Power supply system and optical storage converter

Abstract

The utility model discloses a power supply system and an optical storage converter. The power supply system comprises a first-class power conversion circuit and a second-class power conversion circuit, the input end of the first-class power conversion circuit is electrically connected with a direct current bus, and the output end of the first-class power conversion circuit is electrically connected with a first-class load. The converter is used for converting electric signals on a direct-current bus into first electric signals and outputting the first electric signals to a first-class load; and the input end of the second type of power conversion circuit is electrically connected with the alternating current signal line, the output end of the second type of power conversion circuit is electrically connected with the second type of load, and the second type of power conversion circuit is used for converting the electric signal on the alternating current signal line into a second electric signal and outputting the second electric signal to the second type of load. According to the power supply system and the optical storage converter provided by the embodiment of the invention, the problem that an existing power supply system is too single in working mode and poor in flexibility can be solved.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular, relates to a power supply system and a photovoltaic storage converter. Background Art

[0002] The power supply system of the photovoltaic storage converter can convert high voltage electricity into low voltage electricity to power loads such as relays, fans, IC devices, etc. in the photovoltaic storage converter.

[0003] However, the power supply system in the related art has the problem of single working mode and poor flexibility. Summary of the invention

[0004] The embodiments of the present application provide a power supply system and a photovoltaic storage converter, which solve the problem that the existing power supply system has too single working mode and poor flexibility.

[0005] In a first aspect, an embodiment of the present application provides a power supply system, including:

[0006] A first type of power conversion circuit, wherein an input end of the first type of power conversion circuit is electrically connected to the DC bus, and an output end of the first type of power conversion circuit is electrically connected to a first type of load, and is used to convert an electrical signal on the DC bus into a first electrical signal and output it to the first type of load;

[0007] The second type of power conversion circuit, the input end of the second type of power conversion circuit is electrically connected to the AC signal line, and the output end of the second type of power conversion circuit is electrically connected to the second type of load, for converting the electrical signal on the AC signal line into a second electrical signal and outputting it to the second type of load.

[0008] In a possible implementation of the first aspect, the invention further includes:

[0009] A third type of power conversion circuit, wherein the input end of the third type of power conversion circuit is electrically connected to the output end of the second type of power conversion circuit, and the output end of the third type of power conversion circuit is electrically connected to the DC bus, and is used to convert the second electrical signal output by the second type of power conversion circuit into a third electrical signal and output it to the DC bus.

[0010] In a possible implementation of the first aspect, the first type of load includes a first load and a second load; the first type of power conversion circuit includes a first power conversion circuit and a second power conversion circuit, and the output power of the first power conversion circuit is different from that of the second power conversion circuit;

[0011] The input end of the first power conversion circuit is electrically connected to the DC bus, and the output end of the first power conversion circuit is electrically connected to the first load, for converting the electrical signal of the DC bus into a first electrical signal and outputting it to the first load;

[0012] The input end of the second power conversion circuit is electrically connected to the DC bus, and the output end of the second power conversion circuit is electrically connected to the second load, for converting the electrical signal of the DC bus into a first electrical signal and outputting it to the second load.

[0013] In a possible implementation of the first aspect, the second power conversion circuit has multiple output ends, and different output ends have different output powers.

[0014] In a possible implementation of the first aspect, a voltage of the second electrical signal is greater than a voltage of the first electrical signal; the power supply system further includes a first diode and a second diode;

[0015] A first electrode of the first diode is electrically connected to an output end of the first type power conversion circuit, a first electrode of the second diode is electrically connected to an output end of the second type power conversion circuit, and a second electrode of the first diode and a second electrode of the second diode are connected to the same load;

[0016] Wherein, when both the first type power conversion circuit and the second type power conversion circuit have output signals, the second diode is turned on.

[0017] In a possible implementation of the first aspect, at least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit includes a switch module and a transformer;

[0018] The switch module and the input winding of the transformer are connected in series as the input end of the power conversion circuit;

[0019] The output winding of the transformer serves as the output end of the power conversion circuit.

[0020] In a possible implementation of the first aspect, at least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit further includes a filtering module;

[0021] The input end of the filter module is electrically connected to the output winding of the transformer, and the output end of the filter module serves as the output end of the power conversion circuit.

[0022] In a possible implementation of the first aspect, at least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit further includes a current sampling module;

[0023] The current sampling module, the switch module and the input winding of the transformer are connected in series and serve as the input end of the power conversion circuit.

[0024] In a possible implementation of the first aspect, a protection circuit is further included, and the protection circuit is connected between the power supply and the power conversion circuit;

[0025] The protection circuit includes an anti-reverse connection module and / or a voltage stabilization module.

