JP4715624B2 - Power stabilization system, power stabilization control program, and power stabilization control method - Google Patents

Description

  The present invention relates to a power stabilization technique, for example, a technique effective when applied to a power stabilization technique or the like that suppresses output fluctuations of a distributed power source using a power storage device.

  In recent years, there has been an increase in the interconnection of commercial power systems to distributed power sources such as wind power generators, solar cells, tidal power generators, etc. that use natural energy such as wind power and solar power. However, since the output of a distributed power source using natural energy fluctuates momentarily according to natural conditions such as wind speed, the frequency and voltage of the system may fluctuate, especially in weak power systems such as remote areas and remote islands. May become a problem in the operation of.

  In the future, it may be possible to promote the introduction of a microgrid, which is a small-scale distribution network for supplying power in a specific area. In this microgrid, output fluctuations of distributed power sources using natural energy and power demand fluctuations of demanding equipment cause a supply-demand imbalance, and the tidal current at the interconnection point changes from moment to moment.

  For this reason, the connection point power control is performed, the connection point power flow is made as constant as possible according to the pre-planned value, and an operation that does not adversely affect the commercial system is required. However, a controllable distributed power source such as a gas turbine has a limit in load followability, and there is a problem that fast tidal current fluctuation cannot be suppressed.

  Therefore, a system has been developed that compensates for power fluctuations such as output fluctuations, load fluctuations, power fluctuations, etc. by absorbing or releasing power using a power storage device such as a flywheel or a secondary battery. ing. For example, when compensating for fluctuations in the output of a wind power generator, if the power output of the wind power generator increases, the power output of the power storage device decreases or power absorption increases, and the power output of the wind power generator decreases. In some cases, power fluctuations at the interconnection point between the wind power generator and the power storage device can be compensated by reducing the power absorption of the power storage device or increasing the power release.

  However, since a loss occurs during charging / discharging in the power storage device or power converter, the average stored power amount stored in the power storage device gradually decreases as it is, and finally the lower limit value of the stored power amount As a result, the power fluctuation compensation effect cannot be obtained.

  Similarly, if the average value of the active power fluctuation amount is biased in the direction of charging the power storage device, the average stored power amount stored in the power storage device gradually increases as it is, and finally the stored power amount The upper limit is reached and the power fluctuation compensation effect cannot be obtained.

  Therefore, various control methods have been proposed to correct the average bias of the charge / discharge amount of the power storage device and prevent the stored power amount from sticking to the upper limit and / or lower limit over the long term. ing.

Examples of using a flywheel as the power storage device include Patent Document 1, and examples of using a secondary battery include Non-Patent Document 1 and the like.
In Patent Document 1, in the flywheel control device, the rotational speed is determined based on the difference between the rotational speed of the flywheel (corresponding to the stored electric energy) and the target rotational speed (set between the rotational speed upper limit value and the lower limit value). The average bias of the charge / discharge amount of the flywheel is controlled by adding a correction signal to the output command value to the flywheel so as to approach the target rotation speed.

In Non-Patent Document 1, in a secondary battery control device, a secondary battery terminal voltage (corresponding to the amount of stored power) is set in advance as a threshold (two upper and lower threshold values are set in the terminal voltage allowable range). If exceeded, correct the output command value to the secondary battery so that it approaches the middle direction of the terminal voltage tolerance (add the correction value to the compensation target value that removes the fluctuation component from the active power measurement value of the distributed power supply) By doing so, the average bias of the charge / discharge amount of the secondary battery is controlled.
JP 2001-339995 A NEDO-NP-0004 Feasibility study on wind power generation with storage battery (issued in February 2002)

  However, as a problem caused by adding a correction signal, in Patent Document 1, a correction signal is always added whenever a difference occurs between the stored power amount and the target stored power amount. When the increase / decrease is repeated, the power fluctuation component itself to be compensated is reduced, resulting in a technical problem that a satisfactory output fluctuation compensation effect cannot be obtained.

  In Non-Patent Document 1, since the correction operation is started and ended when the stored power amount exceeds the threshold value, the correction circuit is frequently used particularly when the stored power amount repeatedly increases and decreases across the threshold value. As a result, there is a technical problem that a satisfactory output fluctuation compensation effect cannot be obtained.

  In addition, when correction is performed by adding correction values, the compensation power changes stepwise at the start of addition of correction values or at the end of addition, so that a good output fluctuation compensation effect can be obtained due to extra disturbance due to correction values. There was no technical problem.

  The object of the present invention is to prevent the stored power amount of the power storage device from sticking to the upper limit value and / or the lower limit value in the long term, and to reliably obtain the output fluctuation compensation effect due to charging / discharging of the power storage device. It is to provide power stabilization technology.

  Another object of the present invention is to provide a power stabilization technique capable of more effective power fluctuation compensation while preventing the stored power amount of the power storage device from sticking to the upper limit value and / or the lower limit value in the long term. There is to do.

  According to a first aspect of the present invention, there is provided a power storage device that stores power and absorbs or releases power from an AC power system, and the input / output is performed between the AC power system and the power storage device. A power stabilization system comprising: a power converter that mutually converts power; and a control device that controls a conversion operation of the power converter so as to suppress fluctuations in active power of the AC power system, The control device includes an active power detection unit that detects active power of the AC power system as an active power measurement value, a stored power amount detection unit that detects a stored power amount of the power storage device or a signal corresponding thereto, and the storage A correction signal for correcting the active power measurement value in a direction in which the stored power is discharged when the power amount approaches the upper limit value, and in a direction in which the stored power is charged when the stored power amount approaches the lower limit value. Play Correction signal calculating means for calculating the correction active power by adding the correction signal to the active power measurement value, and calculating the compensation target value by removing the active power fluctuation component from the correction active power Calculation means, compensation power calculation means for subtracting the measured active power value from the compensation target value to calculate compensation power, and conversion of the power converter by a power converter output command value corresponding to the magnitude of the compensation power And a power converter control means for controlling the operation.

