JPH09215339A - Power converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the wiring work for installing a display unit by converting a data signal to a wireless signal and then transmitting the converted signal and then receiving the wireless signal and displaying the operational condition of an inverter section based on the received signal. SOLUTION: The data signals corresponding to the output current value and output voltage value of a DC/AC converter 9 which show the operational condition are output to an antenna ANT1 via a transmission circuit 10b and then the data signals received by the antenna ANT1 are transmitted as electric wave signals from the antenna ANT1. The electric wave signals transmitted by the ANT1 are received by an ANT2 and the electric wave signals are converted to the output data of a CPU circuit of a system-linked controlling circuit 12 by means of a receiving circuit 10e and the output data is input into a display controlling circuit 10f and finally, the content of the operational condition of the AC/DC converter 9 is displayed on a display device 10h. By this method, the wiring work for installing a display unit can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter, and more particularly to a power converter for converting a direct current power source such as a solar cell into an alternating current and connecting it to a commercial power source system to supply power to a load.

[0002]

2. Description of the Related Art A power converter for converting a direct current power source such as a solar cell to an alternating current and connecting it to a commercial power source system to supply electric power to a load is called a grid interconnection type inverter device, for example, Japanese Patent Laid-Open No. 7-170661. 4 and 5 disclosed in US Pat. FIG. 4 is a schematic configuration diagram of a photovoltaic power generation system that is the above distributed power supply system, and FIG. 5 is a basic configuration of a grid interconnection inverter device installed in a house, which is one of the distributed power supply systems. FIG.

In FIG. 4, reference numeral 1 is a power system of a commercial power source, which is provided in a main power source 2 of a power plant, a substation 3 for stepping down the power from the power plant 2 and distributing the power, and a distribution line 4. The circuit breaker 5 and the pole transformer 6 that steps down the supplied electric power and supplies it to each home. Reference numeral 8 denotes a solar cell installed in each house, and the distributed power source 7 includes the solar cell 8 and an inverter 9 that converts a DC voltage output from the solar cell 8 into an AC voltage. Reference numeral 12 denotes a grid interconnection protection circuit, which is a disconnecting switch 11 that is a switch when the commercial power supply system 1 and the distributed power supply 7 are simultaneously supplying power to the in-house load (referred to as interconnection). Is operated to disconnect the distributed power source 7 having the above configuration from the commercial power source system 1. This system interconnection protection circuit 12 detects the frequency variation and voltage variation in the distributed power source 7 system, or the occurrence of a power failure due to the opening of the breaker 5 of the commercial power source power system 1. It has a function of disconnecting the disconnection switch 11. 13 is the load in the house. In such a distributed power generation system, when DC power is output from the solar cell 8, the inverter 9 converts the DC power into AC power of a predetermined frequency and supplies the AC power to the in-house load 13, while Electric power that cannot be covered by the AC power from the mold power source is supplied from the power system 1 of the commercial power source.

In the basic construction of the residential system shown in FIG. 5, 8 is a solar cell and 10 is a grid interconnection type inverter device. That is, this system interconnection type inverter device 10
Is the inverter 9 and the disconnecting switch 1 shown in FIG.
1 and a system interconnection protection circuit 12. In addition, this system interconnection type inverter device 10 includes a cable 1
It has a display unit 15 connected at 4. The display unit 15 is provided so that the user can easily recognize the power generation state of the distributed power source, and is usually attached at eye level. Then, the generated power amount, the integrated power, and the trading charge generated by the solar cells 8 of the distributed power source are reported, and the power generation efficiency of the distributed power source is constantly monitored to detect that the power generation efficiency has deteriorated and to perform maintenance. Notify that it is time to check.