[0026] Based on the same inventive concept, in a second aspect, an embodiment of the present application further provides a photovoltaic storage converter, including the power supply system in the first aspect and any implementation of the first aspect.

[0027] The power supply system and photovoltaic storage converter of the embodiment of the present application include a first type of power conversion circuit and a second type of power conversion circuit, wherein the input end of the first type of power conversion circuit is electrically connected to the DC bus, and the output end of the first type of power conversion circuit is electrically connected to the first type of load, and can be used to convert the electrical signal on the DC bus into a first electrical signal and output it to the first type of load, so the power supply system can support independent power supply from the high-voltage DC bus; and the input end of the second type of power conversion circuit is electrically connected to the AC signal line, and the output end of the second type of power conversion circuit is electrically connected to the second type of load, and can be used to convert the electrical signal on the AC signal line into a second electrical signal and output it to the second type of load, so the power supply system can also support independent power supply from the three-phase AC power grid; and Moreover, when the DC bus and the AC power grid are powered at the same time, the load can also be powered by the high-voltage DC bus and the three-phase AC power grid at the same time. Therefore, it can support both the high-voltage DC bus powering alone and the three-phase AC power grid powering alone, and the high-voltage DC bus and the three-phase AC power grid powering at the same time. Therefore, the power supply system provided in the embodiment of the present application supports three working modes, namely, DC bus powering alone, AC power grid powering alone, and DC bus and AC power grid powering at the same time, thereby improving the flexibility of the power supply system. The sum of the output powers of the first type of power conversion circuit 10 and the second type of power conversion circuit 20 can reach 600W. Compared with the related technology of outputting 600W through a high-power flyback converter, the reliability and safety of the power supply system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 It is a structural schematic diagram of a power supply system provided in an embodiment of the present application;

[0030] Figure 2 This is another structural schematic diagram of the power supply system provided in the embodiment of the present application;

[0031] Figure 3 It is a structural schematic diagram of a first type of power conversion circuit in a power supply system provided in an embodiment of the present application;

[0032] Figure 4This is another structural schematic diagram of the power supply system provided in the embodiment of the present application;

[0033] Figure 5 It is another structural schematic diagram of the first type of power conversion circuit in the power supply system provided in the embodiment of the present application;

[0034] Figure 6 This is another structural schematic diagram of the power supply system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0037] It is obvious to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit or scope of the present application. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (technical solutions for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0038] Before describing the technical solutions provided by the embodiments of the present application, in order to facilitate the understanding of the embodiments of the present application, the present application first specifically describes the problems existing in the related art:

[0039] The power supply system of the photovoltaic storage converter can convert high voltage electricity into low voltage electricity to power the relays, fans, IC devices, etc. in the photovoltaic storage converter.

[0040] In the related art, the same power supply system often only supports a single working mode, for example, the same power supply system is used to draw power from the high-voltage DC bus and the three-phase AC power grid, and converts it into low-voltage DC power to power the load. The same power supply system cannot support multiple working modes at the same time. Therefore, the existing technology has the problem that the working mode of the power supply system is too single and the flexibility is poor.

[0041] In addition, due to the high power level of the photovoltaic storage converter, the power demand for the auxiliary power supply system of the photovoltaic storage converter is often large, which can reach 600W or even higher. In the prior art, the power supply system of the photovoltaic storage converter often uses a single flyback or forward converter to achieve 600W power conversion, and then converts it through a low-power flyback converter to meet the final voltage and safety requirements, which is equivalent to connecting high-power and low-power flyback converters in series. This power supply method has two disadvantages: first, it is difficult to design a single flyback converter with a power level of 600W or even higher; second, the system redundancy is poor. A single flyback converter needs to provide low-voltage auxiliary power supply for the entire system. Once it fails, the entire photovoltaic storage converter cannot work, and the safety and reliability are poor.

[0042] Based on this, the embodiments of the present application provide a power supply system and a photovoltaic storage converter, which can solve the problem that the existing power supply system has an overly single working mode and poor flexibility, and can also solve the problem that the existing power supply system has poor safety and reliability.

[0043] The power supply system and photovoltaic storage converter provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0044] Figure 1 is a schematic diagram of a power supply system provided in an embodiment of the present application, such as Figure 1 As shown, the power supply system 100 includes:

[0045] A first type of power conversion circuit 10, wherein an input end of the first type of power conversion circuit 10 is electrically connected to a DC bus, and an output end of the first type of power conversion circuit 10 is electrically connected to a first type of load, for converting an electrical signal on the DC bus into a first electrical signal and outputting the first electrical signal to the first type of load;

[0046] The second type of power conversion circuit 20, the input end of the second type of power conversion circuit 20 is electrically connected to the AC signal line, and the output end of the second type of power conversion circuit 20 is electrically connected to the second type of load, for converting the electrical signal on the AC signal line into a second electrical signal and outputting it to the second type of load.

