Power converter, photovoltaic power generation system and photovoltaic optimizer

Abstract

The embodiment of the utility model provides a power converter, a photovoltaic power generation system and a photovoltaic optimizer, which are applied to the technical field of power line carrier communication. The power converter comprises a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module and a coupler. Wherein the radio frequency processing circuit is connected with the power transmission line through the coupler so as to receive and transmit radio frequency signals with the power transmission line. In order to realize receiving and transmitting isolation between a receiving signal and a transmitting signal, a first isolator needs to be arranged on a receiving path of a radio frequency processing circuit, and a second isolator needs to be arranged on a transmitting path. At the moment, the radio frequency signal is subjected to up-conversion based on the up-conversion module and then input into the first isolator, and the radio frequency signal output by the second isolator is subjected to down-conversion based on the down-conversion module, so that the two isolators work in a higher frequency band, and the high-isolation isolator is easier to design in the higher frequency band. And high-precision isolation processing under full duplex of the PLC is realized.

Description

Technical Field

[0001] The present application relates to the technical field of power carrier communication, and in particular to a power converter, a photovoltaic power generation system and a photovoltaic optimizer. Background Art

[0002] Power line communication (PLC) technology is a technology that uses power transmission cables as communication channels. In a photovoltaic power generation system, power transmission is achieved between different devices based on power transmission lines. In order to detect and control the working status of each device in the photovoltaic power generation system, different devices in the photovoltaic power generation system can perform business information transmission and interaction based on power carrier communication technology (for example, multiple power converters can perform PLC communication with data collectors, and multiple photovoltaic optimizers can perform PLC communication with power converters). Business information may include working status parameters of the corresponding device, or related control instructions for adjusting the working status of the corresponding device. In actual applications, it is necessary to receive and transmit signals carrying business information based on PLC full-duplex communication technology. However, in full-duplex application scenarios, the receiving signal received and the transmitting signal sent by the same device from the power transmission line based on PLC communication will interfere with each other. Therefore, a corresponding isolator needs to be set between the transmitter and the receiver to achieve mutual isolation between the receiving signal and the transmitting signal.

[0003] Since PLC applications use low-frequency, broadband RF signals for communication, it is difficult to adapt low-frequency, broadband RF signals to design high-precision isolators. Although there are many isolation devices designed in the field of wireless communications for isolating RF signals, the frequency bands of RF signals in the field of wireless communications are very high, and these isolation devices are difficult to adapt to PLC applications. PLC full-duplex communication has very high requirements for the isolation between the received and transmitted RF signals. Therefore, how to perform high-precision isolation processing on the RF signals received and transmitted by PLC full-duplex communication is a major problem. Utility Model Content

[0004] The embodiments of the present application provide a power converter, a photovoltaic power generation system and a photovoltaic optimizer, which realize high-precision isolation design processing of the receiving and transmitting interference noise of relevant devices in the photovoltaic power generation system when performing PLC full-duplex communication.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In the first aspect, a power converter is provided, wherein the power converter is used to communicate with a data collector or a photovoltaic optimizer through a power transmission line, the photovoltaic optimizer is used to connect a photovoltaic power generation panel, and the power converter includes a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module, and a coupler. Wherein: the coupler is used to couple the transmission signal to the power transmission line for transmission to the data collector or the photovoltaic optimizer, and is also used to receive the reception signal transmitted by the data collector or the photovoltaic optimizer to the power converter through the power transmission line. The first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the radio frequency processing circuit. The first output end of the coupler is used to transmit the reception signal to the input end of the up-conversion module. The up-conversion module is used to convert the reception signal into the first radio frequency signal. The radio frequency processing circuit is used to obtain the first radio frequency signal. The output end of the RF processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, the output end of the down-conversion module is connected to the first input end of the coupler, and the first input end of the coupler is used to receive the transmission signal sent by the output end of the down-conversion module. The RF processing circuit is used to: send a second RF signal; the down-conversion module is used to: convert the second RF signal into the transmission signal. The corresponding RF signal is unidirectionally transmitted on the first isolator and the second isolator.

[0007] Exemplarily, taking the transmission of a first RF signal on a first isolator as an example, unidirectional transmission means that the first RF signal can only be transmitted from the input end of the first isolator to the output end of the first isolator, but cannot be transmitted in reverse from the output end of the first isolator to the input end of the first isolator. Taking the transmission of a second RF signal on a second isolator as an example, unidirectional transmission means that the second RF signal can only be transmitted from the input end of the second isolator to the output end of the second isolator, but cannot be transmitted in reverse from the output end of the second isolator to the input end of the second isolator.

[0008] The power converter can realize PLC full-duplex communication based on the power transmission line and the data collector or photovoltaic optimizer. However, in the application scenario of power carrier communication, the frequency of the radio frequency signal transmitted on the power transmission line is relatively low, which is far lower than the operating frequency of wireless radio frequency communication. When performing PLC full-duplex transceiver communication, transceiver isolation is required between the receiving path and the transmitting path to achieve normal operation of receiving and transmitting. This has very high requirements for the isolation between transceiver and transmitter. However, in signal design, many isolation devices are designed for high-frequency wireless communication application scenarios. These isolation devices are difficult to apply to low-frequency radio frequency signals of power carrier communication in terms of impedance characteristic design and working frequency band design. In the embodiment of the present application, the radio frequency signal of power carrier communication is frequency-converted by designing the radio frequency signal between the radio frequency processing circuit of the power converter and the power transmission line, so as to realize that the isolator with excellent performance in the high-frequency wireless communication system can be applied to the scenario of power carrier communication, thereby improving the transceiver isolation and reducing the design complexity of other hardware performance design matching. Specifically, the received signal can be up-converted based on the up-conversion module to obtain a first radio frequency signal with a higher frequency. At this time, it is possible to realize that the isolator (such as the first isolator) with unidirectional conduction transmission characteristics used in the high-frequency wireless communication system is adapted to the power converter to design the unidirectional conduction transmission of the first radio frequency signal. Similarly, the radio frequency processing circuit can also transmit a second radio frequency signal with a higher frequency, and down-convert the second radio frequency signal of the high frequency based on the down-conversion module, so as to process the second radio frequency signal of the high frequency as a transmission signal with a lower frequency, and transmit the low-frequency transmission signal to the power transmission line through a coupler. At this time, the isolator (such as the second isolator) with unidirectional conduction transmission characteristics used in the high-frequency communication system can be set between the radio frequency processing circuit and the down-conversion module. In the embodiment of the present application, the frequency conversion processing of the radio frequency signal is performed by the up-conversion module and the down-conversion module, so as to realize that the isolation device in the high-frequency wireless communication system is adapted to the power converter of the low-frequency power carrier communication technology, and the transceiver interference noise isolation design of the PLC full-duplex communication with high isolation is realized.

