Photovoltaic inverter composite communication system with plc and nfc and initialization method

Abstract

The application discloses a photovoltaic inverter composite communication system with PLC and NFC and an initialization method, multiple photovoltaic inverters are divided into multiple groups, and multiple photovoltaic inverters are connected in series in each group; a switch is arranged on each photovoltaic inverter, and the switch is divided into three gears; a processing unit in each photovoltaic inverter is connected with a PLC module and an NFC module, and the processing unit stores a unique identification ID of the photovoltaic inverter; one NFC module is arranged on the front side and the back side of each photovoltaic inverter, the NFC module includes three working modes, namely, a point-to-point mode, a card reader mode and a card mode; the PLC module includes a sending part and a receiving part, the output end of the sending part and the input end of the receiving part are connected with a power line, and the input end of the sending part and the output end of the receiving part are connected with the processing unit. The photovoltaic inverter sorting during installation is realized, and meanwhile, the real-time detection state of the photovoltaic inverter by an inspection personnel during operation is facilitated.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic inverters and relates to a composite communication system for photovoltaic inverters with PLC and NFC and an initialization method. Background Technology

[0002] A PV inverter, or solar inverter, converts the variable DC voltage generated by PV solar panels into AC power at the grid frequency. This AC power can be fed back into commercial power transmission systems or supplied to off-grid systems. PV inverters typically have a power output of around 100–1000W and can achieve maximum power point tracking for a single PV module or up to four PV modules, converting DC power to 220V AC power.

[0003] Currently, photovoltaic (PV) inverters utilize various communication methods, including wired and wireless communication. However, current wired or wireless communication only uploads the inverter's operational information to a backend server; it doesn't address the inverter's location during actual construction and operation. It cannot determine which module in the array the inverter is connected to, or which nearby PV inverters it is connected to. This makes it difficult for maintenance personnel to identify which inverter in front of them corresponds to which one is recorded in the system, resulting in significant challenges in locating the inverter during operation and maintenance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a photovoltaic inverter composite communication system and initialization method with PLC and NFC, so as to realize the sorting of photovoltaic inverters during installation and facilitate the real-time detection of the status of photovoltaic inverters by inspection personnel during operation.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A photovoltaic inverter composite communication system with PLC and NFC, comprising multiple photovoltaic inverters;

[0007] Multiple photovoltaic inverters are divided into multiple groups, and each group has multiple photovoltaic inverters connected in series.

[0008] Each photovoltaic inverter is equipped with a switch, which has three positions: OFF, PAIR, and ON.

[0009] A processing unit, a PLC module and an NFC module are arranged in each photovoltaic inverter, the processing unit is connected with the PLC module and the NFC module, and the processing unit stores a unique identification ID of the photovoltaic inverter; one NFC module is arranged on the front side and the back side of each photovoltaic inverter, the front side of each photovoltaic inverter faces the photovoltaic inverter located upstream thereof, and the back side faces the photovoltaic inverter located downstream thereof, the NFC module includes three working modes, namely a point-to-point mode, a card reader mode and a card mode; the PLC module includes a sending part and a receiving part, the output end of the sending part and the input end of the receiving part are connected with the power line, and the input end of the sending part and the output end of the receiving part are connected with the processing unit.

[0010] Preferably, a carrier transformer is arranged between the output end of the sending part and the input end of the receiving part of the PLC module and the power line, and the input end of the sending part of the PLC module is connected with a carrier generator.

[0011] Further, a wave trap is arranged on the power line, and the wave trap is located between the carrier transformer and the power input of the power line.

[0012] Preferably, the sending part of the PLC module includes a logic processing unit and a power amplification unit, and the output end of the processing unit, the logic processing unit, the power amplification unit and the power line are connected in sequence; the receiving part of the PLC module includes a detection and shaping unit and a signal amplification unit, and the power line, the signal amplification unit, the detection and shaping unit and the input end of the processing unit are connected in sequence.

