Control assembly of photovoltaic circuit and energy storage system

Abstract

The utility model discloses a control assembly of a photovoltaic circuit and an energy storage system. The control assembly of the photovoltaic circuit is applied to an energy storage system, the photovoltaic circuit comprises a photovoltaic power generation circuit and an MPPT module, the photovoltaic power generation circuit is electrically connected with the MPPT module, and the control assembly comprises a photovoltaic on-off switch, a control module and a discharging circuit. The photovoltaic on-off switch is electrically connected between the MPPT module and a bus of the energy storage system; the control module is used for controlling on and off of the photovoltaic on-off switch; and the discharging circuit is connected in parallel between the photovoltaic power generation circuit and the MPPT module and is used for discharging residual voltage to the input end of the MPPT module. According to the technical scheme of the utility model, the power supply reliability, the power supply sustainability and the power supply safety of the energy storage system can be improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic energy storage technology, and in particular to a control component and energy storage system for a photovoltaic circuit. Background Technology

[0002] Existing electrical energy is usually supplied by the power grid, but with the development of power electronics technology and clean energy, more and more photovoltaic power supply devices can also provide power to loads.

[0003] Photovoltaic power supply equipment includes a grid input terminal, a photovoltaic input terminal, and an energy storage device. The electrical energy provided by both the grid and photovoltaic input terminals can charge the energy storage device, allowing it to continue supplying power to the load during a power outage at the input terminal, thus improving the reliability of the load's power supply. However, when problems such as arcing occur in the electrical signal at the photovoltaic input terminal, the power supply path between the photovoltaic power supply system and the load is disconnected, causing a power outage on the load side and affecting the user experience. Utility Model Content

[0004] This invention provides a control component for a photovoltaic circuit and an energy storage system to improve the power supply reliability, power supply sustainability, and power supply security of the energy storage system.

[0005] In a first aspect, this utility model provides a control component for a photovoltaic circuit, applied to an energy storage system. The photovoltaic circuit includes a photovoltaic power generation circuit and an MPPT module, wherein the photovoltaic power generation circuit is electrically connected to the MPPT module. The control component includes:

[0006] A photovoltaic on / off switch is electrically connected between the MPPT module and the busbar of the energy storage system;

[0007] The control module is used to control the on and off states of the photovoltaic on / off switch;

[0008] A discharge circuit, connected in parallel between the photovoltaic power generation circuit and the MPPT module, is used to discharge residual voltage to the input terminal of the MPPT module.

[0009] Optionally, the photovoltaic on / off switch includes multiple relays, which are connected in series between the MPPT module and the bus.

[0010] Optionally, a soft-start circuit is also included, which includes a mechanical switch and a current limiting circuit, wherein the mechanical switch and the current limiting circuit are connected in series across the two ends of any of the relays.

[0011] Optionally, the control module includes at least one microcontroller unit and at least one communication circuit.

[0012] Optionally, the control module may further include one or more of an arc fault detection circuit, an insulation fault detection circuit, and a leakage fault detection circuit.

[0013] Optionally, the control module further includes a manual operation switch, through which instructions are sent to the control module, and the control module controls the photovoltaic on / off switch according to the instructions.

[0014] Secondly, this utility model also provides an energy storage system, comprising: a bus, a battery, a DC-DC bidirectional converter, an AC-DC inverter, an energy storage system power supply switch, an electrical load connection terminal, a public grid power supply switch, and a public grid connection terminal; the DC-DC bidirectional converter is connected to the bus and the battery; the DC side of the AC-DC inverter is connected to the bus, and the AC side of the AC-DC inverter is connected to the energy storage system power supply switch; the energy storage system power supply switch is connected to the public grid power supply switch; the public grid power supply switch is connected to the public grid connection terminal; the electrical load connection terminal is connected between the energy storage system power supply switch and the public grid power supply switch; the energy storage system also includes the control components of the photovoltaic circuit described in the first aspect.

[0015] Optionally, the control module is also used to control the on and off states of the energy storage system power supply switch and the public grid power supply switch.

