JP5738220B2 - Output smoothing apparatus, output smoothing method and program - Google Patents

Description

  The present invention relates to an output smoothing device, an output smoothing method, and a program for smoothing power generated by a power generation device and outputting the smoothed power to an electric power system.

  In recent years, mass introduction of power generation apparatuses using natural energy such as solar power generation and wind power generation to power systems has been progressing. Power generation using natural energy has the advantage of being clean.

However, power generation using natural energy is unstable, and the generated power rapidly increases and decreases, so there is a demerit that a large amount of disturbance is introduced into the power system. Therefore, the situation is becoming unfavorable for electric power companies that control and maintain the frequency, voltage, etc. of the power system.
As a means for solving this problem, it is proposed to provide a secondary battery connected to the power system and the power generation device, and to charge and discharge the secondary battery to reduce fluctuations in the power output to the power system. Has been.

  By the way, when the output power is controlled by the secondary battery, a loss of power is caused by charging / discharging the secondary battery by the operation of the power conversion device such as an inverter. As a technique for solving this problem, Patent Document 1 discloses a technique for reducing the charge / discharge loss by not charging / discharging the secondary battery when the amount of change in the power output to the power system is sufficiently small. ing.

JP 2008-259357 A

  By the way, when the output power is controlled by the secondary battery, it is necessary to prevent overcharge and overdischarge in order to ensure the safety and life of the secondary battery. However, since the technology described in Patent Document 1 does not perform control based on the charging rate of the secondary battery, output is performed beyond the operating range of the charging rate, and the secondary battery may be deteriorated. On the other hand, in the technique described in Patent Document 1, when control is performed so that the secondary battery is not charged / discharged when the operating range of the charging rate is exceeded, the amount of change in power of the power system is excessive when charging / discharging is stopped. There is a risk of becoming.

  An object of the present invention is to provide an output smoothing device, an output smoothing method, and a program that suppress the amount of change in power output to a power system within a predetermined range and suppress overcharge and overdischarge of a secondary battery. It is in.

The present invention has been made to solve the above-described problem, and is an output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system, and is connected to the power generation device and the power system. Based on the charge rate of the secondary battery, the change rate specification that specifies the upper limit value and the lower limit value of the allowable change rate of power that can be output to the power system, which is monotonically non-decreasing with respect to the charge rate of the secondary battery A power calculation unit that calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power that has been output to the power system in the past, and When the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, the power of the difference between the generated power and the upper limit value is charged in the secondary battery, and the generated power of the power generation device Is the power calculated by the power calculation unit. It is smaller than the lower limit value of a discharge control unit for discharging electric power of the difference between the generated power and the lower limit value from the secondary battery, the change rate specific portion, the charging rate of the secondary battery The allowable rate of change so that the maximum rate is obtained when it is greater than the median value of the predetermined target charging rate, and the minimum rate when the charging rate of the secondary battery is the lower limit value of the operating width of the secondary battery. When the charging rate of the secondary battery is smaller than a median value of a predetermined target charging rate, the change rate specifying unit becomes a minimum rate, and the charging rate of the secondary battery is the secondary battery. The lower limit value of the allowable change rate is specified so that the maximum rate is obtained when the upper limit value of the battery operating width is reached .

The present invention also relates to an output smoothing device that smoothes the electric power generated by the power generation device and outputs the smoothed power to the power system, based on the voltage of the secondary battery connected to the power generation device and the power system. A rate-of-change specifying unit for specifying an upper limit value and a lower limit value of an allowable change rate of power that can be output to the power system, and an upper limit value and a lower limit value of the allowable change rate that are monotonically non-decreasing with respect to the voltage of the secondary battery Is multiplied by the power output to the power system in the past to calculate an upper limit value and a lower limit value of the power that can be output to the power system, and the power calculation unit When the calculated power is larger than the upper limit value, the secondary battery is charged with the difference between the generated power and the upper limit value, and the generated power of the power generator is the lower limit value of the power calculated by the power calculation unit. If it is smaller, the generated power and And a discharge control unit for discharging electric power of the difference between the lower limit value from the secondary battery, the change rate specifying section is, when the voltage of the secondary battery is greater than the median of the predetermined target voltage, maximum When the voltage of the secondary battery is the lower limit value of the operating width of the secondary battery, the upper limit value of the allowable change rate is specified so as to be the minimum rate, and the change rate specifying unit When the voltage of the secondary battery is smaller than the median value of the predetermined target voltage, the minimum rate is obtained, and when the voltage of the secondary battery is the upper limit value of the operation width of the secondary battery, the maximum rate is obtained. A lower limit value of the allowable change rate is specified .

