Air conditioning system based on light storage system

Abstract

The utility model discloses an air conditioning system based on a light storage system, comprising: a light storage system comprising a direct current power supply port; the voltage conversion circuit comprises a direct-current boosting module and a direct-current bus, and the direct-current power supply port is connected to the direct-current bus through the direct-current boosting module; the air conditioner comprises an alternating-current load, a direct-current electricity taking port and an inverter, the alternating-current side of the inverter is connected with the alternating-current load, and the direct-current side of the inverter is connected with the direct-current bus through the direct-current electricity taking port. According to the air conditioner, inversion is carried out directly based on the direct current, compared with a traditional mode that electricity is taken from a power grid or an inverter of an optical storage system, the alternating current-direct current-alternating current voltage conversion process does not need to be carried out, only direct current-alternating current is needed, losses occurring in the voltage conversion process are reduced, the energy-saving effect is improved, and the energy-saving effect is improved. And the air conditioner does not need to be provided with an EMC device, a rectification circuit, a power factor correction circuit and the like, so that the cost of the air conditioner can be greatly reduced.

Description

Technical Field

[0001] This application relates to the technical field of air conditioners, and particularly to an air conditioning system based on a photovoltaic energy storage system. Background Art

[0002] At present, the photovoltaic energy storage system and the variable-frequency air conditioner operate independently as two separate systems. Although there is a solution in the related art at present where the photovoltaic energy storage system is used as a power supply terminal to supply power to the variable-frequency air conditioner at the load end, the essence of the power consumption of the variable-frequency air conditioner has not been improved. For example, in a traditional photovoltaic energy storage system, power is grid-connected through an inverter, and the AC side of the inverter supplies AC power to the variable-frequency air conditioner. Inside the variable-frequency air conditioner, a rectifier and an inverter are used to drive the compressor to work. In fact, this type of variable-frequency air conditioner is a general type and does not optimize power consumption in combination with the photovoltaic energy storage system. Utility Model Content

[0003] The embodiments of this application provide an air conditioning system based on a photovoltaic energy storage system, which can improve the energy-saving effect of the air conditioner and reduce the cost of the air conditioner at the same time.

[0004] In a first aspect, the embodiments of this application provide an air conditioning system based on a photovoltaic energy storage system, including:

[0005] A photovoltaic energy storage system, including a DC power supply port;

[0006] A voltage conversion circuit, including a DC boost module and a DC bus. The DC power supply port is connected to the DC bus through the DC boost module;

[0007] An air conditioner, including an AC load, a DC power extraction port, and an inverter. The AC side of the inverter is connected to the AC load, and the DC side of the inverter is connected to the DC bus through the DC power extraction port.

[0008] In some embodiments, the air conditioner includes an outdoor unit, and the outdoor unit is provided with an outdoor unit main board. The power extraction port of the outdoor unit main board is connected to one side of the DC power extraction port, and the other side of the DC power extraction port serves as the external power interface of the outdoor unit.

[0009] In some embodiments, the photovoltaic energy storage system includes a photovoltaic system and an energy storage unit. The DC power supply port includes a photovoltaic power supply port and an energy storage unit power supply port. The DC boost module includes a first boost module and a second boost module. The photovoltaic power supply port is connected to the DC bus through the first boost module, and the energy storage unit power supply port is connected to the DC bus through the second boost module.

[0010] In some embodiments, the energy storage unit includes a low-voltage battery pack, the second boost module includes a multi-stage DC conversion circuit, and the low-voltage battery pack is connected to the DC bus through the multi-stage DC conversion circuit;

[0011] and / or, the energy storage unit includes a high-voltage battery pack, the second boost module includes a single-stage DC conversion circuit, and the high-voltage battery pack is connected to the DC bus through the single-stage DC conversion circuit.

[0012] In some embodiments, the first boost module includes a first switch module, a first boost inductor, a first charging capacitor, and a first freewheeling diode. One end of the first boost inductor is connected to the positive pole of the photovoltaic power supply port, the other end of the first boost inductor is connected to the positive pole of the DC bus through the first freewheeling diode, the other end of the first boost inductor is also connected to the negative pole of the DC bus through the first switch module, and both ends of the first charging capacitor are respectively connected to the positive and negative poles of the DC bus.

[0013] In some embodiments, the second boost module includes a second switch module, a second boost inductor, a second charging capacitor, and a second freewheeling diode. One end of the second boost inductor is connected to the positive pole of the energy storage unit power supply port, the other end of the second boost inductor is connected to the positive pole of the DC bus through the second freewheeling diode, the other end of the second boost inductor is also connected to the negative pole of the DC bus through the second switch module, and both ends of the second charging capacitor are respectively connected to the positive and negative poles of the DC bus.

[0014] In some embodiments, the voltage conversion circuit further includes a bidirectional conversion circuit. The AC side of the bidirectional conversion circuit is connected to the power grid, and the DC side of the bidirectional conversion circuit is connected to the DC bus.

[0015] In some embodiments, the bidirectional conversion circuit includes an H-bridge circuit. The DC port of the H-bridge circuit is connected to the DC bus, and the AC port of the H-bridge circuit is connected to the power grid through a common-mode inductor.

[0016] In some embodiments, the photovoltaic system includes a plurality of photovoltaic strings, the photovoltaic strings have one or more of the photovoltaic power supply ports, and different photovoltaic power supply ports are correspondingly connected to the first boost modules applicable to different voltages.

[0017] In some embodiments, the AC load includes a variable-frequency compressor and an AC fan.

[0018] The air conditioning system based on the photovoltaic energy storage system according to the embodiments of the present application has at least the following beneficial effects: The photovoltaic energy storage system boosts the voltage through a DC boost module and supplies power to the DC bus. The air conditioner draws power from the DC bus through a DC power taking port and performs inversion, thereby providing an AC working voltage to the AC load. It can be seen from this that the air conditioner according to the embodiments of the present application directly performs inversion based on direct current. Compared with the traditional method of taking power from the power grid or taking power from the inverter of the photovoltaic energy storage system, it does not require an AC-DC-AC voltage conversion process, only requires DC-AC, reduces the loss in the voltage conversion process, improves the energy saving effect, and the air conditioner does not need to be provided with EMC devices, rectifier circuits, power factor correction circuits, etc., which can greatly reduce the cost of the air conditioner.

