JP2016174437A - Power transmission regulating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission regulating system capable of improving profits of owners and investors having renewable energy power generation facilities.SOLUTION: A power transmission regulating system 1 includes: a power reception line 11 provided for each renewable energy power generation apparatus 2; a power transmission line 12 provided on power system 3 side, and a charge line 13 and a discharge line 14 provided on storage energy apparatus 4 side. With the power reception line 11 regarded as input side, on output side, the power transmission line 12 and the charge line 13 are switched by a changeover switch 15. Connection of the discharge line 14 and the power transmission line 12 is turned on and off by a discharge switch 16. Switching and opening/closing of the changeover switch 15 and the discharge switch 16 are controlled by an output control controller 17.SELECTED DRAWING: Figure 1

Description

  The present embodiment relates to a power transmission adjustment system that transmits output power of a renewable energy power generation device such as a solar power generation facility to an electric power system.

  Global warming and depletion of fossil fuels have become problems, and interest in the global environment and energy is rapidly increasing. Under such circumstances, renewable energy such as solar power generation, wind power generation, tidal power generation, and power generation by a fuel cell is attracting attention as an energy source with a small environmental load. In recent years, these renewable energy power generation facilities have been linked to commercial power systems, and surplus power can be sold by customers. This power sales mechanism has helped popularize power generation facilities using renewable energy. doing.

  However, in order to stabilize the power system, if there is a risk of excessive power supply to the power system from the viewpoint of balance between power supply and demand, power is transmitted to the renewable energy power generation facility via the communication network. A suppression instruction is sent out. For a renewable energy power generation facility, when a power transmission suppression instruction is received, the power transmitted to the power system is suppressed within 15 minutes.

  However, restraining the output power to the power grid will result in the loss of part of the power that was originally able to be generated, and from the owners and investors of renewable energy power generation facilities, the power sold will be lost. , Leading to a loss of electricity sales profit. For this reason, there is a demand for the construction of a mechanism for stabilizing the power system while minimizing lost power.

  Therefore, a method has been proposed in which a storage battery is connected to a power conditioner provided for a generator that converts renewable energy into electric power, and the power generated by the power conditioner is partly stored in the storage battery as required ( For example, see Patent Document 1.) According to this method, it is possible to cope with stabilization of the electric power system by suppressing the output of the electric power stored in the storage battery, and it is possible to transmit the electric power stored in the storage battery to the electric power system when the output suppression is canceled (for example, Patent Documents). 1).

JP2012-130096A

  According to the system of Patent Document 1, the transmission power is suppressed in units of power conditioners, and a plurality of power conditioners are not linked. Then, in operation at a power plant having a large number of renewable energy power generation facilities, transmission control becomes complicated, and the number of power conditioners must be provided with control mechanisms, which increases manufacturing costs and operation costs. There was a problem. Moreover, the output suppression by the power conditioner causes a large power conversion loss, and the power that can be transmitted originally is lost, which may be disadvantageous for owners and investors.

  The present embodiment has been made in view of the above situation, and an object thereof is to provide a power transmission adjustment system capable of improving the profits of owners and investors who have renewable energy power generation facilities. .

  The power transmission adjustment system of the present embodiment is a power transmission adjustment system that transmits output power of a plurality of renewable energy power generation devices to an electric power system, and is provided for each of the renewable energy power generation devices. Each power receiving line that receives output power from the power conditioner, a charging line that charges the energy storage device with energy, a discharge line that discharges energy of the energy storage device, a power transmission line that transmits power to the power system, Each of the power receiving lines, each first switch for switching the connection destination to one of the charging line and the power transmission line, a second switch for opening and closing the connection between the discharge line and the power transmission line, A controller that controls the first switch and the second switch. .