  According to a second aspect of the present invention, there is provided a power storage device that stores power and absorbs or releases power from an AC power system, and the input / output is performed between the AC power system and the power storage device. A power stabilization system comprising: a power converter that mutually converts power; and a control device that controls a conversion operation of the power converter so as to suppress fluctuations in active power of the AC power system, The control device includes an active power detection unit that detects active power of the AC power system as an active power measurement value, a stored power amount detection unit that detects a stored power amount of the power storage device or a signal corresponding thereto, and the effective power A compensation target value calculating means for calculating a compensation target value by removing an active power fluctuation component from the power measurement value; a compensation power calculating means for calculating a compensation power by subtracting the measured active power value from the compensation target value; Power converter control means for controlling the conversion operation of the power converter according to a power converter output command value corresponding to the magnitude of compensation power, and discharging the stored power when the stored power amount approaches an upper limit value A correction signal calculating means for calculating a compensation signal for correcting the compensation target value or the compensation power in a direction to charge the stored power when the stored power amount approaches a lower limit in the direction; An electric power stabilization system including an adding means for adding to the compensation target value or the compensation power after passing through a filter for smoothing a steep fluctuation is provided.

According to a third aspect of the present invention, in the power stabilization system according to the first aspect or the second aspect, the correction signal calculation means has a low storage within the range of the stored power amount of the power storage device. A correction start threshold value LS for power amount, a correction end threshold value LE for low storage energy amount, a correction end threshold value HE for high storage energy amount, and a correction start threshold value HS for high storage energy amount are expressed as LS <LE <HE <HS is set, and when the stored power amount decreases and falls below the LS, the output of the correction signal is started in the direction in which the power storage device is charged. When it rises and exceeds the LE, the output of the correction signal is stopped, and when the amount of stored power rises and exceeds the HS, the output of the correction signal is started in the direction of discharging from the power storage device, After that, the amount of stored power decreases and the HE When turned, to provide a stable power system that operates to stop the output of the correction signal.

A fourth aspect of the present invention is a power stabilization control that controls charging and discharging between a power storage device and an AC power system via a power converter so as to suppress fluctuations in active power of the AC power system. An active power detection unit for detecting, in a computer, an active power of the AC power system as an active power measurement value, and a stored power amount detection unit for detecting a stored power amount of the power storage device or a signal corresponding thereto. When the stored power amount approaches the upper limit value, the active power measurement value is set in the direction of discharging the stored power, and when the stored power amount approaches the lower limit value, the active power measurement value is set in the direction of charging the stored power. Correction signal calculation means for calculating a correction signal to be corrected; means for calculating the correction active power by adding the correction signal to the active power measurement value; and an active power fluctuation component from the correction active power. A compensation target value calculating means for calculating a compensation target value; a compensation power calculating means for calculating a compensation power by subtracting the measured active power value from the compensation target value; and a power corresponding to the magnitude of the compensation power. There is provided a power stabilization control program for realizing power converter control means for controlling a conversion operation of the power converter according to a converter output command value.

A fifth aspect of the present invention is a power stabilization control that controls charging and discharging between a power storage device and an AC power system via a power converter so as to suppress fluctuations in active power of the AC power system. An active power detection unit for detecting, in a computer, an active power of the AC power system as an active power measurement value, and a stored power amount detection unit for detecting a stored power amount of the power storage device or a signal corresponding thereto. A compensation target value calculation means for calculating a compensation target value by removing an active power fluctuation component from the active power measurement value, and a compensation power calculation for calculating a compensation power by subtracting the measurement value of the active power from the compensation target value Means, power converter control means for controlling the conversion operation of the power converter according to a power converter output command value according to the magnitude of the compensation power, and the stored power amount to an upper limit value If it is determined, the compensation target value or the correction signal for correcting the compensation power is calculated in the direction of discharging the stored power, and in the direction of charging the stored power when the stored power amount approaches the lower limit value. Provided is a power stabilization control program that realizes correction signal calculation means and addition means for adding the correction signal to the compensation target value or the compensation power after passing the correction signal through a filter for smoothing steep fluctuations. .

According to a sixth aspect of the present invention, in the power stabilization control program according to the fourth aspect or the fifth aspect, the correction signal calculation means has a low power storage range of the power storage device. The correction start threshold value LS at the time of stored power amount, the correction end threshold value LE at the time of low storage power amount, the correction end threshold value HE at the time of high storage power amount, and the correction start threshold value HS at the time of high storage power amount are expressed as LS < LE <HE <HS is set, and when the stored power amount decreases and falls below the LS, the output of the correction signal is started in the direction in which the power storage device is charged, and then the stored power amount When the value rises and exceeds the LE, the output of the correction signal is stopped, and when the stored power amount rises and exceeds the HS, the output of the correction signal is started in the direction of discharging from the power storage device. Then, the amount of stored power decreases and the If it falls below the E, to provide power stabilization control program operating to stop the output of the correction signal.

