Alternating-current and direct-current dual-power supply circuit

Abstract

The utility model relates to an alternating current and direct current dual-power supply circuit which comprises a direct current power supply unit and an alternating current power supply unit. The direct-current power supply unit comprises a switch direct-current booster circuit, the input end of the switch direct-current booster circuit is used for supplying power to a direct-current power supply, and the output end is used for connecting a BUS. The alternating current power supply unit comprises a rectifying unit used for converting power supplied by an alternating current power supply into direct current, a voltage maintaining unit used for maintaining direct current voltage and an isolating circuit used for outputting the direct current to the BUS in an isolating mode. Through the design of the power supply circuit of the alternating current and direct current dual power supplies, internal switch abnormity caused by insufficient energy at the direct current side is avoided, and meanwhile, the alternating current power supply is processed, so that the sampling of alternating current and the detection stability of leakage current are ensured.

Description

Technical Field

[0001] The present application relates to the technical field of power supply circuits, and particularly to an AC-DC dual power supply circuit. Background Art

[0002] In fields such as photovoltaic inverters and household energy storage inverters, the power supply circuit plays a crucial role in converting the power supply and outputting it to the BUS bus, so that subsequent loads can draw power from the BUS bus. Among them, the power supply includes two types: DC power supply and AC power supply. The DC input of the DC power supply, as Figure 1 shown, the DC input is directly output to the BUS bus (BUS+ / BUS-), and power is drawn from the BUS bus to form a DC power supply circuit. For the AC input of the AC power supply, as Figure 2 shown, it needs to be rectified into DC output and then output to the BUS bus (BUS+ / BUS-), and power is drawn from the BUS bus to form an AC power supply circuit.

[0003] Figure 1 The DC power supply circuit shown in Figure 2 and the AC power supply circuit shown in Utility Model Content

[0004] To solve the defects existing in the power supply circuit in photovoltaic inverters and household energy storage inverters, an embodiment of the present utility model provides an AC-DC dual power supply circuit.

[0005] At least one embodiment of the present disclosure provides an AC-DC dual power supply circuit, including:

[0006] A DC power supply unit, including:

[0007] A switched DC boost circuit, whose input end is used to connect to the power supply of the DC power supply, and whose output end is used to connect to the BUS bus;

[0008] An AC power supply unit, including:

[0009] A rectification unit for converting the power supply of the AC power supply into direct current;

[0010] A voltage maintaining unit for maintaining the voltage of the direct current;

[0011] An isolation circuit for isolating and outputting the direct current to the BUS bus.

[0012] The above AC-DC dual-power supply circuit includes a DC power supply unit and an AC power supply unit. The DC power supply unit includes a switched DC boost circuit, whose input terminal is used to connect to the DC power supply, and the output terminal is used to connect to the BUS bus. The AC power supply unit includes a rectification unit for converting the AC power supply into direct current, a voltage maintenance unit for maintaining the DC voltage, and an isolation circuit for isolating and outputting the direct current to the BUS bus. Through the design of the AC-DC dual-power supply circuit, it avoids abnormal switching inside caused by insufficient energy on the DC side, and at the same time, the processing of the AC power supply ensures the stability of AC sampling and leakage current detection.

[0013] As one of the embodiments, the rectification unit includes a bridge rectifier circuit.

[0014] As one of the embodiments, the voltage maintenance unit includes:

[0015] A maintenance capacitor unit, connected in parallel with the output terminal of the rectifier bridge.

[0016] As one of the embodiments, the maintenance capacitor unit includes:

[0017] Two capacitors connected in series.

[0018] As one of the embodiments, the isolation circuit includes:

[0019] A single-switch flyback circuit for isolating and outputting the direct current to the BUS bus;

[0020] A control IC module for controlling the switching device of the single-switch flyback circuit.

[0021] As one of the embodiments, the control IC module includes:

[0022] A power control chip for controlling the switching device of the single-switch flyback circuit;

[0023] A chip power supply circuit for taking power from the direct current to supply power to the power control chip.

[0024] As one of the embodiments, the single-switch flyback circuit includes:

[0025] A switching circuit based on a switching device;

[0026] A transformer, whose primary coil is connected to the switching circuit and is used to connect to the direct current;

[0027] An output circuit, one end of which is connected to the secondary coil of the transformer, and the other end is connected to the BUS bus.

[0028] As one of the embodiments, it further includes:

[0029] A switching unit for controlling the power supply of the AC power supply to the rectifying unit.

[0030] As one embodiment, it further includes:

[0031] A power-taking circuit for taking power from the BUS bus and supplying power to the peripheral circuit according to the taken power.