Further, the present invention is the power generation apparatus an output smoothing method using the output smoothing device for output to the power grid by smoothing power generated, the rate of change identification unit coupled to the power generator and power system The maximum rate when the charging rate of the secondary battery is greater than the median value of the predetermined target charging rate, and the minimum when the charging rate of the secondary battery is the lower limit value of the operating width of the secondary battery The upper limit value of the allowable change rate of power that can be output to the power system is specified so as to be a rate, and the change rate specifying unit is configured such that the charge rate of the secondary battery is smaller than a median value of a predetermined target charge rate When the minimum rate is reached and the charging rate of the secondary battery is the upper limit value of the operating width of the secondary battery, the lower limit value of the allowable change rate is specified so as to be the maximum rate, and the power calculation unit Indicates the upper and lower limit values of the allowable change rate in the past. By multiplying the power output to the power system, the upper limit value and the lower limit value of the power that can be output to the power system are calculated, and the charge / discharge control unit calculates the generated power of the power generation device by the power calculation unit. When the power is greater than the upper limit value, the secondary battery is charged with the difference between the generated power and the upper limit value, and the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit. In this case, the power of the difference between the generated power and the lower limit value is discharged from the secondary battery.

Further, the present invention is an output smoothing method using an output smoothing device that smoothes the power generated by the power generation device and outputs the smoothed power to the power system , wherein the change rate specifying unit is connected to the power generation device and the power system. The maximum rate is obtained when the voltage of the secondary battery is greater than the median value of the predetermined target voltage, and the minimum rate is obtained when the voltage of the secondary battery is the lower limit value of the operating width of the secondary battery. As described above, an upper limit value of an allowable change rate of power that can be output to the power system is specified, and the change rate specifying unit is configured to determine a minimum rate when the voltage of the secondary battery is smaller than a median value of a predetermined target voltage. When the voltage of the secondary battery is the upper limit value of the operating width of the secondary battery, the lower limit value of the allowable change rate is specified so that the maximum rate is obtained, and the power calculation unit The upper and lower limits of The upper limit value and lower limit value of the power that can be output to the power system are calculated by multiplying the applied power, and the charge / discharge control unit is configured so that the generated power of the power generator is the upper limit of the power calculated by the power calculation unit. When the value is larger than the value, the power of the difference between the generated power and the upper limit value is charged to the secondary battery, and the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit, The power of the difference between the generated power and the lower limit value is discharged from the secondary battery.

Further, the present invention provides an output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system based on the charge rate of the secondary battery connected to the power generation device and the power system. A change rate specifying unit for specifying an upper limit value and a lower limit value of an allowable change rate of power that can be output to the electric power system, which is monotonically non-decreasing with respect to a battery charge rate, and an upper limit value and a lower limit value of the allowable change rate. A power calculation unit that calculates an upper limit value and a lower limit value of power that can be output to the power system by multiplying power that has been output to the power system in the past, and the generated power of the power generation device is calculated by the power calculation unit. When the power is greater than the upper limit value, the secondary battery is charged with the difference between the generated power and the upper limit value, and the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit. The generated power and When the power of the difference between the values is made to function as a discharge control unit for discharging from the secondary battery, the change rate specific portion, the charging rate of the secondary battery is greater than the median of the predetermined target charging rate, maximum When the charging rate of the secondary battery is a lower limit value of the operating width of the secondary battery, the upper limit value of the allowable change rate is specified so as to be the minimum rate, and the change rate specifying unit, When the charge rate of the secondary battery is smaller than the median value of the predetermined target charge rate, the minimum rate is obtained, and when the charge rate of the secondary battery is the upper limit value of the operation width of the secondary battery, the maximum rate is obtained. Is a program for specifying the lower limit value of the allowable change rate .

