Power supply circuit microgrid energy system

Abstract

The utility model discloses a power supply circuit micro-grid energy system, a power supply circuit comprises a power grid, a first conversion unit, an energy storage module and a second conversion unit, the first conversion unit is connected with the power grid, the first conversion unit is used for converting electric energy provided by the power grid into direct current from alternating current, and the first conversion unit works in a constant power control mode; the energy storage module is coupled with the first conversion unit; one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the second conversion unit is connected with the load so as to convert and output the electric energy to the load. The circuit operation stability is improved, and the load change influence is reduced.

Description

Technical Field

[0001] This application relates to the technical field of power supply systems, and particularly to a power supply circuit microgrid energy system. Background Art

[0002] In practical applications, the capacity of the grid power supply at many construction sites is relatively small. To meet the demand of high-power loads, the general solution is to configure a diesel engine. The principle is to preferentially consume grid energy and supplement it with the diesel engine when the grid energy is insufficient. Although this can meet the power supply demand, however, in the case of sudden load changes, due to the slow response of the diesel engine, it may instantaneously absorb a large current from the grid, resulting in overload at the grid end. Moreover, the diesel engine also has problems such as high noise, high fuel consumption cost, and low cost performance. Utility Model Content

[0003] The embodiments of this application provide a power supply circuit microgrid energy system to improve the stability of circuit operation and reduce the influence of load changes.

[0004] In a first aspect, the embodiments of this application provide a power supply circuit, and the power supply circuit includes:

[0005] The grid;

[0006] A first conversion unit, the first conversion unit is connected to the grid, and the first conversion unit is used to convert the electric energy provided by the grid from alternating current to direct current;

[0007] An energy storage module, the energy storage module is coupled to the first conversion unit;

[0008] A second conversion unit, one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and is used to convert the direct current provided by the first conversion unit and the energy storage module into alternating current. The other end of the second conversion unit is connected to the load to convert and output electric energy to the load.

[0009] In a possible example, the power supply circuit further includes a bypass switch, one end of the bypass switch is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the bypass switch is connected to the load.

[0010] In a possible example, the energy storage module includes a battery unit, the battery unit includes an energy storage battery, and the energy storage battery is used to output electric energy to the load.

[0011] In a possible example, the battery unit further includes a third conversion unit, and the third conversion unit is used to boost the output voltage of the energy storage battery.

[0012] In a possible example, the third conversion unit is a bidirectional DC conversion control circuit, and the bidirectional DC conversion control circuit is configured to input electrical energy to the energy storage battery or output the electrical energy of the energy storage battery.

[0013] In a possible example, the energy storage module further includes a photovoltaic unit. The photovoltaic unit includes a photovoltaic cell and a fourth conversion unit. One end of the fourth conversion unit is connected to the photovoltaic cell, and the other end is coupled to the coupling end of the first conversion unit, the battery unit, and the second conversion unit. The fourth conversion unit is an MPPT circuit.

[0014] In a possible example, the power supply circuit further includes a charging unit. The charging unit includes a charging pile and a fifth conversion unit. The fifth conversion unit is coupled to the coupling end of the first conversion unit, the battery unit, and the second conversion unit. The fifth conversion unit is configured to output electrical energy from the coupling end to the charging pile, and the fifth conversion unit is a DC conversion control circuit.

[0015] In a possible example, the power supply circuit further includes a backup power generation module. The backup power generation module includes a generator and a control switch. The generator is connected to the control switch, and the control switch is coupled to the coupling end of the second conversion unit and the load.

[0016] In a possible example, the first conversion unit is configured to convert alternating current provided by the power grid into direct current in a constant power mode.

[0017] In a second aspect, an embodiment of the present application provides a microgrid energy system, and the microgrid energy system includes the power supply circuit according to any one of the above first aspects.

