JP5964254B2 - Output leveling system and method for distributed power supply and distributed power supply system - Google Patents

Description

  The present invention relates to an output leveling system and method for a distributed power source for leveling the output of a distributed power source, and a distributed power system.

  2. Description of the Related Art Conventionally, a system using a storage battery (secondary battery) is known as means for suppressing fluctuations in power supplied from a distributed power source to a power system. For example, Patent Document 1 discloses that charge / discharge control of a secondary battery is performed in consideration of fluctuations in output power due to power consumption of a load connected between a distributed power source and a power system. Yes.

JP-A-8-308104

  The storage battery has a limited charge / discharge range. Therefore, for example, when a power fluctuation that exceeds the charge / discharge range of the storage battery occurs, the fluctuation may not be absorbed.

  The present invention has been made in view of such circumstances, and an output leveling system and method for a distributed power source capable of improving the effect of suppressing fluctuations in power supplied from the distributed power source to the power system. An object of the present invention is to provide a distributed power supply system.

The present invention provides a chargeable / dischargeable power storage unit connected to a power line connecting a distributed power source that converts natural energy into electric power and outputs the power system, a power storage related load connected to the power line, and the power storage Charge / discharge command setting means for setting a charge / discharge command for controlling charge / discharge of the means, and surplus of output fluctuation of the distributed power source that cannot be absorbed by charge / discharge control of the power storage means by the charge / discharge command, a load control command setting means for setting a load control command Ru is reduced by the output control of the associated load, the charge and discharge control means for controlling the charging and discharging of the power storage unit based on the charge and discharge command, the load control command A load control means for controlling the power storage related load based on the power distribution means, the power distribution means charge and discharge control and the output of the power storage related load can be leveled dispersion To provide a power supply output leveling system.

According to such an invention, since the output leveling of the distributed power source is performed using not only the power storage means but also the power storage related load, it is possible to suppress output fluctuations that could not be leveled by the power storage means alone. Thus, the effect of leveling the output of the distributed power source can be enhanced.
Also, in specific control, the power storage means is preferentially used to equalize the output of the distributed power source, and when output fluctuations that cannot be suppressed by the power storage means occur, output control by the power storage related load is also used. To do. In this way, by using the power storage related load as an auxiliary, the power storage related load can be maintained in the normal operation state in the case of an output fluctuation that can be suppressed by the power storage means.
The power storage means and the power storage related load may be installed in a common building, for example.

  In the output leveling system of the distributed power source, the charge / discharge command setting unit calculates a correction value for bringing the charging rate of the power storage unit close to a predetermined target charging rate, and uses the correction value to calculate the distributed type Output correction means for correcting the output of the power supply, first target output setting means for setting a first target output that is a target output of the power storage means using the corrected output of the distributed power supply, and the first A first command setting unit configured to set the charge / discharge command based on a difference between a target output and an output of the distributed power source, and the load control command setting unit uses an output of the distributed power source. The load control command is set using a second target output setting means for setting a second target output that is a target output of the power storage related load, and a difference between the second target output and the first target output. Second command setting means Good.

  According to such a configuration, since the output correction unit that performs the correction based on the charging rate of the power storage unit is provided, the charging rate of the power storage unit can be maintained near the target charging rate. In addition, if the charging rate of the power storage means is maintained near the target charge rate, the effect of suppressing fluctuations by the power storage means may be reduced, but this can be compensated by output control of the power storage related load. It becomes. Thereby, it is possible to improve the output suppression effect of the distributed power supply while maintaining the charging rate of the power storage means in the vicinity of the target charging rate.

  In the output leveling system of the distributed power source, the load control command setting means outputs the load control command based on at least one of a usage period of the power storage means, an outside air temperature, and a temperature of the power storage means. It is good also as providing the instruction | command correction | amendment means to correct | amend.

  For example, when the temperature of the power storage means is high or low, if the air conditioning equipment is stopped, the temperature of the power storage means may exceed the proper operating range. Therefore, in such a case, by correcting the load control command, it is possible to activate / deactivate the power storage related load as much as possible.

In the output leveling system of the distributed power source, the power storage related load includes an air conditioning facility for cooling the power storage unit, and output variation of the distributed power source cannot be absorbed by charge control of the power storage unit. The output of the air conditioning equipment is forcibly increased, and when the output fluctuation of the distributed power source cannot be absorbed by the discharge control of the power storage means, the output of the air conditioning equipment is forcibly reduced or the air conditioning equipment is It may be forced to stop.

  In this way, by forcibly increasing or decreasing the output of the air conditioning equipment, the power consumption of the storage-related load can be increased or decreased, which can contribute to the output leveling of the distributed power source. .