[0009] In one possible implementation, the first isolator and / or the second isolator include at least one circulator; when at least one circulator includes multiple circulators, the multiple circulators form a cascade transmission structure, in which the first end of the circulator of the first stage is the input end of the isolator, and the second end of the circulator of the last stage is the output end of the isolator; the second end of the circulator of the front stage in the two adjacent circulators is connected to the first end of the circulator of the rear stage. In an embodiment of the present application, the first isolator and / or the second isolator can be designed based on the circulator. The circulator is a non-reversible device with multiple ports. There is a certain signal transmission order between the multiple ports of the circulator. With any of the multiple ports as the input end, the signal input to the circulator can only be output from the next port corresponding to the any port. At the same time, the circulator also has the characteristics of low transmission insertion loss and high port isolation. In addition, due to the advantages of high isolation of each port of the circulator, the impedance between each port is relatively independent, and the application of the circulator can also reduce the design difficulty of the coupling impedance between different ports. Due to the above-mentioned excellent characteristics of the circulator, it is usually designed as a signal isolation device with unidirectional conduction transmission characteristics in a high-frequency wireless communication system. However, the design of the circulator is also related to the frequency band of the signal. If it is in a low-frequency signal communication system, such as a power carrier communication system, it requires a wide bandwidth, so that the circulator has a large device volume overhead under the low-frequency design, which affects the integration of the equipment; and the working frequency band is narrow, and it is difficult to achieve a good transceiver isolation effect. Therefore, it is difficult to use the circulator as an isolator in a traditional power carrier communication system. In the embodiment of the present application, the RF signal in the power carrier communication system can be frequency-converted through an up-conversion module and a down-conversion module to adapt to the working frequency band of the circulator, thereby realizing the transceiver isolation application of the circulator under full-duplex communication in a low-frequency power carrier communication system. When the circulator is multi-stage series-connected, due to the unidirectional conduction characteristics of multiple circulators, the isolation can be improved to be applied in application scenarios with higher isolation accuracy requirements. Based on this embodiment, the power converter can achieve PLC communication with higher transceiver isolation.

[0010] In a possible implementation, the third end of each circulator is connected to an interference noise isolation circuit, and the interference noise isolation circuit is used to filter out the interference noise signal transmitted from the second end of the corresponding circulator to the third end. In an embodiment of the present application, when the first end of the circulator is the input end and the second end is the output end, the signal transmission order between the three ports of the circulator is: a cyclic order from the first end to the second end and then to the third end. Therefore, when the first end of the circulator is the input end, the second end of the circulator is the output end. When the second end of the circulator is the input end, the third end of the circulator is the output end. Therefore, when there is an interference noise signal reflected back at the second end of the circulator, the interference noise signal will be transmitted from the second end of the circulator to the third end of the circulator, and will be transmitted back to the radio frequency processing circuit through the third end of the circulator. By setting an interference noise isolation circuit at the third end of each circulator, the interference noise signal of the echo generated at the second end of the circulator can be absorbed to improve isolation and anti-interference capabilities.

[0011] Exemplarily, the interference noise isolation circuit is a load matching circuit, and the load matching circuit is used to absorb the interference noise signal. In the embodiment of the present application, the load matching circuit can be a load matching circuit with a certain frequency response, and the interference noise signal of the echo is absorbed based on the load matching circuit. For example, in actual applications, the frequency range of the interference noise signal of the echo can be confirmed, and a load matching circuit with a certain frequency response can be designed to filter and absorb the interference noise signal of this part of the echo.

[0012] In one possible implementation, the up-conversion module includes an up-conversion mixer and a first local oscillator circuit. The input end of the up-conversion mixer is connected to the first output end of the coupler, and the output end of the up-conversion mixer is connected to the input end of the first isolator. The first local oscillator circuit is connected to the reference signal end of the up-conversion mixer. Wherein: the first local oscillator circuit is used to: output a first local oscillator signal located in the first frequency band. The up-conversion mixer is used to: input a received signal located in the second frequency band, and mix the received signal based on the first local oscillator signal to obtain a first radio frequency signal located in the first frequency band, and the first frequency band is higher than the second frequency band. In an embodiment of the present application, based on the first local oscillator circuit providing a high-frequency first local oscillator signal, the up-conversion mixer mixes the low-frequency received signal with the high-frequency first local oscillator signal to obtain a high-frequency first radio frequency signal. For the high-frequency first radio frequency signal, it is easier to design the corresponding first isolator.

[0013] In a possible implementation, the power converter further includes a first filter and a second filter. The first filter is connected between the first output terminal of the coupler and the input terminal of the up-conversion module. The second filter is connected between the output terminal of the up-conversion module and the input terminal of the first isolator. In an embodiment of the present application, based on the first filter, filtering of the clutter in the low-frequency received signal output by the coupler can be achieved. Based on the second filter, filtering of the clutter in the high-frequency first RF signal obtained by the up-conversion process can be achieved. Based on the above operation, the interference noise signal in the signal on the receiving path of the RF processing circuit relative to the power transmission line can be further reduced to improve the isolation of the signal and the signal processing accuracy.

[0014] In a possible implementation, the down-conversion module includes a down-conversion mixer and a second local oscillator circuit. The input end of the down-conversion mixer is connected to the output end of the second isolator, and the output end of the down-conversion mixer is connected to the first input end of the coupler. The second local oscillator circuit is connected to the reference signal end of the down-conversion mixer. Wherein: the second local oscillator circuit is used to: output a second local oscillator signal located in the third frequency band. The down-conversion mixer is used to: input a second radio frequency signal located in the fourth frequency band, mix the second radio frequency signal based on the second local oscillator signal, and obtain a transmission signal located in the third frequency band, and the fourth frequency band is higher than the third frequency band. In an embodiment of the present application, the second local oscillator circuit can provide a low-frequency second local oscillator signal. The down-conversion mixer mixes the high-frequency second radio frequency signal and the low-frequency second local oscillator signal to obtain a low-frequency transmission signal. For the high-frequency second radio frequency signal, it is easier to design the corresponding second isolator, and the down-conversion module is designed at the rear stage of the second isolator to down-convert the second radio frequency signal after the transmission and reception isolation to obtain a low-frequency second radio frequency signal. The low-frequency transmission signal meets the low-frequency band requirements of PLC communication.

[0015] In a possible implementation, the power converter further includes a third filter and a fourth filter. The third filter is connected between the output end of the second isolator and the input end of the down-conversion module. The fourth filter is connected between the output end of the down-conversion module and the first input end of the coupler. In an embodiment of the present application, based on the third filter, it can be implemented that after the output of the radio frequency processing circuit, the clutter in the high-frequency second radio frequency signal that is not input into the down-conversion module is filtered. Based on the fourth filter, it can be implemented that the clutter in the low-frequency transmission signal after the down-conversion process is filtered. Based on the above operation, the interference noise signal in the signal on the transmission path of the radio frequency processing circuit relative to the power transmission line can be further reduced to improve the isolation of the signal and the signal processing accuracy.

[0016] In a possible implementation, the power converter further includes a decoupling circuit. The input end of the radio frequency processing circuit is connected to the output end of the first isolator after being connected to the decoupling circuit. The output end of the radio frequency processing circuit is connected to the input end of the second isolator after being connected to the decoupling circuit. In an embodiment of the present application, a decoupling circuit is provided at the output end and the input end of the radio frequency processing circuit to further improve the transmit-receive isolation.

[0017] In some possible implementations, the RF processing circuit may also include an up-conversion processing device and a down-conversion processing device. In the embodiment of the present application, the up-conversion module and the down-conversion module may be used as devices for adjusting the frequency to adapt the isolation device. In the RF processing circuit, corresponding up-conversion processing devices and down-conversion processing devices may also be additionally provided to perform relevant processing on the RF signal.

[0018] In some possible implementations, the RF processing circuit may not include an up-conversion processing device and a down-conversion processing device. In the embodiment of the present application, the frequency conversion processing of the RF signal can be implemented based on the up-conversion module and the down-conversion module. No related frequency conversion processing is required in the RF processing circuit.