A seventh aspect of the present invention is a power stabilization control that controls charging and discharging between a power storage device and an AC power system via a power converter so as to suppress fluctuations in active power of the AC power system. A method,
Detecting the active power of the AC power system as an active power measurement value,
Detecting the stored power amount of the power storage device or a signal corresponding thereto,
When the stored power amount approaches the upper limit value, the active power measurement value is corrected in the direction of discharging the stored power, and when the stored power amount approaches the lower limit value, the active power measurement value is corrected in the direction of charging the stored power. Calculate the correction signal,
Add the correction signal to the active power measurement value to calculate the corrected active power,
The active power fluctuation component is removed from the corrected active power, the compensation target value is calculated,
Calculate the compensation power by subtracting the measured active power value from the compensation target value,
Control the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power,
A power stabilization control method is provided.
An eighth aspect of the present invention is a power stabilization control that controls charging and discharging between a power storage device and an AC power system via a power converter so as to suppress fluctuations in active power of the AC power system. A method,
Detecting the active power of the AC power system as an active power measurement value,
Detecting the stored power amount of the power storage device or a signal corresponding thereto,
The active power fluctuation component is removed from the active power measurement value, a compensation target value is calculated,
Calculate the compensation power by subtracting the active power measurement value from the compensation target value,
Control the conversion operation of the power converter by a power converter output command value according to the magnitude of the compensation power,
When the stored power amount approaches the upper limit value, the stored power is discharged, and when the stored power amount approaches the lower limit value, the compensation target value or the compensated power is charged. Calculate the correction signal to correct
After passing the correction signal through a filter that smooths steep fluctuations, the correction signal is added to the compensation target value or the compensation power.
A power stabilization control method is provided.

According to a ninth aspect of the present invention, in the power stabilization control method according to the seventh or eighth aspect, the correction start threshold value at the time of low stored power amount is within the range of the stored power amount of the power storage device. LS, correction end threshold value LE at low storage energy amount, correction end threshold value HE at high storage energy amount, and correction start threshold value HS at high storage energy amount so that LS <LE <HE <HS. When the stored power amount decreases and falls below the LS, the correction of the charging power is started in the direction in which the power storage device is charged, and then the stored power amount rises and exceeds the LE The correction of the charging power is stopped, and the correction of the discharge power is started in the direction of discharging from the power storage device when the stored power amount rises and exceeds the HS, and then the stored power amount decreases and the HE Stops the correction of the discharge power when Providing power stabilization control method of so that operation.

According to the first, fourth, and seventh aspects of the present invention described above, since the correction signal is added to the active power measurement value, the correction active power is stepwise at the start of the addition of the correction signal or at the end of the addition. Although changing, when the effective power fluctuation component is removed from the corrected active power in the compensation target value calculation means in the subsequent stage, the high frequency component is removed from the fluctuation component of the corrected active power by the correction signal. As a result, the step change due to the correction signal is smoothed at the compensation target value. In addition, it is not necessary to newly provide a filter for smoothing the step change due to the correction signal. This compensates for the average bias of the charge / discharge amount of the power storage device and prevents the stored power amount from sticking to the upper and lower limit values over the long term, while smoothing the step change of the compensation power and making it more effective Power fluctuation compensation is possible.

According to the second , fifth, and eighth aspects of the present invention described above, the correction signal is passed through a filter that smooths steep fluctuations, whereby a step-like change at the start of addition of the correction signal or at the end of addition. Is smoothed and a good power fluctuation compensation effect is obtained. This compensates for the average bias of the charge / discharge amount of the power storage device and prevents the stored power amount from sticking to the upper and lower limit values over the long term, while smoothing the step change of the compensation power and making it more effective Power fluctuation compensation is possible.

In the first, fourth, and seventh modes, it is not necessary to provide a new filter, but the effect of the correction signal is affected by the time constant of the filter in the compensation target value calculation unit.
On the other hand, in the second, fifth and eighth aspects, it is necessary to newly provide a filter for smoothing steep fluctuations in the correction signal, but the time constant of the newly provided filter is the filter in the compensation target value calculation unit. There is an advantage that it can be set freely regardless of the time constant.

According to the third , sixth, and ninth aspects of the present invention described above, since the correction signal is not always added according to the difference between the stored power amount and the target stored power amount, the stored power amount is the target storage amount. There is no problem that the power fluctuation component itself to be compensated is reduced when the increase / decrease is repeated across the power amount.

  In addition, since the correction start threshold value and the correction end threshold value are set separately, once the correction is started, the correction is completed unless the stored energy level is improved significantly (approaching the correction end threshold value). After the correction is completed, the correction will not resume unless the stored power level is significantly deteriorated (so as to reach the correction start threshold). There is no problem that a satisfactory output fluctuation compensation effect cannot be obtained.

As a result, it is possible to compensate for the average bias of the charge / discharge amount of the power storage device and prevent the stored power amount from sticking to the upper and lower limit values over the long term, and more effectively compensate for power fluctuations.
Thus, according to the power stabilization technology of the present invention, while correcting the average bias of the charge / discharge amount of the power storage device, the state where the stored power amount sticks to the upper and lower limit values in the long term is prevented. Thus, stepwise disturbance due to the correction signal does not occur, the power fluctuation component itself to be compensated does not shrink, and the correction operation is not frequently turned on and off, so that more effective power fluctuation compensation can be achieved.

  According to the present invention, it is possible to prevent the stored power amount of the power storage device from sticking to the upper limit value and / or the lower limit value in the long term, and to reliably obtain the output fluctuation compensation effect due to charging / discharging of the power storage device. Become.