  The output leveling system of the distributed power source may further include a heat storage unit that stores thermal energy released from the air conditioning equipment.

  As described above, by providing the heat accumulation means, it is possible to accumulate thermal energy when the air conditioning equipment is operated excessively. The accumulated thermal energy will be released in the future, so that it can be used effectively without throwing away the thermal energy.

  In the output leveling system of the distributed power source, the storage-related load includes an uninterruptible power supply, and the output of the distributed power source cannot be absorbed by the discharge control of the power storage unit. The power supply device may be disconnected from the power line.

  Thus, when the output fluctuation of the distributed power source cannot be absorbed by the discharge control of the power storage means, the power consumption can be reduced by disconnecting the uninterruptible power supply from the power line, which contributes to output leveling. be able to.

  The present invention provides a distributed power supply system including a distributed power supply that converts natural energy into electric power and outputs the power, and an output leveling system for the distributed power supply.

  The present invention connects chargeable / dischargeable power storage means and a power storage-related load to a power line connecting a distributed power source that converts natural energy into electric power and outputs the power system, and controls charge / discharge of the power storage means The charge / discharge command setting process for setting the charge / discharge command to reduce the surplus of output fluctuation of the distributed power source that cannot be absorbed by the charge / discharge control of the power storage means by the charge / discharge command is reduced by the output control of the power storage related load A load control command setting process for setting a load control command to be performed; a charge / discharge control process for controlling charge / discharge of the power storage means based on the charge / discharge command; and controlling the power storage related load based on the load control command An output leveling method for the distributed power source, comprising: a load control process, and capable of leveling the output of the distributed power source by charge / discharge control of the power storage means and output control of the power storage related load Subjected to.

  According to the present invention, it is possible to improve the effect of suppressing fluctuations in the power supplied from the distributed power source to the power system.

1 is a diagram illustrating a schematic configuration of a distributed power supply system according to an embodiment of the present invention. It is the figure which showed an example of the control block of the system control part shown in FIG. Image of output of distributed power supply system when output leveling is performed using only power storage device, and output of distributed power supply system when output leveling is performed using power storage device and storage related load It is the figure shown by comparing with the image waveform.

  Hereinafter, an output leveling system and method for a distributed power source and a distributed power system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a distributed power supply system according to an embodiment of the present invention. As shown in FIG. 1, a distributed power supply system 1 includes a distributed power supply 2 that converts natural energy into electric power and outputs the electric power. The output of the distributed power source 2 is supplied to the power system 4 through the power line 3. The power line 3 is provided with a power sensor 5 that measures the output of the distributed power source 2. In FIG. 1, only one distributed power supply 2 is shown, but the number of connections of the distributed power supply 2 is not limited. For example, a plurality of distributed power sources 2 may be connected, and in this case, different types of distributed power sources 2 (for example, a wind power generator and a solar power generator) may be connected. Good.

The power line 3 connecting the distributed power source 2 and the power system 4 suppresses fluctuations in the output of the distributed power source 2 and leveles the power supplied to the power system 4. (Hereinafter referred to as “output leveling system 10”).
The output leveling system 10 includes a power storage device 11, a charge / discharge control unit 12 that controls charge / discharge of the power storage device 11, a power storage related load 13, a load control unit 14 that controls the power storage related load 13, a charge / discharge control unit 12 and a load. A system control unit 15 that gives a control command to the control unit 14 is provided.

Although the storage battery used for the electrical storage apparatus 11 is not specifically limited, such as a lithium storage battery, a lead storage battery, and a nickel metal hydride storage battery, it is preferable to use a lithium storage battery from the viewpoint of good followability of charge / discharge. For example, the power storage device 11 is configured by further connecting in parallel a plurality of assembled batteries in which a plurality of lithium ion storage batteries are connected in series. The charge / discharge control unit 12 includes a power conversion device 121 such as an inverter and a drive control circuit 122 that drives the power conversion device 121. The power storage device 11 is connected to the power line 3 via the power conversion device 121 and the transformer 7.
The power storage device 11 is installed in the building 20, and the temperature of the power storage device 11 is maintained in an appropriate operating range by managing the temperature in the building 20. The building 20 is, for example, a container and is preferably a sealed space.

  The power storage related load 13 is installed in the building 20, for example, and is mainly auxiliary equipment that is required when using the power storage device 11. Examples of the power storage related load 13 include, for example, air conditioning equipment for maintaining the temperature of the power storage device 11 in an appropriate operating range, outside of a fan for convection of air, lighting, an uninterruptible power supply device, and the like. The storage-related load 13 is connected to the power line 3 via the DC / AC converter 8 and the transformer 9 and is configured to operate by supplying power from the power line 3. Note that the air conditioning equipment may have only a heating function or only a cooling function, or may be equipment having both functions.