[0005]

By the way, in the above-mentioned conventional grid-connected inverter device 10, the main body and the display unit 15 are separated and wired and connected by the cable 14. Therefore, the display unit 15 requires wiring work because the installation work involves wiring work. If there is no suitable place to attach the display unit 15 in the vicinity of the grid interconnection type inverter device 10, it is necessary to use a long cable 14 and perform wiring work to an appropriate place. . The cable 14 is generally C
A cable having a special structure for outputting calculation data from a PU circuit to a display unit having a display circuit. Therefore, it is necessary to previously attach a predetermined long cable to the main body, and the main body of the grid interconnection inverter device 10 needs a storage space for bundling and storing the excess cable portions due to the wiring work. did.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a system interconnection type inverter device as a power conversion device which does not require wiring work for mounting a display unit. It is to provide a conversion device.

[0007]

In order to achieve the above object, a power converter according to a first aspect of the present invention is an inverter section for converting DC power input from a DC power supply into AC and outputting the AC power, and an inverter section. An inverter main body including a signal conversion unit that converts the content of the operating state into a predetermined data signal and a wireless signal transmission unit that converts the data signal into a wireless signal and transmits the wireless signal, and a wireless signal reception that receives the wireless signal And a display unit for displaying the contents of the operating state of the inverter unit based on the received signal. Thereby, the display of the content of the operating state of the inverter unit by the display unit is received and displayed by the wireless signal.

Further, in the power converter according to the second aspect, the display section according to the first aspect has a solar cell for obtaining a power source for the display section. As a result, the display unit operates by obtaining power from the solar cell.

Further, in the power conversion device according to a third aspect, the display section according to the first or second aspect is configured to include a storage section using an EEPROM. As a result, the display unit stores the content of the operating state of the inverter unit in the EEPROM when the circuit power cannot be obtained from the solar cell.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a power converter according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of a basic configuration of a grid interconnection inverter device that is a power conversion device. FIG. 2 is a circuit block diagram thereof. FIG.
FIG. 3 is an explanatory diagram of a basic configuration of the wireless signal transmitting unit and a wireless signal receiving unit that receives a wireless signal. The same reference numerals as those shown in the conventional embodiment are used for the reference numerals in the figure.

This distributed power source 7 is also a solar cell 8
And a grid interconnection type inverter device 10 which is a power conversion device
It is composed of The grid-connected inverter device 10 of this type is composed of an inverter body 10a and a display unit 10d which is a display unit. As shown in FIG. 2, the inverter body 10a includes a DC / AC converter 9 which is an inverter, a disconnecting switch 11, a grid interconnection control circuit 12, and a transmission circuit 10 which is a radio signal transmitting unit.
b. Further, the display unit 10d includes a receiving circuit 10e that is a wireless signal receiving unit that receives a wireless signal,
Storage unit 1 having display control circuit 10f and EEPROM
0g, a display element 10h for displaying the contents of the operating state of the DC / AC converter 9 of the inverter body 10a, and a solar cell 10i.

The DC / AC converter 9 is an inverter unit for converting DC power input from the solar cell 8 which is a DC power supply to AC and outputting the AC power. The DC / AC converter 9 is connected to the commercial power supply system 1 and is connected to the residential load 13 by AC. Supply power.

The parallel disconnecting switch 11 is a switch for disconnecting the distributed power source 7 from the commercial power source system 1 at the time of interconnection, and is opened / closed by being controlled by the system interconnection control circuit 12.

The system interconnection control circuit 12 is a signal conversion unit for converting the content of the operating state of the DC / AC converter 9 into a predetermined data signal, and the frequency variation and voltage in the system of the distributed power source 7 during interconnection. A CPU for controlling the inverter body by detecting fluctuations or the occurrence of a power failure in the commercial power system 1.
It is configured to have a circuit (not shown). The system interconnection control circuit 12 inputs signals from a voltage sensor and a current sensor provided in the sensor section 10c and outputs a control signal for controlling the DC / AC converter 9. Further, the grid interconnection control circuit 12 detects a frequency abnormality or a voltage abnormality in the system of the distributed power source 7 or a power failure in the commercial power source system based on the voltage signal or the current signal from the sensor unit 10c, and the parallel disconnection switch. 11 to disconnect the distributed power supply 7 from the commercial power supply system 1. Furthermore, the system interconnection control circuit 12 calculates data for displaying the contents of the operating state of the DC / AC converter 9 displayed on the display unit 10d described later, and outputs the calculation result as a predetermined data signal. Perform signal conversion.

