Photovoltaic power supply circuit, control method, electrical equipment and electric energy dispatching method

Abstract

The present invention discloses a photovoltaic power supply circuit, a control method, an electrical device and an electric energy dispatching method. The photovoltaic power supply circuit includes: a photovoltaic power generation device, a DC / DC converter, and a DC / AC converter connected in sequence, wherein the DC / DC converter and the DC / AC converter are connected via a DC bus, and a first energy storage device is connected to the DC bus. The second energy storage device is also included, wherein the input end of the second energy storage device is connected to the DC bus, and the output end of the second energy storage device is connected to the DC / DC converter, and is used to drive the DC / DC converter to operate when the first energy storage device is in an over-discharge state, so that the photovoltaic power generation device generates electricity through the DC / DC converter. Through the present invention, the photovoltaic power supply circuit can be restarted when the first energy storage device is over-discharged, thereby ensuring the power supply stability of the photovoltaic power supply circuit.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, and in particular to a photovoltaic power supply circuit, a control method, an electrical device and an electric energy dispatching method. Background Art

[0002] Figure 1 The structure diagram of the existing photovoltaic power supply circuit is as follows: Figure 1 As shown, the existing photovoltaic power supply circuit is generally composed of a photovoltaic power generation device 1, a first energy storage device 2, a DC / DC converter 3 and a DC / AC converter 4. During the day, the photovoltaic power generation device charges the energy storage device through the DC / DC converter, and at the same time provides electricity to the DC load, and also converts it into AC power through the DC / AC converter for AC load use. If the photovoltaic power generation is insufficient, and the energy storage device is undercharged or consumes too much electricity, it will cause the energy storage device to over-discharge. At this time, the DC / DC converter cannot obtain electricity, resulting in the photovoltaic power generation device being unable to generate electricity, causing the entire system to be paralyzed and unable to restart.

[0003] With regard to the problem in the prior art that when the energy storage device is over-discharged, the photovoltaic power generation device cannot generate electricity through the DC / DC converter, resulting in the photovoltaic power supply circuit being unable to restart, no effective solution has been proposed yet. Summary of the invention

[0004] A photovoltaic power supply circuit, a control method, an electrical device and an electric energy dispatching method are provided in the embodiments of the present invention to solve the problem in the prior art that when an energy storage device is over-discharged, a photovoltaic power generation device cannot generate electricity through a DC / DC converter, resulting in the photovoltaic power supply circuit being unable to restart.

[0005] In order to solve the above technical problems, the present invention provides a photovoltaic power supply circuit, wherein the photovoltaic power supply circuit comprises: a photovoltaic power generation device, a DC / DC converter, and a DC / AC converter connected in sequence, wherein the DC / DC converter and the DC / AC converter are connected via a DC bus, and a first energy storage device is connected to the DC bus, and further comprises:

[0006] A second energy storage device, whose input end is connected to the DC bus and whose output end is connected to the DC / DC converter, is used to drive the DC / DC converter to operate when the first energy storage device is in an over-discharge state, so that the photovoltaic power generation device generates electricity through the DC / DC converter.

[0007] Furthermore, the photovoltaic power supply circuit further includes:

[0008] A first switching power supply, having a first end connected to the DC bus, a second end connected to the second energy storage device, and a third end connected to the DC / DC converter, is used to control the operation of the DC / DC converter.

[0009] Furthermore, the photovoltaic power supply circuit further includes:

[0010] The first switch is arranged between the second energy storage device and the first switching power supply, and is used to control the connection and disconnection between the second switching power supply and the second energy storage device.

[0011] Furthermore, the first switch is a normally closed switch, a control end of which is connected to the first energy storage device, and is configured to be closed when the first energy storage device is in an over-discharge state, and opened when the first energy storage device is not in an over-discharge state.

