Photovoltaic power adapter with power line communication and photovoltaic system

Abstract

The application discloses a photovoltaic power adapter with power carrier communication and a photovoltaic system, wherein the photovoltaic power adapter comprises a voltage boosting circuit, an LC filter circuit and a communication signal transceiving structure; the voltage boosting circuit comprises a capacitor C1, a capacitor C2, an inductor L1, a switch tube Q1 and a switch tube Q2; the LC filter circuit comprises a capacitor C3, an inductor L2 and a switch tube Q3; and the capacitor C1, the capacitor C2 and the capacitor C3 are all non-polarity ceramic capacitors.The application has the beneficial effects that the product has high reliability and stability, the transmission environment of the PLC carrier signal is optimized, the difficulty of field construction and application is reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic base station technology, and in particular to a photovoltaic power adapter with power line carrier communication. Background Technology

[0002] Photovoltaic power adapters are mainly used in base station photovoltaic (PV) upgrade projects. Their primary function is to convert the energy generated by photovoltaic modules and output it to the positive and negative busbars of the battery pack for use by various communication devices. This reduces the base station system's consumption of mains power, thereby reducing carbon emissions and achieving energy conservation and cost reduction in base station operation. Current PV power adapters primarily focus on energy conversion, generally with fixed output voltage values ​​that cannot be changed via communication or other means. However, some solutions utilize RS485 for wired signal transmission to allow for real-time adjustment of PV power adapter parameters.

[0003] The existing solutions have the following problems: 1. Existing adapter products mostly use polarized electrolytic capacitors and other components, which is not conducive to the reverse connection protection function of the product or requires circuitry to increase costs if matching function is required. At the same time, the reliability of electrolytic capacitors in high-temperature applications is also a major hidden danger.

[0004] 2. The battery packs used in each communication base station are of different models and have different specifications. If the operating parameters of the photovoltaic power adapter cannot be modified to match the ideal operating voltage of the battery pack, this will seriously affect the service life of the battery pack. Excessive overvoltage can damage the battery pack or even cause a fire.

[0005] 3. Adapters are typically installed at the bottom of photovoltaic modules. Systems using photovoltaic power adapters are parallel systems, with each unit having two relatively long power lines during system setup. If an RS485 wired transmission solution is used, the various cables become tangled and chaotic during construction. Furthermore, varying construction distances necessitate on-site fabrication of cables, making it highly susceptible to errors when signal and power lines cross, significantly increasing the difficulty of on-site construction and potentially causing equipment damage during the process.

[0006] 4. Power line carrier communication has high power requirements, requiring relatively stable voltage. Furthermore, the battery pack is equivalent to a large and complex capacitor, which will attenuate the power line carrier signal. Load changes, line losses, electromagnetic interference, and signal attenuation on power transmission lines can increase the communication error rate, affecting the stability and reliability of communication. Ensuring the communication quality of power line carrier communication is very difficult.

[0007] Therefore, existing technologies have shortcomings and need to be improved. Summary of the Invention

[0008] The purpose of this invention is to overcome at least some of the shortcomings of the prior art and to provide a photovoltaic power adapter and photovoltaic system with power line carrier communication.

[0009] The technical solution of the present invention is as follows: The present invention provides a photovoltaic power adapter with power line carrier communication, comprising: a boost circuit, an LC filter circuit, and a communication signal transceiver structure;

[0010] The boost circuit includes capacitor C1, capacitor C2, inductor L1, and switching transistors Q1 and Q2. The LC filter circuit includes capacitor C3, inductor L2, and switching transistor Q3. Capacitors C1, C2, and C3 are all non-polarized ceramic capacitors. Switches Q1, Q2, and Q3 are all NMOS transistors. One end of capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of inductor L1. The other end of inductor L1 is electrically connected to the drain of switching transistor Q1 and the source of switching transistor Q2. The gate of switching transistor Q1 is electrically connected to the lower-side drive terminal of the main control MCU. The gate of switching transistor Q2... The upper drive terminal of the main control MCU is electrically connected to the power supply drive terminal of the main control MCU. The drain of the switching transistor Q2 is electrically connected to one end of the capacitor C2 and one end of the inductor L2. The other end of the inductor L2 is electrically connected to one end of the capacitor C3 and the drain of the switching transistor Q3. The source of the switching transistor Q3 is electrically connected to the power output OUT+ terminal of the photovoltaic power adapter. The gate of the switching transistor Q3 is electrically connected to the output anti-reverse transistor drive terminal of the main control MCU. The negative output terminal PV- of the photovoltaic module is electrically connected to the other end of the capacitor C1, the source of the switching transistor Q1, the other end of the capacitor C2, the other end of the capacitor C3, and the power output OUT- terminal of the photovoltaic power adapter. The communication signal transceiver structure is connected to the LC filter circuit to realize power line carrier communication.