[0019] Other features and advantages of the present application will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present application. The objectives and other advantages of the present application can be achieved and obtained through the structures specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a variable frequency air conditioner provided by an embodiment of the present application;

[0021] Figure 2 is a schematic structural diagram of an air conditioning system based on a photovoltaic energy storage system provided by an embodiment of the present application;

[0022] Figure 3 is a circuit diagram of an air conditioning system based on a photovoltaic energy storage system provided by an embodiment of the present application;

[0023] Figure 4 is a schematic structural diagram of another air conditioning system based on a photovoltaic energy storage system provided by an embodiment of the present application;

[0024] Figure 5 is a schematic diagram of a power supply scheme of an air conditioning system based on a photovoltaic energy storage system provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be adjusted in the order that can be obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0026] In the description of the present application, the meaning of "a number of" is one or more, the meaning of "a plurality of" is two or more, and understandings such as "greater than", "less than", "exceeding", etc. do not include the corresponding number, and understandings such as "above", "below", "within", etc. include the corresponding number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0027] The serial numbers assigned to components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0028] Referring to Figure 1 as shown in Figure 1 is a schematic structural diagram of a variable-frequency air conditioner provided by an embodiment of the present application. In the related art, a variable-frequency air conditioner includes an indoor unit and an outdoor unit, and the indoor unit and the outdoor unit are in a separated state. The electric control circuit of the outdoor unit of the variable-frequency air conditioner includes an AC input circuit, a rectifier bridge circuit, and a PFC circuit. The input end of the AC input circuit is connected to an AC power supply, the output end of the AC input circuit is connected to the input end of the rectifier bridge circuit, and the output end of the rectifier bridge circuit is connected to the PFC circuit. The AC current output by the AC power supply enters the AC input circuit, and then passes through the rectifier bridge circuit. The rectifier bridge circuit rectifies the alternating current and outputs direct current. The direct current passes through the PFC circuit to achieve power factor correction and boost, and finally is inverted into alternating current through an inverter and output to a load (compressor) for use. Therefore, the logic of the entire electric control circuit of the outdoor unit is to realize the process of converting alternating current to direct current and then to alternating current, so that the alternating current output by the AC power supply undergoes multiple conversions to generate energy loss. The more conversions there are, the greater the loss. Therefore, the outdoor unit of the traditional variable-frequency air conditioner consumes a large amount of energy.

[0029] At present, the energy storage system and the variable-frequency air conditioner operate independently as two separate systems. Although there is a solution in the related art at present that the energy storage system is used as a power supply end to supply power to the variable-frequency air conditioner at the load end, the essence of power consumption of the variable-frequency air conditioner has not been improved. For example, the traditional energy storage system is connected to the grid through an inverter, and the AC side of the inverter supplies alternating current to the variable-frequency air conditioner, and the variable-frequency air conditioner internally drives the compressor to work through rectification and inversion. The variable-frequency air conditioner of this solution is actually a general type and does not optimize power consumption in combination with the energy storage system.

[0030] Based on this, to solve the above problems, the embodiment of the present application provides an air conditioning system based on a photovoltaic energy storage system. The photovoltaic energy storage system supplies power to the DC bus through a DC boost module. The air conditioner draws power from the DC bus through a DC power taking port and performs inversion, so as to provide an AC working voltage to the AC load. It can be seen that the air conditioner in the embodiment of the present application directly performs inversion based on direct current. Compared with the traditional method of taking power from the power grid or from the inverter of the photovoltaic energy storage system, it does not require an AC-DC-AC voltage conversion process, only requires DC-AC, reduces the loss in the voltage conversion process, improves the energy saving effect, and the air conditioner does not need to be provided with EMC devices, rectifier circuits, power factor correction circuits, etc., which can greatly reduce the cost of the air conditioner.

[0031] The air conditioning system based on the photovoltaic energy storage system will be described below with reference to the accompanying drawings.

[0032] Refer to Figure 2 as shown Figure 2 FIG. 10 is a schematic structural diagram of an air conditioning system of a photovoltaic energy storage system 100 provided by an embodiment of the present application. The air conditioning system based on the photovoltaic energy storage system 100 includes a photovoltaic energy storage system 100, a voltage conversion circuit 200, and an air conditioner 300; the photovoltaic energy storage system 100 includes a photovoltaic energy storage system 110; the voltage conversion circuit 200 includes a DC boost module 210 and a DC bus 220, and the photovoltaic energy storage system 110 is connected to the DC bus 220 through the DC boost module 210; the air conditioner 300 includes an AC load 330, a DC power taking port 310, and an inverter 320. The AC side of the inverter 320 is connected to the AC load 330, and the DC side of the inverter 320 is connected to the DC bus 220 through the DC power taking port 310.

[0033] In the embodiment of the present application, the photovoltaic energy storage system 100 includes a photovoltaic energy storage system 110. The input end of the photovoltaic energy storage system 110 is connected to the input end of the DC boost module 210, and the output end of the DC boost module 210 is connected to the DC bus 220, so that the direct current output by the photovoltaic energy storage system 110 is boosted by the DC boost module 210, and the direct current boosted by the DC boost module 210 is transmitted to the DC bus 220. The air conditioner 300 is provided with a DC power taking port 310, and one side of the DC power taking port 310 is connected to the DC bus 220, and the other side of the DC power taking port 310 is connected to the DC side of the inverter 320, so that the DC side of the inverter 320 is connected to the DC bus 220 through the DC power taking port 310, so that the DC side of the inverter 320 directly obtains the direct current provided by the DC bus 220 through the DC power taking port 310 for inversion. The inverter 320 inverses the direct current obtained from the DC bus 220 into alternating current. Since the AC side of the inverter 320 is connected to the AC load 330, the alternating current output by the AC side of the inverter 320 provides voltage for the AC load 330 to enable the load to work normally.

