JPH10150778A - Remote operation, information display method and its apparatus of system interconnection inverter equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To communicate even through an inverter body is paralleled off from a system power line by receiving communication data modulated by high frequency signal and demodulating to the original frequency, detecting and correcting errors and decoding, making an exclusive signal line unnecessary and preventing transmission error of communication data. SOLUTION: When data sent out from a control section is analog, the data are converted to digital signal of a plurality of bits by A/D converter 12. A modulation section 14 modulates the data to a high frequency signal by frequency modulation and phase modulation in order to superimpose the data to a system power line. next, only the communication band signal is taken out by a bandpass filter 15 and demodulated to binary code from high frequency signal by a demodulation section 16. presence or absence of transmission errors is checked by utilizing redundant bits in a composite circuit 17 and, if an error is detected, a data re-send request is transmitted or the error is corrected. Next, the data are restored to analog signal by a D/A converter 18 as required, signal from an inverter device is recognizes, and information display is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote control of a grid-connected inverter for converting a DC output of a solar cell into AC power and performing a grid-connected operation with a commercial grid in a solar power generation system installed in a house. The present invention relates to an information display method and an information display device.

[0002]

2. Description of the Related Art A residential photovoltaic power generation system has a solar cell module, a junction box, and an inverter as its basic components. The inverter converts the DC output of the solar cell into AC power, and is connected to a commercial system in the home. Function is realized.
The solar cell module and junction box are installed on the roof or outside, and usually do not require any operation. On the other hand, an inverter is a device composed of electronic components and is often installed indoors and serves as a contact point between a solar power generation system and a commercial system. It often has a function to be provided to a user or a system administrator. In addition, the inverter also has a function of protecting the operation / stop of the photovoltaic power generation system, system power failure and other system abnormalities, and functions as a central device of the system.

The operation unit and the information display unit of the inverter are built in the main body or provided in a wired remote controller. When the operation unit and information display unit are built in the main unit,
, Operation switches 22 and an information display unit 23 are arranged. Not limited to the front of the main body, it may be arranged on any of the upper, lower, left and right side surfaces. On the other hand, FIG. 4 shows a case where the operation unit and the information display unit are provided in a wired remote controller.
FIG. 4 is a block diagram of a system interconnection inverter including the wired remote controller. The system interconnection inverter includes a solar cell 9, an inverter device main body 23 that converts the output of the solar cell 9 into AC power and outputs the AC power to a system power line, and a remote controller 25 that remotely controls the inverter device main body 23. The inverter device main body 23 is
Main circuit section 3 which receives power from the power supply as input, converts it into AC power of commercial frequency and outputs it to the commercial system distribution line, interconnection protection switch section 4 for protecting the system when an abnormality occurs, switching operation of the main circuit The control unit 5 controls the main circuit, monitors the input / output voltage / current of the main circuit, the voltage of each part of the circuit, and gives various control commands based on the control to the main circuit. The communication interface unit 24 performs data communication with a dedicated communication cable. Are connected to the U-phase, V-phase and neutral line (G) of the commercial power line 11 in the home. A load 10 is connected to the commercial power line. Dedicated cable is communication cable 2
6 and a power cable 27 to which a remote controller 25 is connected. After determining the arrangement of the inverter device main body 23 and the remote controller 25, a dedicated cable for connecting the two is laid indoors.

[0004]

In the case of a conventional inverter integrated with an operation unit and an information display unit, operations such as confirmation of the power generation amount of the photovoltaic power generation system and operation / stop of the system are operated by the inverter unit main body 23. It is necessary to install the inverter device main body 23 in a place where daily operation is possible, for example, a living room where a person frequently enters and leaves, such as a living room, a kitchen, and an entrance. The inverter device main body 23 is relatively large in size, and has a drawback that it causes pressure on the living space and an uncomfortable feeling in the interior. In addition, due to its size, the installation position is often near the ceiling, and there is a disadvantage that it is difficult to confirm operations and display contents. Furthermore, when the inverter device main body 23 is equipped with a cooling fan, there is a problem that discomfort due to the fan rotation sound is given to the occupant.