[0012] Furthermore, the photovoltaic power supply circuit further includes:

[0013] A photosensitive switch is arranged between the second energy storage device and the first switch, and is used for closing when the natural light intensity is greater than a preset value, and opening when the natural light intensity is less than the preset value.

[0014] Furthermore, the photovoltaic power supply circuit further includes:

[0015] The second switch is arranged between the second energy storage device and the DC bus, and is used to control the connection between the second energy storage device and the DC bus.

[0016] Furthermore, the photovoltaic power supply circuit further includes:

[0017] A second switching power supply, a first end of which is connected to the DC bus, and a second end of which is connected to the DC / AC converter, is used to control the operation of the DC / AC converter.

[0018] The present invention also provides an electrical device, including a load, wherein the load includes a DC load and an AC load, and is characterized in that it also includes the above-mentioned photovoltaic power supply circuit, wherein the DC load is connected to the DC bus of the photovoltaic power supply circuit, and the AC load is connected to the DC / AC converter in the photovoltaic power supply circuit.

[0019] The present invention also provides a control method, which is applied to the above photovoltaic power supply circuit, and the method comprises:

[0020] Monitoring the discharge state of a first energy storage device; wherein the first energy storage device is connected to a DC bus between a DC / DC converter and a DC / AC converter;

[0021] When the first energy storage device is in an over-discharge state, controlling the second energy storage device to drive the DC / DC converter to operate, so that the photovoltaic power generation device in the photovoltaic power supply circuit generates electricity through the DC / DC converter;

[0022] The input end of the second energy storage device is connected to the DC bus, and the output end thereof is connected to the DC / DC converter.

[0023] Further, controlling the second energy storage device to drive the DC / DC converter to operate includes:

[0024] Controlling the first switch to close, so that the first switch power supply is powered, thereby controlling the operation of the DC / DC converter;

[0025] The first switch is arranged between the second energy storage device and the first switching power supply, the first switching power supply has a first end connected to the DC bus, a second end connected to the second energy storage device, and a third end connected to the DC / DC converter.

[0026] Furthermore, after controlling the first switch to close so that the first switch power supply is powered and then controlling the operation of the DC / DC converter, the method further includes:

[0027] Determining whether the power generation voltage of the photovoltaic power generation device meets the power demand of the load and the first switching power supply;

[0028] If yes, the first switch is controlled to be turned off.

[0029] Further, after controlling the first switch to be disconnected, the method further includes:

[0030] Determining whether the remaining electric energy of the second energy storage device is lower than a first threshold;

[0031] If yes, the DC bus is controlled to charge the second energy storage device.

[0032] The present invention also provides an electric energy dispatching method, which is applied to the above-mentioned electrical equipment, and the electric energy dispatching method comprises:

[0033] Determining the operation priority of the loads in the electrical equipment;

[0034] When the power of the first energy storage device is lower than a second threshold, the first energy storage device is controlled to preferentially supply power to a load with a higher operating priority.

[0035] The present invention also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the above-mentioned control method and / or the above-mentioned electric energy scheduling method are implemented.

[0036] By applying the technical solution of the present invention, a second energy storage device is provided. When the first energy storage device is over-discharged and the entire photovoltaic power supply circuit cannot be restarted, the DC / DC converter is driven to operate by the second energy storage device, so that the photovoltaic power generation device generates electricity through the DC / DC converter, thereby realizing the restart of the photovoltaic power supply circuit in the case of over-discharge of the first energy storage device, and ensuring the power supply stability of the photovoltaic power supply circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural diagram of an existing photovoltaic power supply circuit;

[0038] Figure 2 is a structural diagram of a photovoltaic power supply circuit according to an embodiment of the present invention;

[0039] Figure 3 is a structural diagram of a photovoltaic power supply circuit according to another embodiment of the present invention;

[0040] Figure 4 is a structural diagram of an electrical device according to an embodiment of the present invention;

[0041] Figure 5 is a flow chart of a control method according to an embodiment of the present invention;

[0042] Figure 6 Flow chart of a power dispatching method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0045] It should be understood that the term "and / or" used in this article is only a description of the association relationship of 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.