[0034] It can be seen that in the embodiment of the present application, the air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage to the AC load 330. It can be known from this that the air conditioner 300 in the embodiment of the present application directly performs inversion based on direct current. Compared with the traditional method of taking power from the power grid or from the inverter 320 of the photovoltaic energy storage system 100, it does not require an AC-DC-AC voltage conversion process, only requires DC-AC, reduces the loss in the voltage conversion process, improves the energy-saving effect, and the air conditioner 300 does not need to be provided with EMC devices, rectifier circuits, power factor correction circuits, etc., which can greatly reduce the cost of the air conditioner 300.

[0035] In some embodiments of the present application, the air conditioner 300 includes an outdoor unit, and the outdoor unit is provided with an outdoor unit main board. The power-taking port of the outdoor unit main board is connected to one side of the DC power-taking port 310, and the other side of the DC power-taking port 310 serves as the external power supply interface of the outdoor unit.

[0036] In the embodiment of the present application, the outdoor unit of the air conditioner 300 includes an outdoor unit main board, and the power-taking port is arranged on the outdoor unit main board. The power-taking port on the outdoor unit main board is connected to one side of the DC power-taking port 310 of the air conditioner 300, and the other side of the DC power-taking port 310 of the air conditioner 300 serves as the external power supply interface of the outdoor unit. Since the DC power-taking port 310 of the air conditioner 300 is connected to the DC bus 220, the outdoor unit main board obtains the direct current provided by the DC bus 220 through the power-taking port and the DC power-taking port 310 of the air conditioner 300. It can be understood that the inverter 320 is arranged on the outdoor unit main board. Therefore, the inverter 320 inverts the direct current obtained by the outdoor unit main board through the power-taking port and the DC power-taking port 310 of the air conditioner 300 into alternating current, thereby realizing the conversion from direct current to alternating current.

[0037] The outdoor unit and the indoor unit of the variable-frequency air conditioner 300 are in a separated state. In the embodiment of the present application, the power-taking port of the outdoor unit main board is connected to one side of the DC power-taking port 310 of the air conditioner 300, so that the inverter 320 directly obtains the direct current on the DC bus 220 for inversion. The other side of the DC power-taking port 310 of the air conditioner 300 serves as the external power supply interface of the outdoor unit. It can be understood that the other side of the DC power-taking port 310 of the air conditioner 300 is connected to the indoor unit, that is, the outdoor unit is connected to the indoor unit through the other side of the DC power-taking port 310. Since the DC power-taking port 310 is connected to the DC bus 220, the outdoor unit can deliver the direct current on the DC bus 220 obtained through the DC power-taking port 310 to the indoor unit to provide the required DC working voltage for the indoor unit to ensure the normal operation of the indoor unit.

[0038] Under the background of the dual-carbon strategy, wind energy, solar energy, and electric energy, as clean energies, are the main energy sources that are key to develop at present and in the future. However, both wind power generation and photovoltaic power generation are easily restricted by factors such as weather and environment, and the power supply has the characteristic of instability. Then, energy storage technology is proposed to store wind energy, solar energy, and electric energy, which can suppress the fluctuation of energy and is an important means to support the stable use of wind and solar electric energy and improve energy utilization efficiency.

[0039] In some embodiments of the present application, the photovoltaic energy storage system 100 includes a photovoltaic system and an energy storage unit. The photovoltaic energy storage system 110 includes a photovoltaic power supply port and an energy storage unit power supply port. The DC boost module 210 includes a first boost module and a second boost module. The photovoltaic power supply port is connected to the DC bus 220 through the first boost module, and the energy storage unit power supply port is connected to the DC bus 220 through the second boost module.

[0040] The photovoltaic energy storage system 100 is a system that converts solar energy into electric energy and stores it to provide power for people. The photovoltaic energy storage system 100 includes a photovoltaic system and an energy storage unit. The photovoltaic system is used to convert solar energy into electric energy, and the energy storage unit is used to store the generated electric energy. The photovoltaic system also includes a photovoltaic inverter, which is used to convert the electric energy into direct current or alternating current. In the embodiments of the present application, taking advantage of the direct current characteristic of the photovoltaic energy storage system 100, a photovoltaic energy storage system 110 is set in the photovoltaic energy storage system 100. The photovoltaic energy storage system 110 is used to output direct current. It can be understood that the output end of the photovoltaic inverter is connected to the input end of the photovoltaic energy storage system 110. The photovoltaic inverter converts solar energy into direct current and outputs it to the photovoltaic energy storage system 110. In this way, the photovoltaic inverter of the photovoltaic energy storage system 100 directly converts solar energy into direct current, which can reduce the link of converting alternating current to direct current, thereby reducing the loss in the voltage conversion process and improving the energy-saving effect.

[0041] The photovoltaic energy storage system 110 includes a photovoltaic power supply port. The DC boost module 210 includes a first boost module and a second boost module. The photovoltaic power supply port is connected to the input end of the first boost module. In the embodiments of the present application, when the weather condition is sufficient sunlight, the photovoltaic inverter directly converts solar energy into direct current and outputs the direct current to the photovoltaic power supply port through the photovoltaic inverter. The direct current is directly output to the first boost module through the photovoltaic power supply port for boost processing to output a first voltage. Since the photovoltaic power supply port is connected to the DC bus 220 through the first boost module, therefore, the first voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power taking port 310 for inversion, so as to provide an alternating current working voltage for the AC load 330.

