JP2007166719A - Power supply supervisory unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply monitor capable of supplying electric power to a load by generated electric power of a small-scale solar cell panel and commercial power supply, and also ensuring electric power necessary for an operation of the load by the commercial power supply at a reverse power flow, at a low installation cost. <P>SOLUTION: This power supply monitor includes a power line carrier signal communication portion 11 for allowing a circuit breaking portion 10 inserted between an electric power generation G and an indoor power line 4 to operate a circuit breaking action when a breaking command sent in a power line carrier signal through the indoor power-line 4 is received. Furthermore, the power supply monitor builds, in a branch breaker 10 in a power distribution board 3, a reverse/normal power flow measuring circuit 14a for measuring an electric power based on a voltage and a current of the indoor power line 4 and outputting a determination result as a reverse flow when the measured power is actually the reverse power flow; a reverse/normal flow determining portion 14 composed of a command issuing circuit 14b for issuing the breaking command from the determination result; and a power-line carrier signal communication portion 15 for sending the breaking command to the power line carrier signal communication portion 11 in the power line carrier signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply monitoring device used in a grid-connected power generation system.

  In recent years, a grid-connected system that converts direct-current electricity obtained from solar cells and the like into commonly-used alternating current via an inverter device, and can be connected to a general commercial power source supplied from an electric power company. Have been installed in general households. FIG. 5 shows an example. In the system shown in FIG. 5, DC power generated by the solar cell panel 1 is supplied to the inverter device 2 via the connection box 7, and this DC power is supplied by the inverter device 2. It is converted into AC power of commercial frequency and supplied to the indoor power line 4 in the house through the disconnector etc. in the distribution board 3, and consists of a purchased power meter and a sold power meter with a reverse rotation prevention function. It is configured to connect to the lead-in line 6 via a special wattmeter 5.

  By the way, if the generated power of the solar battery panel performs reverse power flow purchase with respect to the distribution line, the above-described special wattmeter 5 is required, and thus there is a problem that the construction cost is high.

  On the other hand, a stand-alone photovoltaic power generation system using a small-capacity solar cell panel that can be installed on a veranda such as an apartment house has been proposed (Non-Patent Document 1).

As shown in FIG. 6, the stand-alone photovoltaic power generation system connects the solar battery panel 1 to the battery BT via the backflow prevention diode D, the switch SW1, the ammeter A1, and the fuse F. It is configured to be connected to a load R via a fuse F, a switch SW2, and an ammeter A2. In the daytime, the switch SW1 is turned on and the switch SW2 is turned off. Charging BT, turning off switch SW1 at night and turning on switch SW2 to supply power of battery BT to load R. Charge current is monitored by ammeter A1, and load current is monitored by ammeter A2. It is supposed to be.
“A Veranda Solar Power Generation That Anyone Can Do” Familiar Introduction to Natural Energy Editor Natural Energy Promotion Citizens Forum October 10, 1999 First edition issued Issuing joint publisher (page 23, Fig. 1)

  By the way, in the stand-alone photovoltaic power generation system as shown in FIG. 6, when the generated power of the solar battery panel 1 is supplied to the power line wired in the dwelling unit in order to increase the energy saving effect, the generated power is It is necessary to prevent the reverse power flow from becoming larger than the power supplied from the electric power company, but for that purpose, it is necessary to install a special wattmeter with the reverse rotation prevention function as described above, and the construction cost There were issues such as.

  Therefore, as shown in FIG. 7, there has been proposed a method of inserting a cutoff circuit 8 with a reverse power flow detection function into the indoor power line 4 to cut off the commercial power supply side and the solar cell panel 1 side when a reverse power flow occurs. Yes.

In the case of FIG. 7, since the cutoff circuit 8 is inserted in the middle of the indoor power line 4, when the cutoff circuit 8 interrupts the indoor power line 4 due to reverse power flow, it is between the cutoff circuit 8 and the distribution board 3. The load R connected to the indoor power line 4 is connected to a commercial power source, and the load R connected to the indoor power line 4 between the power generation device G composed of the solar cell panel 1 and the inverter device 2 and the cutoff circuit 8 is However, when the capacity of the solar cell panel 1 is small as described above, the solar cell panel is turned off when the power line is cut off if the load R on the inverter device 2 side is operating. There is a problem that the power consumption on the one side increases rapidly and the power required for the load R cannot be supplied.