[0011] Furthermore, the communication signal transceiver structure includes a transformer TX1, a capacitor C4, and a PLC power line carrier communication module. The transformer TX1 is a coupling transformer. One end of the capacitor C4 is electrically connected to the source of the switching transistor Q3, and the other end of the capacitor C4 is electrically connected to one end of the primary side of the transformer TX1. The other end of the primary side of the transformer TX1 is electrically connected to the other end of the capacitor C3, and the secondary side of the transformer TX1 is electrically connected to the PLC power line carrier communication module.

[0012] Furthermore, the solution also includes an auxiliary power supply circuit, wherein the positive output terminal PV+ of the photovoltaic module is electrically connected to the positive terminal of diode D1, the power output terminal OUT+ is electrically connected to the positive terminal of diode D2, the negative terminals of diode D1 and D2 are both electrically connected to the positive terminal of the auxiliary power supply circuit, and the negative output terminal PV- and power output terminal OUT- of the photovoltaic module are both electrically connected to the negative terminal of the auxiliary power supply circuit.

[0013] Furthermore, the power circuit and control circuit of the photovoltaic power adapter are not set on the same PCB board, and the capacitors, power semiconductors and inductors of the power circuit are all set on the aluminum substrate.

[0014] Furthermore, the solution may also include a buck circuit in different embodiments, which cooperates with the boost circuit to form a buck-boost circuit.

[0015] Furthermore, the step-down circuit includes switching transistors Q4 and Q5, both of which are NMOS transistors. The gates of switching transistors Q4 and Q5 are electrically connected to the corresponding driving terminals of the main control MCU. The drain of switching transistor Q5 is electrically connected to one end of capacitor C1, the source of switching transistor Q5 is electrically connected to one end of inductor L1 and the drain of switching transistor Q4, and the source of switching transistor Q4 is electrically connected to the other end of capacitor C1.

[0016] The present invention also provides a photovoltaic system comprising a plurality of the above-described photovoltaic power adapters.

[0017] Furthermore, the photovoltaic system also includes a battery pack, a battery pack busbar filter circuit, and an integrated system communication transceiver structure. The photovoltaic power adapter is electrically connected to the battery pack busbar filter circuit and the integrated system communication transceiver structure, respectively, and the battery pack busbar filter circuit is electrically connected to the battery pack.

[0018] Furthermore, the battery pack busbar filtering circuit includes an inductor Ls and a capacitor Cs. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of the inductor Ls and one end of the capacitor Cs. The other end of the inductor Ls is electrically connected to the positive terminal of the battery pack. The power output OUT- terminal of the photovoltaic power adapter is electrically connected to the other end of the capacitor Cs and the negative terminal of the battery pack. This battery pack busbar filtering circuit effectively blocks electromagnetic interference generated by various communication devices connected to the battery pack busbar and the impact of the battery pack's own capacitive characteristics on the PLC carrier communication signal.

[0019] Furthermore, the integrated system communication transceiver structure includes capacitor C5, transformer TX2, and a PLC power line carrier communication module for system operation. Transformer TX2 is a coupling transformer. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of capacitor C5, and the other end of capacitor C5 is electrically connected to one end of the primary winding of transformer TX2. The other end of the primary winding of transformer TX2 is electrically connected to the power output OUT- terminal of the photovoltaic power adapter, and the secondary winding of transformer TX2 is electrically connected to the PLC power line carrier communication module for system operation. This integrated system communication transceiver structure, in conjunction with the communication signal transceiver structure at the photovoltaic power adapter end, forms a master-slave unit PLC power line carrier communication signal transmission channel, effectively ensuring the transmission quality of the PLC power line carrier communication signal and guaranteeing real-time data interaction and stable system operation.