  In such an output leveling system 10, not only the charge / discharge control of the power storage device 11 but also the output control of the power storage related load 13 is actively used to level the output of the distributed power source 2. Therefore, the system control unit 15 sets a charge / discharge control command for the power storage device 11 and an output control command for the power storage related load 13 that suppress output fluctuations of the distributed power source 2.

FIG. 2 is a diagram schematically showing a control block of the system control unit 15. As shown in FIG. 2, the system control unit 15 includes a charge / discharge command setting unit 30 and a load control command setting unit 40. Further, the system control unit 15, as input information, the measurement value Pwt of the output of the distributed power supply 2 [W] (hereinafter, referred to as an "output Pwt of the dispersed type power supply 2".), The SOC of power storage device 11 [ %] Is entered. In the case where the dispersed type power supply 2 was provided with a plurality of the sum of their outputs are input.

The charge / discharge command setting unit 30 includes an output correction unit 31, a first target output setting unit 32, and a first command setting unit 33.
The output correction unit 31, charging rate SOC of the predetermined target charging rate of the power storage device 11 (e.g., 50%) calculates a correction value to approximate SOCtg, output Pwt of the dispersed type power supply 2 using the correction value Correct. The target charge rate SOCtg is information registered in the output correction unit 31 in advance. For example, the output correction unit 31 includes a difference calculation unit 311 that calculates a difference by subtracting the target charge rate SOCtg from the current charge rate SOC, a proportional calculation unit 312 that multiplies the calculation result of the difference calculation unit 311 by a gain Kp, And an addition unit 313 that adds the correction value, which is the output of the proportional calculation unit 312, to the output Pwt [W] of the distributed power supply 2.

  The output Pwt ′ of the distributed power source after the correction value is added is output to the first target output setting unit 32. The first target output setting unit 32 sets the first target output Pt1 that is the target output of the power storage device 11 using the corrected output Pwt ′ of the distributed power supply. For example, the first target output setting unit 32 includes a limiter 321 that suppresses the corrected output Pwt ′ of the distributed power source within a predetermined upper and lower limit range, and a smoothing filter 322 that smoothes the signal that has passed through the limiter 321. ing. The signal after passing through the smoothing filter 322 is output to the first command setting unit 33 as the first target output Pt1.

  The first command setting unit 33 sets the charge / discharge command Pc1 of the power storage device 11 so that the output Pwt of the distributed power source 2 matches the first target output Pt1. For example, the first command setting unit 33 calculates the difference calculated by the difference calculation unit 331 and the difference calculation unit 331 by subtracting the output Pwt of the distributed power source 2 from the first target output Pt1 and the difference calculated by the difference calculation unit 331. And a limiter 332 within the lower limit range. The signal after passing through the limiter 332 is output to the charge / discharge control unit 12 as the charge / discharge command Pc1.

  The load control command setting unit 40 suppresses a surplus of output fluctuation of the distributed power source 2 that cannot be absorbed by the charge / discharge control of the power storage device 11 by the charge / discharge command Pc1 by the output control of the power storage related load 13. Set Pc2. The load control command setting unit 40 includes a second target output setting unit 41 and a second command setting unit 42 as main components.

  The second target output setting unit 41 sets the second target output Pt2 that is the target output of the power storage related load 13 using the output Pwt of the distributed power source 2. For example, the second target output setting unit 41 includes a limiter 411 that suppresses the output Pwt of the distributed power source within a predetermined upper and lower limit range, and a smoothing filter 412 that smoothes a signal that has passed through the limiter 411. The signal after passing through the smoothing filter 412 is output to the second command setting unit 42 as the second target output Pt2.

  In addition to the second target output Pt2, the first target output Pt1 set by the first target output setting unit 32 described above is input to the second command setting unit 42. The second command setting unit 42 sets a load control command Pc2 that matches the second target output Pt2 with the first target output Pt1. For example, the second command setting unit 42 calculates the difference calculated by subtracting the second target output Pt2 from the first target output Pt1 and the difference calculated by the difference calculation unit 421 within a predetermined upper and lower limit range. A limiter 422 is provided. The signal after passing through the limiter 422 is output to the load control unit 14 as a load control command Pc2.