[0019] In some possible implementations, the radio frequency processing circuit can be used as a radio frequency channel for wireless communication. Exemplarily, the power converter can obtain a first radio frequency signal obtained based on the received signal based on the radio frequency processing circuit, and directly transmit the first radio frequency signal wirelessly to realize the transmission of the first radio frequency signal to other communication devices with wireless communication functions. Similarly, the power converter can receive a second radio frequency signal transmitted by other wireless communication devices based on the radio frequency processing circuit, and convert the second radio frequency signal into a transmission signal through a down-conversion module and transmit it to the three-phase power line to assist in realizing PLC communication based on the power converter for other wireless communication devices. In an embodiment of the present application, the power converter can be used as a communication transfer between other wireless communication devices and power carrier communication devices. It receives the second radio frequency signal carrying business information transmitted by other devices, and after processing based on the radio frequency processing circuit and the second isolator, the down-conversion module, etc., obtains a low-frequency transmission, and transmits it to the power transmission line through a coupler, so that other devices connected to the power transmission line (such as photovoltaic optimizers or data collectors) can obtain and analyze. At the same time, the power converter can also obtain a low-frequency first RF signal from the power transmission line through a coupler, and obtain a high-frequency first RF signal after processing based on an up-conversion module, a first isolator, etc., and transmit it through a RF processing circuit for acquisition by other wireless communication devices.

[0020] In a possible implementation, the power converter further includes a data processing circuit; the data processing circuit is connected to the radio frequency processing circuit. Wherein: the data processing circuit is used to: input a first baseband data signal from the radio frequency processing circuit; output a second baseband data signal to the radio frequency processing circuit, and the first baseband data signal and the second baseband data signal are used to indicate business information. The radio frequency processing circuit is also used to: obtain a first baseband data signal according to the first radio frequency signal; obtain a second radio frequency signal according to the second baseband data signal. In an embodiment of the present application, the data processing circuit operates in the digital domain and can parse and process the baseband data signal. The power converter can also process the input first radio frequency signal into a first baseband data signal through the radio frequency processing circuit to provide it to the data processing circuit. The data processing circuit can parse and process the business information carried on the first radio frequency signal based on the first baseband data signal. Similarly, the data processing circuit can also carry some business information on the second baseband data signal and transmit the second baseband data signal to the radio frequency processing circuit. The RF processing circuit processes the second baseband data signal into a second RF signal, and transmits the second RF signal to the down-conversion module, which converts the second RF signal into a transmission signal and transmits it to the power transmission line to perform PLC communication.

[0021] Exemplarily, the power converter can output a second baseband data signal for indicating business information (e.g., relevant adjustment control instruction information sent by the power converter to the photovoltaic optimizer, or relevant working status information sent by the power converter to the data collector, etc.) based on the data processing circuit, obtain the second RF signal based on the RF processing circuit, and then convert the second RF signal into a transmission signal through the down-conversion module and transmit it to the power transmission line. Exemplarily, the power converter can also obtain the corresponding first RF signal from the power transmission line based on the RF processing circuit, and the first RF signal carries relevant business information (e.g., relevant working status information received by the power converter from the photovoltaic optimizer, or relevant adjustment control instruction information received by the power converter from the data collector, etc.). The first RF signal is processed based on the RF processing circuit to obtain the first baseband data signal. The data processing circuit of the power converter parses the first baseband data signal to obtain the corresponding business information.

[0022] Exemplarily, the power converter may further include a memory. The memory is connected to the data processing circuit. In an embodiment of the present application, the data processing circuit may parse and process the interactive business information based on the baseband data signal. Other data may also be processed, such as processing the performance status of the power converter, processing the data collected by the sensor in the photovoltaic optimizer or device, etc. The memory may store some computer programs based on the operation of the data processing circuit of the power converter, may store the device performance status information of the power converter, store the interactive business information, store the data collected by the relevant sensors in the power converter, etc.

[0023] In a second aspect, an embodiment of the present application further provides a photovoltaic power generation system, which includes one or more power converters and a data collector as described in the first aspect above, and the one or more power converters are used to communicate with the data collector through a power transmission line.

[0024] In a third aspect, an embodiment of the present application further provides a photovoltaic power generation system, which includes a power converter and one or more photovoltaic optimizers as described in the first aspect above, wherein the power converter is used to communicate with the one or more photovoltaic optimizers through a power transmission line, and each of the one or more photovoltaic optimizers is used to connect to a photovoltaic power generation panel.

[0025] In a fourth aspect, an embodiment of the present application also provides a photovoltaic optimizer, which is used to connect a photovoltaic power generation panel, transfer the electric energy generated by the photovoltaic power generation panel to a power converter, and communicate with the power converter through a power transmission line. The photovoltaic optimizer includes a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module, and a coupler. Wherein: the coupler is used to couple the transmission signal to the power transmission line for transmission to the power converter, and is also used to receive the reception signal transmitted by the power converter to the photovoltaic optimizer through the power transmission line. The first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the radio frequency processing circuit. The first output end of the coupler is used to transmit the received signal to the input end of the up-conversion module. The up-conversion module is used to: convert the received signal into a first radio frequency signal. The radio frequency processing circuit is used to: obtain the first radio frequency signal. The output end of the RF processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, the output end of the down-conversion module is connected to the first input end of the coupler, and the first input end of the coupler is used to receive the transmission signal sent by the output end of the down-conversion module; the RF processing circuit is used to: send the second RF signal; the down-conversion module is used to: convert the second RF signal into a transmission signal; the corresponding RF signal is unidirectionally transmitted on the first isolator and the second isolator.

[0026] For the description of the technical principles and beneficial effects of the second, third and fourth aspects, please refer to the relevant description of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a photovoltaic power generation system provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the structure of a first power converter provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 1 ;

[0030] Figure 4 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 2 ;

[0031] Figure 5 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 3 ;

[0032] Figure 6 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 4 ;

[0033] Figure 7 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 5 ;

[0034] Figure 8 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 6 ;

[0035] Fig. 9 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 7 ;

[0036] Fig.10 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 8 ;

[0037] Fig.11 A schematic diagram of a second power converter provided in an embodiment of the present application Figure 9 . DETAILED DESCRIPTION

[0038] It should be noted that the terms "first", "second", etc. involved in the embodiments of the present application are only used to distinguish features of the same type and cannot be understood as indicating relative importance, quantity, order, etc.

[0039] The terms "exemplary" or "for example" and the like in the embodiments of the present application are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the related concepts in a specific way.

[0040] The terms "coupling" and "connection" involved in the embodiments of the present application should be understood in a broad sense. For example, they may refer to a direct physical connection, or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0041] Power line carrier (PLC) communication technology is a technology that uses power transmission lines as communication channels. It modulates analog or digital signals on power transmission lines through carriers for transmission, so as to realize interactive communication between multiple nodes based on power transmission lines. Typical PLC communication is point-to-multiple point (P2MP) wired communication, that is, a central control node (CCO) and multiple communication sub-nodes (STA) are set up in the PLC communication system. Multiple communication sub-nodes can communicate with the central control node respectively. Multiple communication sub-nodes can also communicate with each other based on the central control node. As an efficient and stable communication method, PLC can not only complete long-distance signal transmission, but also has high transmission efficiency, good reliability and confidentiality, and is suitable for many practical applications. PLC full-duplex communication can greatly improve the utilization efficiency of PLC spectrum, but the PLC full-duplex communication system requires high-isolation RF devices and circuits to implement.