[0020] The beneficial effects of the present invention using the above scheme are as follows: Using non-polarized ceramic capacitors eliminates the need to consider reverse connection at the input end. Furthermore, even with reverse polarity connection, the photovoltaic module's maximum current limit ensures the safety of the body parasitic diode of the switching transistor. The filter network composed of capacitor C2, inductor L2, and capacitor C3 is an improvement over the traditional circuit topology using pure capacitor energy storage filtering. On one hand, it reduces the impact of filter capacitor design specifications on the attenuation of the PLC carrier signal; on the other hand, the superior CLC filter network has better filtering performance to reduce interference from high-frequency switching signals and other noise sources in the preceding energy conversion circuit on the PLC carrier signal, optimizing the transmission environment of the PLC carrier signal. The PLC power line carrier communication function utilizes power transmission lines to achieve data interaction with the control center, meeting the needs of parameter adjustment and work data acquisition. No additional cables are required; on-site construction only requires straightening the two power lines for each circuit, reducing on-site construction difficulty and improving construction efficiency. Attached Figure Description

[0021] Figure 1A and Figure 1B This is a circuit diagram of a photovoltaic power adapter according to the first embodiment of the present invention.

[0022] Figure 2A and Figure 2B This is a circuit diagram of a photovoltaic power adapter according to a second embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a photovoltaic system circuit according to the first embodiment of the present invention. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] Please refer to the following: Figure 1A and Figure 1B In this embodiment, the present invention provides a photovoltaic power adapter with power line carrier communication, including: a boost circuit, an LC filter circuit, a communication signal transceiver structure, and an auxiliary power supply circuit.

[0026] Please see Figure 1A , Figure 1A It includes a boost circuit, an LC filter circuit, and a communication signal transceiver structure. The boost circuit (i.e., the photovoltaic energy conversion structure) includes capacitor C1, capacitor C2, inductor L1, and switching transistors Q1 and Q2. The LC filter circuit includes capacitor C3, inductor L2, and switching transistor Q3. Capacitors C1, C2, and C3 are all non-polarized ceramic capacitors, and switching transistors Q1, Q2, and Q3 are all NMOS transistors.

[0027] One end of capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of inductor L1. The other end of inductor L1 is electrically connected to the drain of switch Q1 and the source of switch Q2. The gate of switch Q1 is electrically connected to the lower drive terminal of the photovoltaic power adapter's main control MCU. The gate of switch Q2 is electrically connected to the upper drive terminal of the photovoltaic power adapter's main control MCU. The drain of switch Q2 is electrically connected to one end of capacitor C2 and one end of inductor L2. The inductor L2 is connected to one end of capacitor C3 and the drain of switching transistor Q3. The source of switching transistor Q3 is connected to the power output OUT+ terminal of the photovoltaic power adapter, and the gate of switching transistor Q3 is connected to the output anti-reverse transistor drive terminal of the main control MCU. The negative output terminal PV- of the photovoltaic module is connected to the other end of capacitor C1, the source of switching transistor Q1, the other end of capacitor C2, the other end of capacitor C3, and the power output OUT- terminal of the photovoltaic power adapter. During operation, the main control MCU controls switching transistors Q1 and Q2 through a high-frequency switching drive circuit to achieve the boost function. The main control MCU controls switching transistor Q3 through an output anti-reverse drive circuit to achieve the output anti-reverse function. The photovoltaic power adapter also includes input and output voltage and current sampling circuits, storage circuits, and DIP address switches, all electrically connected to the main control MCU. The introduction of DIP address switches allows for the construction of field system communication networks, improving the convenience of field system assembly. The communication signal transceiver structure is connected to the LC filter circuit to realize power line carrier communication.

[0028] Furthermore, the communication signal transceiver structure includes a transformer TX1, a capacitor C4, and a PLC power line carrier communication module. The transformer TX1 is a coupling transformer. One end of the capacitor C4 is electrically connected to the source of the switching transistor Q3, and the other end of the capacitor C4 is electrically connected to one end of the primary side of the transformer TX1. The other end of the primary side of the transformer TX1 is electrically connected to the other end of the capacitor C3, and the secondary side of the transformer TX1 is electrically connected to the PLC power line carrier communication module.

[0029] Further, please refer to Figure 1B , Figure 1B The system includes an auxiliary power supply circuit. The positive output terminal PV+ of the photovoltaic module is electrically connected to the positive terminal of the auxiliary power supply circuit through diode D1, and the power output terminal OUT+ is electrically connected to the positive terminal of the auxiliary power supply circuit through diode D2. The negative output terminal PV- and the power output terminal OUT- of the photovoltaic module are both electrically connected to the negative terminal of the auxiliary power supply circuit. The auxiliary power supply section can enable the photovoltaic module to start up when powered by the input power supply and can also operate when the output terminal is connected to the battery bus network.