The transmission circuit 10b is an FM modulation type radio wave transmission section for converting the data signal into radio wave signals of two different frequencies which are radio signals, and transmits the analog signals SW1 and SW2 and oscillators OSC1 and OSC2. , NOT circuit N1, multiplier M1, oscillator OSC3, and high-frequency amplifier HF1. This transmission circuit 10
A data signal corresponding to the values of the output current and the output voltage of the DC / AC converter 9, which is the content of the operation state, is output to the antenna ANT1 via b, and is transmitted as a radio signal from the antenna ANT1.

The receiving circuit 10e is a radio wave receiving section for receiving and converting a radio wave signal which is a radio signal, and is a high frequency amplifier HF2.
, A detector RF1, and a frequency voltage conversion circuit (hereinafter, FV
An FV1 (referred to as a conversion circuit) and comparators C1 and C2 are provided. The radio signal input from the antenna ANT2 and received by the receiving circuit 10e is converted into output data of the CPU circuit of the system interconnection control circuit 12 and output.

The display control circuit 10f is a signal processing circuit for outputting the output data of the CPU circuit of the system interconnection control circuit 12 based on the radio wave signal to the display element 10h, and calculates the contents of the operating state of the inverter section. CP to display
It has a U circuit and changes and displays the display content of the display element 10h by a switch operation signal from the operation switch SW1 for changing the display content of the display element 10h described later. The display control circuit 10f recognizes the operation state of the DC / AC converter 9 of the grid-connected inverter device 10, for example, as output power, integrated output power amount, normal operation state or occurrence of abnormality by arithmetic processing. Is
The operation switch SW is used as display data of the display element 10h.
It is output based on the operation of 1. It should be noted that, when an abnormality occurs, a notifying circuit may be provided as appropriate for giving a sound or the like based on the abnormality occurrence data.

The memory circuit 10g is the display control circuit 10 described above.
f CPU circuit operation program and display control circuit 10
A circuit for temporarily storing the contents of the operating state converted by signal processing at f, such as ROM, RAM and EEP
It is a memory circuit configured by a memory element of a ROM.

The display element 10h is an inverter body 10a.
In the portion for displaying the contents of the operating state of the DC / AC converter 9 which is the inverter circuit of, the liquid crystal display element for displaying numerical data or the like of a predetermined value is configured. The display element 10h sequentially displays the output power, the integrated output power amount, etc. based on the operation of the operation switch SW1 described later.

The solar cell 10i is for supplying circuit power. Next, the operation of the grid interconnection inverter device 10 having the above configuration will be described. The inverter main body 10a of the system interconnection type inverter device 10 is installed in the vicinity of a distribution board such as a kitchen door in a house, and the display unit 10d is also at a predetermined wall height of a kitchen or the like. Will be installed in the position.

When DC power is output from the solar cell 8,
First, the DC / AC converter 9 converts the AC power. Then, in a state of being connected to the commercial power supply system 1 from the disconnecting switch 11, that is, in a state of being interconnected, the load 13 in the house is connected to the solar battery together with the power from the commercial power supply system via the branch breaker of the distribution board. The electric power output by 8 is supplied. Simultaneously with the supply of this electric power, the grid connection control circuit 12 detects a frequency abnormality or a voltage abnormality in the system of the distributed power source 7 or a power failure of the commercial power source system by the voltage signal and the current signal from the sensor unit 10c. It And abnormal (voltage rise, voltage rise,
Voltage drop, frequency increase and frequency decrease) or not.

