Hybrid inverter and photovoltaic energy storage power supply system

Abstract

The utility model relates to a hybrid inverter and a photovoltaic energy storage power supply system, which belong to the field of electric power and comprise an MPPT (maximum power point tracking) circuit, a bidirectional DC / AC (direct current / alternating current) circuit and a bidirectional DC / DC circuit. The MPPT circuit comprises a bus, and a first capacitor C1 is arranged on the bus; the direct current end of the bidirectional DC / AC circuit is connected with the bus; the bidirectional DC / DC circuit comprises a first inductor L1, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a first connecting end and a second connecting end. According to the hybrid inverter provided by the utility model, one switching tube can be reduced, one inductor can be reduced, and a half of a driving circuit can be reduced, so that the hybrid inverter has few devices, few drives and moderate cost, the EMC problem can be obviously reduced, and the reliability of a system can be improved.

Description

Technical Field

[0001] This utility model relates to the field of power, specifically to a hybrid inverter and photovoltaic energy storage power supply system. Background Technology

[0002] Photovoltaic power generation has been widely adopted, and its proportion in energy use is gradually increasing. However, photovoltaic power generation is intermittent and unstable. Therefore, in recent years, hybrid inverters with energy storage functions have gradually become the development trend of photovoltaic inverters.

[0003] Compared to photovoltaic inverters, hybrid inverters can store excess electricity generated during the day in batteries and release that electricity when needed by local loads or the grid.

[0004] like Figure 11 The diagram shown is a circuit diagram of a hybrid inverter in the prior art. This hybrid inverter includes an MPPT circuit 100, a bidirectional DC / DC circuit 200, and a bidirectional DC / AC circuit 300. In this hybrid inverter system, the bidirectional DC / DC circuit 200 requires two sets of circuits, one for positive and one for negative. Therefore, magnetic components, switching transistors, and drive circuits all require two sets. For example, there are four switching transistors: Q1, Q2, Q3, and Q100. This results in a large number of components and high cost. The positive and negative circuits are not completely decoupled. The oscillations of the switching transistors must follow a strict control sequence; otherwise, short circuits can easily occur, leading to further damage. In addition, the voltage at the battery's positive and negative ports relative to the system reference potential fluctuates at a high frequency, with an amplitude of half the bus voltage. This can cause serious EMC problems, further reducing system reliability and requiring more cost to resolve EMC issues. Utility Model Content

[0005] This utility model is proposed to alleviate or solve at least one aspect or point of the above-mentioned problems.

[0006] This utility model discloses a hybrid inverter, characterized in that it includes: an MPPT circuit, a bidirectional DC / AC circuit, and a bidirectional DC / DC circuit;

[0007] The MPPT circuit includes a bus, and a first capacitor C1 is installed on the bus.

[0008] The DC terminal of the bidirectional DC / AC circuit is connected to the busbar;

[0009] The bidirectional DC / DC circuit includes a first inductor L1, a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a first connection terminal, and a second connection terminal; the first connection terminal of the bidirectional DC / DC circuit is connected to the positive terminal of the battery, and the second connection terminal is connected to the negative terminal of the battery.

[0010] One end of the inductor L3 is connected with the first input end, and the other end is respectively connected with one end of the first switch tube Q1 and one end of the second switch tube Q2;

[0011] The second connection end is respectively connected with the other end of the first switch tube Q1 and one end of the third switch tube Q3; the other end of the second switch tube Q2 is connected with the first end of the bus, and the other end of the third switch tube Q3 is connected with the second end of the bus.

[0012] Preferably, the bidirectional DC / DC circuit further comprises a second inductor L2, and the second connection end is respectively connected with the other end of the first switch tube Q1 and one end of the third switch tube Q3 through the second inductor L2.

[0013] Preferably, the MPPT circuit comprises a third connection end, a fourth connection end, a third inductor L3, a fourth switch tube Q4 and a first diode D1; one end of the third inductor L3 is simultaneously connected with one end of the first diode D1 and one end of the fourth switch tube Q4, and the other end of the third inductor L3 is connected with the first connection end; the other end of the first diode D1 is connected with the first end of the bus; the second connection end is simultaneously connected with the other end of the fourth switch tube Q4 and the second end of the bus.

[0014] Preferably, the MPPT circuit further comprises a seventh connection end, an eighth connection end, a fourth inductor L4, a second diode D2, a fifth switch tube Q5 and a second capacitor C2; the first capacitor C1 and the second capacitor C2 are arranged in series on the bus; one end of the fourth inductor L4 is simultaneously connected with one end of the second diode D2 and one end of the fifth switch tube Q5, and the other end of the second diode D2 is connected with the first end of the bus; the other end of the fourth inductor L4 is connected with the seventh connection end; the eighth connection end is simultaneously connected with the other end of the fifth switch tube Q5 and the second end of the bus.