  In FIG. 7, reference numeral 9 denotes a power outlet, which is configured to connect the load R and the output of the inverter device 2 to the indoor power line 4 via the power outlet 9.

  The present invention has been made in view of the above points, and its purpose is to prevent a reverse power flow without using a power meter with a reverse rotation prevention function, and to achieve a small-scale solar cell panel. To provide a power supply monitoring device that can supply power to the load with the generated power and commercial power supply, and can secure the power necessary for the operation of the load during reverse power flow with the commercial power supply and at low installation cost It is in.

  In order to achieve the above-described object, according to the first aspect of the present invention, there is provided a power supply system for connecting a commercial AC power supply and an AC power supply of a power generator to an indoor power line and supplying power to a load connected to the indoor power line. A circuit interrupting unit that is inserted and connected between the indoor power line and the power generation device that is connected to the indoor power line at a position closer to the termination than the connection point of the load on the termination side of the indoor power line; A connection point between a power line carrier signal communication unit that is connected to a power line and that cuts off the circuit cutoff unit when receiving a cutoff command sent by the power line carrier signal via the indoor power line, and a load on the start side of the indoor power line A reverse power flow determination unit that measures electric power based on a current flowing through an electric circuit between the power line and an indoor lead-in line of a commercial AC power supply and an electric circuit voltage, and outputs the cutoff command when the measured power is reverse power Characterized by comprising a separate power line carrier signal communications unit to be transmitted to the reverse flow through the indoor power line by a power line carrier signal cutoff command output from the determination unit said power line carrier signal communications unit.

  According to a second aspect of the present invention, in the first aspect of the present invention, the reverse power flow determination unit and the separate power line carrier signal transmission are provided in a branch breaker that is arranged in a distribution board and branches the indoor power line from the main line. The power supply monitoring device according to claim 1, wherein a power supply monitoring device is provided.

  According to a third aspect of the present invention, in the first aspect of the invention, the reverse power flow determination unit and the another power line carrier signal transmission unit are provided in a power integrator provided in the indoor lead-in line. And

  The present invention aims to prevent reverse power flow without using a power meter with a reverse rotation prevention function, and can supply power to a load with the generated power of a small-sized solar panel and a commercial power source. The power required for the operation of the load can be secured by the commercial power supply, and the position of the reverse power flow determination unit is at the start side of the power line, and the position of the circuit cutoff unit that cuts off the power line is the output connection position of the power generator Even if it is provided at a distant position, it is possible to send a shut-off command without using a special signal line or the like, and there is an effect that it is possible to provide a power supply monitoring device with low construction cost.

Embodiments of the present invention will be described below.
(Embodiment 1)
This embodiment corresponds to, for example, a small-scale solar battery power generation system that is installed by installing a solar battery panel on the veranda of each dwelling unit of an apartment house. As shown in FIG. A power generator G composed of an inverter device 2 that performs AC conversion and boosting so that the frequency and voltage of the DC power output from the solar battery panel 1 are the same as those of a commercial power source, and the output of the power generator G to the indoor power line 4 A circuit interrupting unit 10 for interrupting the electric circuit at the time of reverse power flow is inserted into the electric circuit connected via the power outlet 9, and the circuit interrupting unit 10 receives the power line carrier signal sent via the indoor power line 4. The power line communication signal communication (Power Line Communication) unit 11 is provided.

  As shown in FIG. 2, the power line carrier signal communication unit 11 receives a power line carrier signal, and when a cutoff command for the circuit cutoff unit 10 is sent by the power line carrier signal, the circuit cutoff unit 10 receives a cutoff control signal. The control circuit 11b includes a control circuit 11b that outputs CS to shut off the circuit shut-off unit 10 and outputs a return control signal RS to the circuit cut-off unit 10 when the return command is issued.

