Power conversion device and power equipment

Abstract

The application relates to a power conversion device and a power equipment, wherein the power conversion device is provided with multiple direct-current input interfaces, an alternating-current input interface, an alternating-current interface, a first rectifying circuit and multiple direct-current conversion circuits; the first end of each direct-current conversion circuit is used for connecting the direct-current input interface or the output end of the first rectifying circuit; the alternating-current input interface can be powered by an alternating-current power supply equipment under the condition that the power conversion device has no other power supply. In the application, the alternating-current power supply equipment can be multiplexed with one or more direct-current conversion circuits after passing through the first rectifying circuit to realize power conversion and supply power, so that a user can power a load based on the electric energy, and the power demand of the user is met.

Description

Technical Field

[0001] This application belongs to the field of power conversion technology, and in particular relates to a power conversion device and power equipment. Background Technology

[0002] Ordinary power conversion systems (PCS) typically support photovoltaic input. However, when sunlight levels are insufficient and the energy storage battery is depleted or there is no mains power input, users cannot use the PCS to power household appliances. This restricts the use of power conversion systems and fails to meet user needs. Utility Model Content

[0003] The purpose of this application is to provide a power conversion device and power equipment, which aims to solve the problem that the application scenarios of power conversion devices are limited in the related technology.

[0004] In a first aspect, embodiments of this application provide a power conversion device, including:

[0005] AC input interface, used to connect AC-powered equipment;

[0006] Multiple DC input interfaces, each of which is used to connect to a corresponding DC power supply device;

[0007] AC interface for connecting to the power grid and / or AC load;

[0008] A first rectifier circuit, wherein the input terminal of the first rectifier circuit is connected to the AC input interface;

[0009] At least one DC-DC converter circuit, wherein the first terminal of each DC-DC converter circuit is used to connect to the DC input interface or to connect to the output terminal of the first rectifier circuit, and the second terminal of each DC-DC converter circuit is connected to the DC bus.

[0010] An AC / DC converter circuit, wherein the DC terminal of the AC / DC converter circuit is connected to the DC bus, and the AC terminal of the AC / DC converter circuit is connected to the AC interface.

[0011] In some embodiments, at least one first controllable switch is further included. The first controllable switch is disposed on the path between the first terminal of the DC-DC converter circuit and the corresponding DC input interface. The first controllable switch is used to disconnect the path when the first terminal of the connected DC-DC converter circuit is connected to the output terminal of the first rectifier circuit.

[0012] In some embodiments, the device further includes an isolated power supply circuit and a first power supply circuit; the isolated power supply circuit is connected to the AC input interface and is used to output isolated first DC power based on the power from the AC input interface; the first power supply circuit is connected to the isolated power supply circuit and the DC bus respectively and is used to provide the power conversion device with operating power based on the first DC power and / or the power from the DC bus.

[0013] In some embodiments, a second power supply circuit is further included, which is connected to the AC interface and the first power supply circuit, for outputting a second DC power based on the power provided by the AC interface, and the first power supply circuit is also used to provide the power conversion device with operating power based on the second DC power.

[0014] In some embodiments, the isolated power supply circuit includes a second rectifier circuit and a flyback switching power supply circuit. The input terminal of the flyback switching power supply circuit is connected to the AC input interface through the second rectifier circuit, and the output terminal of the flyback switching power supply circuit is connected to the first power supply circuit.

[0015] In some embodiments, the system further includes a second controllable switch and a pre-charging circuit, wherein the second controllable switch is connected between the input terminal of the first rectifier circuit and the AC input interface, and the pre-charging circuit is connected in parallel with the second controllable switch.

[0016] In some embodiments, the pre-charging circuit includes a third controllable switch and a current limiting unit, wherein the third controllable switch and the current limiting unit are connected in series and then in parallel with the second controllable switch; and / or

[0017] The power conversion device further includes a fourth controllable switch, which is connected between the second controllable switch and the AC input interface.

[0018] In some embodiments, a DC interface is also included; the DC interface is connected to the DC bus and is used to connect to an energy storage device or a DC load.

[0019] In some embodiments, a connector is provided at the first end of each DC-DC converter circuit and / or the output end of the first rectifier circuit. The connector is used to connect a power transmission line. The first end of the DC-DC converter circuit and the output end of the first rectifier circuit are connected through the power transmission line, so that the first rectifier circuit can be connected to the first end of at least one DC-DC converter circuit.

[0020] In a first aspect, embodiments of this application provide an electrical device, including the power conversion device as described above.