[0046] It should be understood that although the terms first, second, third, etc. may be used to describe switches in the embodiments of the present invention, the switches should not be limited to these terms. These terms are only used to distinguish switches arranged at different positions. For example, without departing from the scope of the embodiments of the present invention, the first switch may also be referred to as the second switch, and similarly, the second switch may also be referred to as the first switch.

[0047] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0048] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity 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 commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0049] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] As mentioned above Figure 1 As shown in , the existing photovoltaic power supply circuit is generally composed of a photovoltaic power generation device 1, a first energy storage device 2, a DC / DC converter 3 and a DC / AC converter 4. During the day, the photovoltaic power generation device 1 charges the energy storage device through the DC / DC converter 3, and at the same time provides electricity to the DC load, and is also converted into AC power through the DC / AC converter 4 for use by the AC load. If the photovoltaic power generation is insufficient, and the energy storage device is undercharged or consumes too much electricity, the energy storage device will be over-discharged. Over-discharge means that the energy storage device continues to discharge after being normally discharged to the cut-off voltage. At this time, the DC / DC converter 3 cannot obtain electricity, resulting in the photovoltaic power generation device 1 being unable to generate electricity, causing the entire system to be paralyzed and unable to restart.

[0052] In view of the above situation, this embodiment provides a photovoltaic power supply circuit. Figure 2 is a structural diagram of a photovoltaic power supply circuit according to an embodiment of the present invention, such as Figure 2 As shown, the photovoltaic power supply circuit includes:

[0053] The photovoltaic power generation device 1, the DC / DC converter 3, and the DC / AC converter 4 are connected in sequence, the DC / DC converter 3 and the DC / AC converter 4 are connected through a DC bus 5, and the first energy storage device 2 is connected to the DC bus 5. The photovoltaic power supply circuit includes: a second energy storage device 6, whose input end is connected to the DC bus 5 and whose output end is connected to the DC / DC converter 3, and is used to supply power to the DC / DC converter 3 when the first energy storage device 2 is over-discharged, so that the photovoltaic power generation device 1 generates electricity through the DC / DC converter 3. Among them, the first end of the second energy storage device 6 includes a first terminal a and a second terminal b, the first terminal a is connected to the first line 51 of the DC bus 5, and the second terminal b is connected to the second line 52 of the DC bus 5. The output end of the second energy storage device 6 is respectively connected to the two wiring terminals of the DC / DC converter 3 through the third terminal c and the fourth terminal d. The capacity of the second energy storage device 6 can be set to meet the operation of the DC / DC converter 3 and last for a preset time.

[0054] The photovoltaic power supply circuit of this embodiment is provided with a second energy storage device 6. When the first energy storage device 2 is over-discharged and the entire photovoltaic power supply circuit cannot be restarted, the DC / DC converter 3 is driven by the second energy storage device 6 to operate, so that the photovoltaic power generation device 1 generates electricity through the DC / DC converter 3, thereby realizing the restart of the photovoltaic power supply circuit in the case of over-discharge of the first energy storage device, and ensuring the power supply stability of the photovoltaic power supply circuit.

[0055] Example 2

[0056] This embodiment provides another photovoltaic power supply circuit. Figure 3 is a structural diagram of a photovoltaic power supply circuit according to another embodiment of the present invention. Figure 3 As shown, in order to drive the DC / DC converter 3 to operate, the photovoltaic power supply circuit further includes: a first switching power supply 7, a first end of which is connected to the DC bus 5, a second end of which is connected to the second energy storage device 6, and a third end of which is connected to the DC / DC converter 3, for controlling the operation of the DC / DC converter 3. In a specific implementation, the first switching power supply 7 is powered by the second energy storage device 6, so that the first switching power supply 7 emits a PWM wave, controls the switch tube in the DC / DC converter 3 to repeatedly switch on and off, and realizes the conversion of the DC voltage or current into a high-frequency square wave voltage or current, and then converts it into a DC voltage output through rectification and smoothing.