Further, the present invention provides an output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system based on the voltage of the secondary battery connected to the power generation device and the power system. A rate-of-change specifying unit for specifying an upper limit value and a lower limit value of an allowable change rate of power that can be output to the power system, which is monotonically non-decreasing with respect to the voltage of the voltage, an upper limit value and a lower limit value of the allowable change rate, Multiplying the power output to the power system by calculating the upper limit value and the lower limit value of the power that can be output to the power system, the generated power of the power generation device is the power calculated by the power calculation unit When the power is larger than the upper limit value, the secondary battery is charged with the difference between the generated power and the upper limit value, and the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit. , The generated power and the lower limit The power of the difference is made to function as a discharge control unit for discharging from the secondary battery, the change rate specifying section is, when the voltage of the secondary battery is greater than the median of the predetermined target voltage, a maximum rate, the When the voltage of the secondary battery is the lower limit value of the operating width of the secondary battery, the upper limit value of the allowable change rate is specified so as to be the minimum rate, and the change rate specifying unit is configured to The allowable change rate so that the minimum rate is obtained when the voltage is smaller than the median value of the predetermined target voltage, and the maximum rate is obtained when the voltage of the secondary battery is the upper limit value of the operation width of the secondary battery. It is a program that specifies the lower limit of .

  According to the present invention, the allowable change rate that is monotonously non-decreasing with respect to the charge rate of the secondary battery is set as the upper limit value and the lower limit value of the allowable change rate of power that can be output to the power system. Therefore, the higher the charging rate of the secondary battery, the smaller the upper limit value of power that can be output to the power system, and the lower the charging rate of the secondary battery, the larger the lower limit value of power that can be output to the power system. In other words, the higher the charging rate of the secondary battery, the more opportunities to discharge the secondary battery, and the lower the charging rate of the secondary battery, the more opportunities to charge the secondary battery. Thereby, the variation | change_quantity of the electric power output to an electric power grid | system can be suppressed in a predetermined range, and the overcharge and overdischarge of a secondary battery can be suppressed.

It is a schematic block diagram which shows the structure of an electric power generation system provided with the output smoothing apparatus by one Embodiment of this invention. It is a figure which shows the relationship between the charging rate of the secondary battery in one Embodiment of this invention, and the allowable change rate of the electric power which can be output to an electric power grid | system. It is a flowchart which shows operation | movement of the output smoothing apparatus by one Embodiment of this invention. It is a figure which shows the example of transition of the charging rate of a secondary battery, the electric power generated by an electric power generating apparatus, and the electric power output to an electric power grid | system. It is a schematic block diagram which shows the structure of an electric power generation system provided with the output smoothing apparatus by other embodiment of this invention. It is a figure which shows the variation of the relationship between the charging rate of a secondary battery, and the allowable change rate of the electric power which can be output to an electric power grid | system.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic block diagram showing a configuration of a power generation system including an output smoothing device 140 according to an embodiment of the present invention.
The power generation system includes a power generation device 110, a power conversion device 120, a secondary battery 130, and an output smoothing device 140.

The power generation apparatus 110 generates power using natural energy such as solar power generation or wind power generation. The power generation device 110 is connected to the power system, and supplies the generated power to the power conversion device 120 and the power system.
The power conversion device 120 is connected to the power system and converts DC power charged and discharged by the secondary battery 130 into AC power.
The secondary battery 130 charges and discharges the power converted by the power conversion device 120 into DC power.
The output smoothing device 140 controls charging / discharging of the secondary battery 130 based on the generated power of the power generation device 110, the charging rate of the secondary battery 130, and the power output to the power system in the past. Smooth the output power. Specifically, in the output smoothing device 140, the amount of change in power when the sum of the power generated by the power generation device 110 and the power output from the power conversion device 120 is output to the power system is within a predetermined range. Thus, the power is smoothed by rate limit control for controlling the allowable change rate of the power.

