitors, voltage sampling circuits, current sampling circuits, etc. It may also include drive circuits and / or control circuits for the power switches.

[0043] The power switching transistor can be an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field-effect transistor (MOSFET), a silicon carbide metal oxide semiconductor field-effect transistor (SiC MOSFET), etc., and the embodiments in this application do not specifically limit it.

[0044] At this point, the DC-DC converter circuit board 11 may also include an interface for outputting voltage sampling signals, an interface for outputting current sampling signals, and an interface for connecting control signals to the power switching transistors. The current sampling signals and voltage sampling signals can be used for Maximum Power Point Tracking (MPPT) control.

[0045] Furthermore, considering that the energy storage reactor used in the DC-DC conversion circuit 111 may be large in actual applications, in another possible implementation, the energy storage reactor may not be placed on the DC-DC conversion circuit board 11, but may be placed on a separate circuit board and then electrically connected to the DC-DC conversion circuit board 11 through an interface.

[0046] In this embodiment, the DC-AC converter circuit 131 is separately disposed on the DC-AC converter circuit board 13. The DC-AC converter circuit 131 can adopt a three-level neutral point clamped (NPC) topology, a three-level active neutral point clamped (ANPC) topology, a flying capacitor type, a full-bridge circuit, etc. This embodiment does not make specific limitations.

[0047] Depending on the topology, the DC-AC converter circuit 131 may include power switches, energy storage reactors (also known as inductors), diodes, capacitors, voltage sampling circuits, current sampling circuits, etc. It may also include drive circuits and / or control circuits for the power switches.

[0048] At this time, the DC-AC converter circuit board 13 may also include an interface for outputting voltage sampling signals, an interface for outputting current sampling signals, and an interface for connecting control signals to each power switch.

[0049] In one possible implementation, the above-mentioned DC-DC conversion circuit board 11, bus circuit board 12 and at least one DC-AC conversion circuit board 13 can be electrically connected by metal wires or metal strips, for example, using copper wires or copper strips.

[0050] In summary, the power converter provided in this application adopts the opposite technical approach to the existing solution, which integrates all the circuits of the main power circuit onto a single circuit board. Instead, the DC-DC conversion circuit, bus capacitor, and DC-AC conversion circuit of the main power circuit are placed on different circuit boards. This approach makes the maintenance of the power converter more convenient and reduces maintenance time and labor costs. For example, when a partial circuit failure occurs, only the circuit board containing the faulty circuit needs to be replaced, while the circuit boards containing the other circuits do not need to be replaced.

[0051] Furthermore, the modular design makes it easier to expand or upgrade the power converter in the future. More circuit boards can be connected in parallel according to the needs without replacing the entire main power circuit. For example, a DC-DC conversion circuit board can be added to increase the input power of the power conversion circuit, or a DC-AC conversion circuit board can be added to increase the output power of the power converter.

[0052] The following explanation will focus on the specific circuit implementation.

[0053] See Figure 2 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 2 .

[0054] For ease of explanation, this application embodiment uses the DC-DC conversion circuit on the DC-DC conversion circuit board 11 as a Boost circuit and the DC-AC conversion circuit on the DC-AC conversion circuit board 23 as a three-level NPC topology for illustration. However, this does not constitute a limitation on the technical solution of this application. For example, the DC-AC conversion circuit can also adopt a three-level ANPC topology, a flying capacitor circuit, a full-bridge inverter circuit, etc.

[0055] In this implementation, the power converter includes multiple bus circuit boards 12 and multiple DC-AC conversion circuit boards 23. This embodiment specifically uses an example comprising three bus circuit boards 12 and three DC-AC conversion circuit boards 23 for illustration.

[0056] The third terminals of each bus circuit board 12 are connected in parallel.

[0057] The fourth terminal of each busbar circuit board 12 is electrically connected to the fifth terminal of a DC-AC converter circuit board 23. The sixth terminal of each DC-AC converter circuit board 23 is connected to a single phase of AC power.