[0057] In order to flexibly control the power on or off of the first switching power supply 7, the above-mentioned photovoltaic power supply circuit also includes: a first switch S1, which is arranged between the second energy storage device 6 and the first switching power supply 7, and is used to control the power on and off between the first switching power supply 7 and the second energy storage device 6.

[0058] In order to ensure that the first switch S1 is automatically closed when the first energy storage device 2 is in an over-discharge state, in this embodiment, the first switch S1 is a normally closed switch, and its control end is connected to the first energy storage device 2, and is used to close when the first energy storage device 2 is in an over-discharge state, and to open when the first energy storage device 2 is not in an over-discharge state. That is, when there is residual power in the first energy storage device 2, the first switch S1 is opened, and when the power of the first energy storage device 2 is exhausted, the first switch S1 is automatically closed, so that the second energy storage device 6 supplies power to the DC / DC converter 3, thereby controlling the entire photovoltaic power supply circuit to restart.

[0059] Since the photovoltaic power generation device 1 generates electricity only when the light intensity is greater than a certain threshold value, and cannot generate electricity when the light intensity is lower than the threshold value, if the light intensity is lower than the above threshold value, even if the DC / DC converter 3 is controlled to operate, the photovoltaic power generation device 1 cannot complete power generation. In order to avoid unnecessary opening of the DC / DC converter 3 and waste of electric energy, the above photovoltaic power supply circuit also includes: a photosensitive switch 8, which is arranged between the second energy storage device 6 and the first switch S1, and is used to close when the natural light intensity is greater than a preset value to control the DC / DC converter 3 to be powered on, and disconnect when the natural light intensity is less than the preset value to control the DC / DC converter 3 to be powered off.

[0060] Since the function of the second energy storage device 6 is to store electrical energy so as to power the DC / DC converter 3 and restart the photovoltaic power supply circuit when over-discharge occurs in the first energy storage device 2, it is necessary to ensure that the second energy storage device 6 has sufficient power under normal circumstances. Therefore, the above-mentioned photovoltaic power supply circuit also includes: a second switch S2, which is arranged between the second energy storage device 6 and the DC bus 5, and is used to control the on and off between the second energy storage device 6 and the DC bus 5, and then control whether the DC bus 5 charges the second energy storage device 6.

[0061] In order to drive the DC / AC converter 4 to operate, the photovoltaic power supply circuit further includes: a second switching power supply 9, a first end of which is connected to the DC bus 5, and a second end of which is connected to the DC / AC converter 4, for controlling the operation of the DC / AC converter 4. In a specific implementation, the second switching power supply 9 is powered by the DC bus 5, so that the second switching power supply 9 emits a PWM wave, controls the switch tube in the DC / AC converter 4 to repeatedly switch on and off, and realizes the conversion of DC power into AC power for output.

[0062] In order to control whether the DC bus 5 charges the first energy storage device 2, as shown in FIG. Figure 3 As shown, the photovoltaic power supply circuit further includes: a third switch S3, which is arranged between the first energy storage device 2 and the DC bus 5. In order to control the on-off between the photovoltaic power generation device 1 and the DC / DC converter 3, as shown in FIG. Figure 3 As shown, the photovoltaic power supply circuit further includes: a fourth switch S4 , which is arranged between the photovoltaic power generation device 1 and the DC / DC converter 3 .