[0016] Optionally, the energy storage system may also include the MPPT module.

[0017] Optionally, the energy storage system may also include the photovoltaic power generation circuit.

[0018] The technical solution of this utility model involves installing a photovoltaic on / off switch between the MPPT module and the busbar of the energy storage system. When a fault occurs in the photovoltaic circuit, the control module can promptly control the photovoltaic on / off switch to the off state, preventing the fault electrical signal from the photovoltaic circuit from being transmitted to the energy storage system through the busbar and affecting the operational reliability of the energy storage system. This improves the power supply reliability, sustainability, and security of the energy storage system. Furthermore, when the photovoltaic on / off switch switches from the on state to the off state, the residual voltage in the MPPT module can be discharged through a discharge circuit, preventing residual voltage from burning out the MPPT module and improving the operational reliability of the MPPT module. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, although the drawings described below are some specific embodiments of this utility model, those skilled in the art can extend and extend to other structures and drawings based on the basic concepts of the device structure, driving method and manufacturing method disclosed and indicated by the various embodiments of this utility model. Undoubtedly, these should all be within the scope of the claims of this utility model.

[0020] Figure 1 A schematic diagram of the structure of a control component for a photovoltaic circuit provided in an embodiment of this utility model;

[0021] Figure 2 A schematic diagram of the structure of another photovoltaic circuit control component provided in an embodiment of this utility model;

[0022] Figure 3 A schematic diagram of the structure of a control component for a photovoltaic circuit provided in another embodiment of this utility model;

[0023] Figure 4 A schematic diagram of the structure of a control component for a photovoltaic circuit provided in another embodiment of this utility model;

[0024] Figure 5 A schematic diagram of the structure of a control component for a photovoltaic circuit provided in an embodiment of this utility model;

[0025] Figure 6 A schematic diagram of the structure of another photovoltaic circuit control component provided in an embodiment of this utility model;

[0026] Figure 7 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the basic concepts disclosed and indicated in the embodiments of this utility model, all other embodiments obtained by those skilled in the art are within the protection scope of this utility model.

[0028] Figure 1This is a schematic diagram of a control component for a photovoltaic circuit provided in an embodiment of the present invention. This control component is applied to an energy storage system. The photovoltaic circuit includes a photovoltaic power generation circuit 11 and an MPPT module 12, which are electrically connected. The control component includes a photovoltaic on / off switch 20, a control module 30, and a discharge circuit 40. The photovoltaic on / off switch 20 is electrically connected between the MPPT module 12 and the bus of the energy storage system. The control module 30 is used to control the on / off state of the photovoltaic on / off switch 20. The discharge circuit 40 is connected in parallel between the photovoltaic power generation circuit 11 and the MPPT module 12 to discharge residual voltage to the input terminal of the MPPT module 12.

[0029] The photovoltaic power generation circuit 11 is used to convert light energy signals into electrical signals; the specific circuit is not limited here. The MPPT (Maximum Power Point Tracking) module photovoltaic circuit always provides power to the energy storage system at maximum power. The photovoltaic on / off switch 20 includes switching devices such as relays, and the discharge circuit 40 includes devices such as resistors; these can be configured according to actual needs and are not specifically limited here.