[0030] In this solution, the power circuit and control circuit of the photovoltaic power adapter are not set on the same PCB board. The control signal and power circuit are separated. The capacitors, power semiconductors, inductors and other components of the power circuit are all mounted on the aluminum substrate. It has a high thermal conductivity and can ensure that the temperature difference between the core and the surface of the product casing is controlled at about 20°C, which can ensure stable and reliable operation even in harsh external high temperature environments of 85°C.

[0031] Please see Figure 2A and Figure 2B In the second embodiment of the photovoltaic power adapter of this solution, unlike the previous embodiment, this embodiment also includes a step-down circuit, which cooperates with the step-up circuit to form a step-up / step-down circuit.

[0032] Specifically, the step-down circuit includes switching transistors Q4 and Q5, both of which are NMOS transistors. The gates of Q4 and Q5 are electrically connected to the corresponding drive terminals of the main control MCU. The drain of Q5 is electrically connected to one end of capacitor C1, and the source of Q5 is electrically connected to one end of inductor L1 and the drain of Q4. The source of Q4 is electrically connected to the other end of capacitor C1. The main control MCU operates through the corresponding drive circuits of switching transistors Q4 and Q5 to achieve the step-down function.

[0033] In this embodiment, the photovoltaic power adapter has a step-up / step-down integrated circuit, which can not only meet the needs of the current mainstream single photovoltaic module, but also the access of a single high-voltage photovoltaic module, and the series connection of multiple low-voltage photovoltaic modules. Its solution has stronger compatibility, but the cost is higher.

[0034] Please see Figure 3 In this embodiment, the present solution also provides a photovoltaic system, including: a plurality of the above-mentioned photovoltaic power adapters, battery packs, battery pack busbar filter circuits and integrated system communication transceiver structures, wherein the photovoltaic power adapters are electrically connected to the battery pack busbar filter circuits and the integrated system communication transceiver structures respectively, and the battery pack busbar filter circuits are electrically connected to the battery packs.

[0035] Furthermore, the battery pack busbar filter circuit includes an inductor Ls and a capacitor Cs. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of the inductor Ls and one end of the capacitor Cs. The other end of the inductor Ls is electrically connected to the positive terminal of the battery pack. The power output OUT- terminal of the photovoltaic power adapter is electrically connected to the other end of the capacitor Cs and the negative terminal of the battery pack.

[0036] Furthermore, the integrated system communication transceiver structure includes capacitor C5, transformer TX2, and a PLC power line carrier communication module for system operation. Transformer TX2 is a coupling transformer. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of capacitor C5, the other end of capacitor C5 is electrically connected to one end of the primary side of transformer TX2, the other end of the primary side of transformer TX2 is electrically connected to the power output OUT- terminal of the photovoltaic power adapter, and the secondary side of transformer TX2 is electrically connected to the PLC power line carrier communication module for system operation.

[0037] In summary, this solution uses non-polarized ceramic capacitors, eliminating the need to consider reverse connection at the input. Furthermore, even with reverse polarity, the photovoltaic module's maximum current limit and the body parasitic diode of the switching transistor ensure safety. The filter network composed of capacitor C2, inductor L2, and capacitor C3 is an improvement over the traditional pure capacitor energy storage filtering method. On one hand, it reduces the impact of filter capacitor design specifications on PLC carrier signal attenuation; on the other hand, the superior CLC filter network offers better filtering performance, reducing interference from high-frequency switching signals and other noise sources in the preceding energy conversion circuit, thus optimizing the PLC carrier signal transmission environment. The PLC power line communication function utilizes power transmission lines to achieve data interaction with the control center, meeting the needs of parameter adjustment and operational data acquisition without requiring additional cabling. On-site construction only requires straightening the two power lines for each circuit, reducing construction difficulty and improving efficiency.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photovoltaic power adapter with power line carrier communication, characterized in that, include: The system includes a boost converter circuit, an LC filter circuit, and a communication signal transceiver structure. The boost converter circuit comprises capacitors C1 and C2, an inductor L1, and transistors Q1 and Q2. The LC filter circuit comprises capacitor C3, inductor L2, and transistor Q3. Capacitors C1, C2, and C3 are non-polarized ceramic capacitors. Transistors Q1, Q2, and Q3 are NMOS transistors. One end of capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of inductor L1. The other end of inductor L1 is electrically connected to the drain of transistor Q1 and the source of transistor Q2. The gate of transistor Q1 is electrically connected to the lower-side drive terminal of the main control MCU. The gate of transistor Q2 is electrically connected to the lower-side drive terminal of the main control MCU. The upper transistor drive terminal is electrically connected. The drain of the switching transistor Q2 is electrically connected to one end of the capacitor C2 and one end of the inductor L2. The other end of the inductor L2 is electrically connected to one end of the capacitor C3 and the drain of the switching transistor Q3. The source of the switching transistor Q3 is electrically connected to the power output OUT+ terminal of the photovoltaic power adapter. The gate of the switching transistor Q3 is electrically connected to the output anti-reverse transistor drive terminal of the main control MCU. The negative output terminal PV- of the photovoltaic module is electrically connected to the other end of the capacitor C1, the source of the switching transistor Q1, the other end of the capacitor C2, the other end of the capacitor C3, and the power output OUT- terminal of the photovoltaic power adapter. The communication signal transceiver structure is connected to the LC filter circuit to realize power line carrier communication.