[0063] Figure 3 The first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are all controllable switches, of which the second switch S2 is a normally open switch, the first switch S1, the third switch S3, and the fourth switch S4 are normally closed switches, the third switch S3 is disconnected only after the first energy storage device 2 reports a fault, the first switch S1 is closed when the first energy storage device 2 is over-discharged, the second switch S2 is closed only when the second energy storage device 6 needs to be charged, and the fourth switch S4 is disconnected when the photovoltaic power generation device 1 does not generate electricity. The photosensitive switch 8 is closed when the light intensity exceeds the first threshold value (daytime) and disconnected when the light intensity is lower than the first threshold value (nighttime). The second energy storage device 6 can select a more expensive energy storage battery that can store for a long time, and the required capacity does not need to be too large, and only needs to provide the power required for the switching power supply during the period of photovoltaic startup.

[0064] When the photovoltaic power generation device 1 starts to generate electricity during the day, the photosensitive switch 8 is closed, and the first switch S1 is powered by the first energy storage device 2. If the first energy storage device 2 has sufficient power, the first switch S1 remains in an open state. If the first energy storage device 2 has insufficient power, the first switch S1 cannot remain in an open state and is then closed. The first switch power supply 7 is powered by the second energy storage device 6, and the DC / DC converter 3 is started. At the same time, the fourth switch S4 is closed, and the photovoltaic power generation device 1 starts to be powered by the DC / DC converter 3. The first energy storage device 2 and the second energy storage device 6 are both batteries. Whether charging is required is determined based on the battery power level. If the first energy storage device 2 needs to be charged, the third switch S3 is closed, and if the second energy storage device 6 needs to be charged, the second switch S2 is closed. During the day, there is sufficient light intensity to meet the consumption of the load and the first switching power supply 7. The energy storage does not need to be charged and no power generation is performed. The photosensitive switch 8 is closed. According to the power generation voltage of the photovoltaic power generation device 1, if the photovoltaic power generation voltage meets the needs of the load and the first switching power supply 7, the first switch S1 is controlled to be disconnected; or during the night period, the photosensitive switch 8 is disconnected, and the second energy storage device 6 is disconnected from the DC / DC converter 3, and no longer supplies power to it.

[0065] Example 3

[0066] This embodiment provides an electrical device, Figure 4 is a structural diagram of an electrical device according to an embodiment of the present invention, such as Figure 4As shown, the electrical equipment includes a load, the load includes a DC load 10 and an AC load 11, and also includes the photovoltaic power supply circuit in the above embodiment, wherein the DC load 10 is connected to the DC bus 5 of the photovoltaic power supply circuit through the fifth switch S5, and the AC load 11 is connected to the DC / AC converter 4 in the photovoltaic power supply circuit through the sixth switch S6. Electric energy is dispatched according to the priority level of load operation, and specifically, the fifth switch S5 and the sixth switch S6 can be controlled to be opened or kept closed according to the energy storage capacity and the operation priority level of the load, so as to extend the use time of the load with a high operation priority level.

[0067] Example 4

[0068] This embodiment provides a control method, which is applied to the photovoltaic power supply circuit in the above embodiment. Figure 5 is a flow chart of a control method according to an embodiment of the present invention, as shown in Figure 5 As shown, the above control method includes:

[0069] S101, monitoring the discharge state of a first energy storage device; wherein the first energy storage device is connected to a DC bus between a DC / DC converter and a DC / AC converter.

[0070] S102, when the first energy storage device is in an over-discharge state, controlling the second energy storage device to drive the DC / DC converter to operate, so that the photovoltaic power generation device in the photovoltaic power supply circuit generates electricity through the DC / DC converter; wherein the input end of the second energy storage device is connected to the DC bus, and the output end thereof is connected to the DC / DC converter.

[0071] The control method of this embodiment determines whether the first energy storage device is over-discharged. When the first energy storage device is over-discharged and the entire photovoltaic power supply circuit cannot be restarted, the second energy storage device is used to drive the DC / DC converter to operate, so that the photovoltaic power generation device generates electricity through the DC / DC converter, thereby realizing the restart of the photovoltaic power supply circuit and ensuring the power supply stability of the photovoltaic power supply circuit.