[0032] As one embodiment, the power-taking circuit includes:

[0033] An auxiliary power supply, the input end of which is used to take power from the BUS bus;

[0034] A dual-switch flyback circuit, the input end of which is connected to the input end of the auxiliary power supply, and the output end is used to supply power to the peripheral circuit. Description of the Drawings

[0035] Figure 1 It is a traditional DC power supply circuit diagram;

[0036] Figure 2 It is a traditional AC power supply circuit diagram;

[0037] Figure 3 It is a circuit module diagram of an AC-DC dual-power supply for a disclosed embodiment;

[0038] Figure 4 It is a circuit diagram of an AC-DC dual-power supply for a disclosed embodiment;

[0039] Figure 5 It is a schematic diagram of the AC power supply process;

[0040] Reference numerals: DC power supply unit 100, AC power supply unit 101, switching unit 102, power-taking circuit 103, switching DC boost circuit 200, rectifying unit 300, voltage maintaining unit 301, isolation circuit 302. Detailed Embodiments

[0041] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0042] Unless otherwise defined, technical terms or scientific terms used in this disclosure shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The "first", "second" and similar terms used in this disclosure do not denote any order, quantity or importance, but are merely used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0043] To keep the following description of the embodiments of this disclosure clear and concise, detailed descriptions of some known functions and known components are omitted in this disclosure.

[0044] An embodiment of this disclosure provides an AC-DC dual-power supply circuit.

[0045] Figure 3 The module diagram of the AC-DC dual-power supply circuit of an embodiment of this disclosure is as Figure 3 shown. The AC-DC dual-power supply circuit of an embodiment of this disclosure includes:

[0046] A DC power supply unit 100, including:

[0047] A switched DC boost circuit 200, whose input terminal is used to connect to the power supply of the DC power source, and whose output terminal is used to connect to the BUS bus;

[0048] An AC power supply unit 101, including:

[0049] A rectification unit 300, which is used to convert the power supply of the AC power source into direct current;

[0050] A voltage maintenance unit 301, which is used to maintain the voltage of the direct current;

[0051] An isolation circuit 302, which is used to isolate and output the direct current to the BUS bus (BUS+ / BUS-).

[0052] As Figure 3 shown, the power supply sources of the AC-DC dual-power supply circuit include an AC power source and a DC power source. The DC power source provides power supply in DC form, and the AC power source provides power supply in AC form.

[0053] The DC power supply unit performs BOOST boost processing on the power supply of the DC power source and provides a stable DC power output to the BUS bus.

[0054] The alternating current power supply of the AC power supply is input to the rectification unit of the AC power supply unit, and the rectification power supply rectifies the power supply in the form of alternating current into direct current.

[0055] As one of the embodiments, Figure 4 It is a circuit diagram of an AC-DC dual power supply for an open embodiment, as Figure 4 shown, the rectification unit includes a bridge rectifier circuit D1. The bridge rectifier circuit D1 is composed of four diodes, and rectifies the power supply in the form of alternating current (GRID_R / GRID_N) into direct current.

[0056] The voltage maintenance unit is used to stabilize the voltage of the direct current, and a voltage stabilizing circuit or a voltage maintenance circuit can be used. As one of the embodiments, the voltage maintenance unit includes a maintenance capacitor unit connected in parallel with the output end of the rectifier bridge, and the maintenance capacitor unit stabilizes the voltage of the direct current through the capacitance components.

[0057] As a preferred embodiment, as Figure 4 shown, the maintenance capacitor unit includes:

[0058] Two capacitors (C3 and C6) connected in series.

[0059] As Figure 3 shown, the stabilized direct current is isolated by the isolation circuit and given to the BUS bus, avoiding abnormal problems in subsequent AC sampling and leakage current detection.

[0060] Among them, the isolation circuit can select a transformer isolation scheme or an optocoupler isolation scheme according to the application scenario of the power supply circuit, and preferably a transformer isolation scheme.

[0061] As a preferred embodiment, the isolation circuit includes:

[0062] A single-ended flyback circuit for isolating and outputting the direct current to the BUS bus;

[0063] A control IC module for controlling the switching device of the single-ended flyback circuit.

[0064] Among them, the single-ended flyback circuit is adjusted according to the switching device of the control IC module to achieve single-ended flyback, effectively eliminating noise and interference signals in the power supply, and further improving the anti-interference ability of subsequent AC sampling and leakage current detection.

[0065] As a preferred embodiment, as Figure 4 shown, the control IC module includes:

[0066] A power control chip U1 for controlling the switching device of the single-ended flyback circuit;

[0067] The chip power-taking circuit is used to take power from the direct current to supply power to the power control chip.