Next, the configuration of the output smoothing device 140 will be described.
The output smoothing device 140 includes an output power measurement unit 141, an output power storage unit 142, a generated power measurement unit 143, a charge rate estimation unit 144, a change rate storage unit 145, a change rate specifying unit 146, a power calculation unit 147, and a charge / discharge. A control unit 148 is provided.
The output power measurement unit 141 measures the power output to the power system.
The output power storage unit 142 stores the power output to the power system immediately before.
The generated power measuring unit 143 measures the power generated by the power generation device 110.
The charging rate estimation unit 144 estimates the charging rate of the secondary battery 130.
The change rate storage unit 145 stores the relationship between the charging rate of the secondary battery 130 and the allowable change rate of power that can be output to the power system.
The change rate specifying unit 146 specifies the upper limit value and the lower limit value of the allowable change rate based on the charge rate estimated by the charge rate estimation unit 144 and the relationship stored in the change rate storage unit 145.
The power calculation unit 147 calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power stored in the output power storage unit 142, respectively.
The charge / discharge control unit 148 outputs the current generated power Pg_now [W] measured by the generated power measuring unit 143 and the power system before the operation cycle ΔT [seconds] before the current stored in the output power storage unit 142. The rate of change (Pg_now−Pgb_now−1) / ΔT [W / sec] is calculated using the power Pgb_now−1 [W]. Further, the charge / discharge control unit 148 controls charging / discharging of the secondary battery 130 based on the upper limit value and the lower limit value calculated by the power calculation unit 147. When power Pgb_now-1 [W] output to the power system before time ΔT [seconds] cannot be measured, power Pb_now-1 output by power converter 120 before operating cycle ΔT [seconds] from the current time [W] may be calculated as the sum Pg_now−1 + Pb_now−1 of the power Pg_now−1 [W] output by the power generation apparatus 110 before the current operation period ΔT [seconds].

Here, the information stored in the change rate storage unit 145 will be described.
FIG. 2 is a diagram showing the relationship between the charging rate of the secondary battery 130 and the allowable change rate of power that can be output to the power system in one embodiment of the present invention.
As shown in FIG. 2, the change rate storage unit 145 stores the relationship between the charging rate of the secondary battery 130 and the upper limit value and lower limit value of the allowable change rate of power that can be output to the power system. The upper limit value and the lower limit value of the allowable change rate are monotonously non-decreasing with respect to the charging rate of the secondary battery 130.

  Specifically, the upper limit value of the allowable change rate is always the maximum rate (for example, 120%) when the charging rate of the secondary battery 130 is equal to or higher than the lower limit value of the target charging rate. On the other hand, when the charging rate of the secondary battery 130 is the lower limit value of the operation width, the minimum rate (for example, 80%) is obtained. The upper limit value of the allowable change rate is a value that monotonously increases in proportion to the charging rate of the secondary battery 130 when the charging rate of the secondary battery 130 is larger than the lower limit value of the operation width and less than the lower limit value of the target charging rate. And a value between the minimum rate and the maximum rate.

  Further, the lower limit value of the allowable change rate is always the minimum rate when the charging rate of the secondary battery 130 is equal to or lower than the upper limit value of the target charging rate. On the other hand, when the charging rate of the secondary battery 130 is the upper limit value of the operation width, the maximum rate is obtained. The lower limit value of the allowable change rate monotonously increases in proportion to the charging rate of the secondary battery 130 when the charging rate of the secondary battery 130 is less than the upper limit value of the operation width and larger than the upper limit value of the target charging rate. Which is a value between the minimum rate and the maximum rate.

Next, the operation of the output smoothing device 140 according to this embodiment will be described.
FIG. 3 is a flowchart showing the operation of the output smoothing apparatus 140 according to an embodiment of the present invention.
First, the charging rate estimation unit 144 of the output smoothing device 140 measures the voltage or current of the secondary battery 130, and estimates the charging rate of the secondary battery 130 based on this (Step S1). Next, based on the charging rate estimated by the charging rate estimating unit 144 and the relationship stored in the changing rate storage unit 145, the change rate specifying unit 146 has an upper limit value of an allowable change rate of power that can be output to the power system, and A lower limit value is specified (step S2).