[0072] Example 5

[0073] This embodiment provides another control method. In this embodiment, controlling the second energy storage device to drive the DC / DC converter to operate includes: controlling the first switch to close so that the first switching power supply is powered, thereby controlling the operation of the DC / DC converter; wherein the first switch is arranged between the second energy storage device and the first switching power supply, the first end of the first switching power supply is connected to the DC bus, the second end is connected to the second energy storage device, and the third end is connected to the DC / DC converter.

[0074] In specific implementation, in order to ensure that the first switch is automatically closed when the first energy storage device is in an over-discharge state, in this embodiment, the first switch is a normally closed switch, and its control end is connected to the first energy storage device, which is used to close when the first energy storage device is in an over-discharge state and disconnect when the first energy storage device is not in an over-discharge state. That is, when there is residual power in the first energy storage device, the first switch is disconnected, and when the power of the first energy storage device is exhausted, the first switch is automatically closed, so that the second energy storage device drives the DC / DC converter to operate, thereby controlling the entire photovoltaic power supply circuit to restart.

[0075] Since the second energy storage device is only a temporary power supply, it is used to control the photovoltaic power supply circuit to restart when the first energy storage device is in an over-discharge state. The second energy storage device cannot be used to power the DC / DC converter for a long time. After the photovoltaic power generation device resumes normal and stable operation, the DC / DC converter can be powered through the DC bus. Therefore, after controlling the first switch to close, so that the first switch power supply is powered, and then controlling the operation of the DC / DC converter, the above control method also includes: judging whether the power generation voltage of the photovoltaic power generation device meets the power demand of the load and the first switch power supply; if so, controlling the first switch to disconnect. After controlling the first switch to disconnect, since the power of the second energy storage device is consumed, it may not be able to meet the demand for the next restart, and it needs to be replenished in time. Therefore, the above control method also includes: judging whether the remaining power of the second energy storage device is lower than the first threshold; if so, controlling the DC bus to charge the second energy storage device. Specifically, the control is set to charge the second energy storage device.

[0076] Example 6

[0077] This embodiment provides an electric energy dispatching method, which is applied to the above-mentioned electrical equipment. Figure 6 is a flow chart of a power dispatching method according to an embodiment of the present invention. Figure 6 As shown, the above-mentioned electric energy scheduling method includes:

[0078] S201, determining the operation priority of the load in the electrical equipment.

[0079] S202: When the power of the first energy storage device is lower than a second threshold, control the first energy storage device to preferentially supply power to a load with a higher operating priority.

[0080] Specifically, in the above-mentioned electrical equipment, the DC load is connected to the DC bus of the photovoltaic power supply circuit through the fifth switch, and the AC load is connected to the DC / AC converter in the photovoltaic power supply circuit through the sixth switch. Electric energy scheduling is performed according to the priority level of load operation. Specifically, the fifth switch and the sixth switch can be controlled to be opened or kept closed according to the energy storage capacity and the load operation priority level to extend the use time of the load with a high operation priority level. For example, when the power of the first energy storage device is lower than the second threshold value, the AC load is determined to be a load with a higher operation level, and the sixth switch is controlled to remain closed and the fifth switch is controlled to be opened.

[0081] Example 7

[0082] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the control method and / or the electric energy scheduling method in the above-mentioned embodiment are implemented.

[0083] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic power supply circuit, characterized in that: The invention comprises a photovoltaic power generation device, a DC / DC converter, and a DC / AC converter connected in sequence, wherein the DC / DC converter and the DC / AC converter are connected via a DC bus, and a first energy storage device is connected to the DC bus, and further comprises: A second energy storage device, whose input end is connected to the DC bus and whose output end is connected to the DC / DC converter, is used to drive the DC / DC converter to operate when the first energy storage device is in an over-discharge state, so that the photovoltaic power generation device generates electricity through the DC / DC converter.

