Control circuit for off-grid photovoltaic system

Abstract

The utility model provides a control circuit for an off-grid photovoltaic system, and the circuit comprises a voltage control circuit which can emit first information based on the monitored condition of a photovoltaic power generation device; the battery management circuit can send second information based on the monitored condition of the energy storage battery; the system master control circuit is connected with the voltage control circuit and the battery management circuit, the system master control circuit can receive and process the first information and the second information so as to generate a first control instruction and a second control instruction, the system master control circuit can send the first control instruction to the voltage control circuit, and the system master control circuit can send the second control instruction to the battery management circuit. The system master controller can also send a second control instruction to the battery management circuit. The control circuit for the off-grid photovoltaic system is high in integration level and convenient to install and maintain.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of energy storage, more particularly to a control circuit for off-grid photovoltaic system. BACKGROUND

[0002] The existing photovoltaic system is composed of photovoltaic power generation system, energy storage battery and power system (lighting, monitoring, electrical equipment, etc.).

[0003] The existing control system has low integration, and is inconvenient to install and maintain. CONTENT OF THE UTILITY MODEL

[0004] The utility model provides a new technical scheme of control circuit for off-grid photovoltaic system, which can at least solve the problem of low integration and inconvenience in installation and maintenance in the prior art.

[0005] According to the utility model, a control circuit for off-grid photovoltaic system is provided, which comprises:

[0006] A voltage control circuit is used for monitoring and controlling the photovoltaic power generation device, and can send first information based on the monitored condition of the photovoltaic power generation device.

[0007] A battery management circuit is used for monitoring and controlling the energy storage battery, and can send second information based on the monitored condition of the energy storage battery.

[0008] A system general control circuit is connected to the voltage control circuit and the battery management circuit, can receive and process the first information and the second information to generate first control instructions and second control instructions, can send the first control instructions to the voltage control circuit to make the voltage control circuit execute the first control instructions, and can also send the second control instructions to the battery management circuit to make the battery management circuit execute the second control instructions.

[0009] Further, the voltage control circuit comprises:

[0010] A boost-buck circuit is used for connecting the photovoltaic power generation device to boost or buck the first voltage emitted by the photovoltaic power generation device, thereby forming a second voltage meeting the predetermined voltage requirement.

[0011] A fast shutdown circuit is connected to the boost-buck circuit, thereby being able to turn on / off the photovoltaic power generation device according to the first control instructions.

[0012] Further, the voltage control circuit further comprises:

[0013] a first power monitoring circuit, which is connected to the fast-off circuit and is used to monitor the output power of the fast-off circuit;

[0014] an output port, one end of which is connected to the first power monitoring circuit, and the other end of which is connected to the system control circuit.

[0015] Further, the voltage control circuit further comprises:

[0016] a second power monitoring circuit, which is connected to the photovoltaic power generation device to monitor the power generation power of the photovoltaic power generation device;

[0017] a first control circuit, which is connected to the second power monitoring circuit, the fast-off circuit, and the first power monitoring circuit through the protection circuit, can receive and send the first information including the power generation power and the output power to the system control circuit, and execute the received first control instruction to control the fast-off circuit to turn on or off.

[0018] Further, the battery management circuit comprises:

[0019] a sampling circuit, which is used to connect the energy storage battery to collect the second information of the energy storage battery, the second information including one or more of the electric quantity, the voltage, the current, the temperature, and the battery internal resistance;

[0020] a second control circuit, which is connected to the sampling circuit to receive the second information and send the second information to the system control circuit, and receive the second control instruction.

[0021] Further, the battery management circuit further comprises:

[0022] a charging management circuit, one end of which is used to connect the energy storage battery, and the other end of which is connected to the second control circuit, the second control circuit being able to execute the second control instruction to control the charging management circuit to charge or stop charging the energy storage battery.

[0023] Further, the battery management circuit further comprises:

[0024] a discharging management circuit, one end of which is used to connect the energy storage battery, and the other end of which is connected to the second control circuit, the second control circuit executing the second control instruction to control the discharging management circuit to discharge or stop discharging.

[0025] Further, the system general control circuit comprises:

[0026] a power supply circuit for connecting the energy storage battery;

[0027] a third control circuit connected to the power supply circuit;

[0028] an input / output interface through which the third control circuit connects the voltage control circuit and the battery management circuit to receive the first information and the second information and send the first control instruction and the second control instruction.

