Photovoltaic power adapter with power line carrier communication and photovoltaic system

Abstract

The invention discloses a photovoltaic power adapter with power line carrier communication and a photovoltaic system. The photovoltaic power adapter comprises a booster circuit, an LC filter circuit and a communication signal transceiving structure, the boost circuit comprises a capacitor C1, a capacitor C2, an inductor L1, a switching tube Q1 and a switching tube Q2, the LC filter circuit comprises a capacitor C3, an inductor L2 and a switching tube Q3, and the capacitor C1, the capacitor C2 and the capacitor C3 are non-polar ceramic capacitors. The invention 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 site construction and application can be reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic base stations, and in particular to a photovoltaic power adapter with power line carrier communication. Background Art

[0002] Photovoltaic power adapters are mainly applied to the base station's superimposed light transformation project. Its main function is to convert and output the energy generated by photovoltaic modules to the positive and negative busbars of the battery pack for various communication devices to use, so as to reduce the power consumption of the base station system from the commercial power, thereby reducing carbon emissions and achieving the purpose of energy conservation and cost reduction in base station operation. The existing photovoltaic power adapters mainly focus on energy conversion. Generally, the fixed output voltage value cannot be changed through communication or other means to set the output parameters; there is also a solution that uses RS485 for wired signal transmission to achieve real-time adjustment of the parameters of the photovoltaic power adapter.

[0003] The existing solutions currently have the following problems: 1. Most of the existing adapter products use polar electrolytic capacitors and other devices, which are not conducive to the anti-reverse connection function requirements of the product or if matching functions are required, the circuit cost will increase. At the same time, the reliability of electrolytic capacitors in high-temperature scenarios is also a major hidden danger.

[0004] 2. The battery pack models used in each communication base station are different, and the specification parameters of the battery packs are also different. If the function of modifying the working parameters of the photovoltaic power adapter to adapt to the ideal working voltage of the battery pack cannot be realized, this will seriously affect the service life of the battery pack. For excessive overvoltage, the battery pack will be damaged or even cause a fire.

[0005] 3. The adapter is generally installed at the bottom of the photovoltaic module. The system solution using the photovoltaic power adapter is a parallel solution. When building the system, each unit has 2 relatively long power lines. If the RS485 wired transmission solution is used, the scene is chaotic when various cables are mixed during construction, and the different on-site construction distances determine that the wires are all processed on-site. It is extremely easy to make mistakes when the signal lines of each path cross the power lines, greatly increasing the on-site construction difficulty and even causing equipment damage during the construction process.

[0006] 4. Power line carrier communication has high requirements for power supply, and the voltage needs to be relatively stable. Moreover, the battery pack is equivalent to a relatively large and complex capacitor, which will cause attenuation to the power line carrier signal. Load changes, line losses, electromagnetic interference, and signal attenuation on the power transmission line will cause an increase in the communication error rate, affecting the stability and reliability of communication. It is very difficult to ensure the communication quality of power line carrier communication.

[0007] Therefore, the existing technology has defects and needs to be improved. Summary of the Invention

[0008] The object of the present invention is to overcome at least part of the deficiencies of the prior art, and to provide a photovoltaic power adapter and a 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, including: a boost circuit, an LC filter circuit, and a communication signal transceiver structure;

[0010] The boost circuit includes a capacitor C1, a capacitor C2, an inductor L1, a switching transistor Q1, and a switching transistor Q2. The LC filter circuit includes a capacitor C3, an inductor L2, and a switching transistor Q3. The capacitor C1, the capacitor C2, and the capacitor C3 are all non-polar ceramic capacitors. The switching transistors Q1, Q2, and Q3 are all NMOS transistors. One end of the capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of the inductor L1 respectively. The other end of the inductor L1 is electrically connected to the drain of the switching transistor Q1 and the source of the switching transistor Q2 respectively. The gate of the switching transistor Q1 is electrically connected to the lower transistor drive terminal. The gate of the switching transistor Q2 is electrically connected to the upper transistor drive terminal. The drain of the switching transistor Q2 is electrically connected to one end of the capacitor C2 and one end of the inductor L2 respectively. 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 respectively. The source of the switching transistor Q3 is electrically connected to the power output OUT+ terminal. 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 respectively. The communication signal transceiver structure is connected to the LC filter circuit for realizing power line carrier communication.

[0011] Further, 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. 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. The secondary side of the transformer TX1 is electrically connected to the PLC power line carrier communication module.