[0058] Specifically, the bus circuit board 12 containing bus capacitors CR1 and CR2 is connected to the DC-AC conversion circuit board 23 that outputs R-phase AC power; the bus circuit board 12 containing bus capacitors CT1 and CT2 is connected to the DC-AC conversion circuit board 23 that outputs T-phase AC power; and the bus circuit board 12 containing bus capacitors CS1 and CS2 is connected to the DC-AC conversion circuit board 23 that outputs S-phase AC power.

[0059] The positive terminal of the fourth terminal of each bus circuit board 12 is represented by 124(OUT+) in the figure; the negative terminal of the fourth terminal of each bus circuit board 12 is represented by 124(OUT-) in the figure; the DC bus midpoint terminal of each bus circuit board 12 is represented by 124(N0) in the figure.

[0060] In this implementation, the power converter can output three-phase AC power. When a fault occurs in the bus capacitor or DC-AC conversion circuit corresponding to a certain phase current, the faulty circuit board can be replaced individually, making the maintenance of the power converter more convenient and reducing maintenance time and labor costs.

[0061] See Figure 3 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 3 .

[0062] The power converter 10 provided in this application embodiment includes: a plurality of bus circuit boards 12 and a DC-AC conversion circuit board 13.

[0063] The third terminals 123 of each bus circuit board 12 are connected in parallel. The positive terminal OUT+ of the fourth terminal 124 of each bus circuit board 12 is connected in parallel to the positive terminal IN+ of the fifth terminal 132 of the DC-AC converter circuit board 13. The negative terminal OUT- of the fourth terminal 124 of each bus circuit board 12 is connected in parallel to the negative terminal IN- of the fifth terminal 132 of the DC-AC converter circuit board 13. The DC bus midpoint terminal N0 of the fourth terminal 124 of each bus circuit board 12 is connected in parallel to the DC bus midpoint terminal N0 of the fifth terminal 132 of the DC-AC converter circuit board 13.

[0064] The DC-AC converter circuit board 13 includes multiple DC-AC converter circuits 131. The AC side of each DC-AC converter circuit 131 is connected to an AC terminal of the sixth terminal 133, and each AC terminal corresponds to one phase of AC power. Specifically, in this embodiment, taking the power converter 10 outputting three-phase AC power as an example, the DC-AC converter circuit board 13 includes three DC-AC converter circuits 131, each of which is used to output one phase of AC power. The DC-AC converter circuit 131 that outputs R-phase AC power is connected to the R-phase output terminal of the sixth terminal 133; the DC-AC converter circuit 131 that outputs S-phase AC power is connected to the S-phase output terminal of the sixth terminal 133; and the DC-AC converter circuit 131 that outputs T-phase AC power is connected to the T-phase output terminal of the sixth terminal 133.

[0065] In this embodiment, the DC-DC converter circuit, bus capacitor, and DC-AC converter circuit of the main power circuit are set on different circuit boards. This method makes the maintenance of the power converter more convenient and reduces maintenance time and labor costs. For example, when a local circuit fails, only the circuit board where the faulty circuit is located needs to be replaced, and the circuit boards where the other circuits are located do not need to be replaced.

[0066] See Figure 4 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 4 .

[0067] In this embodiment, the power converter includes a bus circuit board 12 and multiple DC-AC conversion circuit boards 23. This embodiment specifically uses a configuration of three DC-AC conversion circuit boards 23 as an example.

[0068] The bus circuit board 12 includes multiple fourth terminals, each of which is electrically connected to a fifth terminal of a DC-AC converter circuit board 23. A sixth terminal 133 of each DC-AC converter circuit board 23 is connected to a single phase of AC power.

[0069] The positive terminal of each fourth terminal of the bus circuit board 12, indicated by 124 (OUT+) in the figure, is used to connect to the positive terminal of the corresponding fifth terminal of the DC-AC converter circuit board 23, indicated by 132 (IN+) in the figure. The negative terminal of each fourth terminal of the bus circuit board 12, indicated by 124 (OUT-) in the figure, is used to connect to the negative terminal of the corresponding fifth terminal of the DC-AC converter circuit board 23, indicated by 132 (IN-) in the figure. The DC bus midpoint terminal of each fourth terminal of the bus circuit board 12, indicated by 124 (N0) in the figure, is used to connect to the DC bus midpoint terminal of the corresponding fifth terminal of the DC-AC converter circuit board 23, indicated by 132 (N0) in the figure.