[0047] Among them, the first type of power conversion circuit 10 can be a power conversion circuit that draws power from a high-voltage DC bus. The first type of power conversion circuit 10 can step down the high-voltage DC signal of the DC bus to obtain a low-voltage DC signal, i.e., a first electrical signal, and supply power to the first type of load.

[0048] The first electrical signal refers to the power supply voltage signal required for the normal operation of the first type of load. For example, the power supply voltage range of the first type of load is 18-24.5VDC. Therefore, the first electrical signal can take a value within the power supply voltage range, for example, it can take 24VDC, that is, the first type of power conversion circuit 10 steps down the high-voltage DC signal of the DC bus to obtain a first electrical signal of 24VDC and supply power to the first type of load.

[0049] The first type of load refers to a load that matches the maximum output power of the first type of power conversion circuit 10 .

[0050] The second type of power conversion circuit 20 can be a power conversion circuit that draws power from a three-phase AC power grid. The second type of power conversion circuit 20 can step down the high-voltage AC signal of the three-phase AC power grid to obtain a low-voltage DC signal, i.e., a second electrical signal, and supply power to the second type of load.

[0051] The second electrical signal refers to the power supply voltage signal required for the normal operation of the second type of load. For example, the second type of power conversion circuit 20 steps down the high-voltage AC signal of the three-phase AC power grid to obtain a second electrical signal of 24.5VDC and supplies power to the second type of load.

[0052] The second type of load refers to a load that matches the maximum output power of the second type of power conversion circuit 20 .

[0053] Specifically, the power supply system 100 includes a first type of power conversion circuit 10 and a second type of power conversion circuit 20, wherein the input end of the first type of power conversion circuit 10 is electrically connected to the DC bus, and the output end of the first type of power conversion circuit 10 is electrically connected to the first type of load, so that the electrical signal on the DC bus can be converted into a first electrical signal and output to the first type of load, so that the power supply system can support drawing power from the high-voltage DC bus alone, and the input end of the second type of power conversion circuit 20 is electrically connected to the AC signal line, and the output end of the second type of power conversion circuit is electrically connected to the second type of load, so that the electrical signal on the AC signal line can be converted into a second electrical signal and output to the second type of load, so that the power supply system can also support drawing power from the three-phase AC power grid alone, and when the DC bus and the AC power grid are powered at the same time, the load can also be powered by the high-voltage DC bus and the three-phase AC power grid at the same time.

[0054] According to the power supply system provided in the embodiment of the present application, through the first type of power conversion circuit 10, the electrical signal on the DC bus can be converted into a first electrical signal and output to the first type of load, and through the second type of power conversion circuit 20, the electrical signal on the AC signal line can be converted into a second electrical signal and output to the second type of load. Therefore, it can support both high-voltage DC bus power supply alone, and three-phase AC power grid power supply alone, and also support multiple working modes such as high-voltage DC bus and three-phase AC power grid power supply at the same time, thereby improving the flexibility of the power supply system. In addition, the sum of the output power of the first type of power conversion circuit 10 and the second type of power conversion circuit 20 can reach 600W. Compared with the related technology of outputting 600W through a high-power flyback converter, the reliability and safety of the power supply system are improved.

[0055] In some embodiments, Figure 2 As shown, the power supply system 100 may further include:

[0056] The third type of power conversion circuit 30, the input end of the third type of power conversion circuit 30 is electrically connected to the output end of the second type of power conversion circuit 20, and the output end of the third type of power conversion circuit 30 is electrically connected to the DC bus, and is used to convert the second electrical signal output by the second type of power conversion circuit 20 into a third electrical signal and output it to the DC bus.

[0057] Among them, the third type of power conversion circuit 30 refers to a power conversion circuit that draws power from the output end of the second type of power conversion circuit 20. The third type of power conversion circuit 30 can boost the low-voltage DC power signal output from the output end of the second type of power conversion circuit 20, that is, the second power signal, to obtain a third power signal, and output it to the DC bus, thereby realizing pre-charging of the bus capacitor, and being able to pre-charge the DC bus voltage of the converter to a certain value when the photovoltaic power is not working, and provide sufficient power to complete the grid-connected synchronization of the converter.