[0005] In order to solve the above-mentioned problems of the inverter, when a wired remote controller is used in which the operation unit and the information display unit are separately provided, the inverter device main body 23 can be installed in a space of low utilization such as an attic or a storage room. However, it is necessary to connect the remote controller 25 and the inverter device main body 23 with a dedicated cable, and the laying work of the dedicated cable must be performed, so that there is a problem that a wiring construction cost increases. Further, in the wiring work, there is a concern that an erroneous wiring of the dedicated cable may cause an abnormal operation or a failure of the inverter device main body 23. Further, there is a problem that the cable laying for changing the position of the remote controller 25 needs to be reconstructed.

Further, data transmission through a system power line may be considered without using a dedicated cable, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 5-27295. However, there is a problem in that even if an analog signal is simply modulated at a high frequency and transmitted, an error cannot be corrected for a transmission error.

An object of the present invention is to eliminate the need for a dedicated signal line for remote operation or displaying information, prevent transmission errors of communication data, and enable communication even when the inverter body is disconnected from the system power line. It is an object of the present invention to provide a remote operation / information display method for a grid-connected inverter and a device therefor.

[0008]

SUMMARY OF THE INVENTION According to the present invention, there is provided an inverter device for converting an output of a solar cell into AC power and outputting the AC power to a system power line. A remote operation / information display method for a grid-connected inverter device having a remote operation unit for displaying information of a digital signal for remote operation or information display between the inverter device main body and the remote operation unit. The communication data is encoded by adding redundant bits for error detection and correction, is modulated into a high-frequency signal, is transmitted by being superimposed on a system power line, and the modulated communication data is received from the system power line to be restored. A remote operation and information display method for a grid-connected inverter, wherein the frequency is demodulated to a frequency of, and an error is detected / corrected and decoded.

According to a second aspect of the present invention, the communication data is transmitted in parallel by modulating each bit constituting one byte using different carrier frequency bands and transmitting the communication data in parallel. Remote control and information display method.

According to a third aspect of the present invention, there is provided an inverter main body for converting an output of a solar cell into AC power and outputting the AC power to a system power line, and a remote controller for remotely operating the inverter main body and displaying information of the inverter main body. In the remote operation / information display device of a system interconnection inverter device having an operation unit, the inverter main unit and the remote operation unit are used for error detection and correction of communication data which is a digital signal for remote operation or information display. An encoding circuit that adds and encodes the redundant bits of the above, a modulation circuit that modulates the encoded communication data into a high-frequency signal, and superimposes the communication data on a system power line for transmission, and the communication that is the high-frequency signal from the system power line. A demodulation circuit that extracts and demodulates data, a decoding circuit that detects and corrects an error in the demodulated communication data, and decodes the error. A remote operation and information display device of the system interconnection inverter, characterized in that it comprises, respectively.

According to a fourth aspect of the present invention, the modulating circuit modulates each bit constituting one byte of the communication data with different carrier frequency bands and transmits the data in parallel. It is a remote operation and information display device of the grid interconnection inverter.

The invention according to claim 5 is characterized in that the modulation circuit and the demodulation circuit are connected to a system side of the inverter device main body with respect to an interconnection protection switch arranged therein. Remote operation of the grid-connected inverter
It is an information display device.

According to the first and third aspects of the present invention, the operation information such as the operation / stop state and the power generation amount transmitted from the inverter device main body propagates as a digital signal superimposed on the system power line without passing through a dedicated cable. Demodulated by a remote controller connected to an arbitrary outlet in the home, and necessary information is displayed on a remote control unit. Similarly, a command such as operation / stop transmitted from the remote controller and other data transmission requests are propagated as digital signals superimposed on the system power line, received and demodulated by the inverter device main body, and execute requests from the remote controller. When a data error occurs due to a communication error, the error is detected using the redundant bits, and a data retransmission request or error correction is performed.