[0042] Photovoltaic generation system (PGS) is a power generation system that directly converts solar radiation energy into electrical energy by utilizing the photovoltaic effect of semiconductor materials. Figure 1As shown, the photovoltaic power generation system includes a photovoltaic array 100, a power converter 200, a transformer 400 and a data collector 500. In addition, the photovoltaic power generation system also includes a power grid 600 or a load 700. The photovoltaic array 100 includes a plurality of photovoltaic panels 110 and a plurality of photovoltaic optimizers 120. Each photovoltaic panel 110 of the plurality of photovoltaic panels 110 is correspondingly connected to a photovoltaic optimizer 120 of the plurality of photovoltaic optimizers 120. The plurality of photovoltaic optimizers 120 are respectively connected to the power converter 200 through a power transmission line L. The plurality of power converters 200 are connected to the AC combiner box 300 through the power transmission line L, and the AC combiner box 300 is connected to the transformer 400. The transformer 400 is connected to the power grid 600 or the load 700 through the power transmission line L. Wherein:

[0043] The photovoltaic power generation panel 110 is used to convert solar radiation energy into direct current. The photovoltaic optimizer 120 is used to detect the working power and other working status information of the corresponding photovoltaic power generation panel 110, convert the input low-current direct current into high-current direct current, and transmit the obtained high-current direct current to the power converter 200. The power converter 200 is used to perform direct current boost processing on the input direct current, and invert the direct current after the direct current boost processing to obtain alternating current, and provide alternating current to the AC junction box 300. The power converter 200 is also used to sample and obtain the power information, current information and voltage information of the input direct current and / or the output alternating current. Each AC junction box 300 provides the input alternating current to the transformer 400 after converging. After the transformer 400 transforms the input alternating current, it provides the transformed current to the power grid 600 or the load 700. The data collector 500 is used to record the working status information of the transformer 400, etc. In one example, the power converter 200 may be an inverter.

[0044] For example, in the above Figure 1 In an embodiment of the embodiment, each photovoltaic optimizer 120 in the plurality of photovoltaic optimizers 120 is set as a slave node of the STA, and the power converter 200 is set as a master node of the CCO. The plurality of photovoltaic optimizers 120 and the corresponding power converters 200 can communicate business information based on the PLC technology through the power transmission line L. For example, the photovoltaic optimizer 120 can transmit the working information such as the voltage, current, temperature and working power of the photovoltaic panel 110 to the power converter 200 through the PLC technology, and the power converter 200 can also issue control instruction information to different photovoltaic optimizers 120 based on the PLC technology, such as maximum power point tracking (MPPT) control instructions and conduction control instructions.

[0045] Exemplarily, each power converter 200 in the plurality of power converters 200 may be set as a slave node of the STA, and the data collector 500 may be set as a master node of the CCO. The plurality of power converters 200 and the data collector 500 may communicate business information based on the PLC technology through the power transmission line L. For example, the power converter 200 transmits the sampled power information, current information, and voltage information to the data collector 500 on the power converter 200 side based on the PLC technology, and the data collector 500 may also send control instruction information to the corresponding power converter 200 based on the PLC technology.

[0046] In order to achieve the above Figure 1 In the embodiment shown, the photovoltaic optimizer 120 and the power converter 200 or the data collector 500 communicate with each other by PLC. The embodiment of the present application provides a power converter, which can be a first power converter. Figure 2 As shown, the first power converter 200A includes a radio frequency processing circuit 10 and a coupler 20. The coupler 20 is used to couple the transmission signal to the power transmission line L and transmit it to the data collector 500 or the photovoltaic optimizer 120, and is also used to receive the reception signal transmitted by the data collector 500 or the photovoltaic optimizer 120 to the second power converter 200B through the power transmission line L. The first output end of the coupler 20 is connected to the input end of the radio frequency processing circuit 10. The first output end of the coupler 20 is used to transmit the reception signal to the radio frequency processing circuit 10. The radio frequency processing circuit 10 is used to: receive the reception signal. The radio frequency processing circuit 10 is also used to: send the transmission signal. The output end of the radio frequency processing circuit 10 is connected to the first input end of the coupler 20, and the first input end of the coupler 20 is used to receive the transmission signal sent by the radio frequency processing circuit 10. Among them, the reception signal and the transmission signal are radio frequency signals within the frequency band range of PLC communication application.

[0047] Exemplarily, the coupler 20 may include a plurality of inductors, and a transformer structure may be formed based on the plurality of inductors, the primary winding of the transformer may be connected to the power transmission line L, and the secondary winding of the transformer may be connected to the RF processing circuit 10. A voltage-coupled transmission path may be formed between the RF processing circuit 10 and the power transmission line L based on the transformer.

[0048] In this application Figure 2In the illustrated embodiment, the second input end of the coupler 20 of the first power converter 200A can receive a received signal carrying business information from the power transmission line L, and the received signal can come from the photovoltaic optimizer 120 or the data collector 500. After the received signal is subjected to transformer coupling processing, the received signal subjected to transformer coupling processing is output to the input end of the radio frequency processing circuit 10 through the first output end of the coupler 20. After the radio frequency processing circuit 10 performs relevant signal processing on the received signal, the business information carried by it can be subsequently parsed from the received signal. Similarly, the first power converter 200A can also carry the business information on the transmission signal, and output the transmission signal to the first input end of the coupler 20 through the output end of the radio frequency processing circuit 10. After the coupler 20 performs transformer coupling processing on the transmission signal, the transmission signal subjected to transformer coupling processing is sent to the power transmission line L through the second output end of the coupler 20, so as to transmit the business information to its optimizer 120 or the data collector 500 through the power transmission line L. However, in this embodiment, the input and output ends of the RF processing circuit 10 are coupled to the power transmission line L through the coupler 20. In the case of full-duplex transceiver communication, how to isolate the signals of the receiving end and the transmitting end is a key design for the implementation of the solution. However, in the application scenario of power carrier communication, the frequency of the RF signal as the transmission signal and the receiving signal is usually low, for example, the receiving signal and the transmission signal can usually be in the frequency range of 150kHz-500kHz, or in the frequency range of 0-12MHz. The frequency range of the RF signal of power carrier communication is much lower than the frequency range of the RF signal in scenarios such as wireless communication. Because in the field of signal processing, according to the frequency of the RF signal, the relevant signal processing devices have corresponding device parameter designs, etc. In particular, in the field of wireless communication of RF signals, many isolators are designed based on the matching of impedance and application bandwidth and other performances of the corresponding application frequency band. Therefore, many isolation devices used for transceiver isolation design in traditional wireless communication / optical communication cannot be adapted to the scenario of power carrier communication. In the full-duplex transceiver application, there are extremely high requirements for transceiver isolation. Therefore, how to perform high-precision isolation processing on the receiving signal and transmitting signal of PLC full-duplex communication is a major problem.

[0049] In order to perform high-precision isolation processing on the receiving signal and the transmitting signal of the PLC full-duplex communication, in some possible implementations, the power communication circuit can be a second power converter based on frequency conversion processing. Figure 3 As shown, the second power converter 200B includes a radio frequency processing circuit 10, a coupler 20, a first isolator 40, a second isolator 50, an up-conversion module 60 and a down-conversion module 70. Among them:

[0050] The coupler 20 is used to couple the transmission signal to the power transmission line L for transmission to the data collector 500 or the photovoltaic optimizer 120 , and is also used to receive the reception signal transmitted by the data collector 500 or the photovoltaic optimizer 120 through the power transmission line L to the second power converter 200B.

[0051] The first output end of the coupler 20 is connected to the input end of the up-conversion module 60 , the output end of the up-conversion module 60 is connected to the input end of the first isolator 40 , and the output end of the first isolator 40 is connected to the input end of the RF processing circuit 10 .

[0052] The first output end of the coupler 20 is used to transmit the received signal to the input end of the up-conversion module 60; the up-conversion module 60 is used to convert the received signal into a first radio frequency signal; and the radio frequency processing circuit 10 is used to obtain the first radio frequency signal.