[0030] Specifically, when the photovoltaic circuit is working normally, the control module 30 controls the photovoltaic on / off switch 20 to be in the conducting state. After the photovoltaic power generation circuit 11 converts light energy into an electrical signal, the electrical signal is transmitted to other devices 13 of the energy storage system through the MPPT module 12 and the photovoltaic on / off switch 20 for use by the energy storage system. When the photovoltaic circuit experiences abnormal conditions such as arcing, the control module 30 can control the photovoltaic on / off switch 20 to be in the off state, preventing fault electrical signals in the photovoltaic circuit from entering other devices 13 of the energy storage system through the photovoltaic on / off switch 20, thereby affecting the power supply of other devices 13 in the energy storage system. The energy storage system can provide electrical energy to electrical loads for their use. If fault electrical signals enter the energy storage system, it will affect the power safety of the electrical loads. Therefore, by setting up the control module 30 and the photovoltaic on / off switch 20, when a fault occurs in the photovoltaic circuit, the control module 30 can promptly disconnect the photovoltaic on / off switch 20 to prevent fault electrical signals from entering other devices of the energy storage system, thereby affecting the power supply safety of the energy storage system. In addition, by placing the photovoltaic on / off switch 20 between the MPPT module 12 and the bus of the energy storage system, the photovoltaic circuit can be disconnected from the bus in the event of a photovoltaic circuit failure. This avoids the photovoltaic switch 20 being placed between the energy storage system and the electrical load, which would otherwise affect the power supply reliability of the energy storage system, improve the power supply sustainability of the energy storage system, and ultimately improve the power consumption experience of the electrical load.

[0031] Correspondingly, at the instant the photovoltaic on / off switch 20 is disconnected, the residual voltage of the MPPT module 12 can be quickly discharged through the discharge circuit 40 to prevent the residual voltage from affecting the working reliability of the MPPT module 12. Figure 1 The diagram only shows the discharge circuit 40 including the first resistor R1. The specific structure of the discharge circuit 40 can be set according to actual needs, and no specific limitation is made here.

[0032] The technical solution provided by this utility model involves setting a photovoltaic on / off switch between the MPPT module and the busbar of the energy storage system. When a fault occurs in the photovoltaic circuit, the control module can promptly control the photovoltaic on / off switch to the off state, preventing the fault electrical signal from the photovoltaic circuit from being transmitted to the energy storage system through the busbar and affecting the operational reliability of the energy storage system. This improves the power supply reliability, sustainability, and security of the energy storage system. Furthermore, when the photovoltaic on / off switch switches from the on state to the off state, the residual voltage in the MPPT module can be discharged through a discharge circuit, preventing residual voltage from burning out the MPPT module and improving its operational reliability.

[0033] Understandable Figure 1 The diagram only shows the photovoltaic on / off switch 20, which includes two relays, relay K2 and relay K3, which are simultaneously turned on or off. In other optional embodiments, the photovoltaic on / off switch 20 may also include multiple relays connected in series between the MPPT module 12 and the bus BUS. Figure 2 A schematic diagram of the structure of another photovoltaic circuit control component provided in an embodiment of this utility model is shown below. Figure 2 As shown, the photovoltaic on / off switch 20 includes four relays, namely relay K2, relay K3, relay K4 and relay K5. Relays K2 and K3 are simultaneously turned on or off, and relays K4 and K5 are simultaneously turned on or off.

[0034] Specifically, by setting the photovoltaic on / off switch 20 to include four relays, when two of the linked relays fail to disconnect, the other two linked relays can be controlled to disconnect the electrical connection between the photovoltaic circuit and the bus, thereby improving the disconnection reliability of the photovoltaic on / off switch 20 and enhancing the power supply security of the energy storage system.

[0035] It should be noted that the above description only uses the example of the photovoltaic on / off switch 20 including two or four relays. In other optional embodiments, the photovoltaic on / off switch 20 may also include more than four relays, which can be set according to actual needs. No specific limitation is made here.

[0036] Optional, Figure 3A schematic diagram of the structure of a control component for a photovoltaic circuit provided in another embodiment of this utility model is shown below. Figure 3 As shown, the control components of the photovoltaic circuit also include a soft-start circuit 50, which includes a mechanical switch 52 and a current limiting circuit 51. The mechanical switch 52 and the current limiting circuit 51 are connected in series and then connected across the two ends of any relay.

[0037] The current limiting circuit 51 may include components such as resistors, and the mechanical switch 52 may include electromagnetic switches, etc., which can be set according to actual needs, and no specific limitation is made here. Figure 3 The diagram only shows that the photovoltaic on / off switch 20 includes two relays, namely relay K1 and relay K2. The current limiting circuit 51 includes a resistor. The mechanical switch 52 includes a switch soft-start circuit 50. The resistor R2 and the mechanical switch Q2 are connected in series across the two ends of the relay K2. The resistor R3 and the mechanical switch Q3 are connected in series across the two ends of the relay K3.