  Next, the power calculation unit 147 reads the power output to the power system in the previous control from the output power storage unit 142 (step S3). Next, the power calculation unit 147 multiplies the read power by the upper limit value and the lower limit value specified by the rate-of-change specifying unit 146, respectively, so that the upper limit value and the lower limit value of power that can be output to the power system in the current control. Is calculated (step S4).

Next, the generated power measuring unit 143 measures the power generated by the power generation device 110 (step S5). Next, the charge / discharge control unit 148 determines whether or not the generated power measured by the generated power measurement unit 143 exceeds the upper limit value calculated by the power calculation unit 147 (step S6).
When it is determined that the generated power exceeds the upper limit value (step S6: YES), the charge / discharge control unit 148 calculates power obtained by subtracting the upper limit value from the generated power, and charges the secondary battery 130 with the power. The power converter 120 is controlled so as to operate (step S7).

On the other hand, when the charge / discharge control unit 148 determines that the generated power is equal to or lower than the upper limit value (step S6: NO), the generated power measured by the generated power measurement unit 143 is less than the lower limit value calculated by the power calculation unit 147. It is determined whether or not (step S8).
When the charge / discharge control unit 148 determines that the generated power is less than the lower limit (step S8: YES), the charge / discharge control unit 148 calculates the power obtained by subtracting the generated power from the lower limit, and discharges the power from the secondary battery 130. The power converter 120 is controlled so as to be performed (step S9).

On the other hand, when the charge / discharge control unit 148 determines that the generated power is equal to or higher than the lower limit (step S8: NO), the charge / discharge control unit 148 does not charge / discharge the secondary battery 130 (step S10).
When the charging / discharging control of the secondary battery 130 is performed in step S7 or step S9, or when charging / discharging is not performed in step S10, the output power measuring unit 141 measures the power output to the power system, The value is recorded in the output power storage unit 142 (step S11).
Thereafter, the above-described processing is executed every operation cycle of the output smoothing device 140.

Here, the operation of the output smoothing apparatus 140 according to the present embodiment will be described using a specific example.
FIG. 4 is a diagram illustrating an example of the transition of the charging rate of the secondary battery 130, the power generated by the power generation device 110, and the power output to the power system.
In FIG. 4, time t ₀ to time t ₈ are times for each operation cycle of the output smoothing device 140.
First, as shown in FIG. 4 (A), at time t _1, the secondary since charging rate of the battery 130 is less than the lower limit of the target charging rate, the allowable rate of change of the upper limit and the lower limit is the maximum rate each Minimum rate. Therefore, the upper limit value of the power calculated by the power calculation unit 147 is 120% of the power output at time t ₀ as shown in FIG. 4B, and the lower limit value is output at time t ₀ . 80% of the generated power. Generation power at time t ₁ is greater than the maximum power limit, the power (output power) output to the power grid becomes 120% of the power of the power output at time t _0, the output power and the generated power The secondary battery 130 is charged with the difference power.

Next, as shown in FIG. 4 (A), at time t _2, the secondary charging rate of the battery 130 because at least as large as the lower limit of the target charging rate, the maximum upper limit and the lower limit of the allowable rate of change respectively Rate The minimum rate. Therefore, the upper limit value of electric power calculated by the power calculation unit 147, as shown in FIG. 4 (B), becomes 120% of the power of the output power at time t _1, the lower limit value, the output at time t ₁ 80% of the generated power. Generation power at time t ₂ is smaller than the power limit value, the output power becomes 80% of the power of the output power at time t _1, power of the difference between the output power and the generated power is a secondary battery 130 is charged.
Note that the output smoothing device 140 performs the same operation at times t ₃ and t ₄ .

Next, as shown in FIG. 4 (A), at time t _5, the charging rate of the secondary battery 130 since the middle of the lower limit of the operational range the lower limit of the target charging rate, the relationship shown in FIG. 2 Therefore, the upper limit value of the allowable change rate is 100%, and the lower limit value is the minimum rate. Therefore, the upper limit value of electric power calculated by the power calculation unit 147, as shown in FIG. 4 (B), becomes output power equal power at time t _4, the lower limit value is output at time t ₄ It becomes 80% of the power. Generation power at time t ₅ is smaller than the power limit value, the output power becomes 80% of the power of the output power at time t _4, the power of the difference between the output power and the generated power is a secondary battery 130 is charged.