  Further, more effective power fluctuation compensation can be achieved while preventing the stored power amount of the power storage device from sticking to the upper limit value and / or the lower limit value in the long term.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention relates to a power stabilization system that suppresses fluctuations in the active power of an AC power system. In the following description, an AC power system to which a distributed power source using the natural energy is connected is taken as an example. However, it is not limited to this example. The power stabilization system of the present invention can be applied as long as it is for the purpose of suppressing fluctuations in the active power of the AC power system, such as load fluctuations and fluctuations in the interconnection power flow during microgrid interconnection operation. In the following description, a wind power generator will be described as an example of the distributed power source using the natural energy. However, the present invention is not limited to this example, and may be solar power generation, for example.

(Embodiment 1)
FIG. 1 is a conceptual diagram illustrating an example of a configuration of a power stabilization system according to an embodiment of the present invention, and FIG. 2 illustrates a part of the power stabilization system according to the present embodiment in more detail. It is a block diagram.

  The power stabilization system 100 illustrated in FIG. 1 includes a power storage device 140, a power converter 141, and a control device 150. The power storage device 140 and the power converter 141 are connected to the power system 110 via the power cable 120, the transformer 122, and the transformer 123.

The power storage device 140 is, for example, a flywheel, a secondary battery, a capacitor, or the like.
The power converter 141 is connected to the power system 110 and the power storage based on the power converter output command value PO from the control device 150 (here, the direction in which the power is discharged from the power storage device 140 is “positive”). Power is exchanged with the device 140. When the power storage device 140 is a flywheel, the AC power on the flywheel side and the AC power on the power system 110 side are converted bidirectionally, and when the power storage device 140 is a secondary battery, a capacitor, or the like, The DC power on the secondary battery / capacitor side and the AC power on the power system 110 side are converted bidirectionally.

  Here, it is assumed that the output fluctuation compensation of the distributed power source using natural energy is performed, and the wind power generator 130 is connected to the power system 110 via the power cable 120 and the transformer 121.

  In addition, not only suppression of the output fluctuation | variation of the wind power generator 130 but as above-mentioned, by detecting the effective electric power of the micro grid connection point (in this case, the connection point with respect to the transformer 123 of the power cable 120) in FIG. It can also be applied to the suppression of tidal current fluctuations.

  The control device 150 includes an active power detection unit 151, a compensation target value calculation unit 152, a compensation power calculation unit 153, a power converter control unit 154, a stored power amount detection unit 155, a correction signal calculation unit 156, an addition unit 157, and the like. .

  Although not shown in particular, the control device 150 is configured by a computer including a CPU and the like and a storage device such as a memory and various storage media (such as a hard disk). The control device 150 includes the above-described active power detection unit 151 and compensation target value calculation. For example, a CPU stores the processing (described later) by the unit 152, the compensation power calculation unit 153, the power converter control unit 154, the stored power amount detection unit 155, the correction signal calculation unit 156, the addition unit 157, and the like. This can be realized by reading and executing a predetermined application program (power stabilization control program).

  Alternatively, by the active power detection unit 151, the compensation target value calculation unit 152, the compensation power calculation unit 153, the power converter control unit 154, the stored power amount detection unit 155, the correction signal calculation unit 156, the addition unit 157, and the like of the control device 150 The processing may be realized by hardware such as a dedicated circuit.

  Further, when realized by hardware, it may be controlled using a digital circuit such as a programmable controller, or may be realized by an analog control circuit such as an operational amplifier.

  The active power detection unit 151 includes a voltage detection unit 151 a and a current detection unit 151 b, and detects the active power measurement value PG of the wind power generator 130 based on the voltage / current value at the output end of the wind power generator 130.

  The stored power amount detection unit 155 detects / calculates the stored power amount Es of the power storage device 140 directly or indirectly. For example, when the power storage device 140 is a flywheel, the rotational speed of the flywheel is detected. When the power storage device 140 is a secondary battery, a capacitor, or the like, the terminal voltage is detected, and the stored power amount Es is calculated based on the detection result. To do.

The correction signal calculation unit 156 calculates a correction signal Pc for correcting the active power measurement value PG according to the magnitude of the stored power amount.
That is, the correction signal calculating unit 156 discharges the stored power when the stored power amount Es approaches the upper limit value, and charges the stored power when the stored power amount Es approaches the lower limit value. Then, a correction signal Pc for correcting the active power measurement value PG is calculated.

A more detailed configuration and principle of the correction signal calculation unit 156 will be described in an embodiment 5 described later.
In the case of the present embodiment, the correction signal Pc obtained by the correction signal calculation unit 156 is added to the active power measurement value PG in the addition unit 157 arranged in the preceding stage of the compensation target value calculation unit 152, thereby correcting the corrected active power PG. 'Is obtained and input to the compensation target value calculation unit 152.

  The compensation target value calculation unit 152 is effective from the corrected active power PG ′ by a smoothing process such as an active power fluctuation component removal filter 152a for removing fluctuations such as a low-pass filter illustrated in FIG. 2 or a moving average. The compensation target value PA is calculated by removing the power fluctuation component.

The active power fluctuation component removal filter 152a includes, as an example, a transfer function of a first-order lag element of the time constant TF.
However, as long as the active power fluctuation component removal filter 152a has a function of removing the active power fluctuation component, any number of low-pass filters may be used, or a configuration in which several stages of primary low-pass filters are connected in series. Alternatively, the variation component may be removed by moving average processing.

  The compensation power calculation unit 153 calculates the compensation power ΔPG (here, the direction in which power is discharged from the power storage device 140 is “positive”) by subtracting the active power measurement value PG from the compensation target value PA. To do.