[0021] The beneficial effects of this application embodiment compared with related technologies are as follows: The power conversion device is provided with multiple DC input interfaces, AC input interfaces, AC interfaces, a first rectifier circuit, and multiple DC conversion circuits. The first terminal of each DC conversion circuit is used to connect to the DC input interface or to connect to the output terminal of the first rectifier circuit. The addition of an AC input interface allows power to be supplied to the AC input interface from an AC power supply device (e.g., a fuel / gas generator) when the power conversion device has no other power supply. In this application, the AC power supply device, after passing through the first rectifier circuit, can share one or more DC conversion circuits with the DC input interface for power conversion before supplying power. Thus, users can supply power to their loads based on this electrical energy, meeting their power needs and greatly expanding the application scenarios of the power conversion device. Attached Figure Description

[0022] Figure 1 This is a circuit diagram of a power conversion device provided in an embodiment of this application.

[0023] Figure 2 A circuit diagram of a power conversion device provided in another embodiment of this application.

[0024] Figure 3 A circuit diagram of a power conversion device provided in another embodiment of this application.

[0025] Figure 4 A circuit diagram of a power conversion device provided in another embodiment of this application. Detailed Implementation

[0026] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0027] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] Please refer to Figure 1One embodiment of this application provides a power conversion device 100, including at least one AC input interface 101, multiple DC input interfaces 102, an AC interface 104, a first rectifier circuit 105, multiple DC conversion circuits 106, and an AC-DC conversion circuit 107.

[0030] Each AC input interface 101 is used to connect to an AC power supply device 200. Each DC input interface 102 is used to connect to a DC power supply device 300. An AC interface 104 is used to connect to the power grid or an AC load. The input terminal of the first rectifier circuit 105 is connected to the AC input interface 101. The first terminal of each DC-DC converter circuit 106 is used to connect to the DC input interface 102 or to connect to the output terminal of the first rectifier circuit 105, and the second terminal of each DC-DC converter circuit 106 is connected to the DC bus BUS. The DC terminal of the AC-DC converter circuit 107 is connected to the DC bus BUS, and the AC terminal of the AC-DC converter circuit 107 is connected to the AC interface 104.

[0031] To facilitate a concise demonstration of the circuit principle, Figure 1 In the example, there is one AC input interface 101, one DC input interface 102, and one DC-DC converter circuit 106. It is understood that there can be multiple AC input interfaces 101, DC input interfaces 102, and DC-DC converter circuits 106. Generally, the number of DC input interfaces 102 and DC-DC converter circuits 106 is the same and they correspond one-to-one. Multiple DC input interfaces 102 are used to connect to multiple DC power supply devices 300. One or more AC input interfaces 101 can be configured according to the power rating of the power conversion device 100, and are used to connect to one or more AC power supply devices 200.

[0032] AC power supply equipment 200 can be a power generation device or AC power source, such as a generator (equipment that uses fuel oil as a power source, such as a diesel engine, gasoline engine, or fuel generator). DC power supply equipment 300 can be a photovoltaic power generation device, a wind power generation device, or other forms of DC power source.

[0033] In one embodiment, the power conversion device 100 is further provided with a DC interface 103. The DC interface 103 is used to connect an energy storage device or a DC load. The DC interface 103 is connected to a DC bus. It can be understood that the DC interface 103 can be directly connected to the DC bus, or it can be connected to the DC bus after power conversion by a DC-DC converter circuit.

[0034] The energy storage device includes battery modules, or includes a bidirectional DC-DC converter and battery modules. The battery modules can be connected to DC interface 103 via the bidirectional DC-DC converter. The battery modules include one or more battery packs.

[0035] AC interface 104 is used to obtain AC power from the grid or feed power to the grid, or to supply power to AC loads.

[0036] The first rectifier circuit 105 is used to rectify the AC power input from the AC input interface 101 into DC power and then output it.

[0037] In the technical solution of this application embodiment, the addition of an AC input interface 101 allows the power conversion device 100 to be powered by an AC power supply device 200 when there is no other power supply or insufficient power supply, such as when the DC power supply device 300 of the DC interface 103 of the power conversion device has low power and there is no power supply from the energy storage device or the power grid. In this application, the AC power supply device 200, after passing through the first rectifier circuit 105, can be used with the DC input interface 102 to perform power conversion using one or more DC conversion circuits 106. In this way, the user can use this power to supply power to the load of the DC interface 103 or the AC interface 104, meeting the user's power needs and greatly expanding the application scenarios of the power conversion device. Using one or more DC conversion circuits 106 for power conversion greatly reduces the number of product materials and the product volume, and also reduces the cost of power devices and structures.