[0015] Preferably, the bidirectional DC / AC circuit is an H4 bridge, an H5 bridge or a Heric bridge single-bus topology.

[0016] Preferably, the bidirectional DC / AC circuit is a T-type three-level or I-type three-level double-bus topology.

[0017] Preferably, the MPPT circuit is a multi-input circuit.

[0018] In addition, the utility model also provides a photovoltaic energy storage power supply system, its characterized in that: including hybrid inverter, PV photovoltaic group string, battery group, AC power grid, load, hybrid inverter is connected with PV photovoltaic group string, battery group, AC power grid, load respectively.

[0019] The hybrid inverter and the photovoltaic energy storage power supply system have the advantages of few devices, few drives, moderate cost, simple control, no voltage high-frequency jumping and high reliability.

[0020] Compared with the prior art, the switch tube can be reduced by 1, the inductor can be reduced by 1, and the driving circuit can be reduced by half, so that the device is less, the driving is less, and the cost is moderate. The switch tube of the utility model does not need to distinguish the power frequency tube and the high frequency tube, therefore the control is simple, and the reliability is high. The voltage of the battery positive and negative port to the system reference potential point is stable, and there is no high frequency jump, therefore the EMC performance is more excellent, and the system stability is higher. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is the function block diagram of the photovoltaic energy storage power supply system of the utility model embodiment.

[0022] Figure 2 It is the circuit schematic diagram of the hybrid inverter (H4 bridge) of the utility model embodiment one.

[0023] Figure 3 It is the circuit schematic diagram of the hybrid inverter (Heric bridge) of the utility model embodiment two.

[0024] Figure 4 It is the circuit schematic diagram of the hybrid inverter (Heric bridge) of the utility model embodiment three.

[0025] Figure 5 It is the circuit schematic diagram of the hybrid inverter (T type three level (three phase)) of the utility model embodiment five.

[0026] Figure 6 It is the circuit schematic diagram of the hybrid inverter (T type three level (three phase)) of the utility model embodiment six.

[0027] Figure 7 It is the circuit schematic diagram of the hybrid inverter (T type three level (split phase)) of the utility model embodiment seven.

[0028] Figure 8 It is the circuit schematic diagram of the hybrid inverter (T type three level (split phase)) of the utility model embodiment eight.

[0029] Figure 9 It is the circuit schematic diagram of the hybrid inverter (I type three level (three phase)) of the utility model embodiment nine.

[0030] Figure 10 It is the circuit schematic diagram of the hybrid inverter (I type three level (three phase)) of the utility model embodiment ten.

[0031] Figure 11 It is the circuit schematic diagram of the existing hybrid inverter (H4 bridge). DETAILED DESCRIPTION

[0032] The following description of the embodiments of the present application with reference to the accompanying drawings is provided to explain the overall inventive concept of the present application and should not be understood as a limitation thereof. In the present application, the same reference numerals denote the same or similar components.

[0033] The features described herein can be implemented in different forms and should not be construed as limited to the examples described herein. Rather, these examples are provided as a mere description of only some implementations of the methods, devices, and / or systems described herein, which will be apparent to those skilled in the art after understanding the disclosure.

[0034] Although terms such as "first", "second", and "third" can be used herein to describe various components, assemblies, regions, layers, or portions, these components, assemblies, regions, layers, or portions should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or portion from another component, assembly, region, layer, or portion.

[0035] In the specification, when an element (such as a layer, a region, or a substrate) is described as "on", "connected to", or "coupled to" another element, the element can be directly on, directly connected to, or directly coupled to the other element, or one or more other elements can be interposed therebetween. In contrast, when an element is described as "directly on", "directly connected to", or "directly coupled to" another element, no other element can be interposed therebetween.

[0036] The terms used herein are only used to describe various examples and should not be used to limit the disclosure. The singular form is intended to include the plural form unless the context clearly indicates otherwise. The terms "comprise", "include", and "have" indicate the presence of a stated feature, number, operation, component, element, and / or combination thereof, but do not exclude the presence or addition of one or more other features, numbers, operations, components, elements, and / or combinations thereof.

[0037] In order to enable those skilled in the art to use the content of the present application, the following exemplary embodiments can be given below in conjunction with specific application scenarios, parameters of specific systems, devices and elements, and specific connection modes. However, for those skilled in the art, these embodiments are only examples, and the general principles defined herein can be applied to other embodiments and application scenarios without departing from the spirit and scope of the present application.