It is a block diagram which shows the structure of the power transmission adjustment system which concerns on 1st Embodiment. It is a flowchart which shows the control by the output control controller of a power transmission adjustment system. It is a block diagram which shows the 1st operation example of a power transmission adjustment system. It is a block diagram which shows the effect | action by the 1st operation example of a power transmission adjustment system. It is a block diagram which shows the 2nd operation example of a power transmission adjustment system. It is a block diagram which shows the effect | action by the 2nd operation example of a power transmission adjustment system. It is a block diagram which shows the 3rd operation example of a power transmission adjustment system. It is a block diagram which shows the effect | action by the 3rd operation example of a power transmission adjustment system. It is a block diagram which shows the structure of the power transmission adjustment system which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the power transmission adjustment system which concerns on 3rd Embodiment.

(First embodiment)
As shown in FIG. 1, the power transmission adjustment system 1 is provided between a plurality of renewable energy power generation devices 2 and a power system 3. The power transmission adjustment system 1 receives the output power of the renewable energy power generation device 2 and outputs it to the power system 3. The power transmission adjustment system 1 includes the energy storage device 4 separated from the power system 3 and subordinates, and transmits part or all of the output power of the renewable energy power generation device 2 to the power system 3 according to the power supply / demand situation. Then, the remaining energy is charged in the energy storage device 4. Moreover, according to the state of electric power supply and demand, the discharge power of the energy storage device 4 is also added and transmitted to the power system 3.

  The renewable energy power generation apparatus 2 includes a generator 21 such as solar power generation, wind power generation, and a fuel cell, and a power conditioner 22. The power conditioner 22 is a device that boosts the output voltage of the generator 21, converts DC power into AC power, suppresses harmonics, and controls the power factor. The power conditioner 22 for photovoltaic power generation includes, for example, a DC-DC converter or boost chopper for MPPT (Maximum Power Point Tracking) control, an inverter for orthogonal conversion by PWM control, and an LCR AC for harmonic suppression control A filter circuit and the like are provided. This renewable energy power generation apparatus 2 is driven independently without suppressing the output power by the power transmission adjustment system 1.

  The energy storage device 4 converts and accumulates input power into chemical energy or the like, such as a storage battery, a hydrogen power storage device that generates and stores hydrogen by electrolysis of water, and reconverts it into power. And release.

  The power transmission adjustment system 1 includes an output control controller 17 including a ROM, a processor, a memory, a driver, and a signal receiving circuit in which a program is incorporated. The output controller 17 controls the distribution destination of the output power of the renewable energy power generation device 2 and controls charging / discharging of the energy storage device 4. The distribution destination is the power system 3 and the energy storage device 4.

  The output control controller 17 is connected to an external device 5 such as a central command station that monitors the power flow of the power system 3 and the power conditioner 22 through a wireless or wired communication line. An output control signal is input from the external device 5 to the output controller 17, and an output state signal is input from the power conditioner 22. The output controller 17 performs control according to the output control signal and the output state signal. The output control signal indicates the content of the output that flows to the power system 3, for example, the ratio of the output power that the power transmission adjustment system 1 flows to the power system 3 with respect to the rated value (maximum output power). The output state signal indicates the output power of the renewable energy power generator 2.

  Each structure of the power transmission adjustment system 1 controlled by the output controller 17 will be described. The power transmission adjustment system 1 includes a power receiving line 11 that receives the output power of the renewable energy power generator 2 on the input side. The power receiving line 11 is provided for each renewable energy power generation device 2. On the output side, a power transmission line 12 for transmitting power to the power system 3 and a charging line 13 for transmitting charging power to the energy storage device 4 are provided. Furthermore, the power transmission adjustment system 1 includes a discharge line 14 that discharges the energy of the energy storage device 4.

  The power transmission adjustment system 1 includes a changeover switch 15 and a discharge switch 16. The changeover switch 15 switches the connection to the power receiving line 11 to one of the power transmission line 12 and the charging line 13. The changeover switch 15 is provided for each power receiving line 11. The changeover switch 15 is a device that switches the output destination according to a control signal, and is, for example, an electromagnetic relay switch or a switch IC. The discharge switch 16 is interposed between the discharge line 14 and the power transmission line 12 of the power system 3, and opens and closes the connection between the power transmission line 12 and the discharge line 14. The output controller 17 outputs a control signal to each changeover switch 15 and the discharge switch 16 according to the output control signal and the output state signal, and controls the changeover of each changeover switch 15 and the on / off of the discharge switch 16.