[0042] The energy storage system 110 further includes an energy storage unit power supply port, which is connected to the input end of the second boost module, and the energy storage unit power supply port is connected to the DC bus 220 through the second boost module. It should be noted that after the photovoltaic inverter directly converts solar energy into direct current, in addition to outputting the direct current to the photovoltaic power supply port, the photovoltaic inverter also outputs a part of the direct current to the energy storage unit power supply port. The energy storage unit stores the electric energy. When the weather condition is insufficient sunlight and the photovoltaic power supply port cannot stably provide sufficient direct current, when the energy storage unit has sufficient power, the energy storage unit outputs direct current through the energy storage unit power supply port. Since the energy storage unit power supply port is connected to the input end of the second boost module, the direct current output from the energy storage unit power supply port passes through the second boost module and is boosted, and the second voltage is output. Since the energy storage unit power supply port is connected to the DC bus 220 through the second boost module, therefore, the second voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power taking port 310 and performs inversion, so as to provide an AC working voltage for the AC load 330.

[0043] The electric energy is stored through the energy storage unit. When the weather condition is bad, the direct current can be output through the energy storage unit power supply port and boosted by the second boost module to provide a stable bus voltage for the DC bus 220 to ensure the normal operation of the air conditioner 300; in addition, it can also suppress the fluctuation of energy, support the stable use of electric energy, and is an important means to improve the energy utilization rate.

[0044] It can be seen from this that the air conditioner 300 in the embodiment of the present application directly performs inversion based on the direct current obtained from the DC bus 220. Compared with the traditional method of taking power from the power grid or taking power from the photovoltaic inverter of the energy storage system 100, it does not require an AC-DC-AC voltage conversion process, only requires DC-AC, reduces the loss in the voltage conversion process, and improves the energy saving effect. And by setting the energy storage system 100 to include a photovoltaic system and an energy storage unit, on the one hand, the photovoltaic system can convert solar energy into direct current and provide a stable voltage for the DC bus 220, and on the other hand, the energy storage unit can store the direct current converted from solar energy. When the weather condition is bad, the energy storage unit provides a stable voltage for the DC bus 220. In the embodiment of the present application, compared with the traditional air conditioning system based on the photovoltaic system, the air conditioning system based on the energy storage system 100 of the present application provides multiple ways to provide a stable voltage for the DC bus 220, is suitable for the normal operation of the air conditioning system under different weather conditions, and improves the applicable range of the air conditioning system.

[0045] Refer to Figure 3 , Figure 3FIG. 0 is a schematic structural diagram of another air-conditioning system based on the optical storage system 100 provided by an embodiment of the present application. In some embodiments of the present application, the energy storage unit includes a low-voltage battery pack, the second boost module includes a multi-stage DC conversion circuit, and the low-voltage battery pack is connected to the DC bus 220 through the multi-stage DC conversion circuit. It can be understood that the energy storage unit includes a low-voltage battery pack, the power supply port of the energy storage unit is connected to the input end of the second boost module, the direct current output from the power supply port of the energy storage unit enters the second boost module for boost processing, the second boost module includes a multi-stage DC conversion circuit, and the multi-stage DC conversion circuit performs multiple boost processes on the direct current output from the power supply port of the energy storage unit, so as to increase the output voltage of the low-voltage battery pack and realize the conversion from low voltage to high voltage; since the power supply port of the energy storage unit is connected to the DC bus 220 through the second boost module, the direct current output from the low-voltage battery pack is output to the DC bus 220 after being boosted by the multi-stage DC conversion circuit, and the second voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 draws power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330.

[0046] In some embodiments of the present application, the energy storage unit further includes a high-voltage battery pack, the second boost module includes a single-stage DC conversion circuit, and the high-voltage battery pack is connected to the DC bus 220 through the single-stage DC conversion circuit. It can be understood that the energy storage unit includes a high-voltage battery pack, the power supply port of the energy storage unit is connected to the input end of the second boost module, the direct current output from the power supply port of the energy storage unit enters the second boost module for boost processing, the second boost module includes a single-stage DC conversion circuit, and the single-stage DC conversion circuit performs boost processing on the direct current output from the power supply port of the energy storage unit, so as to increase the output voltage of the high-voltage battery pack and increase the output voltage of the high-voltage battery pack to the second voltage that meets the load usage; since the power supply port of the energy storage unit is connected to the DC bus 220 through the second boost module, the direct current output from the high-voltage battery pack is output to the DC bus 220 after being boosted by the single-stage DC conversion circuit, and the second voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 draws power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330.

[0047] The energy storage unit is used to store the electric energy generated by the photovoltaic system. In the embodiments of the present application, the energy storage unit includes two types of battery packs, namely a low-voltage battery pack and a high-voltage battery pack. It can be understood that when the energy storage unit is a low-voltage battery pack, the second boost module is a multi-stage DC conversion circuit. Since the original output voltage of the low-voltage battery pack is relatively low, a multi-stage DC conversion circuit is required to upgrade the original output voltage of the low-voltage battery pack multiple times and output a second voltage higher than the original output voltage of the low-voltage battery pack, so as to provide a stable bus voltage for the DC bus 220 through the second voltage. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330. When the energy storage unit is a high-voltage battery pack, the second boost module is a single-stage DC conversion circuit. Since the original output voltage of the high-voltage battery pack is relatively high, only a single-stage DC conversion circuit needs to be set to boost the original output voltage of the high-voltage battery pack, and a second voltage capable of providing a stable voltage for the DC bus 220 can be output. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330.

[0048] It should be noted that the output voltage range of the low-voltage battery pack is 42V to 58V. When the voltage of the direct current output through the energy storage unit power supply port is between 42V and 58V, the multi-stage DC conversion circuit is used to perform multi-stage boosting on the direct current output through the energy storage unit power supply port and output a stable bus voltage. The air conditioner 300 directly takes power from the DC bus 220, and the direct current is inverted into alternating current for the load to use. The output voltage range of the high-voltage battery pack is 150V to 450V. When the voltage of the direct current output through the energy storage unit power supply port is between 150V and 450V, the single-stage DC conversion circuit is used to boost the direct current output through the energy storage unit power supply port and output a stable bus voltage. The air conditioner 300 directly takes power from the DC bus 220, and the direct current is inverted into alternating current for the load to use. Those skilled in the art can set the magnitudes of the voltages provided by the low-voltage battery pack and the high-voltage battery pack according to the actual situation. The embodiments of the present application do not limit the magnitudes of the voltages output by the low-voltage battery pack and the high-voltage battery pack.