  When the cutoff control signal CS is input from the power line carrier signal communication unit 11 as shown in FIG. 2, the circuit cutoff unit 10 operates the switching drive circuit 10a such as an electromagnetic driving device to drive the switching contact S off. When the return control signal RS is present, the switching contact S is driven on.

  On the other hand, a circuit shown in FIG. 1B is built in each branch breaker 12 disposed in the distribution board 3.

  That is, in the vessel body 12a of the branch breaker 12, in addition to the circuit breaking mechanism unit 13, a reverse power / forward power measuring circuit 14a and a reverse power / forward power measuring circuit 14a inserted between the switching contact and the indoor power line 4 are provided. The reverse power flow / forward power flow determination unit 14 includes a command generation circuit 14b that generates a cut-off command and a return command from the output of the reverse power flow determination and the return determination from the power source. 4 is provided with a power line carrier signal communication unit 15 that transmits the signal on the power line 4.

  The reverse power / forward power measuring circuit 14a of the reverse power / forward power determining unit 14 is connected in parallel to the indoor power line 4 and a current measuring circuit 140a inserted into the indoor power line 4 as shown in FIG. 1 (c). Voltage measurement circuit 140b, power calculation circuit 140c for calculating power V · I from current I measured by current measurement circuit 140a and voltage V measured by voltage measurement circuit 140b, and calculation by this power calculation circuit 140c. When the power is negative from the generated power and the power supply of the commercial power source is a reverse power flow that is less than the power supply on the power generation device G side, a reverse power flow determination output is generated, and the forward power flow power is predetermined. When it is determined that there is no risk of reverse power flow, the power flow determination circuit 140d generates a return determination output, and the command generation circuit 14 is based on the determination output of the power flow determination circuit 140d. Command is outputted from the power line signal communication section 15.

  A load R is connected to a power outlet 9 provided on the indoor power line 4 between the connection positions of the two power line carrier signal communication units 11 and 15, and the generated power and the commercial power in the solar panel 1 are normally used, that is, in a forward power flow state. The power of the power source is supplied to the operating load R.

  When the power line carrier signal communication unit 15 receives the reverse power flow judgment output from the reverse power / forward power judgment unit 14 here, the power line carrier signal communication unit 15 sends a cutoff command to the power line carrier signal communication via the indoor power line 4 by the power line carrier signal. Send to part 11. The power line carrier signal communication unit 11 outputs a cutoff control signal CS to the circuit cutoff unit 10 when the cutoff command is sent by the power line carrier signal, and turns off the switching contact S of the circuit cutoff unit 10. As a result, the generated power of the power generator G is disconnected from the indoor power line 4, and only the commercial power supply is used to prevent the reverse power flow. At the same time, since all of the operating loads R are supplied with power from the commercial power supply side, unstable operation of the load R due to power shortage does not occur.

  When the forward load power increases due to the increase in the load R used, it is determined that there is no risk of reverse power flow. When the power line carrier signal communication unit 15 receives the return determination output from the reverse power / forward power determination unit 14. The power line carrier signal communication unit 15 transmits a return command to the power line carrier signal communication unit 11 via the indoor power line 4 by the power line carrier signal.

  When a return command is sent by the power line carrier signal, the power line carrier signal communication unit 11 outputs a return control signal RS to the circuit breaker 10 and turns on the switching contact S of the circuit breaker 10. As a result, the commercial power supply and the generated power of the power generator G are supplied to the operating load R.

  By the way, the power line carrier signal communication employs a modulation method such as a low-speed communication with a carrier frequency of 10 kHz to 450 kHz and a transmission speed of about several tens of bps, and a wideband spread spectrum method, a multicarrier modulation method, an OFMD modulation method, Although there are high-speed communication types in which the carrier frequency band is 2 MHz to 30 MHz, the power line carrier signal communication in the present embodiment may be any technically and is not particularly limited.

In addition, the power line carrier signal communication unit 11 can satisfy the functions of the embodiment only with the reception function and the power line carrier signal communication unit 15 with the transmission function. However, the transmission / reception function may be provided as necessary. .
(Embodiment 2)
In the first embodiment described above, the reverse power flow / forward power flow determination unit 14 and the power line carrier signal communication unit 15 are built in each branch breaker 12, but the integrated wattmeter for integrating the total power consumption of the dwelling unit. It may be built in.