[0018] It can be seen that the power supply circuit provided by the present utility model includes a power grid, a first conversion unit, an energy storage module, and a second conversion unit. The first conversion unit is connected to the power grid and is configured to convert the electrical energy provided by the power grid from alternating current into direct current and operate in a constant power control mode. The energy storage module and the first conversion unit are coupled. One end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the second conversion unit is connected to the load to convert and output electrical energy to the load. It can be seen that by converting the electrical energy provided by the power grid into direct current to achieve coupling with the energy storage module and the second conversion circuit on the DC side, compared with directly coupling on the AC side, the circuit can be controlled and adjusted more precisely, effectively coping with sudden load changes, reducing the impact of load changes, and improving the stability and reliability of power supply. At the same time, through the energy storage module, clean energy auxiliary power supply can also be realized, reducing the noise impact and improving the cost performance. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a circuit architecture diagram of an existing power supply circuit provided by an embodiment of the present application;

[0021] Figure 2 is a circuit architecture diagram of a power supply circuit provided by an embodiment of the present application;

[0022] Figure 3 is a circuit architecture diagram of another power supply circuit provided by an embodiment of the present application;

[0023] Figure 4 is a circuit architecture diagram of yet another power supply circuit provided by an embodiment of the present application;

[0024] Figure 5 is a circuit architecture diagram of still another power supply circuit provided by an embodiment of the present application;

[0025] Figure 6 is a circuit architecture diagram of still another power supply circuit provided by an embodiment of the present application;

[0026] Figure 7 is a circuit architecture diagram of still another power supply circuit provided by an embodiment of the present application;

[0027] Figure 8 is a circuit architecture diagram of still another power supply circuit provided by an embodiment of the present application. Detailed implementation manners

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0029] In the description, claims and the above drawings of the present application, terms such as "first", "second", etc. are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0031] Currently, the power supply capacity of the grid power supply at many construction sites is relatively small. To meet the needs of high-power loads, the general solution is to configure a diesel engine. The principle is to preferentially consume grid energy and supplement it with a diesel engine when the grid energy is insufficient. As Figure 1 shown, if the grid capacity current is about 40A and the maximum load demand is 240A, the current demand provided by the diesel engine is about 200A, and the diesel engine undertakes the main power supply. Although this can meet the power supply demand, however, in the case of sudden load changes, due to the slow response of the diesel engine, it may instantaneously absorb a large current from the grid, resulting in overload at the grid end. Moreover, the diesel engine also has problems such as high noise, high fuel consumption cost, and low cost performance.

[0032] To solve the above problems, the present application provides a power supply circuit and a microgrid energy system. Specifically, the power supply circuit includes a grid, a first conversion unit, an energy storage module, and a second conversion unit. The first conversion unit is connected to the grid and is used to convert the electric energy provided by the grid from alternating current to direct current and operate in a constant power control mode; the energy storage module and the first conversion unit are coupled; one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the second conversion unit is connected to the load to convert and output electric energy to the load. In this way, by converting the electric energy provided by the grid into direct current, coupling with the energy storage module and the second conversion circuit on the DC side can be realized. Compared with direct coupling on the AC side, the circuit can be controlled and adjusted more precisely, can effectively respond to sudden load changes, reduce the impact of load changes, and improve the stability and reliability of power supply. At the same time, clean energy auxiliary power supply can also be realized through the energy storage module, reducing the impact of noise and improving the cost performance.

[0033] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0034] Refer to Figures 2 to 8 , the present application provides a power supply circuit, which includes a power grid, a first conversion unit, an energy storage module, and a second conversion unit. The first conversion unit is connected to the power grid, and the first conversion unit is used to convert the electric energy provided by the power grid from alternating current to direct current; the energy storage module and the first conversion unit are coupled; one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, as shown in the DC coupling end (DC bus) in Figures 2 to 8 , and is used to convert the direct current provided by the first conversion unit and the energy storage module into alternating current. The other end of the second conversion unit is connected to a load, as shown in the AC coupling end (AC bus) in Figures 2 to 8 , so as to convert and output electric energy to the load.