[0058] In some embodiments, Figure 3 As shown, the first type of load includes a first load and a second load; the first type of power conversion circuit 10 includes a first power conversion circuit 11 and a second power conversion circuit 12, and the output power of the first power conversion circuit 11 is different from that of the second power conversion circuit 12.

[0059] The input end of the first power conversion circuit 11 is electrically connected to the DC bus, and the output end of the first power conversion circuit 11 is electrically connected to the first load, for converting the electrical signal of the DC bus into a first electrical signal and outputting it to the first load.

[0060] The input end of the second power conversion circuit 12 is electrically connected to the DC bus, and the output end of the second power conversion circuit 12 is electrically connected to the second load, for converting the electrical signal of the DC bus into a first electrical signal and outputting it to the second load.

[0061] Among them, the first power conversion circuit 11 and the second power conversion circuit 12 can both draw power from the high-voltage DC bus side. Since the output powers of the first power conversion circuit 11 and the second power conversion circuit 12 are different, loads with different power requirements can be mounted.

[0062] Specifically, the first type of power conversion circuit 10 may include a first power conversion circuit 11 and a second power conversion circuit 12, and the output power of the first power conversion circuit 11 and the second power conversion circuit 12 may be different. Among them, the input end of the first power conversion circuit 11 is electrically connected to the DC bus, and the output end of the first power conversion circuit 11 is electrically connected to the first load, and the electrical signal of the DC bus can be converted into a first electrical signal and output to the first load, and the input end of the second power conversion circuit 12 is electrically connected to the DC bus, and the output end of the second power conversion circuit 12 is electrically connected to the second load, and the electrical signal of the DC bus can be converted into a first electrical signal and output to the second load. In the embodiment of the present application, the first type of power conversion circuit 10 can supply power to the first load and the second load. When the first power conversion circuit 11 fails, it does not affect the second power conversion circuit to supply power to the second load, thereby improving the redundancy of the system, realizing the power supply decoupling of the load, and avoiding the problem of using a single flyback converter to provide low-voltage auxiliary power supply for the entire system in the prior art. Once it fails, the entire photovoltaic storage converter cannot work, thereby improving the safety and reliability of the power supply system.

[0063] In some embodiments, the second power conversion circuit 12 has multiple output terminals, and different output terminals have different output powers.

[0064] Specifically, the second power conversion circuit 12 can have multiple output terminals, for example, it can output 3 24VDC, and the output power of each channel is different. For example, the first power conversion circuit 11 can output 1 24VDC, with a maximum output power of 300W, to power the cooling fan; the second power conversion circuit 12 can output 3 24VDC, the maximum output power of the first 24VDC is 140W, which can power the spoiler fan, the maximum output power of the second 24VDC is 50W, which can power PV switches, relays, drive boards, IC devices, etc., and the maximum output power of the third 24VDC is 10W, which can power the LEMS external communication board. Therefore, different output powers can be mounted on loads with different power requirements in the photovoltaic storage converter, realizing reasonable power distribution.

[0065] In some embodiments, Figure 4 As shown, the voltage of the second electrical signal is greater than the voltage of the first electrical signal; the power supply system further includes a first diode 40 and a second diode 50;

[0066] The first electrode of the first diode 40 is electrically connected to the output end of the first type power conversion circuit 10, the first electrode of the second diode 50 is electrically connected to the output end of the second type power conversion circuit 20, and the second electrode of the first diode 40 and the second electrode of the second diode 50 are connected to the same load;

[0067] When both the first type power conversion circuit 10 and the second type power conversion circuit 20 have output signals, the second diode is turned on.

[0068] Among them, the diode has a unidirectional conduction characteristic. When the voltage difference between the anode and cathode of the diode is greater than or equal to the forward conduction voltage drop, the diode can be turned on, otherwise the diode is turned off.

[0069] The voltage of the second electrical signal is greater than the voltage of the first electrical signal, which means that the second electrical signal outputted from the output end of the second type power conversion circuit 20 is greater than the first electrical signal outputted from the output end of the first type power conversion circuit 10. For example, the second electrical signal outputted from the output end of the second type power conversion circuit 20 is 24.5 VDC, and the first electrical signal outputted from the output end of the first type power conversion circuit 10 is 24 VDC. At this time, 24.5 VDC is greater than 24 VDC.