The power converter control unit 154 generates a power converter output command value PO that is a command value to the converter according to the magnitude of the compensation power ΔPG.
The control device 150 of the present embodiment having the above-described configuration is characterized in that the corrected active power PG ′ obtained by adding the correction signal Pc to the active power measurement value PG is used as the input value of the compensation target value calculation unit 152.

  By adding the correction signal Pc to the active power measurement value PG, the correction active power PG 'changes stepwise at the start or end of addition of the correction signal. However, when the effective power fluctuation component is removed from the correction active power PG ′ in the compensation target value calculation unit 152 in the subsequent stage, a high frequency component among the fluctuation components of the correction active power caused by the addition of the correction signal is the active power fluctuation. It is removed by the component removal filter 152a. As a result, in the compensation target value PA, the step change due to the correction signal Pc is smoothed, and a good power fluctuation compensation effect can be obtained. In addition, it is not necessary to newly provide a filter for smoothing the step change due to the correction signal Pc.

  This corrects the average bias of the charge / discharge amount of the power storage device 140 and prevents the state where the stored power amount Es sticks to the upper limit value and / or the lower limit value in the long term, while maintaining the compensation power ΔPG. The step change can be smoothed, and more effective power fluctuation compensation can be achieved.

(Embodiment 2)
Next, FIG. 3, FIG. 4, FIG. 5 and FIG. 6 show configuration diagrams of a power stabilization system using the power storage device 140 in the second embodiment.

The difference from the above-described first embodiment is that the correction signal is added and the correction signal is added to the compensation target value after passing through the filter 158 for smoothing steep fluctuations.
That is, in the example of FIGS. 3 and 4, in the control device 150 </ b> A, an adder 157 is provided between the compensation target value calculator 152 and the compensation power calculator 153, and the adder 157 has a compensation target value calculator 152. The correction signal Pc is added to the compensation target value PA output from the filter 158, and the obtained correction compensation target value PA 'is input to the compensation power calculation unit 153.

  In the example of FIGS. 5 and 6, an adder 157 is provided at the subsequent stage of the compensation power calculation unit 153 of the control device 150 </ b> B. In the addition unit 157, the compensation power ΔPG output from the compensation power calculation unit 153 is provided. The correction signal Pc is added through the filter 158, and the obtained correction compensation power ΔPG ′ is input to the power converter control unit 154.

  In the first embodiment, it is not necessary to provide a new filter, but the effect of the correction signal is affected by the time constant of the active power fluctuation component removal filter 152a in the compensation target value calculation unit 152.

  On the other hand, in the second embodiment, it is necessary to newly provide a filter for smoothing steep fluctuations in the correction signal. However, the time constant Tc of the newly provided filter 158 is the time of the filter in the compensation target value calculation unit 152. It can be set freely regardless of the constant TF.

  In the case of the second embodiment, the correction signal Pc is passed through a filter 158 that smooths steep fluctuations, so that the correction compensation target value PA ′ or correction at the start or end of the addition of the correction signal Pc The stepwise change of the compensation power ΔPG ′ is smoothed, and a good power fluctuation compensation effect can be obtained.

  This corrects the average bias of the charge / discharge amount of the power storage device 140 and prevents the state where the stored power amount Es sticks to the upper limit value or the lower limit value in the long run, while changing the compensation power stepwise. Smoothing and more effective power fluctuation compensation are possible.

(Embodiment 3)
Next, FIGS. 7 and 8 are configuration diagrams of a power stabilization system using the power storage device 140 according to the third embodiment.

The power stabilization system in FIG. 7 includes a power storage device 140, a power converter 141, and a control device 150C, and is connected to the power system 110 via the power cable 120 and the transformer 123.
Since the power storage device 140 and the power converter 141 are the same as those described in the first embodiment, the description thereof is omitted.

  Similarly to the description in the first embodiment, assuming that the output fluctuation compensation of the distributed power source using natural energy is performed, the wind power generator 130 is connected to the power system 110 via the transformer 121 and the power cable 120. Assume that they are connected.

  The control device 150C includes an active power detection unit 151, a stored power amount detection unit 155, a correction signal calculation unit 156, a compensation power calculation unit 153, a power converter control unit 154, and the like. Among them, the active power detection unit 151, the stored power amount detection unit 155, and the correction signal calculation unit 156 are the same as those described in the first embodiment, and a description thereof will be omitted.

  As illustrated in FIG. 8, the compensation power calculation unit 153 according to the third embodiment extracts, for example, an active power fluctuation component including a high-pass filter configured with a transfer function of a first-order lag differential element having a time constant TF. The filter 153a extracts the active power fluctuation component from the active power measurement value PG and calculates the compensation power ΔPG (here, the direction in which power is discharged from the power storage device 140 is “positive”).

  As long as the active power fluctuation component extraction filter 153a has a function of extracting the active power fluctuation component, any number of high-pass filters may be used, or a configuration in which several stages of primary high-pass filters are connected in series may be used. .

  The correction signal Pc obtained by the correction signal calculation unit 156 is passed through a filter 158 that smooths steep fluctuations, and then added to the compensation power ΔPG to obtain a correction compensation power ΔPG ′, which is input to the power converter control unit 154. To do.

The power converter control unit 154 generates a power converter output command value PO that is a command value to the power converter 141 in accordance with the magnitude of the corrected compensation power ΔPG ′.
As described above, the control device 150C according to the third embodiment is characterized in that the correction signal Pc calculated by the correction signal calculation unit 156 is passed through a filter that smooths steep fluctuations and then added to the compensation power ΔPG. There is.