[0013] Preferably, the processing unit is connected with an MPPT unit and an inverter unit, the MPPT unit is connected with a photovoltaic module, and the inverter unit is connected with the power line.

[0014] Further, the MPPT unit adopts a boost voltage-boosting DC-DC circuit and adopts a parallel synchronous rectification topology.

[0015] Further, the inverter unit adopts a full-bridge inverter circuit.

[0016] Preferably, the processing unit adopts an MCU chip.

[0017] An initialization method of a photovoltaic inverter composite communication system with PLC and NFC based on any one of the above, including the following processes:

[0018] S1, a plurality of photovoltaic inverters are divided into m groups, and each group contains n photovoltaic inverters;

[0019] S2, the k+1th photovoltaic inverter has not been connected to the photovoltaic module before installation, the front side NFC module and the back side NFC module of the k+1th photovoltaic inverter are in card mode, the surface of the shell of the k+1th photovoltaic inverter is contacted with the surface of the shell of the front side NFC module of the kth photovoltaic inverter, at this time, the unique identification ID of the k+1th photovoltaic inverter is read by the front side NFC module of the kth photovoltaic inverter and is recorded, and the serial connection of a group of photovoltaic inverters is completed in turn according to the connection order of the photovoltaic inverters;

[0020] S3, the unique identification ID of the first photovoltaic inverter in each group is read, and is uploaded to the upper computer;

[0021] S4, after all the input ends of the photovoltaic inverters are connected to the photovoltaic module and the output ends are connected to the power line, all the photovoltaic inverters are adjusted to the ON mode.

[0022] Preferably, when the k-1th photovoltaic inverter is damaged, the kth photovoltaic inverter cannot transmit signals to the k-1th photovoltaic inverter, and the kth photovoltaic inverter transmits signals to the k-2th photovoltaic inverter; the position of the damaged photovoltaic inverter is determined according to the unique identification ID of the missing photovoltaic inverter.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] The present application divides a plurality of photovoltaic inverters into a plurality of groups, each group has a plurality of photovoltaic inverters in series, each photovoltaic inverter has a unique identification ID, and the background system realizes information collection of all photovoltaic inverters and issues instructions through power line PLC. And the photovoltaic inverter uses NFC near field communication to realize the order of the photovoltaic inverter during installation, and facilitates the real-time detection state of the photovoltaic inverter by the inspection personnel during operation, avoiding the hysteresis of calling out the real-time information of the photovoltaic inverter from the background system. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a functional structure diagram of the photovoltaic inverter of the present application;

[0026] Figure 2 It is a PLC module communication working principle diagram of the present application;

[0027] Figure 3 It is a schematic diagram of the composite communication system of the photovoltaic inverter of the present application.

[0028] Among them: 1-photovoltaic module; 2-MPPT unit; 3-inversion unit; 4-processing unit; 5-PLC module; 6-NFC module; 7-detection and shaping unit; 8-signal amplification unit; 9-logic processing unit; 10-power amplification unit; 11-carrier generator; 12-carrier transformer; 13-wave trap. DETAILED DESCRIPTION

[0029] The application will be described in further detail below with reference to the drawings:

[0030] As Figure 3 shown, the photovoltaic inverter composite communication system with PLC and NFC according to the application comprises a plurality of photovoltaic inverters.

[0031] The plurality of photovoltaic inverters are divided into a plurality of groups, and each group is connected in series with a plurality of photovoltaic inverters.

[0032] The input end of the photovoltaic inverter is connected to the photovoltaic module 1, and the output end is connected to the power grid. The photovoltaic inverter in the embodiment is a micro photovoltaic inverter. As Figure 1 shown, the functional units of the photovoltaic inverter include an MPPT unit 2, an inverter unit 3, a processing unit 4, a PLC module 5 and an NFC module 6.