  The power transmission adjustment system 1 includes an energy storage device controller 18 that outputs a control signal to the subordinate energy storage device 4 to control charging and discharging. The output control controller 17 includes a changeover switch 15 and a discharge switch 16. Along with the control, the charging / discharging of the energy storage device 4 is also controlled by sending a control signal to the energy storage device controller 18.

  FIG. 2 is a flowchart showing the control by the output controller 17. When receiving the output control signal from the external device 5 (step S01), the output controller 17 determines whether the output control signal is 100% (step S02). When the output control signal is 100% (step S02, Yes), all the changeover switches 15 are connected to the power transmission line 12 side of the power system 3 (step S03). That is, all the power receiving lines 11 and the power transmission lines 12 are connected, and the output power of all the renewable energy power generation devices 2 is transmitted to the power system 3. Normally, the output control signal is 100%, all the power receiving lines 11 and the power transmission lines 12 are connected, and all the output power is supplied to the power system 3.

  When the output control signal is not 100% (No at Step S02), the output control controller 17 calculates power transmission instruction power for the power system 3 (Step S04). The output controller 17 stores in advance a rated value of each renewable energy power generation device 2 in a memory. The output controller 17 calculates the power transmission instruction power from the sum of the rated values and the ratio indicated by the output control signal. Furthermore, the output controller 17 calculates the current total output power of the renewable energy power generator 2 (step S05). The output controller 17 calculates the current total output power by adding the output power indicated by the output status signal.

  Next, the output controller 17 calculates the power transmission change power to the power system 3 (step S06). The output controller 17 calculates the transmission change power by subtracting the current total output power from the transmission command power.

  When the transmission power change is negative (step S07, Yes), the output controller 17 selects the renewable energy power generation device 2 that flows the output power to the energy storage device 4 side (step S08). Specifically, the output control controller 17 lists the renewable energy generating devices 2 in the order of decreasing output power indicated by the output state signal, and outputs indicated by the output control signal in ascending order until the absolute value of the transmission change power is reached. Add power. And the output control controller 17 selects the renewable energy generator 2 which has output each output electric power totaled until it reaches transmission change electric power.

  When the renewable energy power generation device 2 is selected, the output controller 17 switches the changeover switch 15 of the selected renewable energy power generation device 2 to the charging line 13 side (step S09). That is, the power receiving line 11 and the charging line 13 of the selected renewable energy power generation device 2 are connected, and the output power of the selected renewable energy power generation device 2 is stored in the energy storage device 4.

  When the power transmission change power is positive (step S07, No), the output controller 17 turns on (closes) the discharge switch 16 (step S10). Thereby, in addition to the output power of all the renewable energy generators 2, the discharge power of the energy storage device 4 is transmitted to the power system 3 via the discharge line 14 and the power transmission line 12.

  As shown in FIGS. 3 to 6, such a power transmission adjustment system 1 distributes the output power of the renewable energy power generation device 2 to the energy storage device 4 and the power system 3, thereby controlling the output from the external device 5. Satisfy the demand by the signal. When the output control signal is 100%, the power transmission adjustment system 1 switches all the change-over switches 15 to the power transmission line 12 side as shown in FIG. 3, and the renewable energy power generator 2 as shown in FIG. 4. The entire amount of output power is supplied to the power system 3. When the output control signal is 80%, for example, the power transmission adjustment system 1 switches some changeover switches 15 to the power transmission line 12 side as shown in FIG. 5, and sets other changeover switches 15 to the charging line 13 side. By switching, as shown in FIG. 6, 80% of the output power of the renewable energy power generation device 2 is caused to flow through the power system 3 and the remaining 20% is stored in the energy storage device 4.