  According to the system control unit 15 shown in FIG. 2, based on the output Pwt ′ of the distributed power source 2 after the correction value for bringing the charging rate SOC of the power storage device 11 close to the target charging rate SOC is added. Discharge command Pc1 is set. Therefore, the charge / discharge amount of power storage device 11 is limited as compared with the case where correction based on such a charge rate SOC is not performed. However, according to the present embodiment, the load control command Pc2 is set using the output Pwt of the distributed power source 2 that does not reflect the correction due to the charging rate SOC of the power storage device 11, and thus is caused by the control of the charging rate SOC. Thus, the charge / discharge amount of the power storage device 11 limited can be compensated by the output control of the power storage related load 13.

Next, the operation of the distributed power supply system 1 according to this embodiment will be described.
First, the distributed power source 2 generates power based on natural energy and outputs generated power to the power line 3. The output Pwt of the distributed power source 2 is measured by the power sensor 5 and transmitted to the system control unit 15 via a control device (not shown) of the distributed power source 2.

  In the system control unit 15, the charge / discharge command setting unit 30 (see FIG. 2) equalizes the output Pwt of the distributed power source 2 and performs charge / discharge so that the charge rate SOC of the power storage device 11 approaches the target charge rate SOC. Command Pc1 is set. Further, the load control command setting unit 40 sets a load control command Pc2 for reducing the fluctuation surplus of the output Pwt of the distributed power source 2 that cannot be leveled by the charge / discharge control of the power storage device 11.

  The charge / discharge command Pc 1 set by the charge / discharge command setting unit 30 is output to the drive control circuit 122 of the charge / discharge control unit 12. The drive control circuit 122 of the charge / discharge control unit 12 controls charging / discharging of the power storage device 11 by controlling the power converter 121 based on the charge / discharge command Pc1. Thereby, for example, when the output Pwt of the distributed power source 2 is larger than the first target output Pt1, charging control is performed according to the difference, and the output Pwt of the distributed power source 2 is greater than the first target output Pt1. If it is smaller, discharge control according to the difference is performed.

The load control command Pc2 set by the load control command setting unit 40 is output to the load control unit 14. The load control unit 14 performs output control of the power storage related load 13 based on the load control command Pc2. Thus, for example, the output of the distributed power supply 2 is increased, if only the charge controller of the power storage device 11 that can not be leveled output Pwt, within the allowable temperature of the蓄electrical location 11, the output of the air conditioning equipment (For example, increasing the rotational speed of the compressor motor), increasing the rotational speed of the fan, turning on the lighting, etc., and increasing the power consumption of the storage-related load 13 to increase the power consumption of the distributed power source 2 Contributes to leveling the output.

On the other hand, the distributed power output 2 is decreased, only the discharge control of the power storage device 11 when not be leveled output is within the allowable temperature of the蓄electrical location 11, reducing the output of the air conditioning equipment ( (E.g., reduce the rotational speed of the compressor motor) or stop the air conditioning equipment, lower the rotational speed of the fan or stop the fan, turn off the lighting, disconnect the uninterruptible power supply from the power line 3, etc. The power consumption of the storage-related load 13 is reduced, which contributes to the output leveling of the distributed power source 2.

  Here, regarding the air conditioning equipment, the output control may be adjusted according to the temperature of the power storage device 11. For example, if the temperature of the power storage device 11 is high and the air conditioning equipment is stopped, the temperature of the power storage device 11 may exceed the appropriate operating range, which is not preferable. Therefore, regarding the air conditioning equipment, it is preferable that the output is reduced or the operation is stopped when the temperature of the power storage device 11 is equal to or lower than a predetermined temperature.

  As described above, according to the distributed power supply output leveling system 10 and method and the distributed power supply system 1 according to the present embodiment, not only the power storage device 11 but also the power storage device 11 is required. The power storage related load 13 is also used, and the output of the distributed power source 2 is leveled by cooperative power control of the power storage device 11 and the power storage related load 13. Accordingly, it is possible to suppress fluctuations in the output of the distributed power source 2 that could not be leveled by the power storage device 11 alone, and the leveling effect of the output can be enhanced.

  FIG. 3 shows an image waveform of the output of the distributed power supply system when output leveling is performed using only the power storage device 11, and the distributed power supply system 1 according to the present embodiment, that is, the power storage device 11 and the power storage related It is the figure which compared and showed the image waveform of the output of the distributed power supply system at the time of performing output leveling using the load. As shown in FIG. 3, by performing leveling using the power storage related load 13, it can be seen that fluctuations that could not be absorbed conventionally can be suppressed, and the fluctuation suppressing effect is high.