[0033] The MPPT unit 2 is a DC-DC unit. The MPPT unit 2 performs power conversion on the output of the photovoltaic module 1, adopts a boost DC-DC circuit, adopts a parallel synchronous rectification topology, utilizes the on-resistance of the mosfet tube, has a short switching time, reduces rectification loss and improves efficiency. The MPPT unit 2 performs the maximum power tracking MPPT function, simultaneously collects data such as the input voltage and current of the photovoltaic inverter, the PWM duty cycle, the temperature and the like, and transmits the data to the processing unit 4 by means of a bus.

[0034] The inverter unit 3 is a DC-AC unit. The inverter unit 3 is connected in series after the MPPT unit 2, inverts the direct current output by the MPPT unit 2 into alternating current, and adopts a full-bridge inverter circuit. The inverter unit 3 is connected to the power line, simultaneously collects the input voltage and output voltage of the inverter unit 3, and transmits the data to the processing unit 4 by means of a bus.

[0035] The processing unit 4 comprises an MCU chip. By measuring the voltage and current data of the photovoltaic module 1, the PWM duty cycle of the MOSFET in the MPPT unit 2 is dynamically adjusted, instructions are issued, the power of the photovoltaic module 1 is dynamically adjusted, and the maximum power tracking MPPT function is realized. By measuring the output voltage of the MPPT unit 2 and the data of the power grid, the PWM duty cycle control of the MOSFET in the inverter unit 3 is dynamically adjusted to ensure the stability of the direct current voltage output by the MPPT unit 2. The processing unit 4 communicates with the PLC module 5 and the NFC module 6, outputs the data measured by the MPPT module and the inverter module to the PLC module 5 and the NFC module 6, and simultaneously receives the data of the PLC module 5 and the NFC module 6.

[0036] As Figure 2As shown, the power line carrier wave PLC module 5 is divided into two parts of transmission and reception, the transmission part of the PLC module 5 includes a logic processing unit 9 and a power amplification unit 10, the output end of the processing unit 4, the logic processing unit 9, the power amplification unit 10 and the power line are sequentially connected, the input end of the logic processing unit 9 is connected with the carrier wave generator 11; the receiving part of the PLC module 5 includes a detection and shaping unit 7 and a signal amplification unit 8, the power line, the signal amplification unit 8, the detection and shaping unit 7 and the input end of the processing unit 4 are sequentially connected. The output end of the power amplification unit 10 and the input end of the signal amplification unit 8 are provided with a carrier wave transformer 12 between the power line. A wave blocking device 13 is provided on the power line, and the wave blocking device 13 is located between the carrier wave transformer 12 and the power input of the power line.

[0037] The processing unit 4 sends information through a serial port, the logic processing unit 9 combines the signal with the fundamental frequency signal generated by the carrier wave generator 11, and the high frequency signal is transmitted to the power line through the carrier wave transformer 12 on the power line after power amplification, and then transmitted to the adjacent host computer. The receiving part amplifies the transmitted high frequency signal through the power line, detects and shapes, extracts the information, and transmits it to the serial port of the processing unit 4.

[0038] In the production of the photovoltaic inverter, the unique identification ID of the photovoltaic inverter is stored in the processing unit 4, and the unique identification ID of the photovoltaic inverter is read from the NFC and the PLC in this process.

[0039] The NFC module 6 adopts two reading modes of active and passive. The NFC module 6 has three working modes, namely point-to-point mode, card reader mode and card mode. The NFC module 6 automatically switches the three working modes according to the working mode of the photovoltaic inverter to meet different communication needs.

[0040] The photovoltaic inverter shell is provided with a switch, which has three gears of OFF, PAIR and ON. Each photovoltaic inverter is provided with an NFC module 6 on the front side and the back side. When the inverter is in the OFF state, the photovoltaic inverter is in the shutdown state, the front side NFC module 6 and the back side NFC module 6 are in the card mode; when the photovoltaic inverter is in the PAIR state and the photovoltaic inverter is connected to the photovoltaic module 1, the front side NFC module 6 of the photovoltaic inverter is in the card reader mode, and the back side NFC module 6 is in the card mode; when the photovoltaic inverter is in the ON state, the front side NFC module 6 and the back side NFC module 6 of the photovoltaic inverter are in the card mode; when the photovoltaic inverter is in the ON state and is working, the front side NFC module 6 is in the point-to-point mode, and the back side NFC module 6 is closed.