2. The photovoltaic power adapter with power line carrier communication according to claim 1, characterized in that, The communication signal transceiver structure includes a transformer TX1, a capacitor C4, and a PLC power line carrier communication module. The transformer TX1 is a coupling transformer. One end of the capacitor C4 is electrically connected to the source of the switching transistor Q3, and the other end of the capacitor C4 is electrically connected to one end of the primary side of the transformer TX1. The other end of the primary side of the transformer TX1 is electrically connected to the other end of the capacitor C3, and the secondary side of the transformer TX1 is electrically connected to the PLC power line carrier communication module.

3. The photovoltaic power adapter with power line carrier communication according to claim 1, characterized in that, It also includes an auxiliary power supply circuit, wherein the positive output terminal PV+ of the photovoltaic module is electrically connected to the positive terminal of diode D1, the power output terminal OUT+ is electrically connected to the positive terminal of diode D2, the negative terminals of diode D1 and D2 are both electrically connected to the positive terminal of the auxiliary power supply circuit, and the negative output terminal PV- and power output terminal OUT- of the photovoltaic module are both electrically connected to the negative terminal of the auxiliary power supply circuit.

4. The photovoltaic power adapter with power line carrier communication according to claim 1, characterized in that, The power circuit and the control circuit are not set on the same PCB board. The capacitors, power semiconductors and inductors of the power circuit are all set on an aluminum substrate.

5. The photovoltaic power adapter with power line carrier communication according to any one of claims 1 to 4, characterized in that, It also includes a buck circuit, which works in conjunction with the boost circuit to form a buck-boost circuit.

6. The photovoltaic power adapter with power line carrier communication according to claim 5, characterized in that, The step-down circuit includes switching transistors Q4 and Q5, both of which are NMOS transistors. The gates of switching transistors Q4 and Q5 are electrically connected to the corresponding driving terminals of the main control MCU. The drain of switching transistor Q5 is electrically connected to one end of capacitor C1. The source of switching transistor Q5 is electrically connected to one end of inductor L1 and the drain of switching transistor Q4. The source of switching transistor Q4 is electrically connected to the other end of capacitor C1.

7. A photovoltaic system, characterized in that, It includes several photovoltaic power adapters as described in any one of claims 1 to 6.

8. The photovoltaic system according to claim 7, characterized in that, It also includes a battery pack, a battery pack busbar filter circuit, and an integrated system communication transceiver structure. The photovoltaic power adapter is electrically connected to the battery pack busbar filter circuit and the integrated system communication transceiver structure, respectively. The battery pack busbar filter circuit is electrically connected to the battery pack.

9. The photovoltaic system according to claim 8, characterized in that, The battery pack busbar filter circuit includes an inductor Ls and a capacitor Cs. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of the inductor Ls and one end of the capacitor Cs. The other end of the inductor Ls is electrically connected to the positive terminal of the battery pack. The power output OUT- terminal of the photovoltaic power adapter is electrically connected to the other end of the capacitor Cs and the negative terminal of the battery pack.

10. The photovoltaic system according to claim 8, characterized in that, The integrated system communication transceiver structure includes capacitor C5, transformer TX2, and a PLC power line carrier communication module for system operation. Transformer TX2 is a coupling transformer. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of capacitor C5. The other end of capacitor C5 is electrically connected to one end of the primary side of transformer TX2. The other end of the primary side of transformer TX2 is electrically connected to the power output OUT- terminal of the photovoltaic power adapter. The secondary side of transformer TX2 is electrically connected to the PLC power line carrier communication module for system operation.

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