[0053] The output end of the RF processing circuit 10 is connected to the input end of the second isolator 50, the output end of the second isolator 50 is connected to the input end of the down-conversion module 70, the output end of the down-conversion module 70 is connected to the first input end of the coupler 20, and the first input end of the coupler 20 is used to receive the transmission signal sent by the output end of the down-conversion module 70. The RF processing circuit 10 is used to: send the second RF signal. The down-conversion module 70 is used to: convert the second RF signal into a transmission signal. The corresponding RF signal is unidirectionally transmitted on the first isolator 40 and the second isolator 50.

[0054] In this application Figure 3In the illustrated embodiment, the received received signal can be up-converted based on the up-conversion module 60 to obtain a first RF signal with a higher frequency. The design of the isolator based on the high-frequency first RF signal can realize the adaptation of the isolator (e.g., the first isolator 40) used in the high-frequency communication system to the second power converter 200B. Similarly, the RF processing circuit 10 can also transmit a second RF signal with a higher frequency, and down-convert the high-frequency second RF signal based on the down-conversion module 70 to convert the high-frequency second RF signal into a transmission signal with a reduced frequency, and the frequency of the transmission signal can adapt to the low-frequency frequency range requirements in the scenario of power carrier communication. The low-frequency transmission signal is transmitted to the photovoltaic optimizer 120 or the data collector 500 through the coupler 20 and the power transmission line L. At this time, for the second RF signal, an isolator (e.g., a second isolator 50) used in the high-frequency communication system can be set between the RF processing circuit 10 and the down-conversion module 70 for transceiver isolation. In the embodiment of the present application, the frequency conversion processing of the radio frequency signal is performed through the up-conversion module 60 and the down-conversion module 70, so as to adapt the isolation device in the high-frequency communication system to the second power converter 200B using the low-frequency power carrier communication technology, thereby realizing a high-isolation PLC full-duplex communication receiving and transmitting interference noise isolation design.

[0055] In some possible implementations, the first isolator 40 and the second isolator 50 may be isolators of the same or different types. In theory, any isolator designed for high-frequency signal applications may be implemented and applied in the second power converter 200B of the present application.

[0056] Exemplarily, the first isolator 40 and / or the second isolator 50 can be designed based on a circulator. In an embodiment of the present application, the circulator is a non-reversible device having multiple ports. There is a determined signal transmission order between the multiple ports of the circulator. With any of the multiple ports as the input port, the signal input to the circulator can only be output from the next port corresponding to the any port. At the same time, the circulator also has the characteristics of low transmission insertion loss and high port isolation. In addition, due to the advantages of high isolation of each port of the circulator, the impedance between each port is relatively independent, and the application of the circulator can also reduce the design difficulty of the coupling impedance between different ports. Due to the above-mentioned excellent characteristics of the circulator, it is usually designed as a signal isolation device in a high-frequency communication system. However, the design of the circulator is also related to the frequency band of the signal. If it is in a signal communication system in a low-frequency band, such as a power carrier communication system, it requires a wide bandwidth, so that the circulator has a large device volume overhead under the low-frequency band design, which affects the integration of the device; and the working frequency band is narrow, it is difficult to achieve a good transceiver isolation effect. Therefore, it is difficult to apply a circulator as an isolator in a traditional power converter. In this application Figure 3In the illustrated embodiment, the up-conversion module 60 and the down-conversion module 70 can be used to perform frequency conversion processing on the transmit and receive signals in the power carrier communication system to adapt to the operating frequency band of the circulator, thereby realizing the transmit and receive isolation application of the circulator in full-duplex communication in the low-frequency power carrier communication system.

[0057] In some examples, such as Figure 4 As shown, the first isolator 40 and / or the second isolator 50 include at least one circulator CIR; when at least one circulator CIR includes multiple circulator CIRs, the multiple circulator CIRs form a cascade transmission structure, in which the first end of the circulator CIR of the first stage is the input end of the isolator, and the second end of the circulator CIR of the last stage is the output end of the isolator; the second end of the circulator CIR of the front stage of two adjacent circulators CIR is connected to the first end of the circulator CIR of the rear stage. In the embodiment of the present application, the transceiver isolation can be achieved through the unidirectional conductivity of the circulator CIR, and when the circulator CIR is multi-stage series-connected, due to the unidirectional conductivity of the multiple circulator CIRs, the isolation can be improved to achieve application scenarios with higher isolation accuracy requirements.

[0058] In some examples, such as Figure 5 As shown, the third end of each circulator CIR is connected to an interference noise isolation circuit ISO, and the interference noise isolation circuit ISO is used to filter out the interference noise signal transmitted from the second end of the corresponding circulator CIR to the third end. In the embodiment of the present application, the working principle of the circulator CIR has been described in the above embodiment. It can be seen that when the first end of the circulator CIR is the input end and the second end is the output end, the signal transmission order between the three ports of the circulator CIR is: the signal input at the first end will be output from the second end. The signal input at the second end will be output from the third end. In some application scenarios, such as Figure 5 As shown, the first end of the circulator CIR inputs a radio frequency signal, and the radio frequency signal is output from the second end of the circulator CIR. Affected by the design of the device, the impedance matching of the transmission path, and other designs, the radio frequency signal output from the second end is affected by the reflection of the transmission path and / or the output post-stage device, and an interference noise signal is generated. The interference noise signal reflects the signal input back to the second end of the circulator CIR, and the interference noise signal input from the second end of the circulator CIR is transmitted to the third end of the circulator CIR. For example, the input end side of the radio frequency processing circuit 10 may generate an echo interference noise signal, or the input end side of the down-conversion module 70 may also generate an echo interference noise signal. In order to remove and isolate these echo interference noise signals, an interference noise isolation circuit ISO can be set at the third end of each circulator CIR, and the interference noise signals of these echoes are absorbed by the interference noise isolation circuit ISO.

[0059] For example, Figure 5 The interference noise isolation circuit ISO shown can be a load matching circuit, and the load matching circuit is used to absorb interference noise signals. In the embodiment of the present application, the load matching circuit can be a load circuit with a certain frequency response, based on which the interference noise signal of the echo within a certain frequency range is absorbed. For example, in actual applications, the frequency range of the interference noise signal of the echo can be confirmed, and a load matching circuit with a certain frequency response can be designed to filter and absorb the interference noise signal of this part of the echo.

[0060] In some possible implementations, such as Figure 6 As shown, the up-conversion module 60 includes an up-conversion mixer 61 and a first local oscillator circuit 62. The input end of the up-conversion mixer 61 is connected to the first output end of the coupler 20, and the output end of the up-conversion mixer 61 is connected to the input end of the first isolator 40. The first local oscillator circuit 62 is connected to the reference signal end of the up-conversion mixer 61. Wherein: the first local oscillator circuit 62 is used to: output a first local oscillator signal located in the first frequency band. The up-conversion mixer 61 is used to: input a received signal located in the second frequency band, and perform mixing processing on the received signal based on the first local oscillator signal to obtain a first radio frequency signal located in the first frequency band, and the first frequency band is higher than the second frequency band. In an embodiment of the present application, a high-frequency first local oscillator signal (for example, located in the first frequency band) can be provided based on the first local oscillator circuit 62, and the up-conversion mixer 61 mixes the low-frequency (for example, located in the second frequency band) received signal with the high-frequency first local oscillator signal to obtain a high-frequency first radio frequency signal.

