A photovoltaic power supply system
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUADIAN YUNNAN POWER CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-06-16
Smart Images
Figure CN224367579U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy power supply technology, and in particular to a photovoltaic power supply system. Background Technology
[0002] With the development of technology, the use of renewable and clean energy is becoming increasingly widespread, and photovoltaic power generation has received much attention from researchers. Since the maximum output power of photovoltaic modules is determined by the intensity of sunlight, its output power exhibits significant fluctuations and randomness. This random and uncontrollable characteristic may negatively impact the operation of some critical loads.
[0003] Currently, photovoltaic power generation generally adopts a structure of "photovoltaic array, inverter, box-type transformer, and power grid system". This single power supply method is not conducive to the construction of an "unmanned or minimally staffed" model for new energy power plants. Furthermore, relying solely on photovoltaic power generation can lead to unstable power supply due to prolonged periods of cloudy weather. Utility Model Content
[0004] The purpose of this invention is to provide a photovoltaic power supply system for a box-type transformer load. The box-type transformer receives AC power from both the grid and the solar panels after inversion, while the auxiliary transformer receives AC power from the low-voltage side of the box-type transformer or AC power after inverter inversion. This scheme can reduce the consumption of grid power, and the connection to the grid and solar panels improves the stability of power supply to the box-type transformer load. Furthermore, this application also includes a UPS power supply. When the box-type transformer is disconnected from the grid or experiences a fault trip and the solar panels stop generating electricity at night, the large-capacity battery built into the UPS provides power to the load, thereby achieving mutual backup and switching between photovoltaic power generation, grid, and UPS power supply, thus improving the overall stability, reliability, and security of the power supply.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] One aspect of this utility model provides a photovoltaic power supply system, comprising: a photovoltaic string solar panel and a first inverter, the output terminal of the solar panel being connected to the DC input terminal of the first inverter; a box-type transformer, the first inverter, and an auxiliary transformer, the low-voltage side of the box-type transformer being connected to the AC output terminal of the first inverter and the primary coil of the auxiliary transformer respectively; a first switch control circuit and a UPS power supply, the UPS power supply being connected to the solar panel, the first switch control circuit being connected to the secondary coil of the auxiliary transformer and the input terminal of the UPS power supply respectively, the auxiliary transformer being used to supply power to secondary loads and the UPS power supply, and the UPS power supply being used to supply power to important loads; a control module and a detection module, the control module being connected to the detection module, the first switch control circuit, and the UPS power supply respectively, and the detection module being connected to detect the solar panel; when the voltage of the solar panel is lower than a first preset threshold, the control module controls the first switch control circuit to close the connection between the auxiliary transformer and the UPS power supply.
[0007] In some embodiments, the photovoltaic power supply system further includes a second switch control circuit connected to the control module. The second switch control circuit includes a second electromagnetic circuit breaker. One end of the contactor of the second electromagnetic circuit breaker is connected to the input terminal of the first inverter, and the other end of the contactor of the second electromagnetic circuit breaker is connected to the solar panel.
[0008] In some embodiments, the UPS power supply is connected to the solar panel.
[0009] In some embodiments, a plurality of first diodes are connected in parallel between the UPS power supply and the solar panel, with the positive terminals of the plurality of first diodes connected to the solar panel and the negative terminals of the plurality of first diodes connected to the UPS power supply.
[0010] In some embodiments, the detection module includes a second inverter, an auxiliary transformer, a rectifier bridge, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, and a second capacitor. The input terminal of the second inverter is connected to the solar panel, and the output terminal of the second inverter is connected to the input terminal of the rectifier bridge through the step-down transformer. The positive output terminal of the rectifier bridge outputs a first power supply through the first resistor, and the negative output terminal of the rectifier bridge serves as a first ground point. One end of the first capacitor, one end of the second capacitor, and one end of the second resistor are connected to the first power supply, and the other ends of the first capacitor and the second capacitor are connected to the first ground point. The other end of the second resistor is connected to one end of the fourth resistor and one end of the fifth resistor through the third resistor. The other end of the fifth resistor is connected to the first ground point, and the other end of the fourth resistor is connected to the control module.