[0070] Specifically, the cathodes of the first diode 40 and the second diode 50 are both electrically connected to the same load, the anode of the first diode is connected to the output end of the first type of power conversion circuit 10, and the output end of the first type of power conversion circuit 10 outputs a first electrical signal, and the anode of the second diode is connected to the output end of the second type of power conversion circuit 20, and the output end of the second type of power conversion circuit 20 outputs a second electrical signal greater than the first electrical signal. Therefore, when both the first type of power conversion circuit 10 and the second type of power conversion circuit 20 have output signals, the second diode 50 is turned on and the first diode 40 is turned off, so that the second type of power conversion circuit can preferentially supply power to the load.

[0071] For example, the cathodes of the first diode 40 and the second diode 50 may both be connected to the IC device, so that the second type of power conversion circuit may preferentially power the IC device.

[0072] For another example, the cathodes of the first diode 40 and the second diode 50 can both be connected to the LEMS external communication board, so that the second type of power conversion circuit can preferentially supply power to the LEMS external communication board, and can ensure the normal operation of important components such as IC devices and external communication boards when the bus voltage is insufficient.

[0073] In some embodiments, at least one of the first type power conversion circuit 10, the second type power conversion circuit 20, and the third type power conversion circuit 30 includes a switch module and a transformer;

[0074] The switch module and the input winding of the transformer are connected in series as the input end of the power conversion circuit;

[0075] The output winding of the transformer serves as the output end of the power conversion circuit.

[0076] Among them, the transformer has an input winding and an output winding. There is no electrical connection between the input winding and the output winding, so it has the function of safety isolation. For example, the transformer can connect the input winding to strong electricity and the output winding to weak electricity to achieve isolation between strong electricity and weak electricity.

[0077] Specifically, at least one type of power conversion circuit includes a switch module and a transformer, and the switch module and the input winding of the transformer are connected in series and can serve as the input end of the power conversion circuit, and the output winding of the transformer can serve as the output end of the power conversion circuit. For example, see Figure 5 The first type of power conversion circuit includes a switch module and a transformer T1, the switch module includes Q11 and Q22, and the switch module and the input winding of the transformer can be connected in series and can be used as the input end of the power conversion circuit, and the output winding of the transformer can be used as the output end of the power conversion circuit. By adjusting the duty cycle signal of the gate of Q11 and Q12, the conduction time ratio of Q11 and Q12 can be controlled, so as to combine the turns ratio of the input winding and the output winding of the transformer, not only can the electrical signal of the DC bus be converted into the first electrical signal, realizing the conversion of the electrical signal, but also the safe isolation of strong electricity and weak electricity can be realized, thereby improving the safety performance of the power supply system.

[0078] In some embodiments, you can continue to see Figure 5 , at least one of the first type power conversion circuit 10, the second type power conversion circuit 20, and the third type power conversion circuit 30 further includes a filtering module;

[0079] The input end of the filter module is electrically connected to the output winding of the transformer, and the output end of the filter module serves as the output end of the power conversion circuit.

[0080] Specifically, at least one type of power conversion circuit includes a switch module, a transformer and a filter module, and the input end of the filter module is electrically connected to the output winding of the transformer, and the output end of the filter module can be used as the output end of the power conversion circuit. Figure 5 As shown, D13, C15, D14, and C16 constitute a filtering module of the first power conversion circuit 11. After the output winding of the transformer outputs the first electrical signal, the first electrical signal can be filtered to remove the AC component in the first electrical signal and retain its DC component, thereby reducing the ripple coefficient of the first electrical signal and making the output first electrical signal smoother and more stable, thereby improving the reliability and stability of the power supply system.

[0081] In some embodiments, you can continue to see Figure 5 , at least one of the first type power conversion circuit 10, the second type power conversion circuit 20, and the third type power conversion circuit 30 further includes a current sampling module;

[0082] The current sampling module, the switch module and the input winding of the transformer are connected in series and serve as the input end of the power conversion circuit.

[0083] Specifically, at least one type of power conversion circuit includes a switch module, a transformer, a filter module and a current sampling module, wherein the current sampling module, the switch module and the input winding of the transformer are connected in series as the input end of the power conversion circuit. Figure 5 As shown, in the first power conversion circuit 11, the current transformer CT1 and the resistor Rs1 both have the function of current sampling. By being connected in series in the loop, the current in the loop is sampled. The flyback control chip NCP1342 can output a duty cycle signal according to the sampled current, and output the duty cycle signal to the gate of Q11 to control the conduction time ratio of Q11, that is, to control the working time of the transformer, thereby converting the bus voltage into a first electrical signal. The current sampling module collects the current signal of the loop where the transformer input winding is located in real time, and the duty cycle can be adjusted in real time to automatically realize the conversion of the first electrical signal. The conversion efficiency of the electrical signal is high and the degree of automation is high.