[0029] Further, the system general control circuit further comprises:

[0030] a communication circuit connected to the third control circuit;

[0031] a display circuit, a first port of which is connected to the third control circuit and a second port of which is used for connecting a display screen.

[0032] Further, the system general control circuit further comprises:

[0033] a first input module, a first port of which is connected to the third control circuit and a second port of which is used for connecting a keyboard;

[0034] a second input module, a first port of which is connected to the third control circuit and a second port of which is used for connecting an emergency stop button.

[0035] According to the control circuit for off-grid photovoltaic system, the voltage control circuit can send the first information based on the monitored condition of the photovoltaic power generation device. The battery management circuit can send the second information based on the monitored condition of the energy storage battery. The system general control circuit comprehensively receives the first information and the second information, generates the first control instruction for controlling the voltage control circuit and sends the first control instruction to the voltage control circuit, and generates the second control instruction for controlling the battery management circuit and sends the second control instruction to the battery management circuit. The voltage control circuit executes the first control instruction and the battery management circuit executes the second control instruction. The control circuit integrates the voltage control circuit, the battery management circuit and the system general control circuit together, has high integration, is convenient to install and maintain, and has high reliability and stability.

[0036] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0038] Figure 1 is a schematic diagram of a control circuit for an off-grid photovoltaic system according to an embodiment of the present application;

[0039] Figure 2 is a schematic diagram of a voltage control circuit and a photovoltaic power generation device according to an embodiment of the present application;

[0040] Figure 3 is a schematic diagram of an energy storage battery and a battery management circuit according to an embodiment of the present application;

[0041] Figure 4 is a schematic diagram of a system general control circuit according to an embodiment of the present application.

[0042] Reference signs:

[0043] 10, voltage control circuit; 11, boost-buck circuit; 12, fast turn-off circuit; 13, first power monitoring circuit; 14, output port; 15, second power monitoring circuit; 16, first control circuit; 17, protection circuit;

[0044] 20, battery management circuit; 21, sampling circuit; 22, second control circuit; 23, charge management circuit; 24, discharge management circuit;

[0045] 30, system general control circuit; 31, third control circuit; 32, power supply circuit; 33, input / output interface; 34, communication circuit; 35, display circuit; 36, first input module; 37, second input module. DETAILED DESCRIPTION

[0046] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps set forth in the examples, numerical expressions, and numerical values set forth in the examples are not limiting to the scope of the present application unless otherwise specifically stated.

[0047] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting to the scope of the present application or its applications or uses.

[0048] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0049] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Thus, other examples of the exemplary embodiments can have different values.

[0050] It should be noted that like numerals and letters refer to like items throughout the drawings, and once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0051] The off-grid photovoltaic system control circuit according to the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0052] As shown in Figures 1 to 4 , the off-grid photovoltaic system control circuit according to the embodiments of the present application includes a voltage control circuit 10, a battery management circuit 20, and a system general control circuit 30.

[0053] First, the voltage control circuit 10 is described. The voltage control circuit 10 is used to monitor and control a photovoltaic power generation device, and the voltage control circuit 10 can send out first information based on the monitored condition of the photovoltaic power generation device.

[0054] As shown in Figure 1 and Figure 2 , the voltage control circuit 10 monitors the photovoltaic power generation device to obtain the first information and sends the first information to the system general control circuit 30.

[0055] Next, the battery management circuit 20 is described. The battery management circuit 20 is used to monitor and control an energy storage battery, and the battery management circuit 20 can send out second information based on the monitored condition of the energy storage battery.

[0056] As shown in Figure 1 and Figure 3 , the battery management circuit 20 monitors the energy storage battery to obtain the second information and sends the second information to the system general control circuit 30.

[0057] Then, the system general control circuit 30 is described. The system general control circuit 30 is connected to the voltage control circuit 10 and the battery management circuit 20. The system general control circuit 30 can receive and process the first information and the second information to generate first control instructions and second control instructions, the system general control circuit 30 can send the first control instructions to the voltage control circuit 10 to make the voltage control circuit 10 execute the first control instructions, and the system general control circuit 30 can also send the second control instructions to the battery management circuit 20 to make the battery management circuit 20 execute the second control instructions.

[0058] As shown in Figure 1 and Figure 4 , the system general control circuit 30 is connected to the voltage control circuit 10 and the battery management circuit 20.