[0035] Among them, the first conversion unit can be an AC / DC conversion circuit for converting the alternating current provided by the power grid into direct current.

[0036] Among them, the energy storage module is used to input or output electric energy, and the electric energy output by the energy storage module is direct current.

[0037] Among them, the second conversion unit is a PCS (Power Conversion System) circuit. The second conversion unit is used to convert the electric energy coupled on the DC side into alternating current and output the alternating current to the load to supply power to the load.

[0038] Specifically, when this power supply circuit is specifically applied, it can first determine the energy required by the connected load, and then compare the maximum power supply of the power grid with the required electric energy. If the required energy is less than or equal to the maximum power supply of the power grid, the energy storage module can not output electric energy, so that the first conversion unit converts the electric energy provided by the power grid from alternating current to direct current, and then the second conversion unit converts the direct current into alternating current to supply the obtained alternating current to the load to meet the power consumption requirements of the load. If the energy required by the load is greater than the maximum power supply of the power grid, the electric energy output by the power grid can be determined as the maximum power supply of the power grid. At the same time, the maximum power supply of the power grid and the energy required by the load can be subtracted to obtain an electric energy difference, and the electric energy difference can be determined as the electric energy that the energy storage module needs to provide. The electric energy provided by the power grid can be converted from alternating current to direct current through the first conversion unit, and the direct current is integrated with the electric energy provided by the energy storage module and then jointly output to the second conversion unit to be converted into alternating current through the second conversion unit and output to the load to meet the power consumption requirements of the load.

[0039] In a specific implementation, one end of the second conversion unit for connecting a load is also connected to a filter, which is used to reduce the noise of the electric energy output to the load, improve the power quality, and protect the operation of the load.

[0040] It can be seen that the power supply circuit provided by the present utility model includes a power grid, a first conversion unit, an energy storage module, and a second conversion unit. The first conversion unit is connected to the power grid and is used to convert the electric energy provided by the power grid from alternating current to direct current and operate in a constant power control mode; the energy storage module and the first conversion unit are coupled; one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the second conversion unit is connected to the load to convert and output the electric energy to the load. It can be seen that by converting the electric energy provided by the power grid into direct current, the coupling with the energy storage module and the second conversion circuit on the DC side can be realized. Compared with direct coupling on the AC side, the circuit can be controlled and adjusted more precisely, effectively cope with sudden load changes, reduce the impact of load changes, and improve the stability and reliability of power supply. At the same time, through the energy storage module, auxiliary power supply with clean energy can also be realized, reducing the impact of noise and improving the cost performance.

[0041] See Figures 3 to 8 , in a possible example, the power supply circuit further includes a bypass switch, one end of the bypass switch is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of the bypass switch is connected to the load.

[0042] In a specific implementation, the bypass switch Q1 can be a manually controlled switch. Specifically, after the load is connected, if the electric energy cannot be provided to the load for the load to operate, that is, it is detected that the second conversion circuit does not output electric energy to the load, the management personnel can manually control the bypass switch Q1 to close to directly supply emergency power to the load through the power grid.

[0043] Alternatively, in a specific implementation, Q1 can be an electrically controlled switch. Specifically, after the load is connected, if it is detected that the second conversion circuit fails to output electric energy to the load within a preset time, the bypass switch Q1 can be controlled to close to conduct the line between the power grid and the load, so as to directly supply emergency power to the load through the power grid and meet the power consumption requirements of the load.

[0044] Specifically, the power supply circuit further includes a detection unit (not shown in the figure), and the detection unit is connected to one end of the second conversion circuit connected to the load to detect whether the second conversion circuit normally outputs electric energy and implement the above detection function.

[0045] It can be seen that in this example, by setting the bypass switch, when the system function fails (such as when the power grid is normal and the second conversion unit is damaged), the line where the bypass switch is located can be conducted to realize the emergency power supply of the power grid to the load and meet the power consumption requirements of the load.