According to the second and fourth aspects of the present invention, each bit of the digital signal to which a redundant bit for error correction is added is such that bits constituting one byte are simultaneously modulated by being modulated into high frequency signals of different frequency bands. Transmitted,
Prevent interference of each bit signal.

According to the fifth aspect of the present invention, even when the inverter device main body is stopped and the interconnection protection switch disconnects the inverter output and the system power line, the modulation circuit and demodulation circuit of the inverter device main body and the commercial system Because the connection point with the distribution line is provided on the system side of the interconnection protection switch,
Communication with the remote control unit becomes possible.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of a system interconnection inverter device using a communication device according to the present invention. Since the basic configuration of this system interconnection inverter device is almost the same as that of the device shown in FIG. 4, the same components are denoted by the same reference numerals and description thereof will be omitted. The difference from FIG. 4 is the configuration of the communication interface units 6 and 7 of the inverter body 1 and the remote controller 2. The communication interface units 6 and 7 are connected to the commercial power line 11 in the home.
, The U-phase, the V-phase, and the neutral line, and performs data communication by power line carrier. FIG. 2 shows a block diagram of the communication interface unit. Communication interface 6,7
Is an A / D conversion circuit 12, an encoding circuit 13, a modulation circuit 14, a band-pass filter 15, a demodulation circuit 16,
It comprises a decoding circuit 17 and a D / A conversion circuit 18.

The remote controller 2 includes a remote controller main unit 8 for performing operations, displaying information, performing calculations as needed, and performing data communication by power line transport.
The remote controller 2 is connected to a commercial power line through a household outlet, such as a general household electrical appliance such as a television, a microwave oven, and a refrigerator.

The inverter device main body 1 performs DC-AC conversion in the main circuit section 3 according to a control signal from the control section 5.
Information that needs to be notified to the remote controller 2, for example, the operation / stop state of the inverter, output power, integrated power,
An error code or the like at the time of occurrence of an abnormality is transmitted from the control unit 5 to the commercial power line via the communication interface 6.
As shown in FIG. 2, when the data transmitted from the control unit 5 is an analog signal, the data is first converted into a digital signal of a plurality of bits by the A / D converter 12. Generally, it is often 7 bits or more. Next, in the encoding circuit 13, at least one redundant bit for error detection is added and encoded as at least eight bits.

To transmit this, either parallel transmission or serial transmission can be used. However, in the case of serial transmission, it is necessary to add two bits of the start and stop bits to the 8-bit code before and after, and transmit the data as a total of 10 bits, and it is not possible to improve the transfer speed. Therefore, parallel transmission is desirable. The modulator 14 modulates the data into a high-frequency signal by frequency modulation, phase modulation or the like in order to superimpose the data on the system power line. In the case of parallel transmission, interference of each bit signal is prevented by setting a different carrier frequency band for each bit. The modulated high-frequency signal is first output to both the U-phase and neutral lines and the V-phase to neutral line of the system power line. Only the lines that responded to this are used for the next signal transmission. Thereby, the signal from the inverter main body can be received regardless of whether the remote controller 2 is connected to any outlet in the home irrespective of the U phase and the V phase.

On the other hand, in the remote controller 2, the data transferred to the power line is received by the communication interface unit 7 shown in FIG. First, only the communication band signal is extracted by the band-pass filter 15, and the demodulation unit 16 demodulates the high-frequency signal into a binary code. The decoding circuit 17 checks the presence or absence of a transmission error by using the redundant bits, and if there is an error, sends a data retransmission request or corrects the error. Next, the signal is restored to an analog signal by the D / A conversion circuit 18 as necessary, a signal from the inverter device main body 1 is recognized, and information display and other operations are performed. Signal transmission from the remote controller 2 can be performed by performing the above procedure in reverse.