[0061] In some possible implementations, such as Figure 6 As shown, the down-conversion module 70 includes a down-conversion mixer 71 and a second local oscillator circuit 72. The input end of the down-conversion mixer 71 is connected to the output end of the second isolator 50, and the output end of the down-conversion mixer 71 is connected to the first input end of the coupler 20. The second local oscillator circuit 72 is connected to the reference signal end of the down-conversion mixer 71. Wherein: the second local oscillator circuit 72 is used to: output a second local oscillator signal located in the third frequency band. The down-conversion mixer 71 is used to: input a second radio frequency signal located in the fourth frequency band, and mix the second radio frequency signal based on the second local oscillator signal to obtain a transmission signal located in the third frequency band, and the fourth frequency band is higher than the third frequency band. In an embodiment of the present application, the second local oscillator circuit 72 can provide a low-frequency (for example, located in the third frequency band) second local oscillator signal. The down-conversion mixer 71 mixes the high-frequency (for example, located in the fourth frequency band) second radio frequency signal and the low-frequency second local oscillator signal to obtain a low-frequency transmission signal.

[0062] In some examples, such as Figure 7As shown, the second power converter 200B also includes a first filter F1 and a second filter F2. The first filter F1 is connected between the first output terminal of the coupler 20 and the input terminal of the up-conversion module 60. The second filter F2 is connected between the output terminal of the up-conversion module 60 and the input terminal of the first isolator 40. Exemplarily, according to the different selections of the first filter F1 and the second filter F2, the first filter F1 can be connected between the first output terminal of the coupler 20 and the input terminal of the up-conversion module 60 in series or in parallel. The second filter F2 can also be connected between the output terminal of the up-conversion module 60 and the input terminal of the first isolator 40 in series or in parallel.

[0063] In some examples, such as Figure 7 Shown, the second power converter 200B also includes the 3rd filter F3 and the 4th filter F4. The 3rd filter F3 is connected between the output of the second isolator 50 and the input of the down-conversion module 70. The 4th filter F4 is connected between the output of the down-conversion module 70 and the first input of the coupler 20. Exemplarily, according to the different selections of the 3rd filter F3 and the 4th filter F4, the 3rd filter F3 can be connected between the output of the second isolator 50 and the input of the down-conversion module 70 in series or in parallel. The 4th filter F4 can also be connected between the output of the down-conversion module 70 and the first input of the coupler 20 in series or in parallel.

[0064] Exemplarily, the first filter F1 , the second filter F2 , the third filter F3 , and the fourth filter F4 may be bandpass filters.

[0065] In this application Figure 7 In the illustrated embodiment, based on the first filter F1, filtering of the clutter in the low-frequency received signal output by the coupler 20 can be achieved. Based on the second filter F2, filtering of the clutter in the high-frequency first RF signal obtained by up-conversion processing can be achieved. Based on the third filter F3, filtering of the clutter in the high-frequency second RF signal that is not input into the down-conversion module 70 after being output by the RF processing circuit 10 can be achieved. Based on the fourth filter F4, filtering of the clutter in the low-frequency transmitted signal after down-conversion processing can be achieved. Based on the above filters, the interference noise signal in the RF signal can be further reduced to improve the isolation of the signal and the signal processing accuracy.

[0066] In some possible implementations, such as Figure 8As shown, the second power converter 200B also includes a decoupling circuit 30. The input end of the RF processing circuit 10 is connected to the decoupling circuit 30, and is connected to the output end of the first isolator through the decoupling circuit 30. The output end of the RF processing circuit 10 is coupled to the input end of the second isolator through the decoupling circuit 30. In the embodiment of the present application, based on the decoupling circuit 30, the isolation between the transmitting and receiving signals can be further improved on the basis of the circulator CIR, the filter, etc.

[0067] In some possible implementations, the coupler 20 may include a transformer structure formed by a plurality of inductors. Fig. 9 As shown, the second power converter 200B may also include a DC boost circuit 210, an inverter circuit 220, a sampling circuit 230, and a controller 240. The DC boost circuit 210 is used to obtain DC power, and perform a DC boost process on the DC power to obtain the DC power after the boost process. The inverter circuit 220 is used to perform an inversion process on the DC power to obtain AC power, and output the obtained AC power through a power transmission line L including a three-phase wire (e.g., an A-phase wire, a B-phase wire, and a C-phase wire). The sampling circuit 230 is used to sample and obtain the working state parameters (e.g., current, voltage, etc.) of the DC boost circuit 210 and the inverter circuit 220. The controller 240 is used to control the operation of the DC boost circuit 210 and the sampling circuit 230, and to obtain the working state parameters obtained by circuit sampling. Fig. 9 In the example of the second power converter 200B performing PLC communication with the data collector 500, at this time, the coupler 20 of the second power converter 200B is connected to the power transmission line L at the output end of the inverter circuit 220. Although not shown, when the second power converter 200B performs PLC communication with the photovoltaic optimizer 120, the coupler 20 is coupled to the power transmission line L between the second power converter 200B and the photovoltaic optimizer 120.

[0068] In one example, the second power converter 200B uses PLC full-duplex communication, and its transceiver functions are performed at intervals. Fig. 9As shown, the three-phase wires of the power transmission line L can correspond to the second input terminal, the common terminal, and the second output terminal of the coupler 20. Exemplarily, the second input terminal and the common terminal of the coupler 20 form the input structure of the coupler 20 on the power transmission line L side. For example, when the coupler 20 receives a signal from the power transmission line L, the second input terminal serves as the positive input terminal of the signal of the second power converter 200B on the power transmission line L side, and the common terminal serves as the negative input terminal (or ground terminal) of the signal of the second power converter 200B on the power transmission line L side. The first output terminal and the first ground terminal of the coupler 20 form the output structure of the coupler 20 on the RF processing circuit 10 side, that is, the first output terminal serves as the positive output terminal of the signal on the RF processing circuit 10 side, and the first ground terminal serves as the negative output terminal of the signal on the RF processing circuit 10 side. Exemplarily, when the coupler 20 inputs a transmission signal from the RF processing circuit 10 side, the first input terminal and the second ground terminal of the coupler 20 form an input structure of the coupler 20 on the RF processing circuit 10 side, for example, the first input terminal serves as a positive input terminal of the signal on the RF processing circuit 10 side, and the second ground terminal serves as a negative input terminal of the signal on the RF processing circuit 10; the second output terminal and the common terminal of the coupler 20 form an output structure of the coupler 20 on the power transmission line L side, for example, the second input terminal serves as a positive input terminal of the signal of the second power converter 200B on the power transmission line L side, and the common terminal serves as a negative input terminal (or ground terminal) of the signal of the second power converter 200B on the power transmission line L side. Exemplarily, the present application does not limit the correspondence between the three-phase wires of the power transmission line L and the second input terminal, the common terminal, and the second output terminal.

[0069] In some possible implementations, the RF processing circuit 10 in the second power converter 200B may also include an up-conversion processing device and a down-conversion processing device. In the embodiment of the present application, the up-conversion module 60 and the down-conversion module 70 can be used as devices for adjusting the frequency to adapt the isolation device. In the RF processing circuit 10, corresponding up-conversion processing devices and down-conversion processing devices may also be additionally provided to perform relevant processing on the RF signal.

[0070] In some possible implementations, the RF processing circuit 10 in the second power converter 200B may not include an up-conversion processing device and a down-conversion processing device. In the embodiment of the present application, the frequency conversion processing of the RF signal can be implemented based on the up-conversion module 60 and the down-conversion module 70. There is no need to perform related frequency conversion processing in the RF processing circuit 10.