[0038] Specifically, by connecting a slow-start circuit 50 across the relay, when it is necessary to control the relay to switch from the off state to the on state, the mechanical switch 50 of the slow-start circuit 50 can be controlled to be in the on state first, so that the voltage across the relay can be balanced by the current limiting circuit 51. When the voltage difference across the relay is less than the preset difference, the relay is then controlled to be in the on state, thereby improving the reliability of the relay and avoiding the impact of a large voltage difference on the operation of the relay.

[0039] It is understood that the above description only uses the example of the photovoltaic on / off switch 20 including two relays, with a soft-start circuit 50 connected across both ends of each relay. The photovoltaic on / off switch 20 may also include multiple relays, such as... Figure 4 As shown, the photovoltaic on / off switch 20 includes relays K2 and K4 connected in series, and relays K3 and K5 connected in series. The control component includes two soft-start circuits 50. One end of one soft-start circuit 50 (resistor R4 and mechanical switch Q4) can be electrically connected to the end of relay K2 away from relay K4, and the other end of the soft-start circuit 50 (resistor R4 and mechanical switch Q4) can be electrically connected to the end of relay K4 away from relay K2. One end of the other soft-start circuit 50 (resistor R5 and mechanical switch Q5) can be electrically connected to the end of relay K3 away from relay K5, and the other end of the soft-start circuit 50 (resistor R5 and mechanical switch Q5) can be electrically connected to the end of relay K5 away from relay K3. That is, the soft-start circuits 50 are respectively connected across the two ends of the two relays connected in series, eliminating the need to set a separate soft-start circuit 50 for each relay, reducing the number of soft-start circuits 50 and simplifying the structure of the control component.

[0040] Optional, Figure 5A schematic diagram of the structure of a control component for a photovoltaic circuit provided in an embodiment of this utility model is shown below. Figure 5 As shown, the control module 30 includes at least one microcontroller unit 31 and at least one communication circuit 32.

[0041] Specifically, the number of microcontroller units 31 can be set according to the number of linkage relays. When the control component includes one linkage relay, one microcontroller unit 31 can be set. When the control component includes two linkage relays, two microcontroller units 31 (311 and 312) can be set. Each microcontroller unit 31 is electrically connected to the control terminal of the linkage relay to control the relay to turn on or off. The communication circuit 32 can be electrically connected to the microcontroller unit 31 and the fault detection circuit of the photovoltaic circuit. When the fault detection circuit provides a fault signal to the communication circuit 32, the communication circuit 32 can provide a control signal to the microcontroller unit 31 to control the photovoltaic on / off switch 20 to turn off. Under the action of the control signal, the microcontroller unit 31 controls the photovoltaic on / off switch 20 to turn off, realizing automatic control without manual operation.

[0042] It is understood that the number of communication circuits 32 can be set according to the number of fault detection circuits. When only one fault detection circuit is included, the control component can include one communication circuit 32, and each communication circuit 32 is electrically connected to a fault detection circuit in a one-to-one correspondence. Optionally, the control module may also include one or more of the following: arc fault detection circuit, insulation fault detection circuit, and leakage fault detection circuit.

[0043] Specifically, the arc fault detection circuit can be located between the photovoltaic power generation circuit 11 and the MPPT module 12 to detect the arc discharge status of the output electrical signal of the photovoltaic power generation circuit 11 in a timely manner. When arc discharge occurs, the arc fault detection circuit can promptly transmit the fault electrical signal to the communication circuit 32 for analysis. The communication circuit 32 then transmits a control signal to the microcontroller unit 31 to control the photovoltaic on / off switch to be in the off state, thereby disconnecting the electrical connection between the photovoltaic circuit and the bus in the energy storage system and preventing the fault electrical signal from affecting the operation of the energy storage system. The insulation fault detection circuit can also be located between the MPPT module and the bus. When an insulation fault is detected, the communication circuit 32 and the microcontroller unit 31 can also control the photovoltaic on / off switch to be in the off state. The location of the leakage fault detection circuit can be set according to actual needs. For example, the leakage fault detection circuit is located on the transmission line that is electrically connected to the electrical load in the energy storage system. When a leakage fault is detected in the transmission line, the photovoltaic on / off switch can be controlled to be in the off state through the communication circuit 31 and the microcontroller unit 31 to prevent the photovoltaic circuit from continuously providing electrical signals to the energy storage system, which would cause continuous leakage of electrical signals and create danger, thereby improving the working safety of the energy storage system.