  FIG. 3 shows an example of this embodiment built in the integrating wattmeter 16 connected to the lead-in wire 6 of a detached house. The integrated wattmeter 16 also has a gateway function for reporting the integrated power value of the dwelling unit to the power management center 17 through a network such as the mobile telephone communication network NT. The internal configuration of the integrating wattmeter 16 is not shown.

  By the way, the integrating wattmeter itself is installed by an electric power company, but a business of providing various services to the user using the gateway function described above is also conceivable.

Further, if the power monitoring device including the integrating wattmeter 16 and the power generation device G of the present embodiment is used, the user's electricity usage fee is reduced, and the user can obtain more. On the other hand, the reduction of the user's electricity usage fee is a demerit for the electric power company, but there is an advantage that the capital investment for power supply can be reduced by installing this embodiment in many user homes. Further, since the integrated wattmeter itself is required to be updated periodically, for example, the integrated wattmeter 16 in the present embodiment may be introduced in accordance with the update timing.
(Embodiment 3)
By the way, the power line carrier signal communication unit 11 used in the first embodiment can satisfy the function as the first embodiment only with the reception function, and the power line carrier signal communication unit 15 with the transmission function. When the operation information of the circuit interrupting unit 10 is acquired by the power line carrier signal communication unit 15 from the unit 11, transmission / reception of the power line carrier signal is required on both sides. In this case, the present embodiment aims to reduce costs by sharing a part of the circuit configuration of the receiving circuit provided in the power line carrier signal communication unit 15 and the circuit configuration of the reverse power / forward power measuring circuit 14a. There is a feature in this point.

  That is, in the present embodiment, as shown in FIG. 4, in the reverse power / forward power measurement circuit 14a, the measurement value of the current measurement circuit 140a and the measurement value of the voltage measurement circuit 140b are switched by the multiplexer 140e to switch the A / D converter 140f. Are converted into digital values, and then the power calculation circuit 140c ′ performs power calculation using the digitally converted measurement values, while the reception signal of the reception circuit 15c provided in the power line carrier signal communication unit 15 is multiplexed. By switching to 140e, the signal is input to the A / D converter 140f and A / D converted to share the circuit configuration.

  Here, it is customary to perform multiband reception processing on the digital signal after A / D conversion after A / D conversion of the reception signal using the multicarrier modulation method in high-speed power line carrier signal communication.

  Therefore, in this embodiment, the reception circuit 15a of the power line carrier signal communication unit 15 amplifies the reception signal extracted by the reception signal extraction circuit 15b composed of a coupler by the amplifier 15c, and then switches the A / A by switching the multiplexer 140e. The input signal is input to the D converter 140f, A / D converted by the A / D converter 140f, and the received signal subjected to the A / D conversion is input to the signal processing circuit 15d to perform a demodulation process, whereby reverse power flow / forward power flow The multiplexer 140e and the A / D converter 140f of the power measurement circuit 14a are shared.

  In addition, the transmission circuit 15e of the power line carrier signal communication unit 15 takes in the data of the cutoff command and the return command, which are transmission data, to the transmission signal processing circuit 15f, performs a predetermined encoding process, and converts the encoded signal to D / The digital signal is D / A converted by the A converter 15g, further amplified by the digital amplifier 15h, and then transmitted to the indoor power line 4 via the transmission signal injection circuit 15i which is a coupler.

  Since the configuration other than the above may be the same as the configuration of the first embodiment or the second embodiment, illustration and description thereof are omitted here.

  Thus, in the present embodiment, when the receiving circuit 15a is provided in the power line carrier signal communication unit 15, a part of the circuit configuration of the reverse power / forward power measuring circuit 14a is shared, so that the circuit configuration is simplified and the cost is reduced. Can be planned.

  Even in the OFMD modulation method used for high-speed communication, it is usual to perform demodulation processing on a digital signal after A / D conversion. Therefore, the A / D converter used for this A / D conversion is determined as a reverse power flow / forward power flow. Of course, it may be shared with the A / D converter 14 f of the unit 14.