[0068] Among them, the power control chip U1 adjusts the switching device according to the pulse output to provide a control basis for the single-ended flyback circuit.

[0069] Such as Figure 4 As shown, the chip power-taking circuit includes a voltage-dividing network composed of resistors R7 / R9 / R10 / R11 to divide the direct current voltage into the power supply voltage VCC of the power control chip U1. Among them, the chip power-taking circuit also includes a voltage stabilization circuit composed of a zener diode Z1, a capacitor C12, and a capacitor C13 to ensure the stable power supply of the power control chip U1.

[0070] Among them, the switching device can be a semiconductor switching device, such as a MOS transistor, a triode, or a thyristor, etc. Such as Figure 4 As shown, the switching device selects a MOS transistor Q1, and the power control chip U1 outputs a control signal to the gate of the MOS transistor Q1 through the output resistor R12 to control the switching characteristics of the source and drain.

[0071] As a preferred embodiment, the single-ended flyback circuit includes:

[0072] A switching circuit based on the switching device;

[0073] A transformer, whose primary coil is connected to the switching circuit and is used to access the direct current;

[0074] An output circuit, one end of which is connected to the secondary coil of the transformer, and the other end is connected to the BUS bus.

[0075] Such as Figure 4 As shown, the switching device is a MOS transistor Q1, and the switching circuit based on the MOS transistor Q1 is used to realize the single-ended flyback characteristic on the primary coil side of the transformer. Such as Figure 4 As shown, the switching circuit includes serially connected diodes D3 and D4. The positive pole of the diode D3 is connected to the drain of the MOS transistor Q1, and the negative pole of the diode D4 is connected to the primary coil through the RC unit. The RC unit includes a parallel-connected resistor R2 and capacitor C8. The switching circuit also includes a capacitor C7 connected in parallel with the diode D3.

[0076] Through the processing of the single-ended flyback circuit, the direct current maintained by the voltage maintenance unit is converted into an alternating current output of the secondary coil of the transformer to complete the AC power supply.

[0077] To ensure the stable alternating current output of the secondary coil of the transformer, the single-ended flyback circuit also includes an output circuit on the secondary coil side of the transformer. Such as Figure 4As shown, on the BUS+ side, an RC unit composed of a capacitor C1 and a resistor R2 connected in series is connected in parallel to a diode D2. The positive electrode of the diode D2 is connected to the output of the secondary coil, and the negative electrode serves as a part of the BUS bus output of BUS+. On the BUS- side, an RC unit composed of a capacitor C5 and a resistor R4 connected in series is connected in parallel to a diode D5. The negative electrode of the diode D5 is connected to the output of the secondary coil, and the positive electrode serves as a part of the BUS bus output of BUS-.

[0078] Among them, as Figure 4 shown, to ensure stable AC output, the single-ended flyback circuit further includes a voltage stabilization design with resistors R3, R5, capacitors C2, and C4 led out from the midpoint of the secondary coil of the transformer.

[0079] As one of the embodiments, as Figure 3 shown, the AC-DC dual-power supply circuit of a disclosed embodiment further includes:

[0080] A switch unit 102 for controlling the power supply of the AC power supply to the rectification unit.

[0081] Among them, the switch unit is used to control the power supply path of the AC power supply to the rectification unit. As Figure 5 shown, it is used to implement the following steps S100 to step S101:

[0082] S100, determine whether the PV side meets the power supply conditions;

[0083] S101, if so, maintain the power supply on the AC side, otherwise cut off the power supply on the AC side, use the energy on the PV side for power supply and enter the standby operation state.

[0084] Among them, when the AC-DC dual-power supply circuit of the disclosed embodiment of the present application is applied to a photovoltaic inverter, the PV side generally serves as a DC power supply input. According to the working state of the photovoltaic panel, the system comprehensively determines whether the PV side meets the power supply conditions.

[0085] Among them, the switch unit can be a relay or an electronic switch and is controlled by a controller. The controller is generally a DSP processor of the photovoltaic system. The DSP processor cooperates with the sampling circuit to complete the above-mentioned AC power sampling and leakage current detection, and controls the switch unit according to the sampling and detection results to implement steps S100 to step S101.

[0086] Among them, the power supply on the AC side is related to the AC power supply, and the power supply on the PV side is related to the DC power supply.

[0087] As a preferred embodiment, as Figure 3 shown, the AC-DC dual-power supply circuit of a disclosed embodiment further includes:

[0088] The power-taking circuit 103 is used to take power from the BUS bus and supply power to the peripheral circuit according to the taken power.