[0011] In some embodiments, the detection module further includes an optocoupler, a sixth resistor, and a seventh resistor. The light-emitting input terminal of the optocoupler is connected to the other end of the fourth resistor, the light-emitting output terminal of the optocoupler is connected to a first location, the light-receiving input terminal of the optocoupler is connected to a second power supply through the sixth resistor, the light-receiving output terminal of the optocoupler is connected to one end of the seventh resistor and the control module, and the other end of the seventh resistor is connected to a second location.
[0012] In some embodiments, the first switch control circuit and the second switch control circuit have the same circuit structure. The first switch control circuit includes a first electromagnetic circuit breaker, an NPN transistor, an eighth resistor, a ninth resistor, and a tenth resistor. The collector of the NPN transistor is connected to a second power supply through the tenth resistor. The base of the NPN transistor is connected to one end of the eighth resistor and one end of the ninth resistor. The other end of the eighth resistor is connected to the control module. The other end of the ninth resistor is connected to a second location. The emitter of the NPN transistor is connected to one end of the coil of the first electromagnetic circuit breaker. The other end of the coil of the first electromagnetic circuit breaker is connected to the second location.
[0013] In some embodiments, the first switch control circuit further includes a second diode, the negative terminal of which is connected to one end of the coil terminal of the first electromagnetic circuit breaker and the emitter of the NPN transistor, and the positive terminal of which is connected to the other end of the coil terminal of the first electromagnetic circuit breaker.
[0014] According to an embodiment of the present invention, a photovoltaic power supply system has at least the following beneficial effects: The auxiliary transformer of this application receives power from both the power grid and the inverter power from the solar panels. When the voltage of the solar panels is lower than a first preset threshold, the control module controls the contactor of the first electromagnetic circuit breaker to close through the first switch control circuit, thereby supplying power through the power grid. This application uses power drawn from the solar panels or from the DC input terminal of the inverter via an MC4 photovoltaic connector Y-type one-to-two adapter, thus saving the load's energy consumption from the power grid. Furthermore, this application includes a UPS power supply. When the box-type transformer is disconnected from the power grid or experiences a fault trip and the solar panels stop generating power at night, the large-capacity battery built into the UPS provides power to the load, thereby achieving mutual backup and switching between photovoltaic power generation, the power grid, and the UPS power supply, thereby improving the overall stability, reliability, and security of the power supply.
[0015] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of a photovoltaic power supply system according to an embodiment;
[0018] Figure 2 This is a circuit schematic diagram of the detection module according to an embodiment;
[0019] Figure 3 This is a circuit diagram of the first switch control circuit according to an embodiment. Detailed Implementation
[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0021] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art. The drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.
[0024] The technical solutions of the embodiments of this application are briefly described below:
[0025] According to some embodiments, such as Figure 1 As shown, this application provides a photovoltaic power supply system, which includes:
[0026] A photovoltaic string consists of a solar panel and a first inverter, with the output of the solar panel connected to the DC input of the first inverter.
[0027] The package includes a box-type transformer, a first inverter, and an auxiliary transformer. The low-voltage side of the box-type transformer is connected to the AC output terminal of the first inverter and the primary coil of the auxiliary transformer, respectively.
[0028] The first switch control circuit and the UPS power supply are connected to the solar panel. The first switch control circuit is connected to the secondary coil of the auxiliary transformer and the input terminal of the UPS power supply respectively. The auxiliary transformer is used to supply power to the secondary load and the UPS power supply, and the UPS power supply is used to supply power to the important load.
[0029] The system includes a control module and a detection module. The control module is connected to the detection module, the first switch control circuit, and the UPS power supply. The detection module is connected to the detection solar panel.
[0030] The first switch control circuit includes a first electromagnetic circuit breaker K1, and the contactor of the first electromagnetic circuit breaker K1 is connected to the secondary coil of the auxiliary transformer and the input terminal of the UPS power supply, respectively.
[0031] The working principle of the above embodiment is as follows: when the voltage of the solar panel is lower than a first preset threshold, the control module controls the contactor of the first electromagnetic circuit breaker K1 to close through the first switch control circuit, so that the power grid supplies power to the important load and charges the UPS built-in battery. When the voltage of the solar panel is higher than a second preset threshold, the control module controls the contactor of the first electromagnetic circuit breaker K1 to open through the first switch control circuit, so that the solar panels in the photovoltaic string supply power to the important load and charge the UPS built-in battery.