[0084] It should be noted that in the embodiment of the present application, the model of the flyback control chip is NCP1342, which is merely illustrative and is not used to limit the present application.

[0085] In some embodiments, you can continue to see Figure 5 , the power supply system may further include a protection circuit connected between the power supply and the power conversion circuit;

[0086] The protection circuit includes an anti-reverse connection module and / or a voltage stabilization module.

[0087] Specifically, the power supply system may further include a protection circuit, which is connected between the power supply and the power conversion circuit. The protection circuit may include an anti-reverse connection module and / or a voltage stabilization module. Figure 5 As shown, the diode D11 can prevent the input voltage signal from being reversely connected. When the positive voltage BUS+ and the negative voltage BUS- of the bus voltage are reversely connected, the diode D11 is turned off, which can prevent the current from being reversed and burning the device when the input voltage is reversely connected, and plays a protective role against reverse connection, thereby improving the safety performance of the power supply system. For another example, Figure 5 As shown, C11 and C12 are connected in series to form a voltage stabilizing module, which can eliminate the sharp fluctuation of the input voltage and improve the dynamic stability of the power supply system.

[0088] In one example, if Figure 6 As shown, the power supply system of the photovoltaic storage converter includes a first type of power conversion circuit 10, a second type of power conversion circuit 20, and a third type of power conversion circuit 30. Among them, the first type of power conversion circuit includes a first power conversion circuit 11 and a second power conversion circuit 12. And the first power conversion circuit 11, the second power conversion circuit 12, the second type of power conversion circuit 20, and the third type of power conversion circuit 30 all include a flyback converter.

[0089] Among them, the flyback converter is generally composed of a switch tube, a transformer, and a filter circuit. It is used for voltage conversion and can step down or step up the input terminal Uin and output Uout to power the load. Among them, the duty cycle of the switch tube gate control signal and the turns ratio of the transformer input winding and output winding determine the size of the transformer secondary output voltage Uout.

[0090] In such Figure 6 In the power supply system shown, the first power conversion circuit 11 can be referred to as flyback 1, the second power conversion circuit 12 can be referred to as flyback 2, the second type of power conversion circuit 20 can be referred to as flyback 3, and the third type of power conversion circuit 30 can be referred to as flyback 4.

[0091] It should be noted that in this embodiment, the power conversion circuit is illustrated as a flyback converter, but the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent power conversion circuits within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

[0092] Specifically, Figure 6 As shown, the power supply system includes 4 flyback circuits, among which flyback 1, flyback 2 and flyback 3 are used to convert the power supply Uin (bus DC voltage / three-phase AC voltage) into Uout (DC low voltage 24VDC / 24.5VDC) to supply power to the load. Flyback 4 is used to take power from the output end of flyback 3, boost 24.5VDC and charge the DC bus.

[0093] Flyback 1 (first power conversion circuit 11): powered by the DC bus, the flyback control chip NCP1342 samples the current through the current transformer CT1 and the sampling resistor Rs1, and calculates the duty cycle of the control signal of the switch tube gate according to the sampled current, and then outputs the duty cycle signal to the gate of the switch tubes Q11 and Q12. The switch tubes Q11 and Q12 are turned on / off in response to the duty cycle signal, so as to control when the transformer draws power from the DC bus and convert the high-voltage DC power of the DC bus into a low-voltage DC signal 24VDC. The AC component is filtered out by the filter circuit (D13, C15, D14, C16), and finally outputs 1 Uout = 24VDC with a maximum power of 300W, which can ensure the normal operation of the cooling fan.

[0094] Flyback 2 (the second power conversion circuit 12): powered by a DC bus, the principle is the same as that of flyback 1, and three outputs of Uout = 24 VDC are respectively supplied to loads of different powers, wherein the maximum output power of the first 24 VDC is 140 W, which can carry a spoiler fan, the maximum output power of the second 24 VDC is 50 W, which can carry a PV switch, relay, driver board, IC device, etc., the maximum output power of the third 24 VDC is 10 W, which can carry a LEMS external communication board, thereby realizing a reasonable distribution of power.