[0044] It is understood that the above description only takes the electrical connection of communication circuit 32 with fault detection circuit and microcontroller as an example. On the basis of the electrical connection between communication circuit 32 and microcontroller, communication circuit 32 can communicate with remote control terminal to receive remote control signals transmitted by remote control terminal, and then provide corresponding control signals to microcontroller according to remote control signals, so that microcontroller controls the photovoltaic on / off switch to be turned on or off according to control signals.

[0045] Optional, Figure 6 A schematic diagram of the structure of another photovoltaic circuit control component provided in an embodiment of this utility model is shown below. Figure 6 As shown, the control module 30 also includes a manual operation switch K1. By operating the manual operation switch K1, instructions are sent to the control module 30, and the control module 30 controls the photovoltaic on / off switch 20 according to the instructions.

[0046] The manual operation switch K1 includes knife switches or relays, which can be set according to actual needs, and no specific limitation is made here.

[0047] Specifically, when maintenance personnel perform repairs on the photovoltaic circuit, to prevent the electrical signals in the energy storage system from being transmitted back to the photovoltaic circuit and thus affecting the personal safety of the maintenance personnel, the on / off state of the manual operation switch K1 can be controlled. This allows the control module 30 to control the on / off state of the photovoltaic on / off switch 20 based on the on / off state of the manual operation switch K1, thereby improving the detection safety of the photovoltaic circuit. For example, when the manual operation switch K1 is in the off state, the control module 30 can control the on / off state of the photovoltaic on / off switch 20 based on the fault electrical signal provided by the fault detection circuit; when the manual operation switch K2 is in the on state, the control module 30 directly controls the photovoltaic on / off switch 20 to be in the off state so that maintenance personnel can perform repairs.

[0048] Based on the same inventive concept, this utility model embodiment also provides an energy storage system. Figure 7 A schematic diagram of an energy storage system provided in an embodiment of this utility model is shown below. Figure 7As shown, the energy storage system includes: a bus BUS, a battery 61, a DC-DC bidirectional converter 62, an AC-DC inverter 63, an energy storage system power supply switch 64, a load connection terminal OUT, a public grid power supply switch 65, and a public grid connection terminal IN. The DC-DC bidirectional converter 62 connects to the bus BUS and the battery 61. The DC side of the AC-DC inverter 63 is connected to the bus BUS, and the AC side of the AC-DC inverter 63 is connected to the energy storage system power supply switch 64. The energy storage system power supply switch 64 is connected to the public grid power supply switch 65. The public grid power supply switch 65 is connected to the public grid connection terminal IN. The load connection terminal OUT is connected between the energy storage system power supply switch 64 and the public grid power supply switch 65. The energy storage system also includes a control component for the photovoltaic circuit provided in any embodiment of this utility model. Optionally, the control module 30 is also used to control the on and off states of the energy storage system power supply switch 64 and the public grid power supply switch 65. The energy storage system also includes an MPPT module 12 and a photovoltaic power generation circuit 11.

[0049] The DC-DC bidirectional converter 62 is used to boost or buck a DC signal and convert it into another DC signal. The AC-DC inverter is used to convert the DC signal into an AC signal. The energy storage system power supply switch 64 includes relays K6 and K7, and the public grid power supply switch 65 includes relays K8 and K9. These can be set according to actual needs, and no specific limitation is made here.