[0038] According to one exemplary embodiment of the present application: as Figure 1The diagram shows a functional block diagram of a hybrid inverter system according to various embodiments disclosed herein. A battery pack 101, a PV photovoltaic string 102, and an AC grid 103 are input to a hybrid inverter 104. The hybrid inverter 104 internally includes an MPPT circuit 100, a bidirectional DC / DC circuit 200, and a bidirectional DC / AC circuit 300.

[0039] When the PV photovoltaic string 102 generates sufficient electricity, the electricity generated in the hybrid inverter 104 is used to supply power to the load 105 first, the excess electricity is used to charge the battery pack 101, and the remaining electricity is sold to the AC grid 103.

[0040] When the power generated by the PV photovoltaic string 102 is insufficient or not generated at all, the power of the battery pack 101 is used first to supply power to the load 105. If the power of the battery pack 101 is insufficient, the AC grid 103 will supply power to the load 105.

[0041] Example 1

[0042] like Figure 2 As shown, the hybrid inverter of this utility model includes: an MPPT circuit, a bidirectional DC / AC circuit, and a bidirectional DC / DC circuit. The bidirectional DC / DC circuit includes a first connection terminal, a second connection terminal, a first inductor L1, a first switching transistor Q1, a second switching transistor Q2, and a third switching transistor Q3. The first connection terminal of the bidirectional DC / DC circuit is connected to the positive terminal BAT+ of the battery, and the second connection terminal is connected to the negative terminal BAT- of the battery.

[0043] One end of the first inductor L1 is connected to the first connection terminal, and the other end is connected to one end of the first switch Q1 and one end of the second switch Q2, respectively.

[0044] The second connection terminal is connected to the other end of the first switch Q1 and one end of the third switch Q3 respectively; the other end of the second switch Q2 is connected to the first end of the bus, and the other end of the third switch Q3 is connected to the second end of the bus.

[0045] like Figure 2 As shown, the MPPT circuit includes a bus, on which a first capacitor C1 is installed. The first end of the bus is connected to the first end of the DC side of the bidirectional DC / AC circuit, and the second end of the bus is connected to the second end of the DC side of the bidirectional DC / AC circuit.

[0046] The MPPT circuit comprises a third connecting end, a fourth connecting end, a third inductor L3, a fourth switch tube Q4 and a first diode D1. One end of the third inductor L3 is connected with one end of the first diode D1 and one end of the fourth switch tube Q4, and the other end of the third inductor L3 is connected with the first connecting end; the other end of the first diode D1 is connected with the first end of the bus; the second connecting end is connected with the other end of the fourth switch tube Q4 and the second end of the bus. The third connecting end can be connected with the positive pole PV+ of the photovoltaic, and the fourth connecting end can be connected with the negative pole PV- of the photovoltaic.

[0047] As shown in Figure 2 , wherein the bidirectional DC / AC circuit adopts an H4 bridge circuit structure, which comprises a sixth switch tube Q6, a seventh switch tube Q7, a tenth switch tube Q10, an eleventh switch tube Q11, a fifth inductor L5, a sixth inductor L6, a third capacitor C3, a fifth connecting end and a sixth connecting end. Two interfaces on one side of the H4 bridge are connected with the first end and the second end of the bus respectively, and two interfaces on the other side of the H4 bridge are connected with one end of the fifth inductor L5 and one end of the sixth inductor L6 respectively; the other end of the fifth inductor L5 is connected with one end of the third capacitor C3 and the fifth connecting end simultaneously, and the other end of the sixth inductor L6 is connected with the other end of the third capacitor C3 and the sixth connecting end simultaneously. The fifth connecting end is connected with the L end of the external power grid, and the sixth connecting end is connected with the N end of the external power grid.

[0048] Embodiment two

[0049] As shown in Figure 3 , the hybrid inverter of the utility model, include: MPPT circuit, bidirectional DC / AC circuit and bidirectional DC / DC circuit. Its with Figure 2 MPPT circuit, bidirectional DC / DC's circuit structure is exactly the same. Its with Figure 2 The difference between the embodiment and Figure 3 The bidirectional DC / AC circuit in adopts an Heric bridge circuit structure, which comprises a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a fifth inductor L5, a sixth inductor L6, a third capacitor C3, a fifth connecting end and a sixth connecting end.

[0050] Two interfaces on one side of the bidirectional DC / AC circuit are connected with the first end and the second end of the bus respectively, the fifth connecting end is connected with the L end of the external power grid, and the sixth connecting end is connected with the N end of the external power grid.