[0012] Further, the solution further includes an auxiliary power supply circuit. The positive output terminal PV+ of the photovoltaic module is electrically connected to the positive electrode of a diode D1. The power output OUT+ terminal is electrically connected to the positive electrode of a diode D2. The negative electrodes of the diode D1 and the diode D2 are both electrically connected to the positive extreme of the auxiliary power supply circuit. The negative output terminal PV- of the photovoltaic module and the power output OUT- terminal are both electrically connected to the negative extreme of the auxiliary power supply circuit.

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

[0014] Further, the solution may further include a buck circuit in different embodiments, and the buck circuit cooperates with the boost circuit to form a buck-boost circuit.

[0015] Further, the buck circuit includes a switching transistor Q4 and a switching transistor Q5. Both the switching transistor Q4 and the switching transistor Q5 are NMOS transistors. The gates of the switching transistor Q4 and the switching transistor Q5 are respectively electrically connected to the corresponding driving ends of the main control MCU. The drain of the switching transistor Q5 is electrically connected to one end of the capacitor C1. The source of the switching transistor Q5 is electrically connected to one end of the inductor L1 and the drain of the switching transistor Q4. The source of the switching transistor Q4 is electrically connected to the other end of the capacitor C1.

[0016] The present invention also provides a photovoltaic system, including a plurality of the above-mentioned photovoltaic power adapters.

[0017] Further, the photovoltaic system further includes a battery pack, a battery pack busbar terminal filtering circuit, a battery pack, and an integrated system communication transceiver structure. The photovoltaic power adapter is electrically connected to the battery pack busbar terminal filtering circuit and the integrated system communication transceiver structure, and the battery pack busbar terminal filtering circuit is electrically connected to the battery pack.

[0018] Further, the battery pack busbar terminal 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 electrode 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 electrode of the battery pack. The battery pack busbar terminal filtering circuit part can effectively intercept the electromagnetic interference generated by various communication devices connected to the battery pack busbar and the influence of the capacitance characteristics of the battery pack itself on the PLC carrier communication signal

[0019] Furthermore, the communication transceiver structure of the integrated system includes a capacitor C5, a transformer TX2, and, the transformer TX2 is a coupling transformer. The power output OUT+ terminal of the photovoltaic power adapter is electrically connected to one end of the capacitor C5. The other end of the capacitor C5 is electrically connected to one end of the primary side of the transformer TX2. The other end of the primary side of the transformer TX2 is electrically connected to the power output OUT- terminal of the photovoltaic power adapter. The secondary side of the transformer TX2 is electrically connected to the PLC power line communication module for system operation. The communication transceiver structure of the integrated system and the communication signal transceiver structure at the photovoltaic power adapter end cooperate to form a master-slave unit PLC power line communication signal transmission channel, which can effectively guarantee the transmission quality of the PLC power line communication signal, ensure real-time data interaction and the stability of system operation.

[0020] Adopting the above solution, the beneficial effects of the present invention are as follows: By using non-polar ceramic capacitors, there is no need to consider reverse connection at the input end. And in the case of reverse polarity connection, due to the maximum current limit existing in the photovoltaic module itself, the body parasitic diode of the switching tube can also ensure safety without damage. The filter network composed of capacitor C2, inductor L2, and capacitor C3 is actually an improvement on the traditional circuit topology using pure capacitor energy storage filtering method. On the one hand, it reduces the design specification of the filter capacitor and weakens the attenuation effect on the PLC carrier signal. On the other hand, the better CLC filter network has better filtering performance to reduce the interference of high-frequency switching signals and other noise sources in the front-stage energy conversion circuit on the PLC carrier signal, optimizing the transmission environment of the PLC carrier signal; By using the function of PLC power line communication, data interaction with the control center is realized through the power transmission line, meeting the requirements of parameter adjustment and working data collection. There is no need to additionally increase cables. During on-site construction, only the positive and negative power lines of each circuit need to be sorted out, reducing the on-site construction difficulty and improving the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0023] Figure 3 is a circuit schematic diagram of the photovoltaic system according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0025] Please refer to Figure 1A andFigure 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 refer to 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 a capacitor C1, a capacitor C2, an inductor L1, a switching transistor Q1, and a switching transistor Q2. The LC filter circuit includes a capacitor C3, an inductor L2, and a switching transistor Q3. The capacitor C1, the capacitor C2, and the capacitor C3 are all non-polar ceramic capacitors. The switching transistors Q1, Q2, and Q3 are all NMOS transistors.