If it is determined to be normal, the DC power of the solar cell 8 continues as it is, and the grid-connected inverter device 1
It is converted into alternating current through 0 and the in-house load 13 is output.
The DC / AC converter 9 which is the content of the operating state
A data signal corresponding to the values of the output current and the output voltage is transmitted from the antenna ANT1 as a radio signal via the transmission circuit 10b.

The operation of the transmission circuit 10b is as follows. First, when the output of the CPU circuit of the grid interconnection control circuit 12 is High, that is, output data 1, the analog switch SW1 is ON, C
When the output of the PU circuit is Low, that is, when the output data is 0, the negation circuit N1 is turned on so that the analog switch SW2 is turned on.
It is distributed in. And the analog switch SW1
Is ON, the output of the frequency of f1 Hz is input from the oscillator OSC1 to the multiplier M1. Conversely, when the analog switch SW2 is ON, the output of the oscillator OSC2 is f2H.
The output of the frequency z is input to the multiplier M1. And
The multiplier M1 receives the outputs of the analog switch SW1 and the analog switch SW2 and the output of the oscillator OSC3 at the frequency of f3 Hz, and amplitude-modulates the f1 Hz signal and the f2 Hz signal using the f3 Hz frequency as a carrier. The generated continuous high frequency signal is output. Then, this high frequency signal is input to the high frequency amplifier HF1, amplified in power, converted into a radio signal from the antenna ANT1, and transmitted.

In the operation of the receiving circuit 10e, first, the radio wave signal transmitted through the antenna ANT1 is transmitted to the antenna AN.
A high frequency signal which is received at T2 and is substantially the same as the high frequency signal is input. The high-frequency signal is power-amplified by the high-frequency amplifier HF2 and then demodulated by the detector RF1 into a demodulated signal having a frequency f1 Hz and a frequency f2 Hz. Then, this demodulated signal is input to the FV conversion circuit FV1 and has a frequency f1 Hz and a frequency f2 Hz.
Is converted into a continuously changing voltage signal corresponding to a predetermined voltage value, and this voltage signal is input to the comparator C1 and the comparator C2. The reference voltage V1 compared by the comparator C1 and the reference voltage V2 compared by the comparator C2 are set so that reference voltage V1> reference voltage V2.
Further, the FV converter FV corresponding to the above-mentioned frequency f1 Hz
The output of 1 is a voltage value higher than the reference voltage V1, and the output of the FV converter FV1 corresponding to the frequency f2 Hz is output so as to have a voltage value approximately in the middle between the reference voltage V1 and the reference voltage V2. As a result, the demodulated signal has a frequency f1 Hz.
In the case of, both the outputs of the comparator C1 and the comparator C2 are Hi.
When the frequency of the demodulated signal is f2 Hz, the output of the comparator C1 is Low and the output of the comparator C2 is High. Then, the output data of the comparator C1 and the comparator C2 causes the receiving circuit 10e to output the same output data as the output data of the CPU circuit of the system interconnection control circuit 12.

Then, the output power of the solar cell 8 is displayed by the display element 10h via the display control circuit 10f. Further, the display control circuit 10f sequentially calculates the integrated amount of output power from the temporal transition of the output current and the output voltage,
It is stored in the storage circuit 10g. This integrated amount of output power is the operation switch S of the display unit 10d which is the display unit.
W1 is operated and displayed on the display element 10h.

Further, when it is determined that there is an abnormality or when a power failure is detected, the disconnection switch 11 is immediately opened by the grid interconnection control circuit 12. Then, a data signal corresponding to the occurrence of an abnormality or a power failure is transmitted as a radio wave signal from the antenna ANT1. Then, similar to the above, this radio signal is received by the antenna ANT2 of the display unit 10d, converted by the display control circuit 10f, and displayed by the display element 10h.