[0059] The system master control circuit 30 integrates the received first and second information, generates a first control command for controlling the voltage control circuit 10 and sends the first control command to the voltage control circuit 10, and generates a second control command for controlling the battery management circuit 20 and sends the second control command to the battery management circuit 20. The voltage control circuit 10 executes the first control command, and the battery management circuit 20 executes the second control command.

[0060] For example, the first information is that the photovoltaic power generation device is in normal condition, and the second information is that the energy storage battery's power level is lower than the upper limit threshold. The system's main control circuit 30 integrates the above information and sends a first control command to the voltage control circuit 10 to generate electricity from the energy storage battery and a second control command to the battery management circuit 20 to charge the battery. The voltage control circuit 10 executes the first control command to generate electricity from the energy storage battery, and the battery management circuit 20 executes the second control command to control the energy storage battery to receive power from the voltage control circuit for charging.

[0061] The control circuit for the off-grid photovoltaic system described above includes a voltage control circuit 10 that issues a first message based on the monitored status of the photovoltaic power generation device. A battery management circuit 20 that issues a second message based on the monitored status of the energy storage battery. The system master control circuit 30 integrates the received first and second messages, generates a first control command for controlling the voltage control circuit 10 and sends it to the voltage control circuit 10, and generates a second control command for controlling the battery management circuit 20 and sends it to the battery management circuit 20. The voltage control circuit 10 executes the first control command, and the battery management circuit 20 executes the second control command. This control circuit integrates the voltage control circuit 10, the battery management circuit 20, and the system master control circuit 30, resulting in high integration, ease of installation and maintenance, and high reliability and stability.

[0062] In some embodiments of this invention, the voltage control circuit 10 includes a step-up / step-down circuit 11 and a fast-shutdown circuit 12. The step-up / step-down circuit 11 is connected to a photovoltaic power generation device to step up or step down the first voltage generated by the photovoltaic power generation device, thereby forming a second voltage that meets a predetermined voltage requirement. The fast-shutdown circuit 12 is connected to the step-up / step-down circuit, thereby enabling the photovoltaic power generation device to be turned on / off according to the second control command.

[0063] like Figure 2 As shown, the step-up / step-down circuit 11 is connected to the photovoltaic power generation device. The step-up / step-down circuit 11 can step up or step down the first voltage generated by the photovoltaic power generation device to obtain a second voltage. The voltage of the second voltage meets the usage requirements and better satisfies the needs of charging the energy storage battery and supplying power to the power system.

[0064] likeFigure 2 As shown, the fast shutdown circuit 12 is connected to the buck-boost circuit 11. The fast shutdown circuit 12 receives a second control command to turn the buck-boost circuit 11 on / off to generate electricity, thereby turning the photovoltaic power generation device on / off.

[0065] Furthermore, the voltage control circuit 10 also includes a first power monitoring circuit 13 and an output port 14. The first power monitoring circuit 13 is used to monitor the output power of the fast shutdown circuit 12. One end of the output port 14 is connected to the first power monitoring circuit 13, and the other end is used to connect to the system master control circuit 30.

[0066] like Figure 2 As shown, the first power monitoring circuit 13 is connected to the fast shutdown circuit 12. The first power monitoring circuit 13 can obtain the output power of the fast shutdown circuit 12. One end of the output port 14 is connected to the first power monitoring circuit 13, and the other end is connected to the system master control circuit 30, so that the energy storage battery can be charged and / or the power supply system can be supplied through the system master control circuit 30.

[0067] Furthermore, the voltage control circuit 10 also includes a second power monitoring circuit 15 and a first control circuit 16. The second power monitoring circuit is connected to the photovoltaic power generation device to monitor the power generation of the photovoltaic power generation device. The first control circuit 16 is connected to the second power monitoring circuit 15, the fast shutdown circuit 12, and is connected to the first power monitoring circuit 13 through the protection circuit 17. The first control circuit 16 can receive and send first information including power generation and output power to the system master control circuit 30, and execute the received first control command to control the fast shutdown circuit 12 to turn on or off.

[0068] like Figure 2 As shown, the second power monitoring device is connected to the photovoltaic power generation device. The power generation of the photovoltaic power generation device can be monitored through the second power monitoring device.

[0069] The first control circuit 16 is connected to the second power monitoring circuit 15, the fast shutdown circuit 12, and the first power monitoring circuit 13 via the protection circuit 17. The first control circuit 16 receives the output power of the fast shutdown circuit 12 monitored by the first power monitoring circuit 13 and the power generation of the photovoltaic power generation device monitored by the second power monitoring circuit 15, and sends first information (including the received power generation and output power) to the system master control circuit 30. The first circuit control can also control and execute the first control command received from the system master control circuit 30, thereby controlling the fast shutdown circuit 12 to turn on or off, thus easily realizing the control of the voltage control circuit 10's external power generation, i.e., controlling the on / off of the photovoltaic power generation device's external power generation.