[0032] When it is cloudy or nighttime for an extended period, and the transformer is disconnected from the power grid, trips due to a fault, or the solar panels stop generating electricity, the large-capacity battery built into the UPS will provide power to the critical load.
[0033] This application utilizes power drawn from solar panels or from the DC input of the inverter via an MC4 photovoltaic connector Y-type dual-connector, thereby reducing the load's energy consumption from the grid. Furthermore, simultaneous connection to the grid and solar panels improves the stability and reliability of power supply to the transformer-mounted load. This application also includes a UPS power supply; when the transformer-mounted load is disconnected from the grid, trips due to a fault, or the solar panels stop generating power at night, the UPS's built-in large-capacity battery provides power to the load. This achieves mutual backup and switching between photovoltaic power generation, the grid, and the UPS power supply, thereby improving the overall stability, reliability, and security of the power supply.
[0034] The following is in conjunction with the appendix to this instruction manual. Figures 1 to 3 The preferred embodiments of this disclosure will be further described in detail below.
[0035] According to some embodiments, such as Figure 1 As shown, the photovoltaic power supply system also includes a second switch control circuit connected to the control module. The second switch control circuit includes a second electromagnetic circuit breaker K2. One end of the contactor of the second electromagnetic circuit breaker K2 is connected to the input terminal of the first inverter, and the other end of the contactor of the second electromagnetic circuit breaker K2 is connected to the solar panel and the detection module.
[0036] The working principle of the above embodiment is as follows: when the voltage of the solar panel is lower than the first preset threshold, the control module controls the contactor of the second electromagnetic circuit breaker K2 to open through the second switch control circuit, and controls the contactor of the first electromagnetic circuit breaker K1 to close through the first switch control circuit, so that the power grid supplies power to the important load and charges the built-in battery of the UPS.
[0037] When the voltage of the solar panel is higher than the second preset threshold, the control module controls the contactor of the second electromagnetic circuit breaker K2 to close through the second switch control circuit, and controls the contactor of the first electromagnetic circuit breaker K1 to open through the first switch control circuit, so that the solar panel supplies power to the important load and charges the built-in battery of the UPS.
[0038] When the voltage of the solar panel falls below a first preset threshold, the control module controls the contactor of the second electromagnetic circuit breaker K2 to disconnect via the second switch control circuit. Connecting the UPS power supply to the solar panel allows the excess electricity from the solar panel to charge the UPS power supply, reducing the consumption of grid power and thus saving on electricity costs.
[0039] Furthermore, such as Figure 1 As shown, multiple first diodes D11, D12, and D13 are connected in parallel between the UPS power supply and the solar panel. The positive terminals of the multiple first diodes D11, D12, and D13 are connected to the solar panel, and the negative terminals of the multiple first diodes D11, D12, and D13 are connected to the UPS power supply. This is to prevent the UPS power supply from charging the solar panel in reverse.
[0040] According to some embodiments, such as Figure 2 As shown, the detection module includes a second inverter, a step-down transformer, a rectifier bridge DB, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, and a second capacitor C2. Their specific connection method is as follows:
[0041] The input terminal of the second inverter is connected to the solar panel. The output terminal of the second inverter is connected to the input terminal of the rectifier bridge DB through a step-down transformer. The positive output terminal of the rectifier bridge DB outputs the first power supply V1 through the first resistor R1. The negative output terminal of the rectifier bridge DB serves as the first ground point GND1. One end of the first capacitor C1, one end of the second capacitor C2, and one end of the second resistor R2 are connected to the first power supply V1. The other end of the first capacitor C1 and the other end of the second capacitor C2 are connected to the first ground point GND1. The other end of the second resistor R2 is connected to one end of the fourth resistor R4 and one end of the fifth resistor R5 through the third resistor R3. The other end of the fifth resistor R5 is connected to the first ground point GND1. The other end of the fourth resistor R4 is connected to the control module.