[0046] See Figures 2 to 8 In a possible example, the energy storage module includes battery cells, and the battery cells include energy storage batteries for outputting electric energy to the load. It can be seen that in this example, electric energy can be pre-stored in the energy storage battery, so that when the electric energy required by the load is higher than the maximum electric energy that the power grid can provide, the electric energy stored in the energy storage battery can be output to the load through the second conversion unit to meet the power consumption needs of the load and avoid the problem of power grid overload caused by excessive energy required by the load.

[0047] See Figure 4 and Figures 6 to 8 In a possible example, the battery cell further includes a third conversion unit for boosting the output voltage of the energy storage battery.

[0048] Among them, the third conversion unit can be a DC / DC control circuit, that is, a DC conversion control circuit, to realize the boosting of the energy storage battery voltage and ensure that the electric energy output by the energy storage battery can be delivered to the second conversion unit and output to the load after conversion by the second conversion unit.

[0049] It can be seen that in this example, by connecting the third conversion unit to one end of the energy storage battery coupled to the second conversion unit, when the voltage of the energy storage battery is low, the third conversion unit can be used to boost the voltage, so that the voltage of the energy storage battery is increased and then connected to the second conversion unit, so that the second conversion unit can convert the direct current provided by the energy storage battery into alternating current and output it to the load.

[0050] In a possible example, the third conversion unit is a bidirectional DC conversion control circuit for inputting electric energy to the energy storage battery or outputting the electric energy of the energy storage battery.

[0051] In specific implementation, when the third conversion unit operates in the forward direction, that is, when one end of the third conversion unit connected to the energy storage battery is used as the input end and the end connected to the second conversion circuit (that is, the end coupled to the DC side) is used as the output end, the third conversion unit can boost the voltage of the energy storage battery to ensure that the electric energy provided by the energy storage battery can be smoothly delivered to the load. When the third conversion unit operates in the reverse direction, that is, when one end of the third conversion unit connected to the second conversion circuit (which can also be regarded as the end connected to the power grid) is used as the input end and the end connected to the energy storage battery is used as the output end, when no load is connected or the electric energy required by the load is lower than the maximum electric energy provided by the power grid, all or part of the electric energy output by the power grid can be input into the energy storage battery through the third conversion unit to realize the charging of the energy storage battery and improve the power utilization rate.

[0052] It can be seen that in this example, by setting the third conversion unit as a bidirectional DC conversion control circuit, not only can the voltage of the energy storage battery be boosted, but also the excess electric energy on the power supply side such as the power grid can be input into the energy storage battery to charge the energy storage battery and improve the utilization rate of electric energy.

[0053] Referring to Figures 5 to 8 , in a possible example, the energy storage module further includes a photovoltaic unit, the photovoltaic unit includes a photovoltaic cell and a fourth conversion unit, one end of the fourth conversion unit is connected to the photovoltaic cell, and the other end is coupled to the coupling end of the first conversion unit, the battery unit, and the second conversion unit, and the fourth conversion unit is an MPPT circuit.

[0054] In specific implementation, the battery unit and the photovoltaic unit are configured with power supply priorities. For example, the power supply priority of the battery unit can be higher than that of the photovoltaic unit. In this way, when the energy storage battery is needed to assist in power supply, the electric energy that the energy storage battery needs to provide can be further compared with the maximum electric energy that the energy storage battery can provide. If the electric energy that the energy storage battery needs to provide is less than or equal to the maximum electric energy that the energy storage battery can provide, the energy storage battery is used to assist in power supply. If the electric energy that the energy storage battery needs to provide is greater than the maximum electric energy that the energy storage battery can provide, on the basis of the power supply of the energy storage battery, the photovoltaic cell can be further used to assist in power supply to meet the power consumption needs of the load.