[0071] In some possible implementations, such as Fig.10As shown, the RF processing circuit 10 can also be used as a transceiver RF channel for wireless communication. The RF processing circuit 10 can receive a second RF signal carrying business information transmitted by other wireless communication devices W, and after processing based on the RF processing circuit 10 and the second isolator 50, the down-conversion module 70, etc., a low-frequency transmission signal is obtained, and transmitted to the power transmission line L through the coupler 20, so as to be acquired and analyzed by the photovoltaic optimizer 120 or the data collector 500 connected to the power transmission line L. At the same time, the second power converter 200B can also obtain the low-frequency receiving signal sent by the photovoltaic optimizer 120 or the data collector 500 from the power transmission line L through the coupler 20, and after processing based on the up-conversion module 60, the first isolation device 40, etc., a high-frequency first RF signal is obtained, and transmitted through the RF processing circuit 10, so as to be acquired by other wireless communication devices W. Exemplarily, the RF processing circuit 10 can realize the reception and transmission of RF signals based on the transceiver antenna. Based on this architecture, the embodiment of the present application can improve the layout flexibility of the second power converter 200B and some supporting devices in the photovoltaic power generation system, and can realize PLC communication and wireless communication based on a second power converter 200B.

[0072] In some possible implementations, such as Fig.11 As shown, the second power converter 200B also includes a data processing circuit 80; the data processing circuit 80 is connected to the RF processing circuit 10. Among them, the data processing circuit 80 is used to: input a first baseband data signal from the RF processing circuit 10; output a second baseband data signal to the RF processing circuit 10, and the first baseband data signal and the second baseband data signal are used to indicate business information. The RF processing circuit 10 is also used to: obtain a first baseband data signal according to the first RF signal; obtain a second RF signal according to the second baseband data signal. In the embodiment of the present application, the operation of the device for data processing operation is based on the baseband data signal. The controller 240 of the second power converter 200B can transmit business information to the data processing circuit 80, and the data processing circuit 80 generates a second baseband data signal based on the business information, and transmits the second baseband data signal to the RF processing circuit 10. The RF processing circuit 10 can perform relevant RF processing (such as modulation, filtering, etc.) on the second baseband data signal to obtain a second RF signal, and transmit the signal to the power transmission line L based on the second isolator 50 and the down-conversion module 70 of the subsequent stage. Alternatively, the RF processing circuit 10 obtains a first RF signal from the power transmission line L through the first isolator 40, the up-conversion module 60, etc. of the previous stage, processes the first RF signal into a first baseband data signal, and transmits it to the data processing circuit 80, which is then transmitted to the controller 240 by the data processing circuit 80. The controller 240 performs relevant control operations according to the control instructions carried in the business information of the first baseband data signal.

[0073] For example, Fig.11 As shown, the second power converter 200B may further include a memory M. The memory M is connected to the data processing circuit 80. In an embodiment of the present application, the data processing circuit 80 may parse and process the business information of the second power converter 200B interaction. Other data may also be processed, such as processing the device performance state of the second power converter 200B, processing the data collected by the sensor of the second power converter 200B, etc. The memory M may store some computer programs based on the operation of the data processing circuit 80, may store the device performance state information of the second power converter 200B, store the interactive business information, store the data collected by the sensor of the second power converter 200B, etc.

[0074] In some possible implementations, such as Fig.11 As shown, the second power converter 200B also includes a communication module 90. The data processing circuit 80 is also connected to the communication module 90. The communication module 90 includes a wireless communication module 91 and / or an optical communication module 92. In an embodiment of the present application, the data processing circuit 80 can also realize interaction with other communication devices based on the additionally provided communication module 90, for example, wireless communication interaction is realized by using the wireless communication module 91, or optical communication interaction is realized based on the form of wired optical fiber deployment. Under this implementation mode, the communication compatibility of the second power converter 200B in the photovoltaic power generation system based on PLC communication is increased, and the layout flexibility of some related devices supporting the second power converter 200B is improved.

[0075] The embodiment of the present application also provides a photovoltaic optimizer, which is used to connect the photovoltaic power generation panel, transfer the electric energy generated by the photovoltaic power generation panel to the power converter, and communicate with the power converter through the power transmission line. The photovoltaic optimizer includes a radio frequency processing circuit, a coupler, a first isolator, a second isolator, an up-conversion module and a down-conversion module. Among them: the coupler is used to couple the transmission signal to the power transmission line for transmission to the power converter, and is also used to receive the reception signal transmitted by the power converter to the photovoltaic optimizer through the power transmission line. The first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the radio frequency processing circuit. The first output end of the coupler is used to transmit the received signal to the input end of the up-conversion module. The up-conversion module is used to: convert the received signal into a first radio frequency signal; the radio frequency processing circuit is used to: obtain the first radio frequency signal. The output end of the RF processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, the output end of the down-conversion module is connected to the first input end of the coupler, and the first input end of the coupler is used to receive the transmission signal sent by the output end of the down-conversion module. The RF processing circuit is used to: send the second RF signal. The down-conversion module is used to: convert the second RF signal into a transmission signal; the corresponding RF signal is unidirectionally transmitted on the first isolator and the second isolator.

[0076] Regarding the beneficial effects and technical principles of the RF processing circuit, coupler, first isolator, second isolator, up-conversion module and down-conversion module in the photovoltaic optimizer, reference may be made to the relevant description in the above-mentioned second power converter embodiment, which will not be repeated here.

[0077] When the second power converter recorded in the above embodiment is set in the photovoltaic power generation system, based on the embodiment of the above second power converter, the layout flexibility of the photovoltaic power supply system can be improved. In the field of photovoltaic power generation, in order to control photovoltaic devices, obtain the working state of photovoltaic power generation panels, obtain the power information of power converters, and perform power scheduling on power converters, it is necessary to perform real-time communication between the second power converter and the data collector, and between the second power converter and the photovoltaic optimizer. Based on factors such as cost and reliability, information is usually transmitted between the data collector and the second power converter, and between the second power converter and the photovoltaic optimizer through PLC technology. And with the increase of the capacity of the photovoltaic power generation system and the power of the second power converter, the distance between different photovoltaic power generation panels will also be farther and farther. Through the second power converter of the embodiment of the present application, compatible PLC communication and wireless communication can be achieved, thereby improving the layout flexibility between different devices in the photovoltaic power generation system, so as to adapt to the technical development of the photovoltaic power system. At the same time, when the photovoltaic components are laid out, different devices can independently deploy the above second power converter, or jointly deploy the above second power converter to solve different user needs. Similarly, the photovoltaic optimizer based on the above-mentioned devices including the RF processing circuit, the coupler, the first isolator, the second isolator, the up-conversion module and the down-conversion module can also improve the communication isolation and the related layout flexibility of the photovoltaic optimizer.

[0078] The embodiment of the present application provides a power converter, a photovoltaic power generation system and a photovoltaic optimizer, which are applied to the field of power carrier communication technology of photovoltaic power generation. The power converter includes a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module and a coupler. Wherein: the second input end and the second output end of the coupler are respectively connected to the power transmission line, the first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the radio frequency processing circuit. The output end of the radio frequency processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, and the output end of the down-conversion module is connected to the first input end of the coupler. The radio frequency processing circuit is used to: obtain a first radio frequency signal; send a second radio frequency signal; the corresponding radio frequency signal is unidirectionally transmitted on the first isolator and the second isolator. In the embodiment of the present application, first, based on the up-conversion module and the down-conversion module, the frequency of the signal interacting with the power transmission line can be adjusted by frequency conversion, so as to adapt the various isolation device designs under the high-frequency communication system in the power converter in the low-frequency scenario of the power carrier communication, thereby realizing the high isolation design of the full-duplex transceiver channel in the power converter using the power carrier communication. Second, based on the structure of the circulator as an isolation device, a system design with low insertion loss, high isolation end and easier impedance design can be realized. Third, the interference noise isolation circuit is designed on the circulator, which can realize the absorption and filtering of the echo interference noise signal on the transmission path, so as to further improve the isolation and anti-interference performance. Fourth, based on the design of multiple bandpass filters, the isolation and anti-interference performance can be further improved. Fifth, the isolation and anti-interference performance can be further improved by the design of the decoupling circuit. Sixth, based on the design of the radio frequency processing circuit combined with PLC communication and wireless communication, a power converter can be compatible with PLC communication capability and wireless communication capability, so as to facilitate the deployment of different devices in the photovoltaic power generation system, thereby improving the layout flexibility and communication diversity of different devices in the photovoltaic power generation system.