[0095] Flyback 3 (second type power conversion circuit 20): powered by a three-phase AC power grid, the three-phase AC power is rectified and then stepped down. The step-down principle is the same as that of flyback 1, and two Uout = 24.5VDC are obtained to supply loads with different powers. Among them, the maximum output power of the first 24.5VDC is 10W, which can carry the LEMS external communication board. Moreover, since 24.5VDC>24VDC and the diodes D3 and D4 are opposite, flyback 3 can give priority to supplying power to the external communication board to speed up the power supply of flyback 4 to the busbar. The maximum output power of the second 24.5VDC is 200W, which can be used to mount IC devices and flyback 4. Since D1 and D2 are opposite, flyback 3 can give priority to powering IC devices. Therefore, when the three-phase AC power grid and the DC bus are powered at the same time, the three-phase AC power grid can be used to power IC devices and external communication boards. There is no need to draw power from the bus. Only the bus capacitors are pre-charged through flyback 4, thereby speeding up the charging speed of the bus capacitors by flyback 4, and the bus capacitors can be charged to the preset value more quickly.

[0096] It should be noted that D1 and D2 are opposite to each other, D3 and D4 are opposite to each other, and the Uout of flyback 3 is greater than the Uout of flyback 2. This allows flyback 3 to prioritize powering IC devices and external communication systems, reducing power drawn from the bus, thereby enabling priority charging of the bus and accelerating the charging speed of the bus.

[0097] Flyback 4 (third type power conversion circuit 30): powered by the 24.5VDC output of flyback 3, the 24.5VDC is boosted and charged to the bus capacitor according to the start-up command issued by the IC device and the bus pre-charge voltage reference signal.

[0098] It should be noted that the same type of transformers T1, T2, and T3 are used in flyback 1 to flyback 3, which can reduce the cost of purchase and maintenance. The inventor has found that the switch tube control chip on the high-voltage side can be selected as NCP1342. Since NCP1342 has a soft switch function, it can reduce the loss of the high-voltage side switch tube. The low-voltage side does not need to consider the switching loss, so the low-cost control chip UC3843 can be selected, thereby reducing power loss and saving costs.

[0099] In the embodiment of the present application, flyback 1 and flyback 2 are powered by the DC bus and can support operation in the voltage range of 500-1600VDC bus; flyback 3 is powered by the three-phase AC power grid and can support operation in the voltage range of 640-920VAC; flyback 4 is powered by the 24VDC output side of flyback 3 and connected to the high-voltage DC bus of the converter after boosting. Therefore, the power supply system supports three working modes: power supply by the high-voltage DC bus alone, power supply by the three-phase AC power grid alone, and power supply by the high-voltage DC bus and the three-phase AC power grid at the same time, with higher flexibility.

[0100] In another example, see Figure 6 , when the high-voltage DC bus is powered alone, the power supply system needs to power all components of the photovoltaic storage converter, such as the cooling system, sampling and control system, and communication system. The power supply system converts the high-voltage DC bus voltage into 4 independent 24VDC outputs through flyback 1 and flyback 2. Flyback 1 outputs 1 24VDC to power the cooling fan, with a power supply power of approximately 300W. Flyback 2 outputs 3 24VDC, the first one is for the spoiler fan, with a power supply power of approximately 140W; the first one is for PV switches, relays, IC devices, driver boards, etc., with a power supply power of approximately 150W; the third one is for the external communication LEMS board, with a power supply power of approximately 10W.

[0101] When the three-phase AC grid supplies power alone, if the scenario of precharging the DC bus is not considered, the power supply system only needs to supply power to the communication system and control system of the photovoltaic storage converter to ensure that the system is controlled. If the scenario of precharging the DC bus is considered, the power supply system needs to supply power to the flyback 4 in addition to the communication system and the control system. The power supply system rectifies the three-phase AC into DC through flyback 3, and then converts it into two 24.5VDC outputs. The first one is for the external communication LEMS board, with a power supply power of about 10W; the second one is for the control IC device, with a power supply power of about 20W, and for the flyback 4 precharge power supply, with a power supply power of about 180W.

[0102] When the high-voltage DC bus and the three-phase AC power grid are powered at the same time, both flyback 2 and flyback 3 can power the control IC device and the LEMS board, wherein the control IC device is powered by diodes D1 and D2, and the LEMS board is powered by diodes D3 and D4. Set the output voltage of flyback 3 to be higher than the output voltage of flyback 2. For example, set the output voltage of flyback 3 to 24.5VDC and the output voltage of flyback 2 to 24VDC. When AC and DC are powered at the same time, the control IC device and the LEMS board will take power from flyback 3 first, that is, from the AC power supply side. With this power supply method, when the power supply power of flyback 4 is constant, the maximum possible power can be provided for the grid-connected synchronization of the system.