[0042] The step-down transformer is used to reduce voltage, the rectifier bridge DB is used to convert AC to DC, and the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 are used for current limiting and voltage division. The first capacitor C1 and the second capacitor C2 are used for filtering, with the capacitance of the first capacitor C1 being greater than that of the second capacitor C2. The larger capacitor filters low frequencies, and the smaller capacitor filters high frequencies.
[0043] According to some embodiments, such as Figure 2 As shown, the detection module also includes an optocoupler U, a sixth resistor R6, and a seventh resistor R7, and their specific connection methods are as follows:
[0044] The light-emitting input terminal of the optocoupler U is connected to the other end of the fourth resistor R4. The light-emitting output terminal of the optocoupler U is connected to the first location GND1. The light-receiving input terminal of the optocoupler U is connected to the second power supply V2 through the sixth resistor R6. The light-receiving output terminal of the optocoupler U is connected to one end of the seventh resistor R7 and the control module. The other end of the seventh resistor R7 is connected to the second location GND2.
[0045] Among them, the optocoupler U plays the role of isolation detection.
[0046] The working principle of the above embodiment is as follows: When the voltage of the solar panel is lower than the first preset threshold, the light emitted by the light-emitting side of the optocoupler U is dimmer, almost extinguished. The electrical signal 101 received by the control module is low, indicating that the current solar irradiance is low. Then, the control module controls the contactor of the second electromagnetic circuit breaker K2 to open through the second switch control circuit, and controls the contactor of the first electromagnetic circuit breaker K1 to close through the first switch control circuit, so that power is supplied from the grid to the important load and the UPS built-in battery is charged. When the voltage of the solar panel is higher than the second preset threshold, the light emitted by the light-emitting side of the optocoupler U is brighter. The electrical signal 101 received by the control module is higher, indicating that the current solar irradiance is high. Then, the control module controls the contactor of the second electromagnetic circuit breaker K2 to close through the second switch control circuit, and controls the contactor of the first electromagnetic circuit breaker K1 to open through the first switch control circuit, so that power is supplied from the solar panel to the important load and the UPS built-in battery is charged.
[0047] According to some embodiments, such as Figure 3 As shown, the first switch control circuit and the second switch control circuit have the same circuit structure. The first switch control circuit also includes an NPN transistor Q, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10. Their specific connection methods are as follows.
[0048] The collector of NPN transistor Q is connected to the second power supply V2 through the tenth resistor R10. The base of NPN transistor Q is connected to one end of the eighth resistor R8 and one end of the ninth resistor R9. The other end of the eighth resistor R8 is connected to the control module. The other end of the ninth resistor R9 is connected to the second ground GND2. The emitter of NPN transistor Q is connected to one end of the coil of the first electromagnetic circuit breaker K1. The other end of the coil of the first electromagnetic circuit breaker K1 is connected to the second ground GND2.
[0049] The working principle of the above embodiment is as follows: When the voltage of the solar panel is lower than the first preset threshold, the control module outputs a high-level electrical signal 201 to the base of the NPN transistor Q, turning on the NPN transistor Q and energizing the contactor of the first electromagnetic circuit breaker K1, allowing power to be supplied from the grid to the critical load and charging the UPS's built-in battery. When the voltage of the solar panel is higher than the second preset threshold, the control module outputs a low-level electrical signal 201 to the base of the NPN transistor Q, turning off the NPN transistor Q and energizing the contactor of the first electromagnetic circuit breaker K1, allowing power to be supplied from the solar panel to the critical load and charging the UPS's built-in battery.
[0050] According to some embodiments, such as Figure 3 As shown, the first switch control circuit also includes a second diode D2. The negative terminal of the second diode D2 is connected to one end of the coil of the first electromagnetic circuit breaker K1 and the emitter of the NPN transistor Q, and the positive terminal of the second diode D2 is connected to the other end of the coil of the first electromagnetic circuit breaker K1.
[0051] The working principle of the above embodiment is as follows: when the NPN transistor Q goes from being turned on to being turned off, the coil terminal of the first electromagnetic circuit breaker K1 goes from being energized to being de-energized, and the coil terminal of the first electromagnetic circuit breaker K1 freewheels through the second diode D2.
[0052] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
[0053] Although this disclosure has been described with reference to several typical embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Because this disclosure can be embodied in many forms without departing from the spirit or substance of this application, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.