[0041] The photovoltaic inverter is in OFF mode, or the photovoltaic inverter input is not connected to the photovoltaic module 1, which is not working and not powered, and the NFC is in card mode, which is equivalent to an IC card using RFID technology. The NFC module 6 stores the unique identification ID of the photovoltaic inverter, which can be read by a handheld NFC inspection device or other photovoltaic inverters in card reader mode.

[0042] The photovoltaic inverter sorting and initialization method is as follows:

[0043] Step one, divide the plurality of photovoltaic inverters into m groups, each group containing n photovoltaic inverters.

[0044] Step two, the k+1 photovoltaic inverter has not been connected to the photovoltaic module 1 before installation, and the front and back NFC modules 6 are in card mode. The NFC module 6 stores the unique identification ID of the k+1 photovoltaic inverter. The construction personnel contact the surface of the k+1 photovoltaic inverter with the surface of the NFC module 6 on the front side of the k photovoltaic inverter, at which time the k photovoltaic inverter reads the unique identification ID of the k+1 photovoltaic inverter and records it. The construction personnel sequentially complete the input work of the entire photovoltaic inverter string according to the connection order of the photovoltaic inverter.

[0045] Step three, the construction personnel use a handheld NFC inspection device to approach the first photovoltaic inverter in each group, read the unique identification ID of the first photovoltaic inverter in each group, and the handheld NFC inspection device will automatically record the unique identification ID and upload it to the upper computer.

[0046] Step four: all photovoltaic inverter inputs are connected to the photovoltaic module 1, and the outputs are connected to the AC bus, all of which are in ON mode. At this time, the photovoltaic inverter PLC module 5 is working. The photovoltaic inverter PLC module 5 can send signals, and can also accept PLC signals from the upper computer or adjacent photovoltaic inverters.

[0047] As Figure 3As shown, taking the kth photovoltaic inverter in the jth group as an example, the kth photovoltaic inverter records the unique identification ID of the k+1th photovoltaic inverter, the kth photovoltaic inverter adjusts the PLC signal frequency, power, etc. through the PLC module 5, the kth photovoltaic inverter only accepts the signal sent by the k+1th photovoltaic inverter, and filters out the signals from other photovoltaic inverters. The kth photovoltaic inverter sends signals at the same time, and the k-1th photovoltaic inverter only accepts the signal of the kth photovoltaic inverter. Since the host computer stores the unique identification ID of the first photovoltaic inverter in the m groups, the host computer only accepts the signal sent by the first photovoltaic inverter, and filters out other signals. At this time, the information chain is established: host computer, first photovoltaic inverter, second photovoltaic inverter, third photovoltaic inverter, and so on. The unique identification ID of the nth photovoltaic inverter is transmitted to the n-1th photovoltaic inverter. The n-1th inverter increases its own unique identification ID on the basis of it, and so on, and the first inverter transmits to the host computer, which includes the unique identification ID of all photovoltaic inverters in the string.

[0048] After the host computer collects the unique identification ID of the m groups, it is automatically grouped and marked that the photovoltaic inverter is in the jth group and the kth position, and the position information of all photovoltaic inverters is obtained through the information chain. In addition to obtaining its own position information, the kth photovoltaic inverter will also obtain the position information of other photovoltaic inverters in the jth group.

[0049] When the k-1th photovoltaic inverter is damaged, the kth photovoltaic inverter cannot transmit signals to the k-1th photovoltaic inverter, and the kth photovoltaic inverter stores the position information of all photovoltaic inverters in the group. The kth photovoltaic inverter adjusts the signal transmission with the k-2th photovoltaic inverter to ensure the integrity of the information of the photovoltaic inverters in the group.