Min Next, as shown in FIG. 4 (A), at time t _6, since the charging rate of the secondary battery 130 is the lower limit and the equivalent operational width, both the upper limit and the lower limit of the allowable rate of change Rate. Therefore, the upper limit value and the lower limit value of the power calculated by the power calculating portion 147 is 80% of the power of the power output at time t ₅ none. Therefore, the output power becomes 80% of the power of the output power at time t _5, the power of the difference between the output power and the generated power is charged in the secondary battery 130.

Next, as shown in FIG. 4 (A), at a time t _7, the secondary charging rate of the battery 130 because at least as large as the lower limit of the target charging rate, the maximum upper limit and the lower limit of the allowable rate of change respectively Rate The minimum rate. Therefore, the upper limit value of electric power calculated by the power calculation unit 147, as shown in FIG. 4 (B), becomes 120% of the power of the output power at time t _6, the lower limit value, the output at time t ₆ 80% of the generated power. Generation power at time t ₇ is smaller than the power limit value, the output power becomes 80% of the power of the output power at time t _6, the power of the difference between the output power and the generated power is a secondary battery 130 is charged.
The output smoothing apparatus 140 performs the same operation applies to the time t _8.

Meanwhile, the output smoothing device 140 at time t ₆ is regardless of the relationship shown in FIG. 2, when the control using the following allowable change rate maximum rate than the minimum rate uniformly, output power, FIG. 4 (B as shown in the dotted line portion of) the 120% of the power of the power output at time t _5. Therefore, the power at time t ₅ is charged to the secondary battery 130 is less as compared with the power charged by the control according to the present embodiment described above. Therefore, when controlling the charging and discharging without following the relationship shown in FIG. 2, as shown in FIG. 4 (A), as compared to the control according to the present embodiment described above, the after time t ₅ of the secondary battery 130 The charging rate is lowered. From this, according to the present embodiment, the output smoothing device 140 changes the upper limit value and the lower limit value of the allowable change rate according to the charge rate of the secondary battery 130, thereby reducing the charge rate of the secondary battery 130. It can be seen that the target charging rate can be approached.

  Thus, according to the present embodiment, the output smoothing device 140 is monotonously non-decreasing with respect to the charging rate of the secondary battery 130 as the upper limit value and the lower limit value of the allowable change rate of power that can be output to the power system. Set the allowable change rate. Therefore, the higher the charging rate of the secondary battery 130, the smaller the upper limit value of power that can be output to the power system, and the lower the charging rate of the secondary battery 130, the larger the lower limit value of power that can be output to the power system. Become. That is, the higher the charging rate of the secondary battery 130, the more opportunities to discharge the secondary battery 130, and the lower the charging rate of the secondary battery 130, the more opportunities to charge the secondary battery 130. Thereby, the variation | change_quantity of the electric power output to an electric power grid | system can be suppressed in a predetermined range, and the overcharge and overdischarge of the secondary battery 130 can be suppressed.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

FIG. 5 is a schematic block diagram showing a configuration of a power generation system including an output smoothing device 140 according to another embodiment of the present invention.
For example, in the present embodiment, the case where the change rate specifying unit 146 specifies the upper limit value and the lower limit value of the allowable change rate based on the charge rate of the secondary battery 130 has been described, but the present invention is not limited thereto. As shown in FIG. 5, the output smoothing device 140 includes a voltage measuring unit 149 instead of the charging rate estimating unit 144, and the change rate specifying unit 146 determines the allowable change rate based on the voltage measured by the voltage measuring unit 149. An upper limit value and a lower limit value may be specified. In this case, the change rate storage unit 145 stores the relationship between the voltage of the secondary battery 130 and the allowable change rate of power that can be output to the power system, instead of the relationship shown in FIG.