[0038] In some embodiments, the DC-DC converter circuit 106 includes a boost circuit, a buck circuit, or a buck-boost circuit. Among the DC-DC converter circuits 106, the DC-DC converter circuit 106 connected to the DC input interface 102 uses Maximum Power Point Tracking (MPPT) control, while the DC-DC converter circuit 106 connected to the AC input interface 101 uses Power Factor Correction (PFC) control. Therefore, during multiplexing, if the same DC-DC converter circuit 106 is connected to the AC power supply device 200, it will not be connected to the DC power supply device 300. That is, when it is detected that the AC power supply device 200 is connected to the DC-DC converter circuit 106 and is online, the power supply to the corresponding DC power supply device 300 will be disabled.

[0039] Please refer to Figure 1In some embodiments, the power conversion device 100 further includes at least one first controllable switch S1, each first controllable switch S1 being disposed on the path between the first terminal of the DC-DC converter 106 and the corresponding DC input interface 102. The first controllable switch S1 is used to disconnect the path when the first terminal of the connected DC-DC converter 106 is connected to the output terminal of the first rectifier circuit 105. This can prevent a DC-DC converter 106 from being simultaneously connected to both the DC input interface 102 and the AC input interface 101, ensuring that the DC-DC converter 106 operates in a suitable control mode and improving energy efficiency; it also prevents the input power of the DC-DC converter 106 from being too high, affecting the lifespan of the power conversion device 100, or even directly damaging the devices.

[0040] The first controllable switch S1 is, for example, a switching device such as a relay or contactor. The first controllable switch S1 can be located in the DC input interface 102, or it can be located on the line between the first terminal of the DC-DC converter circuit 106 and the corresponding DC input interface 102. The controller of the power conversion device 100 controls its first controllable switch S1 to be turned on when the DC-DC converter circuit 106 is connected to the DC input interface 102, and controls its first controllable switch S1 to be turned off when the DC-DC converter circuit 106 is connected to the AC input interface 101. The controller is, for example, an Energy Management System (EMS) controller, such as a Digital Signal Processing (DSP) controller.

[0041] In some embodiments, the first rectifier circuit 105 includes a rectifier bridge. Optionally, the first rectifier circuit 105 further includes a filter capacitor connected to the output terminal of the rectifier bridge.

[0042] Please refer to Figure 2 In some embodiments, the power conversion device 100 further includes an isolated power supply circuit 108 and a first power supply circuit 109. The isolated power supply circuit 108 is connected to the AC input interface 101. The isolated power supply circuit 108 is used to output isolated first DC power based on the power from the AC input interface 101. The first power supply circuit 109 is connected to the isolated power supply circuit 108 and the DC bus BUS, respectively, and is used to provide operating power to the power conversion device 100 based on the first DC power or the power from the DC bus BUS.

[0043] The first power supply circuit 109 can employ a flyback converter, utilizing its transformer to isolate the internal input and output, reducing the risk of short circuits. Similarly, the isolated power supply circuit 108 can also isolate the internal input and output, preventing short circuits caused by short-circuiting with the lines supplying power to the first power supply circuit 109. In this embodiment, when the energy storage device is without power or has no mains power input, the power conversion device 100 can be started and powered based on the electrical energy from the AC input interface 101.

[0044] In some embodiments, the first power supply circuit 109 is a single-level multi-output or multi-level output circuit, used to provide the same or different operating voltages to various parts of the power conversion device 100.

[0045] In some embodiments, the isolated power supply circuit 108 includes a second rectifier circuit 1081 and a flyback switching power supply circuit 1082. The input terminal of the flyback switching power supply circuit 1082 is connected to the AC input interface 101 through the second rectifier circuit 1081. The output terminal of the flyback switching power supply circuit 1082 is connected to the first power supply circuit 109.

[0046] The second rectifier circuit 1081 includes a rectifier bridge. The second rectifier circuit 1081 rectifies the AC power from the AC input interface 101 into DC power before outputting it. The flyback switching power supply circuit 1082 can be a conventional flyback converter, and is not limited here. The flyback switching power supply circuit 1082 performs voltage conversion on the DC power output from the second rectifier circuit 1081 to output a first DC power to the first power supply circuit 109.

[0047] In some embodiments, the power conversion device 100 further includes a second power supply circuit 110, which is connected to the AC interface 104 and the first power supply circuit 109. The second power supply circuit 110 is used to output a second DC power based on the power provided by the AC interface 104, and the first power supply circuit 109 is also used to provide operating power for the power conversion device 100 based on the second DC power.