  In the present embodiment, the building 20 may be further provided with heat storage means for storing thermal energy from the air conditioning equipment. Examples of the heat storage means include a large container containing water or oil with low reactivity. That is, when the output of the distributed power source 2 is increased and the charging control of the power storage device 11 and the control of increasing the output of the air conditioning equipment in the power storage related load 13 are performed, the cooling effect or heating effect of the air conditioning equipment is enhanced. It becomes supercooled and overheated. Therefore, in such a case, it is possible to effectively use the thermal energy released from the air conditioning equipment by temporarily storing excess thermal energy and then releasing the thermal energy from the heat storage means in the future. It becomes possible.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 Distributed power supply system 2 Distributed power supply 3 Power line 4 Power system 5 Power sensor 10 Output leveling system 11 of a distributed power supply 11 Power storage device 12 Charge / discharge control unit 13 Power storage related load 14 Load control unit 15 System control unit 30 Charge / discharge command Setting unit 31 Output correction unit 32 First target output setting unit 33 First command setting unit 40 Load control command setting unit 41 Second target output setting unit 42 Second command setting unit 121 Power converter 122 Drive control circuits 311, 331, 421 Difference calculation unit 312 Proportional calculation unit 313 Addition unit 321, 332, 411, 422 Limiter 322, 412 Smoothing filter

Claims (9)

Chargeable / dischargeable power storage means connected to a power line connecting a distributed power source that converts natural energy into electric power and outputs the power system, and
A storage-related load connected to the power line;
Charge / discharge command setting means for setting a charge / discharge command for controlling charge / discharge of the power storage means;
The surplus of the output fluctuation of the distributed power sources that can not be absorbed by the charge and discharge control of the power storage unit by the charge and discharge command, a load control command setting means for setting a load control command Ru is reduced by the output control of the electric storage-related load ,
Charge / discharge control means for controlling charge / discharge of the power storage means based on the charge / discharge command;
Load control means for controlling the power storage related load based on the load control command,
An output leveling system of a distributed power source capable of leveling the output of the distributed power source by charge / discharge control of the power storage means and output control of the power storage related load. The charge / discharge command setting means includes:
Calculating a correction value for bringing the charging rate of the power storage unit close to a predetermined target charging rate, and correcting the output of the distributed power source using the correction value;
First target output setting means for setting a first target output, which is a target output of the power storage means, using the output of the distributed power source after correction;
First command setting means for setting the charge / discharge command based on a difference between the first target output and the output of the distributed power source;
The load control command setting means, using the output of the distributed power supply, a second target output setting means for setting a second target output that is a target output of the power storage related load;
2. The output leveling system for a distributed power source according to claim 1, further comprising: a second command setting unit configured to set the load control command using a difference between the second target output and the first target output.   The load control command setting unit corrects the load control command based on at least one of a usage period of the power storage unit, an outside air temperature, and a temperature of the power storage unit. Output leveling system for distributed power supplies. The power storage related load includes an air conditioning facility for cooling the power storage means,
When the output fluctuation of the distributed power source cannot be absorbed by the charging control of the power storage means, forcibly increase the output of the air conditioning equipment,
The output of the said air-conditioning equipment is forcibly reduced or the said air-conditioning equipment is forcibly stopped when the output fluctuation of the said distributed power supply cannot be absorbed by the discharge control of the said electrical storage means. The output leveling system of the distributed power source described.   The output leveling system of the distributed power supply according to claim 4, further comprising heat storage means for storing cooling energy of the air conditioning equipment. The power storage related load includes an uninterruptible power supply,
The output leveling of the distributed power supply according to any one of claims 1 to 5, wherein the uninterruptible power supply is disconnected from the power line when the output fluctuation of the distributed power supply cannot be absorbed by the discharge control of the power storage means. System.   The output leveling system for a distributed power source according to any one of claims 1 to 6, wherein the power storage means and the power storage related load are installed in a common building. A distributed power source that converts natural energy into electric power and outputs it,
A distributed power supply system comprising the output leveling system of the distributed power supply according to any one of claims 1 to 7. Connect the chargeable / dischargeable power storage means and the power storage related load to the power line connecting the distributed power source that converts the natural energy into electric power and output the power system,
A charge / discharge command setting process for setting a charge / discharge command for controlling charge / discharge of the power storage means;
A load control command setting process for setting a load control command for reducing an excess of fluctuations in output of the distributed power source that cannot be absorbed by charge / discharge control of the power storage means by the charge / discharge command, by output control of the power storage related load;
A charge / discharge control process for controlling charge / discharge of the power storage means based on the charge / discharge command;
A load control process for controlling the power storage related load based on the load control command,
An output leveling method for a distributed power source capable of leveling the output of the distributed power source by charge / discharge control of the power storage means and output control of the power storage related load.

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