[0089] Among them, the peripheral circuit includes the core circuit of the photovoltaic system inverter or the household energy storage inverter application system, such as the controller of the switching unit, etc., which is used to ensure the stable power supply of the peripheral circuit according to the AC-DC dual power supply circuit, and at the same time ensure the operation of the AC-DC dual power supply circuit.

[0090] As one of the embodiments, the power-taking circuit includes:

[0091] An auxiliary power supply, the input end of which is used to take power from the BUS bus;

[0092] A dual-switch flyback circuit, the input end of which is connected to the input end of the auxiliary power supply, and the output end of which is used to supply power to the peripheral circuit.

[0093] The auxiliary power supply indirectly realizes taking power from the DC power supply and the AC power supply by taking power from the BUS bus, and then through the isolation and coupling of the dual-switch flyback circuit, it ensures the anti-interference ability of the subsequent circuit to take power.

[0094] The AC-DC dual power supply circuit of the embodiments of the present disclosure includes a DC power supply unit and an AC power supply unit. The DC power supply unit includes a switching DC boost circuit, the input end of which is used to access the power supply of the DC power supply, and the output end of which is used to connect to the BUS bus. The AC power supply unit includes a rectification unit for converting the power supply of the AC power supply into direct current, a voltage maintaining unit for maintaining the voltage of the direct current, and an isolation circuit for isolating and outputting the direct current to the BUS bus. Through the design of the AC-DC dual power supply circuit, it avoids the abnormal switching inside caused by insufficient energy on the DC side, and at the same time, the processing of the AC power supply ensures the stability of the AC power sampling and the leakage current detection.

[0095] For the present disclosure, the following points need to be explained:

[0096] (1) The accompanying drawings of the embodiments of the present disclosure only relate to the structures involved in the embodiments of the present disclosure, and other structures can refer to the general design.

[0097] (2) For the sake of clarity, in the accompanying drawings used to describe the embodiments of the present invention, the thickness and size of the layer or structure are enlarged. It can be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element can be "directly" on or under the other element, or there can be an intermediate element.

[0098] (3) Without conflict, the embodiments of the present disclosure and the features in the embodiments may be combined with each other to obtain new embodiments. The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. The protection scope of the present disclosure shall be subject to the protection scope of the claims.

[0099] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0100] The above embodiments only represent several implementation manners of the present application, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. An AC / DC dual power supply circuit, characterized in that: include: DC power supply unit, comprising: The switching DC boost circuit has an input end for connecting to a DC power supply and an output end for connecting to a BUS bus; AC power supply unit, comprising: A rectifier unit, used to convert the AC power supply into DC power; A voltage maintaining unit, used for maintaining the voltage of the direct current; The isolation circuit is used to isolate and output the DC power to the BUS bus.

2. The AC / DC dual power supply circuit according to claim 1, characterized in that: The rectifying unit comprises a bridge rectifying circuit.

3. The AC / DC dual power supply circuit according to claim 1, characterized in that: The voltage maintaining unit comprises: The maintaining capacitor unit is connected in parallel with the output end of the rectifier bridge.

4. The AC / DC dual power supply circuit according to claim 3, characterized in that: The holding capacitor unit comprises: Two capacitors connected in series.

5. The AC / DC dual power supply circuit according to claim 1, characterized in that: The isolation circuit comprises: A single-tube flyback circuit, used for isolating and outputting the DC power to the BUS bus; The control IC module is used to control the switch device of the single-tube flyback circuit.

6. The AC / DC dual power supply circuit according to claim 5, characterized in that: The control IC module includes: A power control chip, used to control the switch device of the single-tube flyback circuit; The chip power supply circuit is used to obtain power from the direct current to supply power to the power control chip.

7. The AC / DC dual power supply circuit according to claim 5, characterized in that: The single-tube flyback circuit comprises: Switching circuits based on switching devices; A transformer, whose primary coil is connected to the switch circuit and is used to access the direct current; The output circuit has one end connected to the secondary coil of the transformer and the other end connected to the BUS busbar.

8. The AC / DC dual power supply circuit according to any one of claims 1 to 7, characterized in that: Also includes: The switch unit is used to control the AC power supply to the rectifier unit.

9. The AC / DC dual power supply circuit according to any one of claims 1 to 7, characterized in that: Also includes: The power taking circuit is used to take power from the BUS bus and supply power to the peripheral circuit according to the power taken.

10. The AC / DC dual power supply circuit according to claim 9, characterized in that: The power taking circuit comprises: Auxiliary power supply, the input end is used to draw power from the BUS bus; A dual-tube flyback circuit has an input end connected to the input end of the auxiliary power supply, and an output end used to power the peripheral circuit.

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