[0048] The second power supply circuit 110 can employ a flyback converter, using its transformer to isolate the internal AC interface 104 from the output, reducing the risk of short circuits. For example, the second power supply circuit 110 includes a rectifier circuit and another flyback converter (not shown). The input of the other flyback converter is connected to the AC input interface 101 via the rectifier circuit, and the output of the other flyback converter is connected to the first power supply circuit 109.

[0049] In some embodiments, the power conversion device 100 further includes three diodes D1, D2, and D3. Diode D1 is forward-biased and connected between the DC bus BUS and the first power supply circuit 109. Diode D2 is forward-biased and connected between the isolated power supply circuit 108 and the first power supply circuit 109. Diode D3 is forward-biased and connected between the second power supply circuit 110 and the first power supply circuit 109. The three diodes D1, D2, and D3 are used to prevent the current supplied to the DC bus BUS from flowing back to the corresponding power supply, thus avoiding damage to the power supply.

[0050] Please refer to Figure 3 In some embodiments, the power conversion device 100 further includes a second controllable switch S2 and a pre-charging circuit 111. The second controllable switch S2 is connected between the input terminal of the first rectifier circuit 105 and the AC input interface 101. The pre-charging circuit 111 is connected in parallel with the second controllable switch S2. The second controllable switch S2 is, for example, a relay or contactor. When the DC-DC converter 106 is connected to the output terminal of the first rectifier circuit 105 and the AC power supply device 200 can provide power, the second controllable switch S2 is controlled to open, and the pre-charging circuit 111 is controlled to open to pre-charge the first terminal of the DC-DC converter 106, specifically the input capacitor of the first terminal, to prevent the power provided by the AC input interface 101 from causing a large current surge to the DC-DC converter 106. After pre-charging is completed, the pre-charging circuit 111 is controlled to open, and the second controllable switch S2 is opened.

[0051] In some embodiments, the pre-charging circuit 111 includes a third controllable switch S3 and a current-limiting unit R1. The third controllable switch S3 and the current-limiting unit R1 are connected in series and then in parallel with the second controllable switch S2. The third controllable switch S3 is, for example, a switching device such as a relay or a contactor. The current-limiting unit R1 includes a current-limiting resistor.

[0052] In some embodiments, the power conversion device 100 further includes a fourth controllable switch S4. The fourth controllable switch S4 is connected between the second controllable switch S2 and the AC input interface 101. The fourth controllable switch S4 is, for example, a switching device such as a relay or contactor. The fourth controllable switch S4 is used to control the redundancy control between the first rectifier circuit 105 and the AC input interface 101. In the event of failure of the second controllable switch S2 or the third controllable switch S3, the fourth controllable switch S4 can also control the on / off state of the path.

[0053] In some embodiments, the power conversion device 100 further includes a controllable switch S5, which is connected between the AC and AC interfaces of the AC-DC conversion circuit 107.

[0054] Please refer to Figure 4In some embodiments, a connector 112 is provided at the first end of each DC-DC converter 106 and / or the output end of the first rectifier circuit 105. The connector 112 is used to plug in a power transmission line 113, and the first end of the DC-DC converter 106 and the output end of the first rectifier circuit 105 are connected through the power transmission line 113, so that the first rectifier circuit 105 can be connected to the first end of at least one DC-DC converter 106.

[0055] in, Figure 4 In the example, both the first terminal of the DC-DC converter 106 and the output terminal of the first rectifier circuit 105 are equipped with connectors 112. Whether the connectors 112 between the first terminal of the DC-DC converter 106 and the first rectifier circuit 105 are connected via power transmission lines 113 can be configured according to user needs. For example, when the user does not require AC power supply equipment 200 such as a generator for input, no power transmission lines 113 are configured between the output terminals of all DC-DC converters 106 and the first rectifier circuit 105, meaning they are disconnected. In this case, the DC-DC converter 106 is used to perform power conversion on the DC power input from the DC power supply equipment 300, such as performing maximum power point tracking on the solar energy input from the photovoltaic module before outputting power. When the user has AC power supply equipment 200 such as a generator connected, the first rectifier circuit 105 can be connected to a corresponding DC-DC converter 106, or to multiple corresponding DC-DC converters 106, using the corresponding DC-DC converter 106 to perform power conversion on the DC power output from the first rectifier circuit 105 before output. Connector 112 can be a connector that only transmits power; in other embodiments, connector 112 can be a connector that can simultaneously transmit power and communicate. The form of the connector is not limited to any particular shape. Connecting the power transmission line 113 using connector 112 can improve wiring efficiency and reduce the user's product installation costs.

[0056] In some embodiments, the power conversion device 100 can be directly connected to the first terminal of the DC-DC converter 106 and the output terminal of the first rectifier circuit 105 by wires, and a switch is provided on each wire to control the on / off state of each wire. The user can operate the switch to control the first terminal of the corresponding DC-DC converter 106 to be connected to the output terminal of the first rectifier circuit 105.