[0049] It should be noted that in some embodiments of the present application, the AC load 330 includes a variable-frequency compressor and an AC fan. Those skilled in the art can select the type of the AC load 330 according to the actual situation. The embodiments of the present application do not limit the type of the AC load 330.

[0050] In some embodiments of the present application, the photovoltaic system includes a plurality of photovoltaic strings, and the photovoltaic strings have one or more photovoltaic power supply ports, and different photovoltaic power supply ports are correspondingly connected to first boost modules applicable to different voltages.

[0051] It can be understood that the photovoltaic string is one of the most important components in the photovoltaic energy storage system 100. The photovoltaic string can directly convert solar light into electrical energy. When solar radiation hits the surface of the photovoltaic string, it stimulates the electrons in the photovoltaic string, causing the electrons to jump out of the semiconductor material and form an electric current. This electric current enters the energy storage unit through a wire and then starts to store electrical energy. In the embodiment of the present application, the photovoltaic system includes multiple photovoltaic strings, and the multiple photovoltaic strings are connected in series to form the photovoltaic system. The photovoltaic string has at least one or more photovoltaic power supply ports. When the photovoltaic string has multiple photovoltaic power supply ports, the voltages output by different photovoltaic power supply ports are different. Therefore, different photovoltaic power supply ports are correspondingly connected to first boost modules suitable for different voltages.

[0052] In one embodiment, the output voltage of a photovoltaic string is 20V. When the photovoltaic system includes 3 photovoltaic strings, namely the first photovoltaic string, the second photovoltaic string, and the third photovoltaic string, the first photovoltaic string, the second photovoltaic string, and the third photovoltaic string are connected in series in sequence. The photovoltaic string has two photovoltaic power supply ports, namely the first photovoltaic power supply port and the second photovoltaic power supply port. The first photovoltaic power supply port is connected to the output end of the first photovoltaic string, and the second photovoltaic power supply port is connected to the output end of the third photovoltaic string. Therefore, the first photovoltaic power supply port outputs a voltage of 20V, the second photovoltaic power supply port outputs a voltage of 60V, and the first photovoltaic power supply port and the second photovoltaic power supply port are respectively connected to first boost modules suitable for 20V voltage and 60V voltage.

[0053] By setting that the photovoltaic system includes multiple photovoltaic strings, and the photovoltaic string has at least one or more photovoltaic power supply ports, the photovoltaic systems composed of different numbers of photovoltaic strings have different output voltages, and the voltages output by the photovoltaic power supply ports at different positions are also different. Different photovoltaic power supply ports are correspondingly connected to first boost modules suitable for different voltages. Therefore, the photovoltaic system can provide multiple different voltages of different magnitudes to be suitable for loads with different working voltages, improving the adaptability of the photovoltaic system.

[0054] It should be noted that those skilled in the art can determine the number of photovoltaic strings according to the actual situation according to the preset voltage required to be output by the photovoltaic system. The embodiment of the present application does not limit the number of photovoltaic strings. Those skilled in the art can set the number of photovoltaic power supply ports and the specific connection relationship of the photovoltaic power supply ports according to the actual situation. The embodiment of the present application does not limit the number of photovoltaic power supply ports and the specific connection relationship of the photovoltaic power supply ports.

[0055] Refer to Figure 3 and Figure 4 , Figure 4It is the circuit diagram of the air-conditioning system based on the optical storage system 100 provided by the embodiments of the present application. In an embodiment of the present application, the photovoltaic power supply port is connected to the DC bus 220 through the first boost module. The first boost module includes a first switch module Q1, a first boost inductor PV1-L, a first charging capacitor C5, and a first freewheeling diode D1. One end of the first boost inductor PV1-L is connected to the positive pole of the photovoltaic power supply port, and the other end of the first boost inductor PV1-L is connected to the positive pole of the DC bus 220 through the first freewheeling diode D1. The other end of the first boost inductor PV1-L is also connected to the negative pole of the DC bus 220 through the first switch module Q1. Both ends of the first charging capacitor C5 are respectively connected to the positive and negative poles of the DC bus 220.

[0056] One end of the first boost inductor PV1-L is connected to the positive pole of the photovoltaic power supply port, and the other end of the first boost inductor PV1-L is also connected to the negative pole of the DC bus 220 through the first switch module Q1. When the first switch module Q1 is turned on, the direct current output from the positive pole of the photovoltaic power supply port charges the first boost inductor PV1-L, forming a charging loop of the photovoltaic power supply port - the first boost inductor PV1-L - the first switch module Q1 - the negative pole of the DC bus 220. Since the other end of the first boost inductor PV1-L is connected to the positive pole of the DC bus 220 through the first freewheeling diode D1, and one end of the first charging capacitor C5 is connected to the positive pole of the DC bus 220, and the other end of the first charging capacitor C5 is connected to the negative pole of the DC bus 220. When the first switch module Q1 is turned off, the direction of the direct current flow is the first boost inductor PV1-L - the first freewheeling diode D1 - the first charging capacitor C5 - the negative pole of the DC bus 220, forming a first energy storage loop to achieve the energy storage of the first charging capacitor C5. The voltage across both ends of the first charging capacitor C5 is used to provide a stable bus voltage for the DC bus 220, so that the air conditioner 300 can draw power from the DC bus 220 through the DC power taking port 310 for inversion, thereby providing an AC working voltage for the AC load 330.