  When the compensation power calculation unit 153 extracts the active power fluctuation component from the active power measurement value PG by a high-pass filter or the like to obtain the compensation power ΔPG, the correction signal Pc cannot be added to the preceding stage of the high-pass filter, and the compensation power ΔPG It is necessary to add to. Here, by passing the correction signal Pc through a filter 158 that smooths steep fluctuations, a step change at the start or end of addition of the correction signals is smoothed, and a good power fluctuation compensation effect can be obtained. .

  According to the third embodiment, the average bias of the charge / discharge amount of the power storage device 140 is corrected, and the state where the stored power amount Es sticks to the upper limit value and / or the lower limit value in the long term is prevented. On the other hand, the step change of the compensation power is smoothed, and more effective power fluctuation compensation is possible.

(Embodiment 4)
9 and 10 are configuration diagrams of a power stabilization system using the power storage device 140 in the fourth embodiment.

The difference from the first embodiment described above is that the correction signal is added to the position where the correction signal is added, and a filter that smoothes steep fluctuations after the correction signal is added.
That is, in control device 150D of the fourth embodiment, adder 157 and filter 158 are arranged in series between compensation target value calculator 152 and compensation power calculator 153.

  The compensation target value PA output from the compensation target value calculation unit 152 is added with the correction signal Pc in the addition unit 157, passes through the filter 158 as the correction compensation target value PA ′, and is smoothed, and then the compensation power calculation unit 153. Is input.

  In the first embodiment, it is not necessary to provide a new filter, but the effect of the correction signal is affected by the time constant TF of the active power fluctuation component removal filter 152a in the compensation target value calculation unit 152.

  On the other hand, as illustrated in FIG. 10, in the fourth embodiment, it is necessary to newly provide a filter 158 that smoothes the steep fluctuation of the correction signal, but the time constant Tc of the newly provided filter 158 is The compensation target value calculation unit 152 can be set freely regardless of the time constant TF of the active power fluctuation component removal filter 152a.

However, it is necessary that the time constant Tc of the newly provided filter 158 ≦ the time constant TF of the filter in the compensation target value calculation unit 152.
In the case of the fourth embodiment, after adding the correction signal Pc to the compensation target value PA, the value passed through the filter 158 that smooths the steep fluctuation is set as the compensation compensation target value PA ′, and the compensation power calculation unit 153 Therefore, after adding the correction signal Pc to the compensation target value PA, the correction signal is passed through a filter 158 that smooths the steep fluctuation, so that the correction compensation target at the start or end of the addition of the correction signal Pc is obtained. The step change of the value PA ′ is smoothed, and a good power fluctuation compensation effect can be obtained.

  This corrects the average bias of the charge / discharge amount of the power storage device 140 and prevents the stored power amount Es from sticking to the upper limit value and / or the lower limit value in the long term, while making a stepped compensation power. The change is smoothed, and more effective power fluctuation compensation is possible.

(Embodiment 5)
FIG. 11 shows a configuration diagram of the correction signal calculation unit 156 in the power stabilization system according to the fifth embodiment. The configuration of the correction signal calculation unit 156 shown in FIG. 11 can be applied in common to the correction signal calculation unit 156 in the first to fourth embodiments.

The correction signal calculation unit 156 receives the stored power amount Es calculated by the stored power amount detection unit 155 as an input, and outputs a correction signal Pc (corresponding to power as a signal property).
In the correction signal calculation unit 156, the correction start threshold value LS at the time of low storage power amount, the correction end threshold value LE at the time of low storage power amount, the correction end threshold value HE at the time of high storage energy amount, and the correction start at the time of high storage energy amount A threshold value HS is provided.

  And within the allowable operating range of the stored energy amount Es (power storage capacity) in the power storage device 140 (for example, between the upper and lower limit values and the lower limit value of the rotational speed for the flywheel, and the upper and lower limit values and the lower limit value of the terminal voltage for the secondary battery. LS <LE <HE <HS.

Further, the correction signal Pcm (≦ 0.0) at the time of low stored power amount and the correction signal Pcp (≧ 0.0) at the time of high storage power amount are set.
In the case of the fifth embodiment, based on the relationship between the stored power amount Es and each of LS, LE, HE, and HS, the correction signal Pcm, 0 ( Zero) or one of the correction signals Pcp is output.

  The correction signal calculation unit 156 starts outputting the correction signal Pcm as the correction signal Pc when the stored power amount Es decreases and falls below the correction start threshold value LS for the low stored power amount. Since the correction signal Pcm is a negative signal, the power converter output command value PO shifts in the direction in which the power storage device 140 is charged by the correction signal Pcm, thus eliminating the average decrease in the stored power amount Es. can do.

  Thereafter, when the stored power amount Es rises and exceeds the low storage power amount correction end threshold value LE, the correction signal calculation unit 156 stops outputting the correction signal Pcm. That is, the correction signal Pc becomes zero.

  Similarly, the correction signal calculation unit 156 starts outputting the correction signal Pcp as the correction signal Pc when the stored power amount Es rises and exceeds the correction start threshold value HS at the time of high storage power amount. Since the correction signal Pcp is a positive signal, the power converter output command value PO shifts in the direction of discharging from the power storage device 140 by the correction signal Pcp, thereby eliminating the average increase in the stored power amount Es. can do.

  Thereafter, when the stored power amount Es decreases and exceeds the high storage power amount correction end threshold value HE, the correction signal calculation unit 156 stops outputting the correction signal Pcp. That is, the correction signal Pc becomes zero.