  By the way, by using a device-embedded network technology called EMIT (Embedded Micro Internetworking Technology) (a network technology having a function of easily incorporating middleware into a device and connecting to the network, hereinafter referred to as EMIT technology). Various equipment (illumination equipment, air conditioning equipment, power equipment, sensors) from external terminals (not shown) such as mobile phones, PCs (Personal Computers), PDAs (Personal Digital Assistants), PHSs (Personal Handy phone Systems) An electric lock, a web camera, and the like are hereinafter referred to as an EMIT terminal.) There is a system that can access <not shown> to remotely monitor and control the EMIT terminal.

  Note that the EMIT terminal is a built-in device equipped with a microcomputer, and is a device-embedded middleware for connecting to the network and is equipped with EMIT software that realizes the EMIT technology.

  As a system to which the above-mentioned EMIT technology is applied (hereinafter referred to as an EMIT system), an external terminal remotely monitors and controls an EMIT terminal via a center server (not shown) provided on the Internet. For example, a configuration in which an EMIT terminal is directly accessed from an external terminal equipped with EMIT software to remotely monitor and control the EMIT terminal without using a center server.

  When the power line carrier signal communication unit 11 and the power line carrier signal communication unit 15 used in the power supply monitoring device of the present invention are configured as an EMIT terminal using EMIT network technology, for example, a building (detached house) By monitoring the state of the EMIT terminal remotely from an external terminal <not shown>, it is possible to manage the energy of the entire building.

  The load R may be configured to include the power line carrier signal communication unit 15 and the reverse power flow / forward power flow determination unit 14. In this case, the power line carrier communication unit 15 may constitute the above-described EMIT terminal. .

1A and 1B are diagrams illustrating an overall configuration, FIG. 1A is a block diagram of an entire configuration, FIG. 2B is a circuit block diagram in a branch breaker, and FIG. FIG. 3 is a block diagram of a circuit interruption unit according to the first embodiment. FIG. 6 is an overall configuration diagram of a second embodiment. FIG. 10 is a block diagram of a main part of the third embodiment. It is a block diagram of the conventional grid connection type power generation system. It is a circuit diagram of a stand-alone power generation system using a small-scale solar cell panel. It is a block diagram of the prior art example of the power supply monitoring apparatus used for the electric power generation system using a small-sized solar cell panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell panel 2 Inverter apparatus 3 Distribution board 4 Power line 9 Power outlet 10 Circuit interruption | blocking part 11 Power line carrier signal communication part 12 Branch breaker 12a Body 13 Circuit interruption | blocking mechanism part 14 Reverse power flow / forward power flow determination part 14a Reverse power flow / forward Power flow measurement circuit 14a
140a Current measurement circuit 140b Voltage measurement circuit 140c Power calculation circuit 140d Power flow determination circuit 14b Command generation circuit 15 Power line carrier signal communication unit R Load G Power generation device

Claims (3)

Used in a power supply system that connects a commercial AC power source and an AC power source of a power generator to an indoor power line and supplies power to a load connected to the indoor power line,
A circuit interrupter inserted and connected between the power generator and the indoor power line connected to the indoor power line at a position closer to the end than the connection point of the load on the terminal side of the indoor power line;
A power line carrier signal communication unit that is connected to the indoor power line and receives the cutoff command sent by the power line carrier signal through the indoor power line,
The power is measured based on the current flowing through the circuit between the connection point of the load on the start side of the indoor power line and the indoor lead-in line of the commercial AC power and the circuit voltage. A reverse power flow determination unit that outputs a command;
A power supply monitoring apparatus comprising: another power line carrier signal communication unit that transmits a cut-off command output from the reverse power flow determination unit to the power line carrier signal communication unit via the indoor power line by a power line carrier signal. The said reverse power flow determination part and said another power line carrier signal transmission part are provided in the branch breaker which is arrange | positioned in a distribution board and branches the said indoor power line from a trunk line, The said another power line carrier signal transmission part is provided. The power supply monitoring device described. 2. The power monitoring apparatus according to claim 1, wherein the reverse power flow determination unit and the another power line carrier signal transmission unit are provided in a power integrator provided in the indoor lead-in line.

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