[0057] In another embodiment of the present application, the photovoltaic power supply port is connected to the DC bus 220 through a first boost module. The first boost module includes a first switch module Q1, a first boost inductor PV1-L, a first charging capacitor C5, and a first freewheeling diode D1. One end of the first boost inductor PV1-L is connected to the positive pole of the photovoltaic power supply port, and the other end of the first boost inductor PV1-L is connected to the positive pole of the DC bus 220 through the first freewheeling diode D1. The other end of the first boost inductor PV1-L is also connected to the negative pole of the DC bus 220 through the first switch module Q1. The two ends of the first charging capacitor C5 are respectively connected to the positive and negative poles of the DC bus 220. The first boost module further includes a third switch module Q2, a third boost inductor PV2-L, a third charging capacitor C6, and a third freewheeling diode D2. One end of the third boost inductor PV2-L is connected to the positive pole of the photovoltaic power supply port, and the other end of the third boost inductor PV2-L is connected to the positive pole of the DC bus 220 through the third freewheeling diode D2. The other end of the third boost inductor PV2-L is also connected to the negative pole of the DC bus 220 through the third switch module Q2. The two ends of the third charging capacitor C6 are respectively connected to the positive and negative poles of the DC bus 220.

[0058] It can be understood that when both the first switch module Q1 and the third switch module Q2 are turned on, a part of the direct current output from the positive pole of the photovoltaic power supply port charges the first boost inductor PV1-L, forming a charging loop of photovoltaic power supply port - first boost inductor PV1-L - first switch module Q1 - negative pole of the DC bus 220. Since the other end of the first boost inductor PV1-L is connected to the positive pole of the DC bus 220 through the first freewheeling diode D1, and one end of the first charging capacitor C5 is connected to the positive pole of the DC bus 220, and the other end of the first charging capacitor C5 and the negative pole of the DC bus 220, when the first switch module Q1 is turned off, the direction of the direct current flow is first boost inductor PV1-L - first freewheeling diode D1 - first charging capacitor C5 - negative pole of the DC bus 220, forming a first energy storage loop to realize the energy storage of the first charging capacitor C5, and using the voltage across the first charging capacitor C5 to provide a stable bus voltage for the DC bus 220, so that the air conditioner 300 can draw power from the DC bus 220 through the DC power taking port 310 for inversion, thereby providing an AC working voltage for the AC load 330. At the same time, another part of the direct current output from the positive pole of the photovoltaic power supply port charges the third boost inductor PV2-L, forming a charging loop of photovoltaic power supply port - third boost inductor PV2-L - third switch module Q2 - negative pole of the DC bus 220. Since the other end of the third boost inductor PV2-L is connected to the positive pole of the DC bus 220 through the third freewheeling diode D2, and one end of the third charging capacitor C6 is connected to the positive pole of the DC bus 220, and the other end of the third charging capacitor C6 and the negative pole of the DC bus 220, when the third switch module Q2 is turned off, the direction of the direct current flow is third boost inductor PV2-L - third freewheeling diode D2 - third charging capacitor C6 - negative pole of the DC bus 220, forming a second energy storage loop to realize the energy storage of the third charging capacitor C6, and using the voltage across the third charging capacitor C6 to provide a stable bus voltage for the DC bus 220, so that the air conditioner 300 can draw power from the DC bus 220 through the DC power taking port 310 for inversion, thereby providing an AC working voltage for the AC load 330.

[0059] In the embodiment of the present application, when both the first switch module Q1 and the third switch module Q2 are turned off, the first boost module can provide a stable bus voltage for the DC bus 220 simultaneously through the voltage across the first charging capacitor C5 and the voltage across the third charging capacitor C6. Compared with providing a stable bus voltage for the DC bus 220 only through the voltage across the first charging capacitor C5, the bus voltage provided for the DC bus 220 simultaneously through the voltage across the first charging capacitor C5 and the voltage across the third charging capacitor C6 is higher, which can ensure that when both the first switch module Q1 and the third switch module Q2 are turned off, the first boost module can still have enough voltage to supply to the DC bus 220. The air conditioner 300 draws power from the DC bus 220 through the DC power taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330.

[0060] In some embodiments of the present application, the energy storage unit power supply port is connected to the DC bus 220 through a second boost module. Wherein, the second boost module includes a second switch module Q4, a second boost inductor L1, a second charging capacitor C3, and a second freewheeling diode Q3. One end of the second boost inductor L1 is connected to the positive pole of the energy storage unit power supply port, the other end of the second boost inductor L1 is connected to the positive pole of the DC bus 220 through the second freewheeling diode Q3, the other end of the second boost inductor L1 is also connected to the negative pole of the DC bus 220 through the second switch module Q4, and both ends of the second charging capacitor C3 are respectively connected to the positive and negative poles of the DC bus 220.

[0061] One end of the second boost inductor L1 is connected to the positive pole of the energy storage unit power supply port, and the other end of the second boost inductor L1 is also connected to the negative pole of the DC bus 220 through the second switch module Q4. When the second switch module Q4 is turned on, the direct current output from the positive pole of the photovoltaic power supply port charges the second boost inductor L1, forming a charging loop of the energy storage unit power supply port - the second boost inductor L1 - the second switch module Q4 - the negative pole of the DC bus 220. Since the other end of the second boost inductor L1 is connected to the positive pole of the DC bus 220 through the second freewheeling diode Q3, and one end of the second charging capacitor C3 is connected to the positive pole of the DC bus 220, and the other end of the second charging capacitor C3 and the negative pole of the DC bus 220, when the second switch module Q4 is turned off, the flowing direction of the direct current is the second boost inductor L1 - the second freewheeling diode Q3 - the second charging capacitor C3 - the negative pole of the DC bus 220, forming a third energy storage loop to realize the energy storage of the second charging capacitor C3, and using the voltage across the second charging capacitor C3 to provide a stable bus voltage for the DC bus 220, so that the air conditioner 300 draws power from the DC bus 220 through the DC power taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330.

[0062] In another embodiment of the present application, the second boost module further includes a battery module BAT, which is used to charge the second boost inductor L1 so that when the second switch module Q4 is turned off, the second boost inductor L1 has enough power to charge the second charging capacitor C3, thereby realizing the charging of the second charging capacitor C3. The voltage across the second charging capacitor C3 is used to provide a stable bus voltage for the DC bus 220, so that the air conditioner 300 draws power from the DC bus 220 through the DC power taking port 310 for inversion, and then provides an AC operating voltage for the AC load 330.