[0051] Embodiment three

[0052] As shown in Figure 4 , the hybrid inverter of the utility model, include: MPPT circuit, bidirectional DC / AC circuit and bidirectional DC / DC circuit. Its with Figure 3The circuit structure of the MPPT circuit, the bidirectional DC / AC circuit and the bidirectional DC / DC circuit in the hybrid inverter is the same. Figure 3 The difference between the embodiment and the embodiment shown in

[0053] As shown in Figure 4 , the bidirectional DC / DC circuit comprises a first connecting end, a second connecting end, a first inductor L1, a second inductor L2, a first switch Q1, a second switch Q2 and a third switch Q3.

[0054] One end of the first inductor L1 is connected with the first connecting end, and the other end is connected with one end of the first switch Q1 and one end of the second switch Q2 respectively.

[0055] The other end of the second switch Q2 is connected with the first end of the bus, and the other end of the third switch Q3 is connected with the second end of the bus.

[0056] Embodiment Four

[0057] As shown in Figure 5 , the hybrid inverter comprises an MPPT circuit, a bidirectional DC / AC circuit and a bidirectional DC / DC circuit. Figure 4 The circuit structure of the bidirectional DC / DC circuit in the hybrid inverter and the bidirectional DC / DC circuit in the hybrid inverter is the same. Figure 4 The difference between the embodiment and the embodiment shown in

[0058] As shown in Figure 5 , the MPPT circuit comprises a bus, and a first capacitor C1 and a second capacitor C2 are arranged in series on the bus.

[0059] One end of the third inductor L3 is connected with one end of the fourth switch Q4 and one end of the first diode D1, and the other end of the first diode D1 is connected with the first end of the bus.

[0060] One end of the fourth inductor L4 is connected with one end of the second diode D2 and one end of the fifth switch tube Q5, and the other end of the second diode D2 is connected with the first end of the bus. The other end of the fourth inductor L4 is connected with the seventh connection end. The eighth connection end is connected with the other end of the fifth switch tube Q5 and the second end of the bus. The seventh connection end can be connected with the positive pole PV2+ of the photovoltaic, and the eighth connection end can be connected with the negative pole PV- of the photovoltaic.

[0061] As shown in Figure 5 , the bidirectional DC / AC circuit is a T-type three-level structure, which comprises a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a twelfth switch tube Q12, a thirteenth switch tube Q13, a fourteenth switch tube Q14, a fifteenth switch tube Q15, a sixteenth switch tube Q16, a seventeenth switch tube Q17, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5. The interfaces on one side of the bidirectional DC / AC circuit are connected with the first end and the second end of the bus, and the series connection point of the first capacitor C1 and the second capacitor C2, and the interfaces on the other side of the bidirectional DC / AC circuit are connected with the three-phase external interfaces L-1, L-2, L-3 and the N interface.

[0062] Example five

[0063] As shown in Figure 6 , the hybrid inverter of the utility model, comprising: MPPT circuit, bidirectional DC / AC circuit and bidirectional DC / DC circuit. Wherein, MPPT circuit, bidirectional DC / AC circuit and Figure 5 The structure is exactly the same, and the difference between it and Figure 5 , only in that, its bidirectional DC / DC circuit is different, and the bidirectional DC / DC circuit structure of its bidirectional DC / DC circuit is exactly the same as that in Figure 2 , which will not be repeated here.

[0064] Example six

[0065] As shown in Figure 7 , the hybrid inverter of the utility model, comprising: MPPT circuit, bidirectional DC / AC circuit and bidirectional DC / DC circuit. Wherein, MPPT circuit, bidirectional DC / DC circuit and Figure 5 The structure is exactly the same, and the difference between it and Figure 5 , only in that, its bidirectional DC / AC circuit is different, and the bidirectional DC / AC circuit adopts T-type three-level (split phase) structure.

[0066] As shown in Figure 7As shown, the bidirectional DC / AC circuit includes a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12, a thirteenth switch Q13, a fifth inductor L5, a sixth inductor L6, a third capacitor C3, and a fourth capacitor C4. One side of the bidirectional DC / AC circuit is connected to the first and second ends of the bus, and the series connection point of the first capacitor C1 and the second capacitor C2, respectively. The other side of the bidirectional DC / AC circuit is connected to the three-phase external interfaces L-1, L-2, and N interface, respectively.