FIG. 6 is a diagram showing variations in the relationship between the charging rate of the secondary battery 130 and the allowable change rate of power that can be output to the power system.
Moreover, in this embodiment, although demonstrated using the relationship shown in FIG. 2 as a relationship between the charging rate of the secondary battery 130 memorize | stored in the change rate memory | storage part 145, and the allowable change rate of the electric power which can be output to an electric power grid | system, It is not limited to this. For example, the change rate storage unit 145 may store other relationships as shown in FIGS. 6 (A) to 6 (G). 2 and 6, the upper limit value and the lower limit value of the allowable change rate are in a relationship that is not monotonously non-decreasing with respect to the charging rate of the secondary battery 130.

  The output smoothing device 140 described above has a computer system therein. The operation of each processing unit described above is stored in a computer-readable recording medium in the form of a program, and the above processing is performed by the computer reading and executing this program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  DESCRIPTION OF SYMBOLS 110 ... Power generation device 120 ... Power converter 130 ... Secondary battery 140 ... Output smoothing device 141 ... Output power measurement part 142 ... Output power memory | storage part 143 ... Power generation power measurement part 144 ... Charging rate estimation part 145 ... Change rate memory | storage part 146 ... Change rate specifying unit 147 ... Power calculating unit 148 ... Charge / discharge control unit 149 ... Voltage measuring unit

Claims (6)