[0063] In some embodiments of the present application, the voltage conversion circuit 200 further includes a bidirectional conversion circuit. The AC side of the bidirectional conversion circuit is connected to the power grid, and the DC side of the bidirectional conversion circuit is connected to the DC bus 220.

[0064] By setting that the voltage conversion circuit 200 further includes a bidirectional conversion circuit, the bidirectional conversion circuit is used to convert direct current into alternating current and / or convert alternating current into direct current. The AC side of the bidirectional conversion circuit is connected to the power grid, and the DC side of the bidirectional conversion circuit is connected to the DC bus 220. Since the DC side of the bidirectional conversion circuit is connected to the DC bus 220, when the weather condition is sufficient sunlight, the air conditioner 300 draws a part of the power from the DC bus 220 through the DC power taking port 310 for inversion to provide an AC operating voltage for the AC load 330. In addition, the bidirectional conversion circuit obtains direct current from the DC bus 220, then converts the direct current into alternating current and outputs it to the power grid through the AC side of the bidirectional conversion circuit. When the weather condition is insufficient sunlight and the power of the energy storage unit is insufficient, the bidirectional conversion circuit obtains alternating current from the power grid through the AC side, converts the alternating current into direct current, and outputs a stable bus voltage to the DC bus 220 through the DC side of the bidirectional conversion circuit. The air conditioner 300 draws power from the DC bus 220 through the DC power taking port 310 for inversion to provide an AC operating voltage for the AC load 330.

[0065] In some embodiments of the present application, the bidirectional conversion circuit includes an H-bridge circuit. The DC port of the H-bridge circuit is connected to the DC bus 220, and the AC port of the H-bridge circuit is connected to the power grid through a common-mode inductor.

[0066] The H-bridge circuit includes four switching tubes and a first capacitor C18. The four switching tubes are respectively a first switching tube Q5, a second switching tube Q6, a third switching tube Q7, and a fourth switching tube Q8. It can be understood that the H-bridge circuit controls the switching of the first switching tube Q5, the second switching tube Q6, the third switching tube Q7, and the fourth switching tube Q8 through pulse width modulation (PWM) drive. When the weather condition is sufficient sunlight, the air conditioner 300 takes a part of the power from the DC bus 220 through the DC power extraction port 310 for inversion to provide an AC working voltage to the AC load 330. In addition, the bidirectional conversion circuit obtains DC power from the DC bus 220, and pulse width modulation (PWM) drive controls the first switching tube Q5 and the fourth switching tube Q8 of the H-bridge circuit to turn on, and the second switching tube Q6 and the third switching tube Q7 to turn off. The H-bridge circuit inverses the DC power into AC power. Since the AC port of the H-bridge circuit is connected to the power grid through a common mode inductor, the AC power is output to the power grid through the AC port of the H-bridge circuit. When the weather condition is insufficient sunlight and the power of the energy storage unit is insufficient, the bidirectional conversion circuit obtains the AC power of the power grid through the AC port, and pulse width modulation (PWM) drive controls the first switching tube Q5 and the fourth switching tube Q8 of the H-bridge circuit to turn off, and the second switching tube Q6 and the third switching tube Q7 to turn on. The H-bridge circuit converts the AC power into DC power. Since the DC port of the H-bridge circuit is connected to the DC bus 220, the DC power is output to the DC bus 220 through the DC port of the H-bridge circuit to provide a stable voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power extraction port 310 for inversion to provide an AC working voltage to the AC load 330.

[0067] It should be noted that in some embodiments of the present application, the type of the switching tube can be a bipolar power transistor, and the type of the switching tube can also be a field effect transistor. In special high-voltage occasions, the type of the switching tube is an insulated gate bipolar transistor. Those skilled in the art can select the type of the switching tube according to the actual situation, and the embodiments of the present application do not limit the type of the switching tube.

[0068] It should be noted that the common mode inductor includes a first common mode inductor L00 and a second common mode inductor L11. It can be understood that when the electrical signal is transmitted through the circuit in the transmission lines between the power grid and the DC bus, signal interference will be generated, affecting the accuracy and stability of the electrical signal. By setting the AC port of the H-bridge circuit to be connected to the power grid through the first common mode inductor L00 and the second common mode inductor L11, the common mode noise in the circuit can be suppressed, electromagnetic interference can be reduced, so as to be able to cancel or reduce the influence of the signal and improve the quality and reliability of the signal.

[0069] The embodiments of the present application will be further explained below through a general embodiment.

[0070] Refer to Figures 1 to 5, the air conditioning system based on the photovoltaic and energy storage system 100 includes the photovoltaic and energy storage system 100, and the photovoltaic and energy storage system 100 includes a DC power supply port 110; the voltage conversion circuit 200 includes a DC boost module 210 and a DC bus 220, and the DC power supply port 110 is connected to the DC bus 220 through the DC boost module 210; the air conditioner 300 includes an AC load 330, a DC power extraction port 310 and an inverter 320, the AC side of the inverter 320 is connected to the AC load 330, and the DC side of the inverter 320 is connected to the DC bus 220 through the DC power extraction port 310. In the embodiment of the present application, the DC power characteristic of the photovoltaic and energy storage system 100 is utilized to reduce the link of AC-DC conversion, directly realize the inversion of DC to AC, thereby reducing the loss in the voltage conversion process, and further achieving the purpose of energy saving. The photovoltaic and energy storage system 100 supplies power to the DC bus 220 through the DC boost module 210 for boosting, and the air conditioner 300 extracts power from the DC bus 220 through the DC power extraction port 310 for inversion, so as to provide an AC working voltage to the AC load 330. It can be seen that the air conditioner 300 in the embodiment of the present application directly performs inversion based on DC power. Compared with the traditional method of obtaining power from the power grid or from the inverter 320 of the photovoltaic and energy storage system 100, it does not require an AC-DC-AC voltage conversion process, only requires DC-AC, reduces the loss in the voltage conversion process, improves the energy saving effect, and the air conditioner 300 does not need to be provided with EMC devices, rectifier circuits, power factor correction circuits, etc., which can greatly reduce the cost of the air conditioner 300.