[0070] In this implementation, the capacitors, being relatively few in number, can be centrally located on a single circuit board, allowing the power converter to output three-phase AC power. When a fault occurs in the DC-AC conversion circuit corresponding to a particular phase current, the faulty circuit board can be replaced individually, making power converter maintenance more convenient and reducing maintenance time and labor costs.

[0071] The following describes other implementation methods of power converters.

[0072] See Figure 5 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 5 .

[0073] Figure 5 The following explanation will continue using a power converter comprising three bus circuit boards 12 and three DC-AC conversion circuit boards 13 as an example.

[0074] The power converter also includes: at least one input circuit board 14, at least one protection switch circuit board 15, and at least one AC filter circuit board 16.

[0075] Taking a power converter that outputs three-phase AC power as an example, the power converter includes three protection switch circuit boards 15 and three AC filter circuit boards 16. Each protection switch circuit board 15 corresponds to one phase of AC power, and each AC filter circuit board 16 corresponds to one phase of AC power.

[0076] When each input circuit board 14 provides a DC input to one DC-DC converter circuit board 11, the number of input circuit boards 14 and DC-DC converter circuit boards 11 is the same. It should be understood that one input circuit board 14 may also provide a DC input to multiple DC-DC converter circuit boards 11, or multiple input circuit boards 14 may collectively provide a DC input to one DC-DC converter circuit board 11.

[0077] The input circuit board 14 includes a DC input interface 142, a switching circuit 141, and a seventh terminal 143. The DC input interface 142 is used to connect to a DC power supply and is electrically connected to the first terminal of the switching circuit 141. The second terminal of the switching circuit 141 is electrically connected to the seventh terminal 143, and the seventh terminal 143 is electrically connected to the first terminal of the DC-DC converter circuit board.

[0078] The DC power supply connected to the DC input interface 142 can be a PV module. A voltage sampling circuit and / or a current sampling circuit can also be included between the DC input interface 142 and the switching circuit. The input circuit board 14 can realize two-in-one or multiple-in-one DC input through the switching circuit 141. In one possible implementation, the input circuit board 14 can also include output ports for voltage sampling signals and / or current sampling signals.

[0079] The protection switch circuit board 15 includes an eighth terminal 152, a protection switch 151, and a ninth terminal 153. The eighth terminal 152 is electrically connected to the sixth terminal and the first terminal of the protection switch 151, and the second terminal of the protection switch 151 is electrically connected to the ninth terminal 153. The protection switch 151 may include a relay, and may also include a fuse (such as a fuse), etc., which are not specifically limited in this embodiment.

[0080] When the protection switch 151 includes active control devices such as relays, the protection switch circuit board 15 also includes an interface for connecting control signals to the relays.

[0081] The protection switch 151 can disconnect the electrical connection between the DC-AC conversion circuit and the subsequent circuit to achieve circuit protection. In one possible implementation, the protection switch circuit board 15 may also include a voltage sampling circuit and / or a current sampling circuit, and the protection switch circuit board 15 may also include corresponding output ports for voltage sampling signals and / or current sampling signals.

[0082] The AC filter circuit board 16 includes a tenth terminal 161, a filter circuit 162, and an AC output port 163. The tenth terminal 162 is electrically connected to the ninth terminal 153 and the first terminal of the filter circuit 161, and the second terminal of the filter circuit 161 is electrically connected to the AC output port 163. The filter circuit 161 may include components such as capacitors and inductors. In one possible implementation, the AC filter circuit board 16 may also include a voltage sampling circuit and / or a current sampling circuit, and the AC filter circuit board 16 may have corresponding output ports for voltage sampling signals and / or current sampling signals.

[0083] The AC output port 163 of the AC filter circuit board 16 can be connected to the output of the power converter, and then connected to the three-phase AC power grid 31.

[0084] In one possible implementation, the input circuit board 14, DC-DC converter circuit board 11, bus circuit board 12, DC-AC converter circuit board 13, protection switch circuit board 15, and AC filter circuit board 16 can be electrically connected by metal wires or metal strips, for example, copper wires or copper strips.