[0050] Specifically, when the public grid power supply switch 65 is in the ON state, the AC signal from the public grid side can be transmitted to the electrical load 66 through the public grid power supply switch 65. The electrical signal provided by the photovoltaic circuit can be transmitted to the DC-DC bidirectional converter 62 through the photovoltaic on / off switch 20. The DC-DC bidirectional converter 62 converts the electrical signal and provides it to the battery 61 for storage. Alternatively, the DC signal can be converted to an AC signal by the AC-DC inverter 63 and then transmitted to the electrical load 66 through the energy storage system power supply switch 64. When the public grid side experiences a power outage, the electrical energy stored in the battery 61 can be converted by the DC-DC bidirectional converter 62 and the AC-DC inverter 63 and then transmitted to the electrical load 66 through the energy storage system power supply switch 64, improving the uninterrupted power supply and reliability of the energy storage system. In addition, when the photovoltaic circuit fails, the control module 30 only controls the photovoltaic on / off switch 20 to be in the off state, which does not affect the power supply status of the public grid or battery 61 to the load in the energy storage system, thereby improving the continuity of power supply and enhancing the user experience.

[0051] The energy storage system includes the control component of the photovoltaic circuit provided in any of the above embodiments, that is, it includes the technical features of the control component of the photovoltaic circuit. Therefore, it has the beneficial effects of the control component of the photovoltaic circuit. The similarities can be referred to the description above.

[0052] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control component for a photovoltaic circuit, applied in an energy storage system, wherein the photovoltaic circuit includes a photovoltaic power generation circuit and an MPPT module, the photovoltaic power generation circuit being electrically connected to the MPPT module, characterized in that, The control component includes: A photovoltaic on / off switch is electrically connected between the MPPT module and the busbar of the energy storage system; The control module is used to control the on and off states of the photovoltaic on / off switch; A discharge circuit, connected in parallel between the photovoltaic power generation circuit and the MPPT module, is used to discharge residual voltage to the input terminal of the MPPT module.

2. The control component of the photovoltaic circuit according to claim 1, characterized in that, The photovoltaic on / off switch includes multiple relays, which are connected in series between the MPPT module and the bus.

3. The control component for the photovoltaic circuit according to claim 2, characterized in that, It also includes a soft-start circuit, which comprises a mechanical switch and a current limiting circuit, wherein the mechanical switch and the current limiting circuit are connected in series across the two ends of any of the relays.

4. The control component for the photovoltaic circuit according to claim 1, characterized in that, The control module includes at least one microcontroller unit and at least one communication circuit.

5. The control component for the photovoltaic circuit according to claim 4, characterized in that, The control module also includes one or more of an arc fault detection circuit, an insulation fault detection circuit, and a leakage fault detection circuit.

6. The control component for the photovoltaic circuit according to claim 4, characterized in that, The control module also includes a manual operation switch, through which instructions are sent to the control module, and the control module controls the photovoltaic on / off switch according to the instructions.

7. An energy storage system, comprising: Busbar, battery, DC-DC bidirectional converter, AC-DC inverter, energy storage system power supply switch, load connection terminal, public grid power supply switch and public grid connection terminal; The DC-DC bidirectional converter is connected to the bus and the battery; The DC side of the AC-DC inverter is connected to the bus, and the AC side of the AC-DC inverter is connected to the power supply switch of the energy storage system. The power supply switch of the energy storage system is connected to the power supply switch of the public power grid. The public power grid power supply switch is connected to the public power grid access terminal; The electrical load access terminal is connected between the power supply switch of the energy storage system and the power supply switch of the public power grid. The energy storage system is characterized in that it further includes a control component for the photovoltaic circuit as described in any one of claims 1 to 6.

8. The energy storage system according to claim 7, characterized in that, The control module is also used to control the on / off state of the power supply switch of the energy storage system and the power supply switch of the public power grid.

9. The energy storage system according to claim 7, characterized in that, The energy storage system also includes the MPPT module.

10. The energy storage system according to claim 7, characterized in that, The energy storage system also includes the photovoltaic power generation circuit.

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