[0079] The controller and data processing circuit involved in the embodiments of the present application may be a chip. For example, it may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0080] The memory involved in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0081] In the several embodiments provided in the present application, it should be understood that the disclosed systems, circuits and devices can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the circuits and modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0082] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one device or distributed on multiple devices. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0083] In addition, each functional module in each embodiment of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0084] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power converter, characterized in that: The power converter is used to communicate with a data collector or a photovoltaic optimizer through a power transmission line, the photovoltaic optimizer is used to connect a photovoltaic power generation panel, and the power converter includes a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module and a coupler; wherein: The coupler is used to couple the transmission signal to the power transmission line for transmission to the data collector or the photovoltaic optimizer, and is also used to receive the reception signal transmitted by the data collector or the photovoltaic optimizer to the power converter through the power transmission line; The first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the RF processing circuit; The first output end of the coupler is used to transmit the received signal to the input end of the up-conversion module; the up-conversion module is used to: convert the received signal into a first radio frequency signal; the radio frequency processing circuit is used to: obtain the first radio frequency signal; The output end of the RF processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, the output end of the down-conversion module is connected to the first input end of the coupler, and the first input end of the coupler is used to receive the transmission signal sent by the output end of the down-conversion module; the RF processing circuit is used to: send a second RF signal; the down-conversion module is used to: convert the second RF signal into the transmission signal; the corresponding RF signal is unidirectionally transmitted on the first isolator and the second isolator.

2. The power converter according to claim 1, characterized in that: The first isolator and / or the second isolator includes at least one circulator; when the at least one circulator includes multiple circulators, the multiple circulators form a cascade transmission structure, in which the first end of the circulator at the first stage is the input end of the isolator, and the second end of the circulator at the last stage is the output end of the isolator; the second end of the circulator at the front stage of two adjacent stages of the circulators is connected to the first end of the circulator at the rear stage.

3. The power converter according to claim 2, characterized in that: The third end of each circulator is connected to an interference noise isolation circuit, and the interference noise isolation circuit is used to filter out interference noise signals transmitted from the second end to the third end of the corresponding circulator.

4. The power converter according to claim 3, characterized in that: The interference noise isolation circuit is a load matching circuit, and the load matching circuit is used to absorb the interference noise signal.

5. The power converter according to any one of claims 1 to 4, characterized in that: The up-conversion module includes an up-conversion mixer and a first local oscillator circuit; the input end of the up-conversion mixer is connected to the first output end of the coupler, and the output end of the up-conversion mixer is connected to the input end of the first isolator; the first local oscillator circuit is connected to the reference signal end of the up-conversion mixer; wherein: The first local oscillator circuit is used to: output a first local oscillator signal in a first frequency band; The up-conversion mixer is used to: input the received signal in the second frequency band, mix the received signal based on the first local oscillator signal, and obtain the first radio frequency signal in the first frequency band, where the first frequency band is higher than the second frequency band.

6. The power converter according to claim 5, characterized in that: The power converter also includes a first filter and a second filter; The first filter is connected between the first output end of the coupler and the input end of the up-conversion module; The second filter is connected between the output end of the up-conversion module and the input end of the first isolator.

7. The power converter according to any one of claims 1 to 4, characterized in that: The down-conversion module includes a down-conversion mixer and a second local oscillator circuit; the input end of the down-conversion mixer is connected to the output end of the second isolator, and the output end of the down-conversion mixer is connected to the first input end of the coupler; the second local oscillator circuit is connected to the reference signal end of the down-conversion mixer; wherein: The second local oscillator circuit is used to: output a second local oscillator signal in a third frequency band; The down-conversion mixer is used to: input the second RF signal located in the fourth frequency band, mix the second RF signal based on the second local oscillator signal, and obtain the transmission signal located in the third frequency band, and the fourth frequency band is higher than the third frequency band.

8. The power converter according to claim 7, characterized in that: The power converter also includes a third filter and a fourth filter; The third filter is connected between the output end of the second isolator and the input end of the down-conversion module; The fourth filter is connected between the output end of the down-conversion module and the first input end of the coupler.

9. The power converter according to any one of claims 1 to 4, characterized in that: The power converter also includes a decoupling circuit; The input end of the radio frequency processing circuit is connected to the output end of the first isolator after being connected to the decoupling circuit; The output end of the radio frequency processing circuit is connected to the input end of the second isolator after being connected to the decoupling circuit.

10. The power converter according to any one of claims 1 to 4, characterized in that: The power converter further includes a data processing circuit; the data processing circuit is connected to the radio frequency processing circuit; wherein, The data processing circuit is used to: input a first baseband data signal from the radio frequency processing circuit; output a second baseband data signal to the radio frequency processing circuit, wherein the first baseband data signal and the second baseband data signal are used to indicate service information; The radio frequency processing circuit is further configured to: obtain the first baseband data signal according to the first radio frequency signal; and obtain the second radio frequency signal according to the second baseband data signal.

11. A photovoltaic power generation system, characterized in that: It comprises one or more power converters and data collectors as claimed in any one of claims 1 to 10, wherein the one or more power converters are used to communicate with the data collector through the power transmission line.

12. A photovoltaic power generation system, characterized in that: It comprises a power converter as described in any one of claims 1 to 10 and one or more photovoltaic optimizers, wherein the power converter is used to communicate with the one or more photovoltaic optimizers through the power transmission line, and each of the one or more photovoltaic optimizers is used to connect to a photovoltaic power generation panel.

13. A photovoltaic optimizer, characterized in that: The photovoltaic optimizer is used to connect the photovoltaic power generation panel, transfer the electric energy generated by the photovoltaic power generation panel to the power converter, and communicate with the power converter through the power transmission line; the photovoltaic optimizer includes a radio frequency processing circuit, a first isolator, a second isolator, an up-conversion module, a down-conversion module and a coupler; wherein: The coupler is used to couple the transmission signal to the power transmission line for transmission to the power converter, and is also used to receive the reception signal transmitted by the power converter to the photovoltaic optimizer through the power transmission line; The first output end of the coupler is connected to the input end of the up-conversion module, the output end of the up-conversion module is connected to the input end of the first isolator, and the output end of the first isolator is connected to the input end of the RF processing circuit; The first output end of the coupler is used to transmit the received signal to the input end of the up-conversion module; the up-conversion module is used to: convert the received signal into a first radio frequency signal; the radio frequency processing circuit is used to: obtain the first radio frequency signal; The output end of the RF processing circuit is connected to the input end of the second isolator, the output end of the second isolator is connected to the input end of the down-conversion module, the output end of the down-conversion module is connected to the first input end of the coupler, and the first input end of the coupler is used to receive the transmission signal sent by the output end of the down-conversion module; the RF processing circuit is used to: send a second RF signal; the down-conversion module is used to: convert the second RF signal into the transmission signal; the corresponding RF signal is unidirectionally transmitted on the first isolator and the second isolator.

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