[0085] In summary, the power converter provided in this application embodiment places the switching circuit, DC-DC conversion circuit, bus capacitor, DC-AC conversion circuit, protection switch, and filter circuit on different circuit boards. This method makes the maintenance of the power converter more convenient and reduces maintenance time and labor costs. For example, when a local circuit fails, only the circuit board where the faulty circuit is located needs to be replaced, and the circuit boards where the other circuits are located do not need to be replaced.

[0086] Furthermore, the modular design makes it easier to expand or upgrade the power converter in the future. More circuit boards can be connected in parallel according to the needs without replacing the entire main power circuit. For example, input circuit boards and DC-DC conversion circuit boards can be added to increase the input power of the power conversion circuit, or DC-AC conversion circuit boards, protection switch circuit boards, AC filter circuit boards, etc. can be added to increase the output power of the power converter.

[0087] Furthermore, the power converter can use a controller to process the acquired voltage and current signals, as well as to control various parts of the main power circuit. The implementation of the controller is explained below with reference to the attached diagram.

[0088] See Figure 6 This figure is a schematic diagram of the power converter provided in an embodiment of this application. Figure 6 .

[0089] In this implementation, the power converter 10 also includes a controller board 17, on which a controller 171 is provided.

[0090] The controller 171 can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a digital signal processor (DSP), or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof; this application embodiment does not specifically limit the specific type of PLD.

[0091] In this embodiment, the controller 171 can control the operating state of other circuit boards based on the sampling signals of other circuit boards. For example, the DC-DC converter circuit board 11 may include a first sampling signal terminal 114, the bus circuit board 12 may include a second sampling signal terminal 124, the DC-AC converter circuit board 13 may include a third sampling signal terminal 134, the input circuit board 14 may include a fourth sampling signal terminal 144, the protection switch circuit board 15 may include a fifth sampling signal terminal 154, and the AC filter circuit board 16 may include a sixth sampling signal terminal 164.

[0092] One or more of the above-mentioned first sampling signal terminal 114, second sampling signal terminal 124, third sampling signal terminal 134, fourth sampling signal terminal 144, fifth sampling signal terminal 154, and sixth sampling signal terminal 164 are electrically connected to the sampling signal receiving terminal 172 on the controller board, thereby transmitting the sampling signal to the controller 171. The sampling signals transmitted by each sampling signal terminal may include voltage sampling signals and / or current sampling signals, which are not specifically limited in this embodiment.

[0093] Correspondingly, the controller board 17 includes one or more interfaces for connecting sampling signals.

[0094] In addition, the DC-DC conversion circuit board 11 also includes a first control signal terminal 125, the DC-AC conversion circuit board 13 also includes a second control signal terminal 135, and the protection switch circuit board 15 may also include a fourth control signal terminal 155.

[0095] The first control signal terminal 125, the second control signal terminal 135, and the fourth control signal terminal 155 are used to connect to the third control signal terminal 173 on the controller board 17. The controller 171 can transmit control signals to the corresponding devices through the third control signal terminal 173, thereby controlling the working state of the DC-DC converter circuit, the DC-AC converter circuit, and the protection switch.

[0096] The sampling signals and status signals of each part of the main power circuit are collected to the controller board 17 through a wiring harness, and then transmitted to the controller 171. The controller 171 can perform logical summarization, generate corresponding control signals and send them to the corresponding circuits to ensure the normal operation of the power converter.

[0097] Furthermore, the power converter 10 also includes a power supply system 181, which can supply power to the controller 17.

[0098] In one possible implementation, the power supply system 181 and the controller 171 are located on the same circuit board.

[0099] In another possible implementation, such as Figure 6 As shown, considering that the controller 171 or the power system 181 may also have the risk of failure in actual applications, in order to reduce the maintenance cost when a single controller 171 or power system 181 fails, the power system 181 may also be set on a separate circuit board, such as the power system 181 being set on the power board 18.

[0100] In summary, the solution provided in this application implements a modular design for each circuit, breaking down the main power circuit into individual circuit boards, which are electrically connected and can be used in parallel. Sampling and control signals are aggregated to a single controller via lead terminals for logic control. This modular design makes future expansion or upgrades of the power converter easier, for example, by connecting more circuit boards in parallel without replacing the entire main power circuit. The modular design also simplifies maintenance, reducing time and labor costs. In case of a partial fault, only the circuit board containing the faulty circuit needs replacement, rather than the entire main power circuit, thus lowering maintenance costs.