[0057] The power conversion device 100 can be a device with an energy storage device, that is, the energy storage device can be built into the power conversion device 100. Alternatively, the power conversion device 100 can also be a separate PCS device. In some embodiments, the independent power conversion device 100 can be used in conjunction with an independent energy storage device to form a system.

[0058] This application also provides an electrical device, including the power conversion device 100 as described in any of the above embodiments.

[0059] The electrical equipment can be a standalone power conversion device 100, or it can be a power supply device with energy storage.

[0060] When the power equipment is a power supply device that includes an energy storage device, the power supply device may also include a power conversion device 100. The power conversion device 100 and the energy storage device are integrated, that is, they are both housed in the same housing.

[0061] Alternatively, when the power equipment is a standalone power conversion device 100, the power conversion device 100 and the independent energy storage device can be connected via corresponding connecting lines or connectors. In situations where the DC power supply device 300 is underpowered and neither the energy storage device nor the power grid provides power, the power equipment can connect to the AC power supply device 200 to activate the power conversion device 100 to supply power to the load, thus meeting the user's electricity needs.

[0062] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A power conversion device, characterized in that, include: AC input interface, used to connect AC-powered equipment; Multiple DC input interfaces, each of which is used to connect to a corresponding DC power supply device; AC interface, used to connect to the power grid or AC load; A first rectifier circuit, the input terminal of which is connected to the AC input interface; At least one DC-DC converter circuit, wherein the first terminal of each DC-DC converter circuit is used to connect to the DC input interface or to connect to the output terminal of the first rectifier circuit, and the second terminal of each DC-DC converter circuit is connected to the DC bus. An AC / DC converter circuit, wherein the DC terminal of the AC / DC converter circuit is connected to the DC bus, and the AC terminal of the AC / DC converter circuit is connected to the AC interface.

2. The power conversion device as described in claim 1, characterized in that, It also includes at least one first controllable switch, which is disposed on the path between the first terminal of the DC-DC converter circuit and the corresponding DC input interface. The first controllable switch is used to disconnect the path when the first terminal of the connected DC-DC converter circuit is connected to the output terminal of the first rectifier circuit.

3. The power conversion device as described in claim 1, characterized in that, It also includes an isolated power supply circuit and a first power supply circuit; the isolated power supply circuit is connected to the AC input interface, and the isolated power supply circuit is used to output isolated first DC power based on the power of the AC input interface; the first power supply circuit is connected to the isolated power supply circuit and the DC bus respectively, and is used to provide the power conversion device with operating power based on the first DC power and / or the power of the DC bus.

4. The power conversion device as described in claim 3, characterized in that, It also includes a second power supply circuit, which is connected to the AC interface and the first power supply circuit, and is used to output a second DC power based on the power provided by the AC interface. The first power supply circuit is also used to provide the power conversion device with operating power based on the second DC power.

5. The power conversion device as described in claim 3, characterized in that, The isolated power supply circuit includes a second rectifier circuit and a flyback switching power supply circuit. The input terminal of the flyback switching power supply circuit is connected to the AC input interface through the second rectifier circuit, and the output terminal of the flyback switching power supply circuit is connected to the first power supply circuit.

6. The power conversion device according to any one of claims 1 to 5, characterized in that, It also includes a second controllable switch and a pre-charging circuit. The second controllable switch is connected between the input terminal of the first rectifier circuit and the AC input interface, and the pre-charging circuit is connected in parallel with the second controllable switch.

7. The power conversion device as described in claim 6, characterized in that, The pre-charging circuit includes a third controllable switch and a current limiting unit, wherein the third controllable switch and the current limiting unit are connected in series and then connected in parallel with the second controllable switch; and / or The power conversion device further includes a fourth controllable switch, which is connected between the second controllable switch and the AC input interface.

8. The power conversion device as described in claim 1, characterized in that, It also includes a DC interface; the DC interface is connected to the DC bus and is used to connect to energy storage devices or DC loads.

9. The power conversion device as described in claim 1, characterized in that, Each of the DC-DC converter circuits has a connector at its first terminal and / or the output terminal of the first rectifier circuit. The connector is used to connect a power transmission line. The first terminal of the DC-DC converter circuit is connected to the output terminal of the first rectifier circuit through the power transmission line, so that the first rectifier circuit can be connected to the first terminal of at least one of the DC-DC converter circuits.

10. An electrical device, characterized in that, Includes the power conversion device as described in any one of claims 1 to 9.

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