[0055] Specifically, referring to Figure 6 , the electric energy generated by the photovoltaic unit can also be input into the energy storage battery through the third conversion unit to charge the energy storage battery, increase the electric energy storage capacity, and improve the utilization rate of electric energy.

[0056] It can be seen that in this example, by setting the photovoltaic unit, the functional modes and power supply amounts of the power supply circuit can be further expanded, the power consumption needs of larger loads can be met, and the application range of the power supply circuit can be expanded. At the same time, configuring an MPPT circuit for the photovoltaic cell can maximize the utilization of environmental conditions, improve the energy conversion efficiency and the stability of the system.

[0057] Referring to Figure 7 , in a possible example, the power supply circuit further includes a charging unit, the charging unit includes a charging pile and a fifth conversion unit, the fifth conversion unit is coupled to the coupling end of the first conversion unit, the battery unit, and the second conversion unit, and the fifth conversion unit is used to output electric energy from the coupling end to the charging pile, and the fifth conversion unit is a DC conversion control circuit.

[0058] Among them, the charging pile is a DC charging pile. The fifth conversion unit can be a DC / DC control circuit, that is, a DC conversion control circuit.

[0059] In a specific implementation, while meeting the power consumption requirements of the load, the power supply circuit can also meet the demand for the output electric energy of the charging pile. Specifically, the power grid can be prioritized to supply energy to the charging pile. When the maximum energy supply provided by the power grid is less than the demand for the output electric energy of the charging pile, the battery unit or the photovoltaic unit can be used to supply electric energy to the charging pile. The specific power supply method can refer to the above-mentioned method of the power grid, battery unit, and photovoltaic unit supplying power to the load, and will not be elaborated further here.

[0060] It can be seen that in this example, by setting a charging unit for the power supply circuit, the electric energy provided by the power grid, energy storage battery, and photovoltaic battery can be supplied to devices such as electric vehicles through the charging pile to supply energy to them, thereby expanding the applicable scenarios of the power supply circuit and improving the functionality of the power supply circuit.

[0061] See Figure 8 , in a possible example, the power supply circuit further includes a backup power generation module. The backup power generation module includes a generator and a control switch. The generator is connected to the control switch, and the control switch is coupled to the coupling end of the second conversion unit and the load.

[0062] Among them, the generator can be a diesel engine.

[0063] In a specific implementation, after detecting the connection of the load, if it is detected that the second conversion circuit fails to output electric energy to the load within a preset time period, it indicates that the second conversion circuit is faulty, or it indicates that the energy storage battery and the photovoltaic battery are out of power and the power grid is faulty. At this time, the bypass switch Q1 can be closed to conduct the circuit connecting the power grid and the load, so that the power grid supplies emergency power to the load. When closing the bypass switch, at the same time, compare the maximum energy supply of the power grid and the electric energy required by the load. If the electric energy required by the load is less than or equal to the maximum energy supply of the power grid, detect whether the power grid outputs electric energy to the load within the second preset time period. If so, maintain the power supply. If not, it indicates that the power grid is faulty. At this time, the control switch Q2 can be closed to conduct the generator and the load, so as to supply emergency power to the load through the generator.

[0064] If the electric energy required by the load is greater than the maximum energy supply of the power grid, the control switch Q2 can be directly closed to conduct the generator and the load, so as to supply auxiliary power to the load through the generator to prevent the power grid from being overloaded. At the same time, detect whether the power grid outputs electric energy to the load within the second preset time period. If so, maintain the power supply. If not, it indicates that the power grid is faulty. At this time, the energy supply of the generator can be increased to supply emergency power to the load through the generator. Among them, it can be identified whether the power grid outputs electric energy by detecting whether the electric energy input at the load end is less than the electric energy required by the load. If so, the power grid has no electric energy output, indicating that the power grid is faulty.