[0050] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the above embodiments of the present application have been described in detail, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced, without departing from the spirit and scope of the present application. Any modification or equivalent replacement, which should be covered in the protection scope of the claims of the present application.

Claims

1. A method for initializing a photovoltaic inverter composite communication system with PLC and NFC, characterized in that, The photovoltaic inverter composite communication system comprises a plurality of photovoltaic inverters; The plurality of photovoltaic inverters are divided into a plurality of groups, and each group is connected in series with a plurality of photovoltaic inverters; Each photovoltaic inverter is provided with a switch, and the switch is divided into three gears, namely OFF, PAIR and ON; Each photovoltaic inverter is provided with a processing unit (4), a PLC module (5) and an NFC module (6), the processing unit (4) is connected with the PLC module (5) and the NFC module (6), and the processing unit (4) stores the unique identification ID of the photovoltaic inverter; each photovoltaic inverter is provided with an NFC module (6) on the front side and the back side, the front side of each photovoltaic inverter faces the photovoltaic inverter located upstream thereof, the back side faces the photovoltaic inverter located downstream thereof, the NFC module (6) comprises three working modes, namely a point-to-point mode, a card reader mode and a card mode; the PLC module (5) comprises a sending part and a receiving part, the output end of the sending part and the input end of the receiving part are connected with a power line, and the input end of the sending part and the output end of the receiving part are connected with the processing unit (4); The output end of the sending part and the input end of the receiving part of the PLC module (5) are provided with a carrier transformer (12) between the power line, and the input end of the sending part of the PLC module (5) is connected with a carrier generator (11); A wave barrier (13) is arranged on the power line, and the wave barrier (13) is located between the carrier transformer (12) and the power input of the power line; The sending part of the PLC module (5) comprises a logic processing unit (9) and a power amplification unit (10), and the output end of the processing unit (4), the logic processing unit (9), the power amplification unit (10) and the power line are connected in sequence; the receiving part of the PLC module (5) comprises a detection and shaping unit (7) and a signal amplification unit (8), and the power line, the signal amplification unit (8), the detection and shaping unit (7) and the input end of the processing unit (4) are connected in sequence; The processing unit (4) is connected with an MPPT unit (2) and an inverter unit (3), the MPPT unit (2) is connected with a photovoltaic module (1), and the inverter unit (3) is connected with the power line; The MPPT unit (2) adopts a boost voltage DC-DC circuit and a parallel synchronous rectification topology; The inverter unit (3) adopts a full-bridge inverter circuit; The initialization method comprises the following processes: S1, the plurality of photovoltaic inverters are divided into m groups, and each group comprises n photovoltaic inverters; S2, the front side NFC module (6) and the back side NFC module (6) of the k+1th photovoltaic inverter are in the card mode before being connected with the photovoltaic module (1), the surface of the shell of the k+1th photovoltaic inverter is contacted with the surface of the shell of the front side NFC module (6) of the kth photovoltaic inverter, at this time, the unique identification ID of the k+1th photovoltaic inverter is read by the front side NFC module (6) of the kth photovoltaic inverter and recorded, and the series connection of a group of photovoltaic inverters is sequentially recorded according to the connection order of the photovoltaic inverters; S3, the unique identification ID of the first photovoltaic inverter in each group is read and uploaded to an upper computer. S4, all photovoltaic inverter inputs are connected to photovoltaic modules (1), and the output is connected to the power line, and all are adjusted to ON mode; When the k-1th photovoltaic inverter is damaged, the kth photovoltaic inverter cannot transmit signals to the k-1th photovoltaic inverter, and the kth photovoltaic inverter transmits signals to the k-2th photovoltaic inverter; according to the unique identifier ID of the missing photovoltaic inverter, the position of the damaged photovoltaic inverter is determined.

2. The method of initializing a photovoltaic inverter composite communication system with PLC and NFC according to claim 1, characterized in that, The processing unit (4) adopts an MCU chip.

Images