[0101] Based on the power converters provided in the above embodiments, this application also provides a power conversion system, which will be described in detail below with reference to the accompanying drawings.

[0102] See Figure 7 This figure is a schematic diagram of the power conversion system provided in an embodiment of this application.

[0103] The power conversion system includes: photovoltaic module 50 and power converter 10.

[0104] The power converter 10 is specifically a photovoltaic inverter. The power converter 10 is used to invert the direct current output from the photovoltaic module 50 into alternating current.

[0105] In one possible implementation, the output of the power converter 10 can be connected to a three-phase AC power grid.

[0106] The power conversion system may include multiple photovoltaic modules 50, which may be connected in series, parallel or mixed to increase the output power.

[0107] For details on the specific implementation of the power converter 10, please refer to the description in the above embodiments. The embodiments of this application will not be repeated here.

[0108] In summary, in this power conversion system, the various circuits of the main power circuit of the power converter are set on different circuit boards, which makes maintenance more convenient and reduces maintenance time and labor costs. For example, in the event of a partial circuit failure, only the circuit board containing the faulty circuit needs to be replaced, while the circuit boards containing the remaining circuits do not need to be replaced. In addition, the modular design also makes it easier for the power converter to be expanded or upgraded in the future, as more circuit boards can be connected in parallel according to needs without replacing the entire main power circuit.

[0109] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0110] The above description of the disclosed embodiments enables those skilled in the art to make or use 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 disclosed herein.

Claims

1. A power converter, characterized in that, include: At least one DC-DC conversion circuit board (11), a bus circuit board (12), and at least one DC-AC conversion circuit board (13); The DC-DC conversion circuit board (11) includes a first terminal (112), a DC-DC conversion circuit (111), and a second terminal (113); the first terminal (112) is electrically connected to the first DC side of the DC-DC conversion circuit (111), and the second terminal (113) is electrically connected to the second DC side of the DC-DC conversion circuit (111); The bus circuit board (12) includes a third terminal (123), a positive DC bus, a negative DC bus, a fourth terminal (124), a first bus capacitor, and a second bus capacitor. One end of the positive DC bus is electrically connected to the positive terminal of the third terminal (123), and the other end is electrically connected to the positive terminal of the fourth terminal (124). The midpoint of the DC bus is connected to the midpoint terminal of the DC bus of the fourth terminal (124). One end of the negative DC bus is electrically connected to the negative terminal of the third terminal (123), and the other end is electrically connected to the negative terminal of the fourth terminal (124). The first bus capacitor is electrically connected between the positive DC bus and the midpoint of the DC bus, and the second bus capacitor is electrically connected between the negative DC bus and the midpoint of the DC bus. The DC-AC converter circuit board (13) includes a fifth terminal (132), a DC-AC converter circuit (131), and a sixth terminal (133); the fifth terminal (132) is electrically connected to the third DC side of the DC-AC converter circuit (131), and the sixth terminal (133) is electrically connected to the AC side of the DC-AC converter circuit (131); The first terminal (112) is used to electrically connect to the DC power supply (20), each of the second terminals (113) is connected in parallel and electrically connected to the third terminal (123); the fourth terminal (124) is electrically connected to the fifth terminal (132); and the sixth terminal (133) is used to electrically connect to the AC network (30).

2. The power converter according to claim 1, characterized in that, The power converter includes multiple bus circuit boards (12) and multiple DC-AC conversion circuit boards (13); The third terminals (123) of each of the bus circuit boards (12) are connected in parallel; The fourth terminal (124) of each of the bus circuit boards (12) is electrically connected to the fifth terminal (132) of one of the DC-AC converter circuit boards (13); The sixth terminal (133) of each of the said DC-AC converter circuit boards (13) is connected to one phase of AC power.