[0027] One end of the capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of the inductor L1 respectively. The other end of the inductor L1 is electrically connected to the drain of the switching transistor Q1 and the source of the switching transistor Q2 respectively. The gate of the switching transistor Q1 is electrically connected to the lower transistor driving terminal of the main control MCU of the photovoltaic power adapter. The gate of the switching transistor Q2 is electrically connected to the upper transistor driving terminal of the main control MCU of the photovoltaic power adapter. The drain of the switching transistor Q2 is electrically connected to one end of the capacitor C2 and one end of the inductor L2 respectively. 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 respectively. The source of the switching transistor Q3 is electrically connected to the power output OUT+ terminal. 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 respectively. During operation, the main control MCU controls the switching transistors Q1 and Q2 to work through a high-frequency switching drive circuit, thereby realizing the boost function. The main control MCU controls the switching transistor Q3 to work through an output reverse protection drive circuit, thereby realizing the output reverse protection function. The photovoltaic power adapter is also provided with an input and output voltage and current sampling circuit, a storage circuit, and a DIP address switch, all of which are electrically connected to the main control MCU. The DIP address switch is introduced and can be used for the construction of the on-site system communication network, improving the convenience of on-site system assembly. The communication signal transceiver structure is connected to the LC filter circuit for realizing power line carrier communication.

[0028] Furthermore, the communication signal transceiver structure includes a transformer TX1, a capacitor C4 and a PLC power carrier communication module, the transformer TX1 is a coupling transformer, one end of the capacitor C4 is electrically connected to the source of the switch tube Q3, 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 carrier communication module.

[0029] For further information, see Figure 1B , Figure 1B It 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 a diode D1, the power output OUT+ terminal is electrically connected to the positive terminal of the auxiliary power supply circuit through a diode D2, the negative output terminal PV- of the photovoltaic module and the power output OUT- terminal are both electrically connected to the negative terminal of the auxiliary power supply circuit, and the auxiliary power supply part can not only realize the power supply startup of the photovoltaic module input, but also operate when the output terminal is connected to the battery bus network.

[0030] The power circuit and control circuit of the photovoltaic power adapter of this solution are not set on the same PCB board. The design of separating the control signal and the power circuit is adopted. The capacitors, power semiconductors, inductors, etc. of the power circuit are all loaded on the aluminum substrate. It has super thermal conductivity to ensure that the temperature difference between the core temperature and the surface of the product shell is controlled at about 20°C, ensuring stable and reliable operation even in the harsh external high temperature environment of 85°C.

[0031] See also Figure 2A and Figure 2B In the second embodiment of the photovoltaic power adapter of the present solution, different from the previous embodiment, the present embodiment also includes a buck circuit, and the buck circuit cooperates with the boost circuit to form a buck-boost circuit.

[0032] Specifically, the step-down circuit includes a switch tube Q4 and a switch tube Q5, both of which are NMOS tubes, the gate of the switch tube Q4 and the gate of the switch tube Q5 are electrically connected to the corresponding driving end of the main control MCU, the drain of the switch tube Q5 is electrically connected to one end of the capacitor C1, the source of the switch tube Q5 is electrically connected to one end of the inductor L1 and the drain of the opening tube Q4, and the source of the switch tube Q4 is electrically connected to the other end of the capacitor C1. The main control MCU works through the corresponding drive circuit switch tubes Q4 and Q5 to achieve the step-down function.

[0033] In this embodiment, the photovoltaic power adapter has a buck-boost integrated functional circuit, which can not only meet the use of current mainstream single photovoltaic modules, but also meet the access use of single high-voltage photovoltaic modules, and can also meet the series connection use of multiple low-voltage photovoltaic modules. Its solution has stronger compatibility but higher cost.

[0034] Please refer to Figure 3 , in this embodiment, the solution also provides a photovoltaic system, including: a plurality of the above-mentioned photovoltaic power adapters, a battery pack, a battery pack busbar end filter circuit, a battery pack, and an integrated system communication transceiver structure. The photovoltaic power adapter is electrically connected to the battery pack busbar end filter circuit and the integrated system communication transceiver structure, and the battery pack busbar end filter circuit is electrically connected to the battery pack.

[0035] Further, the battery pack busbar end 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 electrode of the battery pack, and the power output OUT- terminal of the photovoltaic power adapter is electrically connected to the other end of the capacitor Cs and the negative electrode of the battery pack.