  When the total output power of all the renewable energy power generation devices 2 has not reached the rate indicated by the output control signal, the power transmission adjustment system 1 turns on (closes) the discharge switch 16 as shown in FIG. Thereby, as shown in FIG. 8, the energy stored in the energy storage device 4 is converted into electric power and transmitted to the electric power system 3.

  As described above, the power transmission adjustment system 1 performs power transmission adjustment only by switching between power transmission and charging of the plurality of renewable energy power generation apparatuses 2 without performing power suppression control by the power conditioner 22. Therefore, the power transmission control is simple, and the power transmission adjustment system 1 is sufficient for one of the plurality of renewable energy power generation apparatuses 2, so that the manufacturing cost and the operation cost are also reduced.

  Regardless of the output control signal from the external device 5, the output of the renewable energy power generation device 2 is not suppressed, and temporarily untransmitted power is discharged from the energy storage device 4. That is, no unnecessary power is generated. Conventionally, the power lost due to the suppression of the output power is effectively utilized as the sold power. In addition, the power conditioner 22 with efficient rated driving can be rated driven. Therefore, no power conversion loss or output error occurs, and lost power can be further reduced.

  Further, according to the power transmission adjustment system 1, the energy storage device 4 is provided not under the power transmission end of the power system 3 but under the power transmission adjustment system 1 and can be separated from the power transmission line 12. Therefore, the opportunity for unnecessary energy accumulation in the energy storage device 4 is reduced. Therefore, the chance of power conversion loss of the energy storage device 4 is reduced, and lost power can be further reduced. Product deterioration of the energy storage device 4 is also reduced by reducing the opportunity for energy storage in the energy storage device 4. Moreover, since the energy storage device 4 is not the power transmission end, the work of separating the power system 3 and the energy storage device 4 is not required, and the maintenance of the energy storage device 4 becomes easy.

  As described above, the power transmission adjustment system 1 is provided with the changeover switch 15 for switching the connection destination to one of the charging line 13 and the power transmission line 12 with respect to the power receiving line 11, and to the charging line 13 and the power system 3 for the energy storage device 4. A discharge switch 16 that opens and closes the discharge line 14 is provided, and the changeover switch 15 and the discharge switch 16 are controlled by the output controller 17, so that the cost is reduced and the power that should have been lost is sold. It can be used effectively as electric power.

  The output controller 17 controls the changeover switch 15 to connect the power receiving line 11 and the charging line 13 in order of increasing output of the power conditioner 22. The power transmission adjustment system 1 is an alternative of transmitting power to the power system 3 or charging the energy storage device 4. With this configuration, the accumulation of energy in the energy storage device 4 is minimized. It is possible to suppress lost power caused by power conversion loss and the like, and it can be used more effectively as sold power.

(Second Embodiment)
As shown in FIG. 9, in the second embodiment, a plurality of power transmission adjustment systems 1 are integrated and controlled by the cloud device 19. The cloud device 19 is a so-called computer, and is connected to an external device 5 that manages the power flow of the power system 3 such as a central command station and each power transmission adjustment system 1 via a communication network so that signals can be transmitted and received.

  The cloud device 19 receives a comprehensive output control signal for all the power transmission adjustment systems 1 under management from the central command station, determines the output control mode of each power transmission adjustment system 1, and outputs an output control signal indicating the content of each determination. It transmits to the power transmission adjustment system 1. That is, the cloud device 19 is a higher-level device having the same function as the output control controller 17 for the power transmission adjustment system 1. The cloud device 19 calculates the transmission change power from the power transmission instruction power derived from the output control signal received from the central command station and the total of the current total output power of each power transmission adjustment system 1, and each power transmission adjustment system 1 To distribute. The total of the current total output power is calculated by receiving the output state signal from the power conditioner 22 of each renewable energy power generation device 2.