[0070] In some embodiments of the utility model, battery management circuit 20 includes sampling circuit 21 and second control circuit 22. Sampling circuit 21 is used to connect energy storage battery to collect the second information of energy storage battery, and the second information includes one or more of power, voltage, current, temperature and battery resistance. Second control circuit 22 connects sampling circuit 21 to receive second information and send second information to system general control circuit 30, and receives second control instruction.

[0071] As shown in Figure 3 Sampling circuit 21 connects energy storage battery. Second control circuit 22 connects sampling circuit 21. Sampling circuit 21 collects second information (power, voltage, current, temperature, battery resistance of energy storage battery) and sends second information to second control circuit 22. Second control sends second information to system general control circuit 30, and receives second control instruction from system general control circuit 30.

[0072] In some embodiments of the utility model, battery management circuit 20 further includes charging management circuit 23. One end of charging management circuit 20 is used to connect energy storage battery, and the other end connects second control circuit 22, and second control circuit 22 can execute second control instruction to control charging management circuit 23 to charge or stop charging energy storage battery.

[0073] Charging management circuit 23 connects energy storage battery and second control circuit 22. Second control circuit 22 controls charging management circuit 23. Thus, it can be easily controlled to charge or stop charging energy storage battery.

[0074] In some embodiments of the utility model, battery management circuit 20 further includes discharge management circuit 24, one end of discharge management circuit 24 connects energy storage battery, and the other end connects second control circuit 22, and second control circuit 22 executes second control instruction to control discharge management circuit 24 to discharge or stop discharging.

[0075] Discharge management circuit 24 connects energy storage battery and second control circuit 22. Second control circuit 22 controls discharge management circuit 24. Thus, it can be easily realized that energy storage battery discharges (supplies power) or stops discharging (supplies power) to the power system.

[0076] In some embodiments of the utility model, system general control circuit 30 includes power supply circuit 32, third control circuit 31 and input / output interface 33. Power supply circuit 32 is used to connect energy storage battery. Third control circuit 31 connects power supply circuit 32. Third control circuit 31 connects voltage control circuit 10 and battery management circuit through input / output interface 33 to receive first information and second information, and sends first control instruction and second control instruction.

[0077] As shown in Figure 4As shown, the system total control circuit 30 comprises a power supply circuit 32, a third control circuit 31 and an input / output interface 33. The power supply circuit 32 provides power for the third control circuit 31. The third control circuit receives the first information and the second information, and comprehensively processes the first information and the second information to generate the first control instruction and the second control instruction. The input / output interface 33 can comprise two, to connect the voltage control circuit 10 and the battery management circuit 20 respectively, so as to realize the control of the system total control circuit 30 on the voltage control circuit 10 and the battery management circuit 20.

[0078] Further, the system total control circuit 30 further comprises a communication circuit 34 and a display circuit 35. The communication circuit 34 is connected to the third control circuit 31. The first port of the display circuit 35 is connected to the third control circuit 31, and the second port thereof is used to connect a display screen. Wherein, the communication circuit 34 can be a 4G module, a 5G module, an RS485 module, etc.

[0079] As shown, Figure 4 the third control circuit 31 is connected to the communication circuit 34 and the display circuit 35. The communication circuit 34 can communicate with the outside world, so as to facilitate remote control. The display circuit 35 is connected to a display, which can display the operation of the third control circuit 31 to relevant personnel.

[0080] Further, the system total control circuit 30 further comprises a first input module 36 and a second input module 37. The first port of the first input module 36 is connected to the third control circuit 31, and the second port thereof is used to connect a keyboard. The first port of the second input module 37 is connected to the third control circuit 31, and the second port thereof is used to connect an emergency stop button.

[0081] As shown, Figure 4 the third control circuit 31 is connected to the first input module 36 and the second input module 37. The first input module 36 is connected to a keyboard, and relevant personnel can input instructions to the third control circuit 31 through the keyboard. The second input module 37 is connected to an emergency stop button, which can stop the third control circuit 31 in an emergency, so as to stop the whole control circuit from operating.