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

[0037] In summary, in this solution, non-polar ceramic capacitors are used, eliminating the need to consider reverse connection at the input. Moreover, in the case of reverse polarity connection, due to the maximum current limit of the photovoltaic module itself, the body parasitic diode of the switching transistor can also ensure safety without damage. The filter network composed of capacitor C2, inductor L2, and capacitor C3 is actually an improvement on the traditional circuit topology using pure capacitor energy storage filtering. On the one hand, it reduces the design specification of the filter capacitor to weaken the attenuation effect on the PLC carrier signal. On the other hand, the superior CLC filter network has better filtering performance to reduce the interference of high-frequency switching signals from the front-stage energy conversion circuit and other noise sources on the PLC carrier signal, optimizing the transmission environment of the PLC carrier signal. The function of PLC power line communication is used to realize data interaction with the control center through the power transmission line, meeting the requirements of parameter adjustment and working data acquisition. There is no need to add extra cables, and on-site construction only requires straightening the positive and negative power lines for each circuit, reducing the on-site construction difficulty and improving the construction efficiency.

[0038] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A photovoltaic power adapter with power carrier communication, characterized in that: include: Boost circuit, LC filter circuit, communication signal transceiver structure; The boost circuit includes a capacitor C1, a capacitor C2, an inductor L1, a switch tube Q1 and a switch tube Q2; the LC filter circuit includes a capacitor C3, an inductor L2 and a switch tube Q3; the capacitor C1, the capacitor C2 and the capacitor C3 are all non-polar ceramic capacitors; the switch tubes Q1, the switch tubes Q2 and the switch tubes Q3 are all NMOS tubes; one end of the capacitor C1 is electrically connected to the positive output terminal PV+ of the photovoltaic module and one end of the inductor L1, respectively; the other end of the inductor L1 is electrically connected to the drain of the switch tube Q1 and the source of the switch tube Q2, respectively; the gate of the switch tube Q1 is electrically connected to the lower tube driving end, and the gate of the switch tube Q2 is electrically connected to the upper tube driving end. The drain of the switch tube Q2 is electrically connected to one end of the capacitor C2 and one end of the inductor L2 respectively, the other end of the inductor L2 is electrically connected to one end of the capacitor C3 and the drain of the switch tube Q3 respectively, the source of the switch tube Q3 is electrically connected to the power output OUT+ terminal, the gate of the switch tube Q3 is electrically connected to the output anti-reverse tube driving terminal, and the negative output terminal PV- of the photovoltaic component is electrically connected to the other end of the capacitor C1, the source of the switch tube Q1, the other end of the capacitor C2, the other end of the capacitor C3, and the power output OUT- terminal respectively; the communication signal transceiver structure is connected to the LC filter circuit to realize power carrier communication.

2. The photovoltaic power adapter with power 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 carrier communication module. The transformer TX1 is a coupling transformer. One end of the capacitor C4 is electrically connected to the source of the switch tube Q3, 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 carrier communication module.

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

4. The photovoltaic power adapter with power carrier communication according to claim 1, characterized in that: The power circuit and the control circuit are not arranged on the same PCB board, and the capacitor, power semiconductor and inductor of the power circuit are all arranged on the aluminum substrate.

5. The photovoltaic power adapter with power carrier communication according to any one of claims 1 to 4, characterized in that: It also includes a step-down circuit, which cooperates with the step-up circuit to form a step-up and step-down circuit.

6. The photovoltaic power adapter with power carrier communication according to claim 5, characterized in that: The step-down circuit includes a switch tube Q4 and a switch tube Q5, both of which are NMOS tubes. The gate of the switch tube Q4 and the gate of the switch tube Q5 are respectively electrically connected to the corresponding driving end of the main control MCU, the drain of the switch tube Q5 is electrically connected to one end of the capacitor C1, the source of the switch tube Q5 is electrically connected to one end of the inductor L1 and the drain of the opening tube Q4, and the source of the switch tube Q4 is electrically connected to the other end of the capacitor C1.

7. A photovoltaic system, characterized in that: It comprises a plurality of photovoltaic power adapters as claimed 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 end filter circuit, a battery pack and an integrated system communication transceiver structure. The photovoltaic power adapter is electrically connected to the battery pack busbar end filter circuit and the integrated system communication transceiver structure, and the battery pack busbar end filter circuit is electrically connected to the battery pack.

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

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

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