[0065] In a specific implementation, if it is detected that the second conversion circuit can output electrical energy to the load within a preset time period, but the electrical energy it outputs is less than the electrical energy required by the load, it indicates that at least one of the energy storage battery, photovoltaic battery, and power grid is out of power or faulty. At this time, the control switch Q2 can also be closed to conduct the generator and the load, so as to supply emergency power to the load through the generator.

[0066] It can be seen that in this example, by setting up the backup power generation module, when the system function fails (such as the second conversion unit is damaged, or at least one of the energy storage battery, photovoltaic battery, and power grid is out of power or faulty), emergency power can be supplied to the load through the generator to meet the power consumption needs of the load.

[0067] In a possible example, the first conversion unit is used to convert the alternating current provided by the power grid into direct current in a constant power mode. In this example, by operating the first conversion unit in the constant power mode, the energy provided by the power grid can be maximally utilized when the load requires it, and the problem of load overload will not occur. When the load fluctuates and exceeds the power supply of the power grid, the fluctuating energy can be provided to the load by the microgrid energy system through the second conversion unit to meet the power consumption needs of the load.

[0068] The present utility model also proposes a microgrid energy system, which includes a power supply circuit. The specific structure of the power supply circuit refers to the above-mentioned embodiments. Since this microgrid energy system adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one.

[0069] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A power supply circuit, characterized in that: The power supply circuit comprises: Power grid; A first conversion unit, the first conversion unit is connected to the power grid, and the first conversion unit is used to convert the electric energy provided by the power grid from alternating current to direct current; An energy storage module, wherein the energy storage module is coupled to the first conversion unit; A second conversion unit, one end of the second conversion unit is coupled to the coupling end of the first conversion unit and the energy storage module, and is used to convert the direct current provided by the first conversion unit and the energy storage module into alternating current, and the other end of the second conversion unit is connected to a load to convert the electric energy and output it to the load.

2. The power supply circuit according to claim 1, characterized in that: The power supply circuit further includes a bypass switch, one end of which is coupled to the coupling end of the first conversion unit and the energy storage module, and the other end of which is connected to the load.

3. The power supply circuit according to claim 1, characterized in that: The energy storage module includes a battery unit, the battery unit includes an energy storage battery, and the energy storage battery is used to output electric energy to the load.

4. The power supply circuit according to claim 3, characterized in that: The battery unit further includes a third conversion unit, and the third conversion unit is used to increase the output voltage of the energy storage battery.

5. The power supply circuit according to claim 4, characterized in that: The third conversion unit is a bidirectional DC conversion control circuit, and the bidirectional DC conversion control circuit is used to input electric energy to the energy storage battery or output electric energy from the energy storage battery.

6. The power supply circuit according to claim 3, characterized in that: The energy storage module also includes a photovoltaic unit, which includes a photovoltaic cell and a fourth conversion unit. One end of the fourth conversion unit is connected to the photovoltaic cell, and the other end is coupled to the first conversion unit, the battery unit and the coupling end of the second conversion unit. The fourth conversion unit is an MPPT circuit.

7. The power supply circuit according to claim 3, characterized in that: The power supply circuit also includes a charging unit, which includes a charging pile and a fifth conversion unit. The fifth conversion unit is coupled to the first conversion unit, the battery unit and the coupling end of the second conversion unit. The fifth conversion unit is used to output electric energy from the coupling end to the charging pile. The fifth conversion unit is a DC conversion control circuit.

8. The power supply circuit according to claim 1, characterized in that: The power supply circuit further includes a backup power generation module, which includes a generator and a control switch, wherein the generator is connected to the control switch, and the control switch is coupled to a coupling end between the second conversion unit and the load.

9. The power supply circuit according to claim 1, characterized in that: The first conversion unit is used to convert the alternating current provided by the power grid into direct current in a constant power mode.

10. A microgrid energy system, characterized in that: The microgrid energy system comprises the power supply circuit according to any one of claims 1 to 9.

Images