[0082] Although some specific embodiments of the present application have been described in detail by examples, those skilled in the art should understand that the above examples are only for illustration, but not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A control circuit for an off-grid photovoltaic system, characterized by, The application relates to a photovoltaic power generation system, which comprises: a voltage control circuit (10) for monitoring and controlling a photovoltaic power generation device, the voltage control circuit (10) being capable of sending first information based on the monitored condition of the photovoltaic power generation device; a battery management circuit (20) for monitoring and controlling an energy storage battery, the battery management circuit (20) being capable of sending second information based on the monitored condition of the energy storage battery; a system general control circuit (30) connected with the voltage control circuit (10) and the battery management circuit (20), the system general control circuit (30) being capable of receiving and processing the first information and the second information to generate first control instructions and second control instructions, the system general control circuit (30) being capable of sending the first control instructions to the voltage control circuit (10) to enable the voltage control circuit (10) to execute the first control instructions, and the system general control circuit being also capable of sending the second control instructions to the battery management circuit (20) to enable the battery management circuit (20) to execute the second control instructions.

2. The control circuit for off-grid photovoltaic systems according to claim 1, characterized in that, The voltage control circuit (10) comprises: a boost-buck circuit (11) connected with the photovoltaic power generation device to boost or buck the first voltage generated by the photovoltaic power generation device to form a second voltage meeting the predetermined voltage requirement; a fast-off circuit (12) connected with the boost-buck circuit (11) to enable the photovoltaic power generation device to be turned on or turned off according to the first control instructions.

3. The control circuit for an off-grid photovoltaic system according to claim 2, wherein, The voltage control circuit (10) further comprises: a first power monitoring circuit (13) connected with the fast-off circuit (12) to monitor the output power of the fast-off circuit (12); an output port (14) having one end connected with the first power monitoring circuit (13) and the other end connected with the system general control circuit (30).

4. The control circuit for off-grid PV systems according to claim 3, characterized in that, The voltage control circuit (10) further comprises: a second power monitoring circuit (15) connected with the photovoltaic power generation device to monitor the power generation of the photovoltaic power generation device; a first control circuit (16) connected with the second power monitoring circuit (15), the fast-off circuit (12) and the first power monitoring circuit (13) through a protection circuit (17), the first control circuit (16) being capable of receiving and sending the first information including the power generation and the output power to the system general control circuit (30) and executing the received first control instructions to control the fast-off circuit (12) to be turned on or turned off.

5. The control circuit for off-grid photovoltaic systems according to claim 1, characterized in that, The battery management circuit (20) comprises: a sampling circuit (21) connected with the energy storage battery to collect second information of the energy storage battery, the second information including one or more of the electric quantity, the voltage, the current, the temperature and the internal resistance of the battery; The second control circuit (22) is connected with the sampling circuit (21) to receive the second information and send the second information to the system control circuit (30), and receives the second control instruction.

6. The control circuit for an off-grid photovoltaic system of claim 5, wherein, The battery management circuit (20) further comprises: A charging management circuit (23) having one end connected with the energy storage battery and the other end connected with the second control circuit (22), and the second control circuit (22) can execute the second control instruction to control the charging management circuit (23) to charge or stop charging the energy storage battery.

7. The control circuit for off-grid PV systems according to claim 5, characterized in that, The battery management circuit (20) further comprises: A discharging management circuit (24) having one end connected with the energy storage battery and the other end connected with the second control circuit (22), and the second control circuit (22) executes the second control instruction to control the discharging management circuit (24) to discharge or stop discharging.

8. The control circuit for off-grid photovoltaic systems according to claim 1, characterized in that, The system control circuit (30) comprises: A power supply circuit (32) connected with the energy storage battery; A third control circuit (31) connected with the power supply circuit (32); An input / output interface (33) connected with the voltage control circuit (10) and the battery management circuit (20) through the third control circuit (31) to receive the first information and the second information, and send the first control instruction and the second control instruction.

9. The control circuit for an off-grid photovoltaic system of claim 8, wherein, The system control circuit (30) further comprises: A communication circuit (34) connected with the third control circuit (31); A display circuit (35) having a first port connected with the third control circuit (31) and a second port connected with a display screen.

10. The control circuit for an off-grid photovoltaic system of claim 8, wherein, The system control circuit (30) further comprises: A first input module (36) having a first port connected with the third control circuit (31) and a second port connected with a keyboard; A second input module (37) having a first port connected with the third control circuit (31) and a second port connected with an emergency stop button.

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