2. The photovoltaic power supply circuit according to claim 1, characterized in that: The photovoltaic power supply circuit also includes: A first switching power supply, having a first end connected to the DC bus, a second end connected to the second energy storage device, and a third end connected to the DC / DC converter, is used to control the operation of the DC / DC converter.

3. The photovoltaic power supply circuit according to claim 2, characterized in that: The photovoltaic power supply circuit also includes: The first switch is arranged between the second energy storage device and the first switching power supply, and is used to control the on-off between the first switching power supply and the second energy storage device.

4. The photovoltaic power supply circuit according to claim 3, characterized in that: The first switch is a normally closed switch, a control end of which is connected to the first energy storage device, and is used for closing when the first energy storage device is in an over-discharge state, and opening when the first energy storage device is not in the over-discharge state.

5. The photovoltaic power supply circuit according to claim 4, characterized in that: The photovoltaic power supply circuit also includes: A photosensitive switch is arranged between the second energy storage device and the first switch, and is used for closing when the natural light intensity is greater than a preset value, and opening when the natural light intensity is less than the preset value.

6. The photovoltaic power supply circuit according to claim 1, characterized in that: The photovoltaic power supply circuit also includes: The second switch is arranged between the second energy storage device and the DC bus, and is used to control the connection between the second energy storage device and the DC bus.

7. The photovoltaic power supply circuit according to claim 1, characterized in that: The photovoltaic power supply circuit also includes: A second switching power supply, a first end of which is connected to the DC bus, and a second end of which is connected to the DC / AC converter, is used to control the operation of the DC / AC converter.

8. An electrical device, comprising a load, wherein the load comprises a DC load and an AC load, characterized in that: It also includes the photovoltaic power supply circuit according to any one of claims 1 to 7, wherein the DC load is connected to a DC bus of the photovoltaic power supply circuit, and the AC load is connected to a DC / AC converter in the photovoltaic power supply circuit.

9. A control method, applied to the photovoltaic power supply circuit according to any one of claims 1 to 7, characterized in that: The method comprises: Monitoring the discharge state of a first energy storage device; wherein the first energy storage device is connected to a DC bus between a DC / DC converter and a DC / AC converter; When the first energy storage device is in an over-discharge state, controlling the second energy storage device to drive the DC / DC converter to operate, so that the photovoltaic power generation device in the photovoltaic power supply circuit generates electricity through the DC / DC converter; The input end of the second energy storage device is connected to the DC bus, and the output end thereof is connected to the DC / DC converter.

10. The control method according to claim 9, characterized in that: Controlling the second energy storage device to drive the DC / DC converter to operate includes: Controlling the first switch to close, so that the first switch power supply is powered, thereby controlling the operation of the DC / DC converter; The first switch is arranged between the second energy storage device and the first switching power supply, the first switching power supply has a first end connected to the DC bus, a second end connected to the second energy storage device, and a third end connected to the DC / DC converter.

11. The control method according to claim 10, characterized in that: After controlling the first switch to close so that the first switch power supply is powered, and then controlling the DC / DC converter to operate, the method further includes: Determining whether the power generation voltage of the photovoltaic power generation device meets the power demand of the load and the first switching power supply; If yes, the first switch is controlled to be turned off.

12. The control method according to claim 11, characterized in that: After controlling the first switch to be disconnected, the method further includes: Determining whether the remaining electric energy of the second energy storage device is lower than a first threshold; If yes, the DC bus is controlled to charge the second energy storage device.

13. An electric energy dispatching method, applied to the electrical equipment according to claim 8, characterized in that: The electric energy dispatching method comprises: Determining the operation priority of the loads in the electrical equipment; When the power of the first energy storage device is lower than a second threshold, the first energy storage device is controlled to preferentially supply power to a load with a higher operating priority.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the control method described in any one of claims 9 to 12 and / or the electric energy scheduling method described in claim 13 are implemented.

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