3. The power converter according to claim 1, characterized in that, The power converter includes: a plurality of bus circuit boards (12) and a DC-AC converter circuit board (13); The third terminals (123) of each of the bus circuit boards (12) are connected in parallel; The positive terminals of the fourth terminal (124) of each of the bus circuit boards (12) are connected in parallel to the positive terminal of the fifth terminal (132) of the DC-DC converter circuit board (13); The negative terminals of the fourth terminal (124) of each of the bus circuit boards (12) are connected in parallel to the negative terminal of the fifth terminal (132) of the DC-DC converter circuit board (13); The DC bus midpoint terminals of the fourth terminal (124) of each of the bus circuit boards (12) are connected in parallel to the DC bus midpoint terminals of the fifth terminal (132) of the DC-AC converter circuit board (13); The DC-AC conversion circuit board (13) includes a plurality of DC-AC conversion circuits (131), and the AC side of each DC-AC conversion circuit (131) is connected to an AC terminal of the sixth terminal (133), and each AC terminal corresponds to a phase of AC power.

4. The power converter according to claim 1, characterized in that, The power converter includes: one bus circuit board (12) and multiple DC-AC converter circuit boards (13); The bus circuit board (12) includes a plurality of fourth terminals (124), each of the fourth terminals (124) being electrically connected to a fifth terminal (132) of a DC-AC converter circuit board (13); The sixth terminal (133) of each of the said DC-AC converter circuit boards (13) is connected to one phase of AC power.

5. The power converter according to any one of claims 1-4, characterized in that, The power converter further includes: at least one input circuit board (14), at least one protection switch circuit board (15), and at least one AC filter circuit board (16); The input circuit board (14) includes a DC input interface (142), a switching circuit (141), and a seventh terminal (143); the DC input interface (142) is used to connect to the DC power supply and is electrically connected to the first end of the switching circuit (141), the second end of the switching circuit (141) is electrically connected to the seventh terminal (143), and the seventh terminal (143) is electrically connected to the first terminal (112); The protection switch circuit board (15) includes an eighth terminal (152), a protection switch (151) and a ninth terminal (153); the eighth terminal (152) is electrically connected to the sixth terminal (133) and the first end of the protection switch (151), and the second end of the protection switch (151) is electrically connected to the ninth terminal (153); The AC filter circuit board (16) includes a tenth terminal (162), a filter circuit (161), and an AC output port (163); the tenth terminal (162) is electrically connected to the ninth terminal (153) and the first end of the filter circuit (161), and the second end of the filter circuit (161) is electrically connected to the AC output port (163).

6. The power converter according to claim 5, characterized in that, The power converter includes multiple protection switch circuit boards (15) and multiple AC filter circuit boards (16); Each of the protection switch circuit boards (15) and a corresponding AC filter circuit board (16) is used to transmit one phase of AC power.

7. The power converter according to claim 5, characterized in that, The power converter also includes a controller board (17), which includes a controller (171); The DC-DC converter circuit board (11) further includes a first sampling signal terminal (114), the bus circuit board (12) further includes a second sampling signal terminal (124), the DC-AC converter circuit board (13) further includes a third sampling signal terminal (134), the input circuit board (14) further includes a fourth sampling signal terminal (144), the protection switch circuit board (15) further includes a fifth sampling signal terminal (154), and the AC filter circuit board (16) further includes a sixth sampling signal terminal (164). One or more of the first sampling signal terminal (114), the second sampling signal terminal (124), the third sampling signal terminal (134), the fourth sampling signal terminal (144), the fifth sampling signal terminal (154), and the sixth sampling signal terminal (164) are electrically connected to the sampling signal receiving terminal (172) on the controller board (17).

8. The power converter according to claim 7, characterized in that, The power converter also includes a power supply system (181); The power supply system (181) is used to supply power to the controller (171); The power supply system (181) is located on the controller board (17); Alternatively, the power system (181) may be located on a separate circuit board.

9. The power converter according to claim 7, characterized in that, The DC-DC converter circuit board (11) further includes a first control signal terminal (125), and the DC-AC converter circuit board (13) further includes a second control signal terminal (135). The first control signal terminal (125) and the second control signal terminal (135) are electrically connected to the third control signal terminal (173) on the controller board (17).

10. A power conversion system, characterized in that, The power conversion system includes the power converter according to any one of claims 1-9, and further includes a photovoltaic module; The photovoltaic module is the DC power supply.

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