[0103] The power supply system provided in the embodiment of the present application has the function of precharging the DC bus. When the photovoltaic power is not working, that is, when the DC bus is out of power, the control power supply for the photovoltaic storage converter is realized through the flyback 3, and then the control IC device can issue a control instruction to the flyback 4 to control the operation of the flyback 4. The control instruction includes an enable working signal and a bus precharge voltage reference signal, which can realize the controllable startup and voltage value of the bus precharge function. At the same time, through the multi-flyback top structure, three working modes such as supporting high-voltage DC bus power supply alone, three-phase AC power grid power supply alone, and high-voltage DC bus and three-phase AC power grid power supply at the same time are realized; the power supply of the heat dissipation system and the control and drive system power supply are decoupled to a certain extent, which increases the safety of the power supply system; by designing a low-voltage to high-voltage circuit, it is realized to pre-charge the converter bus capacitor and support the grid-connected synchronization function of the converter; through the reasonable distribution of power, the modular design of multiple flybacks is realized, reducing the design and production costs.

[0104] It should be noted that, through research by the inventors, it is found that since the supply voltage ranges and power requirements of flyback 1, flyback 2, and flyback 3 are similar, a modular design can be adopted.

[0105] Based on the same inventive concept, in the second aspect, the embodiments of the present application also provide a photovoltaic storage converter, including the power supply system provided by any of the above embodiments, so the photovoltaic storage converter has all the beneficial effects of the above power supply system.

[0106] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0107] It should be understood that in the embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0108] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A power supply system, characterized in that: include: A first type of power conversion circuit, wherein an input end of the first type of power conversion circuit is electrically connected to a DC bus, and an output end of the first type of power conversion circuit is electrically connected to a first type of load, and is used to convert an electrical signal on the DC bus into a first electrical signal and output the first electrical signal to the first type of load; A second type of power conversion circuit, wherein the input end of the second type of power conversion circuit is electrically connected to the AC signal line, and the output end of the second type of power conversion circuit is electrically connected to the second type of load, for converting the electrical signal on the AC signal line into a second electrical signal and outputting it to the second type of load.

2. The power supply system according to claim 1, characterized in that: Also includes: A third type of power conversion circuit, wherein the input end of the third type of power conversion circuit is electrically connected to the output end of the second type of power conversion circuit, and the output end of the third type of power conversion circuit is electrically connected to the DC bus, and is used for converting the second electrical signal output by the second type of power conversion circuit into a third electrical signal and outputting it to the DC bus.

3. The power supply system according to claim 1, characterized in that: The first type of load includes a first load and a second load; the first type of power conversion circuit includes a first power conversion circuit and a second power conversion circuit, and the output power of the first power conversion circuit is different from that of the second power conversion circuit; The input end of the first power conversion circuit is electrically connected to the DC bus, and the output end of the first power conversion circuit is electrically connected to the first load, for converting the electrical signal of the DC bus into a first electrical signal and outputting the first electrical signal to the first load; The input end of the second power conversion circuit is electrically connected to the DC bus, and the output end of the second power conversion circuit is electrically connected to the second load, for converting the electrical signal of the DC bus into a first electrical signal and outputting it to the second load.

4. The power supply system according to claim 3, characterized in that: The second power conversion circuit has a plurality of output terminals, and different output terminals have different output powers.

5. The power supply system according to claim 1, characterized in that: The voltage of the second electrical signal is greater than the voltage of the first electrical signal; the power supply system further includes a first diode and a second diode; The first electrode of the first diode is electrically connected to the output end of the first type power conversion circuit, the first electrode of the second diode is electrically connected to the output end of the second type power conversion circuit, and the second electrode of the first diode and the second electrode of the second diode are connected to the same load; Wherein, when both the first-type power conversion circuit and the second-type power conversion circuit have output signals, the second diode is turned on.

6. The power supply system according to claim 2, characterized in that: At least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit includes a switch module and a transformer; The switch module and the input winding of the transformer are connected in series as the input end of the power conversion circuit; The output winding of the transformer serves as the output end of the power conversion circuit.

7. The power supply system according to claim 6, characterized in that: At least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit further includes a filtering module; The input end of the filter module is electrically connected to the output winding of the transformer, and the output end of the filter module serves as the output end of the power conversion circuit.

8. The power supply system according to claim 7, characterized in that: At least one of the first type of power conversion circuit, the second type of power conversion circuit, and the third type of power conversion circuit further includes a current sampling module; The current sampling module, the switch module and the input winding of the transformer are connected in series and serve as the input end of the power conversion circuit.

9. The power supply system according to claim 1, characterized in that: Also included is a protection circuit, the protection circuit being connected between the power supply and the power conversion circuit; The protection circuit includes an anti-reverse connection module and / or a voltage stabilization module.

10. A photovoltaic storage converter, characterized in that: Comprising a power supply system as claimed in any one of claims 1 to 9.

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