In the above operation, the system interconnection type inverter device 10 is a system interconnection control circuit 12 which is a signal conversion unit for converting the contents of the operating state of the DC / AC converter 9 into a predetermined data signal. A radio signal received by including an inverter body 10a including a transmission circuit 10b that is a radio wave transmission unit that converts the data signal into a radio wave signal and transmits the radio signal, and a reception circuit 10e that is a radio signal reception unit that receives the radio signal. By the display unit 10d having the display element 10h for displaying the content of the operating state of the inverter unit based on the above, the display by the display unit 10d is received and displayed by the radio signal which is a radio signal. . Therefore, the wiring work between the inverter body 10a and the display unit 10d is unnecessary, and the display unit 10d can be easily installed without worrying about the wiring. Further, the display unit 10d has a solar cell 10i and operates by obtaining power from the solar cell 10i. Therefore, the power supply wiring and the battery for operating the display unit 10d are unnecessary. In addition, troublesome work such as battery replacement becomes unnecessary. In addition, the display unit 1
0d is supposed to have a storage unit of an EEPROM. Thereby, the display unit 10d stores the content of the operating state of the inverter unit in the EEPROM when the circuit power cannot be obtained from the solar cell. Therefore, it is possible to easily hold the calculation data of the integrated power without using a backup battery power source for holding the stored data.

In the description of the above embodiment,
Although the radio signal is described as a radio signal, the present invention is not limited to this, and may be a signal by light such as infrared rays. Further, the signal modulation system is not limited to the amplitude modulation system based on the change in frequency, and a frequency modulation system or the like may be used. Further, the power source of the display unit is not limited to the solar cell, but a battery or the like may be used. Further, the storage unit is not limited to one having an EEPROM.

[0029]

In the power converter according to the first aspect of the present invention, since the display of the contents of the operating state of the inverter section by the display section is received and displayed by a radio signal,
Wiring work between the display unit and the display unit is unnecessary, and the display unit can be easily installed without worrying about wiring.

In addition to the effect of the power conversion device according to the first aspect, the power conversion device according to the second aspect operates by receiving power from the solar cell, so that the power supply wiring for operating the display unit and No batteries are needed.

Further, in addition to the effects of the power conversion device according to claim 1 or 2, the power conversion device according to claim 3 displays the operating state of the inverter part when the circuit power cannot be obtained from the solar cell. Since the data is stored in the EEPROM, it is possible to easily hold the calculated data of the integrated power without using a backup battery power source for holding the stored data.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic configuration of a grid interconnection inverter device according to a first embodiment of the present invention.

FIG. 2 is a circuit block diagram thereof.

FIG. 3 is an explanatory diagram of a basic configuration of the wireless signal transmitting unit and the wireless signal receiving unit.

FIG. 4 is a schematic configuration diagram of a photovoltaic power generation system that is an explanatory diagram of a distributed power supply system.

FIG. 5 is an explanatory diagram of a basic configuration of a conventional grid-connected inverter device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply power system 7 Distributed power supply 8 Solar cell 9 DC / AC converter (inverter part) 10 System interconnection type inverter device 10a Inverter body 10b Transmission circuit (radio signal transmission part) 10d Display unit (display part) 10e Reception circuit (Wireless signal receiving unit) 10g Storage unit 10i Solar cell 11 Disconnection switch 12 System interconnection control circuit

Claims (3)

[Claims] 1. An inverter unit that converts DC power input from a DC power supply into AC and outputs the AC power, a signal conversion unit that converts the contents of the operating state of the inverter unit into a predetermined data signal, and the data signal by radio. A display unit that includes an inverter body that includes a wireless signal transmission unit that converts the signal into a signal and transmits the signal, and a wireless signal reception unit that receives the wireless signal, and displays the content of the operating state of the inverter unit based on the received signal. An electric power conversion device comprising: 2. The power conversion device according to claim 1, wherein the display unit has a solar cell for obtaining a power source for the display unit. 3. The power conversion device according to claim 1, wherein the display unit has a storage unit formed of an EEPROM.