The inverter device main body 1 is stopped at night because the solar cell 9 does not generate power, and is disconnected from the system by the interconnection protection switch 4. Even in such a state, there is still a need to confirm operation data such as the accumulated power generation amount of the inverter device. As shown in FIG. 1, connection points A,
Since B and C are provided on the system side with respect to the interconnection protection switch 4, if a part of the communication interface unit 6 and the control unit 5 necessary for communication control is in a standby state, the communication with the remote controller unit 2 is performed. Communication is possible.

[0022]

As described above, according to the first and third aspects of the present invention, the operation / operation transmitted from the inverter device body is performed.
Operation information such as stop state and power generation amount is propagated as a digital signal superimposed on the system power line without passing through a dedicated cable, and a dedicated signal line is not required between the inverter and the remote controller, simplifying installation work It is possible, and there is no worry about incorrect connection at the time of construction. In addition, operation and information confirmation can be performed by connecting to an arbitrary outlet in the home, so that portability of the remote controller can be improved. Further, since communication is performed using a digital signal to which an error correction code is added, occurrence of abnormal operation such as erroneous operation or erroneous display due to a data transmission error can be suppressed.

According to the second and fourth aspects of the present invention, the carrier frequency band transmitted in parallel is set to be different for each bit, thereby preventing interference of each bit signal.

According to a fifth aspect of the present invention, the modulation circuit and the demodulation circuit of the inverter device main body and the commercial power system are connected to each other even when the inverter device main body is stopped and the interconnection protection switch disconnects the inverter output and the system power line. Since the connection point with the distribution line is located on the system side of the interconnection protection switch, communication with the remote control unit is possible, so the inverter stops operating at night, etc., and the interconnection protection switch Accordingly, communication with the remote operation unit is possible even when the power line is disconnected from the system power line.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a system interconnection inverter using a remote operation / information display device according to the present invention.

FIG. 2 is a block diagram of a communication interface unit.

FIG. 3 is a perspective view of an inverter device main body having a built-in operation unit and an information display unit.

FIG. 4 is a block diagram of a conventional grid-connected inverter having a wired remote controller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverter main body 2 Remote controller 3 Main circuit part 4 Interconnection protection switching part 5 Control part 6, 7 Communication interface part 8 Remote controller main part 9 Solar cell

Claims (5)

[Claims] 1. An inverter device main body for converting an output of a solar cell into AC power and outputting the AC power to a system power line, and a remote operation unit for remotely operating the inverter device body and displaying information on the inverter device main body. In the remote operation / information display method for a grid interconnection inverter device, communication data, which is a digital signal for remote operation or information display, between the inverter device main body and the remote operation unit, is used for error detection / correction. Redundant bits are added and encoded, modulated to a high-frequency signal, transmitted by being superimposed on a system power line, and the modulated communication data is received from the system power line and demodulated to the original frequency to detect and correct errors. Remote operation and information display method of a grid-connected inverter, characterized in that decoding is performed by decoding. 2. modulating each bit constituting one byte of the communication data with a carrier frequency band different from each other;
2. The method according to claim 1, wherein the transmission is performed in parallel. 3. An inverter device main body for converting an output of a solar cell into AC power and outputting the AC power to a system power line, and a remote operation unit for remotely operating the inverter device main body and displaying information of the inverter main body. In the remote operation / information display device for a grid-connected inverter device, the inverter main unit and the remote operation unit add redundant bits for error detection and correction of communication data, which is a digital signal for remote operation or information display. An encoding circuit that modulates and encodes the communication data into a high-frequency signal, and superimposes the communication data on a system power line for transmission; and demodulates the communication data that is the high-frequency signal from the system power line. And a decoding circuit for detecting and correcting an error in the demodulated communication data to decode the communication data. Remote control and information display device of the system interconnection inverter, characterized in that. 4. The system interconnection inverter according to claim 3, wherein the modulation circuit modulates each bit constituting one byte of the communication data with a different carrier frequency band and transmits the modulated data in parallel. Remote operation and information display device. 5. The system interconnection according to claim 3, wherein the inverter circuit body is connected to the modulation circuit and the demodulation circuit on a system side with respect to an interconnection protection switch disposed therein. Inverter remote operation / information display device.