[0067] Example 7

[0068] like Figure 8 As shown, the hybrid inverter of this utility model includes: an MPPT circuit, a bidirectional DC / AC circuit, and a bidirectional DC / DC circuit. The MPPT circuit, the bidirectional DC / AC circuit, and... Figure 7 The structure is exactly the same as that in the text, which is consistent with... Figure 7 The only difference lies in the bidirectional DC / DC circuit; the bidirectional DC / DC circuit here uses... Figure 2 The bidirectional DC / DC circuit in it.

[0069] Example 8

[0070] like Figure 9 As shown, the hybrid inverter of this utility model includes: an MPPT circuit, a bidirectional DC / AC circuit, and a bidirectional DC / DC circuit. The MPPT circuit, the bidirectional DC / DC circuit, and... Figure 6 The structure is exactly the same as that in the text, which is consistent with... Figure 6 The only difference is that its bidirectional DC / AC circuit is different; its bidirectional DC / AC circuit adopts a type I three-level (three-phase) structure.

[0071] like Figure 9 As shown, the bidirectional DC / AC circuit includes a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, a ninth switch Q9, a tenth switch Q10, an eleventh switch Q11, a twelfth switch Q12, a thirteenth switch Q13, a fourteenth switch Q14, a fifteenth switch Q15, a sixteenth switch Q16, a seventeenth switch Q17, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5. One side of the bidirectional DC / AC circuit is connected to the first and second ends of the bus, and the series connection point of the first capacitor C1 and the second capacitor C2, respectively. The other side of the bidirectional DC / AC circuit is connected to the three-phase external interfaces L-1, L-2, L-3, and N interface, respectively.

[0072] Example 9

[0073] As Figure 10 shown, the hybrid inverter of the utility model, include: MPPT circuit, bidirectional DC / AC circuit and bidirectional DC / DC circuit. Wherein, MPPT circuit, bidirectional DC / AC circuit with Figure 9 The structure is completely same, it with Figure 9 The difference, only in, its bidirectional DC / DC circuit is different, the bidirectional DC / DC circuit here adopts Figure 2 Bidirectional DC / DC circuit in

[0074] The hybrid inverter and photovoltaic energy storage power supply system of the utility model have the advantages of less device, less drive, moderate cost, simple control, no voltage high frequency jump and high reliability. The switch tube of the utility model can reduce 1, the inductance can reduce 1, the drive circuit can reduce half, so the device is less, the drive is less, and the cost is moderate.

[0075] The switch tube of the utility model does not need to distinguish the power frequency tube and high frequency tube, so the control is simple, and the reliability is high. The voltage of the battery positive and negative port to the system reference potential point of the utility model is stable, and there is no high frequency jump, so the EMC performance is better, and the system stability is higher.

[0076] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that the embodiments can be changed, element combination without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and its equivalents.

Claims

1. A hybrid inverter, characterized by: The application relates to a hybrid inverter. The MPPT circuit comprises a bus, and a first capacitor C1 is arranged on the bus. The direct-current end of the bidirectional DC / AC circuit is connected with the bus. The bidirectional DC / DC circuit comprises a first inductor L1, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a first connecting end and a second connecting end. One end of the inductor L3 is connected with the first input end, and the other end is respectively connected with one end of the first switch tube Q1 and one end of the second switch tube. The second connecting end is respectively connected with the other end of the first switch tube Q1 and one end of the third switch tube Q3. The other end of the second switch tube Q2 is connected with the first end of the bus, and the other end of the third switch tube Q3 is connected with the second end of the bus.

2. The inverter of claim 1, wherein: The bidirectional DC / DC circuit further comprises a second inductor L2, and the second connecting end is respectively connected with the other end of the first switch tube Q1 and one end of the third switch tube Q3 through the second inductor L2.

3. The inverter of claim 1, wherein: The MPPT circuit comprises a third connecting end, a fourth connecting end, a third inductor L3, a fourth switch tube Q4 and a first diode D1.

4. The inverter of claim 3, wherein: The MPPT circuit further comprises a seventh connecting end, an eighth connecting end, a fourth inductor L4, a second diode D2, a fifth switch tube Q5 and a second capacitor C2.

5. The inverter of claim 1, wherein: The bidirectional DC / AC circuit is an H4 bridge, an H5 bridge or a Heric bridge single-bus topology.

6. The inverter of claim 1, wherein: The bidirectional DC / AC circuit is a T-type three-level or I-type three-level double-bus topology.

7. The inverter of claim 1, wherein: The MPPT circuit is a multi-input circuit.

8. A photovoltaic energy storage power supply system characterized by: The application further relates to a PV photovoltaic group string, a battery pack, an AC power grid and a load, wherein the hybrid inverter is connected with the PV photovoltaic group string, the battery pack, the AC power grid and the load respectively.

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