  According to the power stabilization system using the power storage device 140 having the configuration of each embodiment of the present invention described above, the correction signal is not always added according to the difference between the stored power amount and the target stored power amount. Therefore, there is no problem that the power fluctuation component itself to be compensated is reduced when the stored power amount repeatedly increases and decreases across the target stored power amount.

  In addition, since the correction start threshold value and the correction end threshold value are set separately, once the correction is started, the correction is completed unless the stored energy level is improved significantly (approaching the correction end threshold value). After the correction is completed, the correction is not resumed unless the stored power level is greatly deteriorated (so as to reach the correction start threshold value). As a result, the correction signal calculation unit 156 is frequently used. Therefore, there is no problem in that the correction operation by ON / OFF is turned ON / OFF, and a satisfactory output fluctuation compensation effect cannot be obtained.

  Thus, the average bias of the charge / discharge amount of the power storage device 140 is corrected to prevent the stored power amount Es from sticking to the upper limit value and / or the lower limit value in the long term, and the output of the wind power generator 130. When fluctuation occurs, more effective power fluctuation compensation is possible.

About the effect of the electric power stabilization system using the electric power storage apparatus 140 demonstrated above, the verification result by this inventor is shown below.
Here, an actual measurement waveform in which correction control (hereinafter referred to as “correction control according to the present invention”) is performed in the power stabilization system using the power storage device 140 based on the first and fifth embodiments is shown. In the correction control according to the present invention, in the power stabilization system using the power storage device 140 in the first embodiment, the correction signal Pc is calculated based on the fifth embodiment and input to the compensation target value calculating unit 152. The correction signal Pc is added to the active power measurement value PG.

  For comparison, an upper / lower threshold value (not divided into a correction start threshold value and a correction end threshold value) is provided in the compensation target value calculation unit 152, and a correction signal Pc ′ is output when the threshold value is exceeded. A simulation result in the case where the correction signal Pc ′ is added to the target value PA (hereinafter referred to as “correction control according to the prior art”) is also shown.

  Note that it is difficult to change the configuration in the control device 150 in the actual machine, and even if the configuration is changed, the output of the wind power generator 130 that is the compensation target cannot be reproduced by wind. By modeling the power stabilization system using the power storage device 140 in the case of performing and inputting the output data of the wind power generator 130 measured in the actual machine (that is, inputting the same data), the simulation result is obtained. It has gained.

  FIG. 12 shows a measured waveform of the stored power amount Es (Es in FIG. 12) when correction control according to the present invention is performed, and a stored power amount Es (Es in FIG. 12) when correction control according to the conventional technique is performed. ') Shows the simulation results.

  From the waveform of FIG. 12, both the case where the correction control according to the prior art is performed and the case where the correction control according to the present invention is performed operate so as to prevent the stored electric energy Es from reaching the upper limit value. I understand.

  FIG. 13 shows an actually measured waveform of the correction signal Pc (Pc in FIG. 13) when the correction control according to the present invention is performed, and a correction signal Pc ′ (when the correction control according to the prior art is performed) (in FIG. 13). The simulation result of Pc ′) is shown.

  From the waveform of FIG. 13, when correction control according to the prior art is performed, the correction signal Pc ′ is added from the vicinity of 7800 seconds to the vicinity of 8700 seconds, but the stored electric energy Es is calculated as a compensation target value around 8000 seconds. It can be seen that the correction operation is frequently performed (ON / OFF) by finely increasing and decreasing near the lower limit threshold value of the unit 152.

  On the other hand, when the correction control according to the present invention is performed, the correction signal Pc is added from the vicinity of 7400 seconds to the vicinity of 9700 seconds. Since the correction start threshold value and the correction end threshold value are set separately for LS, LE, HE, and HS as described above, the time during which the correction signal Pc is added is longer than in the correction control according to the prior art. However, it can be seen that the phenomenon that the correction operation in the correction signal calculation unit 156 frequently enters and exits does not occur.

  FIG. 14 shows an actually measured waveform of the compensation target value PA (Pa in FIG. 14) when correction control according to the present invention is performed, and the compensation target value PA (in FIG. 14) when correction control according to the prior art is performed. The simulation result of Pa ′) and the simulation result of the compensation target value PA (Pao in FIG. 14) when no correction is performed.

  From the waveform of FIG. 14, when correction control according to the prior art is performed, the compensation target value is obtained when the correction signal Pc is added when the elapsed time is around 7800 seconds, or when the addition of the correction signal Pc is finished around 8700 seconds. PA (Pao) changes stepwise. It can also be seen that the compensation target value PA also causes hunting when the correction operation frequently enters and exits (ON / OFF) around 8000 seconds.

  On the other hand, when the correction control according to the present invention is performed, the correction signal Pc is added in the vicinity of 7400 seconds, but the stepwise change is smoothed by the active power fluctuation component removal filter 152a of the compensation target value calculation unit 152, and the correction is performed. It can be seen that the value gradually increases with respect to the compensation target value PA (Pao in FIG. 14) when no is performed.

  FIG. 15 shows an actually measured waveform of compensation power ΔPG (ΔPg in FIG. 15) when correction control according to the present invention is performed, and compensation power ΔPG (ΔPg in FIG. 15) when correction control according to the prior art is performed. ') Shows the simulation results.

  From the waveform in FIG. 15, when correction control according to the conventional technique is performed, the compensation power ΔPg ′ changes stepwise around 7800 seconds and 8700 seconds. It can also be seen that the compensation power ΔPg ′ is causing hunting around 8000 seconds.