An output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system,
Based on the charging rate of the secondary battery connected to the power generation device and the power system, the upper limit of the allowable change rate of power that can be output to the power system, which is monotonously non-decreasing with respect to the charging rate of the secondary battery A change rate specifying unit for specifying a value and a lower limit,
A power calculation unit that calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past;
When the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, the power of the difference between the generated power and the upper limit value is charged in the secondary battery, and the generated power of the power generation device A charge / discharge control unit for discharging the generated power and the difference between the lower limit values from the secondary battery when the power calculation unit is smaller than the lower limit value of the calculated power ,
The change rate specifying unit has a maximum rate when the charging rate of the secondary battery is larger than a median value of a predetermined target charging rate, and the charging rate of the secondary battery is a lower limit value of the operating width of the secondary battery. The upper limit of the allowable change rate is specified so that the minimum rate is obtained,
When the change rate specifying unit has a charge rate of the secondary battery smaller than a median value of a predetermined target charge rate, the minimum rate is obtained, and the charge rate of the secondary battery is an upper limit value of the operation width of the secondary battery. An output smoothing device that specifies a lower limit value of the allowable change rate so that the maximum rate is obtained . An output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system,
Based on the voltage of the secondary battery connected to the power generation device and the power system, the upper limit value of the allowable change rate of power that can be output to the power system, which is monotonously non-decreasing with respect to the voltage of the secondary battery, and A rate-of-change specifying part for specifying a lower limit value,
A power calculation unit that calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past;
When the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, the power of the difference between the generated power and the upper limit value is charged in the secondary battery, and the generated power of the power generation device A charge / discharge control unit for discharging the generated power and the difference between the lower limit values from the secondary battery when the power calculation unit is smaller than the lower limit value of the calculated power,
When the change rate specifying unit has a maximum rate when the voltage of the secondary battery is greater than the median value of the predetermined target voltage, and the voltage of the secondary battery is the lower limit value of the operating width of the secondary battery In addition, the upper limit value of the allowable change rate is specified so as to be the minimum rate,
When the change rate specifying unit has a minimum rate when the voltage of the secondary battery is smaller than the median value of the predetermined target voltage, and the voltage of the secondary battery is the upper limit value of the operating width of the secondary battery In addition, the output smoothing device is characterized in that the lower limit value of the allowable change rate is specified so as to be the maximum rate . An output smoothing method using an output smoothing device for smoothing the power generated by the power generation device and outputting it to the power system,
The rate-of-change specifying unit has a maximum rate when a charging rate of a secondary battery connected to the power generation device and the power system is larger than a median value of a predetermined target charging rate, and the charging rate of the secondary battery is When it is the lower limit value of the operation width of the secondary battery, the upper limit value of the allowable change rate of power that can be output to the power system is specified so as to be the minimum rate
The change rate specifying unit has a minimum rate when the charging rate of the secondary battery is smaller than a median value of a predetermined target charging rate, and the charging rate of the secondary battery is an upper limit value of the operating width of the secondary battery. And specify the lower limit value of the allowable change rate so as to be the maximum rate,
The power calculation unit calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past,
The charge / discharge control unit, when the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, charges the secondary battery with the difference between the generated power and the upper limit value, When the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit, the difference between the generated power and the lower limit value is discharged from the secondary battery. Method. An output smoothing method using an output smoothing device for smoothing the power generated by the power generation device and outputting it to the power system,
The rate-of-change specifying unit has a maximum rate when the voltage of the secondary battery connected to the power generation device and the power system is greater than the median value of a predetermined target voltage, and the voltage of the secondary battery is the voltage of the secondary battery. When it is the lower limit value of the operation width, the upper limit value of the allowable change rate of power that can be output to the power system is specified so as to be the minimum rate,
When the voltage of the secondary battery is smaller than the median value of the predetermined target voltage, the change rate specifying unit has a minimum rate, and the voltage of the secondary battery is an upper limit value of the operating width of the secondary battery In addition, the lower limit value of the allowable change rate is specified so as to be the maximum rate,
The power calculation unit calculates the upper limit value and the lower limit value of power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past,
The charge / discharge control unit, when the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, charges the secondary battery with the difference between the generated power and the upper limit value, When the generated power of the power generation device is smaller than the lower limit value of the power calculated by the power calculation unit, the difference between the generated power and the lower limit value is discharged from the secondary battery. Method. An output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system,
Based on the charging rate of the secondary battery connected to the power generation device and the power system, the upper limit of the allowable change rate of power that can be output to the power system, which is monotonously non-decreasing with respect to the charging rate of the secondary battery Change rate specifying part for specifying the value and the lower limit,
A power calculation unit that calculates the upper limit value and the lower limit value of the power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past,
When the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, the power of the difference between the generated power and the upper limit value is charged in the secondary battery, and the generated power of the power generation device When the power calculation unit is smaller than the lower limit value of the power calculated, it functions as a charge / discharge control unit that discharges the power of the difference between the generated power and the lower limit value from the secondary battery ,
The change rate specifying unit has a maximum rate when the charging rate of the secondary battery is larger than a median value of a predetermined target charging rate, and the charging rate of the secondary battery is a lower limit value of the operating width of the secondary battery. The upper limit of the allowable change rate is specified so that the minimum rate is obtained,
When the change rate specifying unit has a charge rate of the secondary battery smaller than a median value of a predetermined target charge rate, the minimum rate is obtained, and the charge rate of the secondary battery is an upper limit value of the operation width of the secondary battery. A program that specifies a lower limit value of the allowable change rate so that the maximum rate is obtained . An output smoothing device that smoothes the power generated by the power generation device and outputs it to the power system,
Based on the voltage of the secondary battery connected to the power generation device and the power system, the upper limit value of the allowable change rate of power that can be output to the power system, which is monotonously non-decreasing with respect to the voltage of the secondary battery, and Change rate specifying part for specifying the lower limit value,
A power calculation unit that calculates the upper limit value and the lower limit value of the power that can be output to the power system by multiplying the upper limit value and the lower limit value of the allowable change rate by the power output to the power system in the past,
When the generated power of the power generation device is larger than the upper limit value of the power calculated by the power calculation unit, the power of the difference between the generated power and the upper limit value is charged in the secondary battery, and the generated power of the power generation device When the power calculation unit is smaller than the lower limit value of the power calculated, it functions as a charge / discharge control unit that discharges the power of the difference between the generated power and the lower limit value from the secondary battery,
When the change rate specifying unit has a maximum rate when the voltage of the secondary battery is greater than the median value of the predetermined target voltage, and the voltage of the secondary battery is the lower limit value of the operating width of the secondary battery In addition, the upper limit value of the allowable change rate is specified so as to be the minimum rate,
When the change rate specifying unit has a minimum rate when the voltage of the secondary battery is smaller than the median value of the predetermined target voltage, and the voltage of the secondary battery is the upper limit value of the operating width of the secondary battery In addition, a program for specifying a lower limit value of the allowable change rate so as to obtain a maximum rate .

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