Claims
1. A photovoltaic power supply system, characterized in that, The photovoltaic power supply system includes: A photovoltaic string of solar panels and a first inverter, wherein the output terminal of the solar panels is connected to the DC input terminal of the first inverter; The package includes a box-type transformer, a first inverter, and an auxiliary transformer, wherein the low-voltage side of the box-type transformer is connected to the AC output terminal of the first inverter and the primary coil of the auxiliary transformer, respectively. The first switch control circuit and the UPS power supply are connected to the solar panel. The first switch control circuit is connected to the secondary coil of the auxiliary transformer and the input terminal of the UPS power supply. The auxiliary transformer is used to supply power to the secondary load and the UPS power supply, and the UPS power supply is used to supply power to the important load. The system includes a control module and a detection module. The control module is connected to the detection module, a first switch control circuit, and a UPS power supply. The detection module is connected to detect the solar panel. When the voltage of the solar panel is lower than a first preset threshold, the control module controls the first switch control circuit to close the connection between the auxiliary transformer and the UPS power supply.
2. The photovoltaic power supply system according to claim 1, characterized in that, The photovoltaic power supply system also includes a second switch control circuit connected to the control module. The second switch control circuit includes a second electromagnetic circuit breaker. One end of the contactor of the second electromagnetic circuit breaker is connected to the input terminal of the first inverter, and the other end of the contactor of the second electromagnetic circuit breaker is connected to the solar panel and the detection module.
3. The photovoltaic power supply system according to claim 1, characterized in that, The UPS power supply is connected to the solar panel.
4. The photovoltaic power supply system according to claim 3, characterized in that, A plurality of first diodes are connected in parallel between the UPS power supply and the solar panel. The positive terminals of the plurality of first diodes are connected to the solar panel, and the negative terminals of the plurality of first diodes are connected to the UPS power supply.
5. The photovoltaic power supply system according to claim 1, characterized in that, The detection module includes a second inverter, a step-down transformer, a rectifier bridge, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, and a second capacitor. The input terminal of the second inverter is connected to the solar panel, and the output terminal of the second inverter is connected to the input terminal of the rectifier bridge through the step-down transformer. The positive output terminal of the rectifier bridge outputs a first power supply through the first resistor, and the negative output terminal of the rectifier bridge serves as a first ground point. One end of the first capacitor, one end of the second capacitor, and one end of the second resistor are connected to the first power supply, and the other ends of the first capacitor and the second capacitor are connected to the first ground point. The other end of the second resistor is connected to one end of the fourth resistor and one end of the fifth resistor through the third resistor. The other end of the fifth resistor is connected to the first ground point, and the other end of the fourth resistor is connected to the control module.
6. The photovoltaic power supply system according to claim 5, characterized in that, The detection module further includes an optocoupler, a sixth resistor, and a seventh resistor. The light-emitting input terminal of the optocoupler is connected to the other end of the fourth resistor, the light-emitting output terminal of the optocoupler is connected to a first location, the light-receiving input terminal of the optocoupler is connected to a second power supply through the sixth resistor, the light-receiving output terminal of the optocoupler is connected to one end of the seventh resistor and the control module, and the other end of the seventh resistor is connected to a second location.
7. The photovoltaic power supply system according to claim 2, characterized in that, The first switch control circuit and the second switch control circuit have the same circuit structure. The first switch control circuit includes a first electromagnetic circuit breaker, an NPN transistor, an eighth resistor, a ninth resistor, and a tenth resistor. The collector of the NPN transistor is connected to a second power supply through the tenth resistor. The base of the NPN transistor is connected to one end of the eighth resistor and one end of the ninth resistor. The other end of the eighth resistor is connected to the control module. The other end of the ninth resistor is connected to a second location. The emitter of the NPN transistor is connected to one end of the coil of the first electromagnetic circuit breaker. The other end of the coil of the first electromagnetic circuit breaker is connected to the second location.
8. The photovoltaic power supply system according to claim 7, characterized in that, The first switch control circuit further includes a second diode, the negative terminal of which is connected to one end of the coil terminal of the first electromagnetic circuit breaker and the emitter of the NPN transistor, and the positive terminal of which is connected to the other end of the coil terminal of the first electromagnetic circuit breaker.