  As a result, the supervised renewable energy power generators 2 can be managed in an integrated manner, and it is not necessary to carry out complicated power transmission control for each renewable energy power generator 2. In addition, the operating cost is reduced, and lost power can be efficiently suppressed.

(Third embodiment)
As shown in FIG. 10, in the third embodiment, the power transmission adjustment system 1 performs power transmission adjustment independently, regardless of the presence or absence of an output control signal from the external device 5. The cloud device 19 receives the information from a device on the network that directly or indirectly transmits the information indicating the power generation amount, such as the Japan Meteorological Agency, analyzes the information, and sends an output control signal to each power transmission adjustment system 1. Generate and send. Examples of the information indicating the power generation amount directly or indirectly include cloud amount information, sunshine amount information, weather forecast and the like in addition to the information indicating the power generation amount.

  The cloud device 19 calculates a predicted value of the power generation amount of each renewable energy device 2 according to a known method based on information indicating the power generation amount directly or indirectly, and suppresses transmission power according to the predicted value. Alternatively, an output control signal for discharging energy from the energy storage device 4 to the power system 3 is transmitted to each power transmission adjustment system 1. Thereby, independent control of the lost power can be performed independently of the integrated control of the power system 3 by the output control signal of the external device 5.

(Other embodiments)
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. Specifically, a combination of the first to third embodiments in various combinations is also included. The above embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

  For example, if the energy storage device 4 can transmit power to the power system 3, the timing is arbitrary, in addition to the case where the total output power does not satisfy the content of the output control signal, the case where the output control signal is 100%, Even when the output control signal is not received, the discharge switch 16 may be turned on (closed).

  Moreover, the power transmission adjustment system 1 may be provided with the renewable energy power generation device 2 and the energy storage device 4, or the power transmission adjustment system 1 is connected to the existing renewable energy power generation device 2 and the energy storage device 4. Also good.

DESCRIPTION OF SYMBOLS 1 Power transmission adjustment system 11 Power receiving line 12 Power transmission line 13 Charging line 14 Discharge line 15 Changeover switch 16 Discharge switch 17 Output control controller 18 Energy storage apparatus controller 19 Cloud apparatus 2 Renewable energy power generation apparatus 21 Generator 22 Power conditioner 3 Electric power system 4 Energy storage device 5 External device

Claims (9)

A power transmission adjustment system that transmits output power of a plurality of renewable energy power generation devices to a power system,
Each receiving line that is provided in units of the renewable energy power generation device and receives output power from a power conditioner of the renewable energy power generation device;
A charging line for charging the energy storage device with energy;
A discharge line for discharging the energy of the energy storage device;
A power transmission line for transmitting power to the power system;
Each first switch that is provided in units of the power receiving line and switches the connection destination to one of the charging line and the power transmission line;
A second switch for opening and closing a connection between the discharge line and the power transmission line;
A controller for controlling each of the first switches and the second switch;
Providing
Power transmission adjustment system characterized by. The controller is
A receiving means for receiving a signal indicating the output content from the outside;
Controlling the first switch and the second switch based on the signal;
The transmission adjustment system according to claim 1. The controller is
Controlling the first switch so as to connect the power receiving line and the charging line in ascending order of output of the power conditioner;
The power transmission adjustment system according to claim 1 or 2. A cloud device that is provided via a network and transmits a signal indicating the output content to the controller;
The power transmission adjustment system according to any one of claims 1 to 3. The cloud device
Receiving means for receiving output information of the inverter;
Generating means for generating a signal indicating the output content based on the output information received by the receiving means;
Having
The power transmission adjustment system according to claim 4. Comprising the energy storage device;
The power transmission adjustment system according to any one of claims 1 to 5. The energy storage device is a hydrogen power storage device that generates and stores hydrogen by electrolysis of a storage battery or water,
The power transmission adjustment system according to claim 6. The renewable energy power generation device is a solar power generation system;
The power transmission adjustment system according to any one of claims 1 to 7. Comprising the renewable energy device;
The power transmission adjustment system according to any one of claims 1 to 8.

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