[0071] In the embodiments of the present application, three power supply schemes for the air-conditioning system based on the optical storage system 100 are provided. The optical storage system 100 includes a photovoltaic system and an energy storage unit. The photovoltaic system is used to convert solar energy into electrical energy, and the energy storage unit is used to store the generated electrical energy. When the light is sufficient, the optical storage system 100 has sufficient power generation. The direct current output by the optical storage system 100 is boosted by the first boost module and a stable bus voltage is output. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330. When the light is insufficient and the energy storage unit has enough power, the energy storage unit discharges. When the energy storage unit is a low-voltage battery pack, the second boost module is a multi-stage DC circuit. The direct current output by the low-voltage battery pack is output to the DC bus 220 after being boosted by the multi-stage DC conversion circuit, and the second voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330. When the energy storage unit is a high-voltage battery pack, the second boost module is a single-stage DC circuit. Therefore, the direct current output by the high-voltage battery pack is output to the DC bus 220 after being boosted by the single-stage DC conversion circuit, and the second voltage is used to provide a stable bus voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330. When the light is insufficient and the energy storage unit has insufficient power, power is taken from the power grid. The alternating current of the power grid passes through the H-bridge circuit. The H-bridge circuit converts the alternating current into direct current and delivers the direct current to the DC bus 220 to provide a stable bus voltage for the DC bus 220. The air conditioner 300 takes power from the DC bus 220 through the DC power-taking port 310 for inversion, so as to provide an AC working voltage for the AC load 330. The above three power supply schemes in the embodiments of the present application cooperate with each other to provide a stable bus voltage for the DC bus 220, and at the same time improve the diversity of the power supply methods of the air-conditioning system based on the optical storage system 100, so that the air conditioner 300 can directly obtain direct current from the DC bus 220 for inversion under various different weather conditions, so as to provide an AC working voltage for the AC load 330, thereby ensuring the normal operation of the air conditioner 300.

[0072] It should be understood that in this application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (one) of the following" or its similar expression refers to any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b, or c may mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0073] In several embodiments provided by this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of devices or units can be in electrical, mechanical, or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] It should also be understood that the various embodiments provided in the embodiments of this application can be combined arbitrarily to achieve different technical effects.

[0075] The above has specifically described the preferred embodiments of this application, but this application is not limited to the above embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of this application, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An air conditioning system based on a photovoltaic energy storage system, characterized in that, Comprising: A photovoltaic and energy storage system, including a DC power supply port; A voltage conversion circuit, including a DC boost module and a DC bus, and the DC power supply port is connected to the DC bus through the DC boost module; An air conditioner, including an AC load, a DC power extraction port, and an inverter, the AC side of the inverter is connected to the AC load, and the DC side of the inverter is connected to the DC bus through the DC power extraction port.

2. The air conditioning system according to claim 1, wherein, The air conditioner includes an outdoor unit, the outdoor unit is provided with an outdoor unit main board, the power extraction port of the outdoor unit main board is connected to one side of the DC power extraction port, and the other side of the DC power extraction port serves as the external power interface of the outdoor unit.

3. The air conditioning system according to claim 1, characterized in that, The photovoltaic and energy storage system includes a photovoltaic system and an energy storage unit, the DC power supply port includes a photovoltaic power supply port and an energy storage unit power supply port, the DC boost module includes a first boost module and a second boost module, the photovoltaic power supply port is connected to the DC bus through the first boost module, and the energy storage unit power supply port is connected to the DC bus through the second boost module.

4. The air conditioning system according to claim 3, characterized in that, The energy storage unit includes a low-voltage battery pack, the second boost module includes a multi-stage DC conversion circuit, and the low-voltage battery pack is connected to the DC bus through the multi-stage DC conversion circuit; And / or, the energy storage unit includes a high-voltage battery pack, the second boost module includes a single-stage DC conversion circuit, and the high-voltage battery pack is connected to the DC bus through the single-stage DC conversion circuit.

5. The air conditioning system according to claim 3, wherein, The first boost module includes a first switch module, a first boost inductor, a first charging capacitor, and a first freewheeling diode. One end of the first boost inductor is connected to the positive pole of the photovoltaic power supply port, the other end of the first boost inductor is connected to the positive pole of the DC bus through the first freewheeling diode, the other end of the first boost inductor is also connected to the negative pole of the DC bus through the first switch module, and both ends of the first charging capacitor are respectively connected to the positive and negative poles of the DC bus.

6. The air conditioning system according to claim 3, wherein, The second boost module includes a second switch module, a second boost inductor, a second charging capacitor, and a second freewheeling diode. One end of the second boost inductor is connected to the positive pole of the energy storage unit power supply port, the other end of the second boost inductor is connected to the positive pole of the DC bus through the second freewheeling diode, the other end of the second boost inductor is also connected to the negative pole of the DC bus through the second switch module, and both ends of the second charging capacitor are respectively connected to the positive and negative poles of the DC bus.

7. The air-conditioning system according to claim 1, wherein The voltage conversion circuit further includes a bidirectional conversion circuit, the AC side of the bidirectional conversion circuit is connected to the power grid, and the DC side of the bidirectional conversion circuit is connected to the DC bus.

8. The air conditioning system according to claim 7, characterized in that, The bidirectional conversion circuit includes an H-bridge circuit, the DC port of the H-bridge circuit is connected to the DC bus, and the AC port of the H-bridge circuit is connected to the power grid through a common-mode inductor.

9. The air conditioning system according to claim 3, wherein The photovoltaic system includes a plurality of photovoltaic strings, the photovoltaic strings have one or more of the photovoltaic power supply ports, and different photovoltaic power supply ports are correspondingly connected to the first boost modules applicable to different voltages.

10. The air conditioning system according to claim 1, wherein, The AC load includes a variable frequency compressor and an AC fan.

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