On the other hand, when the correction control according to the present invention is performed, it can be seen that the compensation power ΔPG (ΔPg) does not cause a steep change in step or hunting.
FIG. 16 shows a measured waveform of the distributed power source active power (PG + ΔPG) (Pg + ΔPg in FIG. 16) after compensation when correction control according to the present invention is performed, and after compensation when correction control according to the prior art is performed. 16 shows the simulation result of the distributed power source active power (PG + ΔPG) (Pg + ΔPg ′ in FIG. 16) and the active power measurement value PG (before compensation) (Pg in FIG. 16).

  From the waveform of FIG. 16, when correction control according to the prior art is performed, power fluctuations are smoothed, but the distributed power source active power (Pg + ΔPg ′) after compensation is around 7800 seconds and 8700 seconds of elapsed time. ) Changes step by step. In addition, it can be seen that the compensated distributed power source active power (Pg + ΔPg ′) causes hunting around 8000 seconds.

  On the other hand, in the distributed power source active power (Pg + ΔPg) when the correction control according to the present invention is performed, there is no stepwise change or hunting, and the fluctuation of the active power of the distributed power source (wind generator 130) is smoothed. You can see that.

  As described above, according to the power stabilization system 100 using the power storage device 140 disclosed in the above-described embodiments of the present invention, the average bias of the charge / discharge amount of the power storage device 140 is corrected. The compensation target value PA, the compensation power ΔPG, and the distributed power source after compensation are enabled by adding the correction signal Pc while preventing the stored power amount Es from sticking to the upper limit value and / or the lower limit value in the long term. Steep step changes such as power (Pg + ΔPg) and hunting can be prevented.

  As a result, the power storage device 140 capable of compensating for the power fluctuation of the power system 110 due to the output fluctuation of the wind power generator 130 more efficiently and effectively within the allowable operating range of the power storage device 140 is used. A power fluctuation compensation system can be provided.

  Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is a conceptual diagram which shows an example of a structure of the electric power stabilization system which is Embodiment 1 of this invention. It is the block diagram which illustrated a part of electric power stabilization system which is Embodiment 1 of this invention in detail. It is a block diagram which shows the structure of the electric power stabilization system using the electric power storage apparatus in Embodiment 2 of this invention. It is the block diagram which illustrated a part of electric power stabilization system of Embodiment 2 of this invention in detail. It is a block diagram which shows the modification of a structure of the electric power stabilization system using the electric power storage apparatus in Embodiment 2 of this invention. It is the block diagram which illustrated a part of electric power stabilization system of the modification of Embodiment 2 of this invention in detail. It is a block diagram which shows the structure of the power stabilization system using the electric power storage apparatus in Embodiment 3 of this invention. It is the block diagram which illustrated a part of electric power stabilization system of Embodiment 3 of this invention in detail. It is a block diagram which shows the structure of the electric power stabilization system using the electric power storage apparatus in Embodiment 4 of this invention. It is the block diagram which illustrated a part of electric power stabilization system of Embodiment 4 of this invention in detail. It is a conceptual diagram which shows an example of a structure and effect | action of a correction signal calculating part in the electric power stabilization system which is Embodiment 5 of this invention. It is a diagram which compares and shows the simulation result of transition of the stored electric energy at the time of the actual measurement waveform of the stored electric energy at the time of performing correction control by this invention, and the correction control by a prior art. It is a diagram which compares and shows the measurement result of the correction signal at the time of performing correction control by the prior art, and the simulation result of the correction signal at the time of performing correction control by the prior art. It is a diagram which compares and shows the actual measurement waveform of the compensation target value at the time of performing correction control by this invention, and the actual measurement waveform of the compensation target value at the time of performing correction control by a prior art. It is a diagram which compares and shows the actual measurement waveform of the compensation electric power when the correction control by this invention is performed, and the actual measurement waveform of the compensation electric power when the correction control by a prior art is performed. FIG. 7 shows a comparison between an actual measurement waveform of distributed power source active power after compensation when correction control according to the present invention is performed and an actual measurement waveform of distributed power source power after compensation when correction control according to the prior art is performed. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Power stabilization system 110 Power system 120 Electric power cable 121 Transformer 122 Transformer 123 Transformer 130 Wind generator 140 Power storage device 141 Power converter 150 Control device 150A Control device 150B Control device 150C Control device 150D Control device 151 Active power Detection unit 151a Voltage detection unit 151b Current detection unit 152 Compensation target value calculation unit 152a Active power fluctuation component removal filter 153 Compensation power calculation unit 153a Active power fluctuation component extraction filter 154 Power converter control unit 155 Storage power amount detection unit 156 Correction signal Arithmetic unit 157 Adder 158 Filter Es Storage energy HE Correction end threshold at high storage energy HS Correction start threshold at high storage energy LE Correction end threshold at low storage energy LS Low storage energy Correction start Value PA compensation target value PA 'correction compensation target value Pc correction signal Pc' correction signal Pcm positive correction signal Pcp negative correction signal PG active power measurement value PG 'correction active power PO power converter output command value ΔPG compensation power ΔPG '' Correction compensation power

Claims (9)

A power storage device that stores power and absorbs or discharges power to or from the AC power system;
A power converter that mutually converts the power input and output between the AC power system and the power storage device;
A control device for controlling the conversion operation of the power converter so as to suppress fluctuations in the active power of the AC power system;
A power stabilization system including:
The controller is
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
When the stored power amount approaches the upper limit value, the active power measurement value is corrected in the direction of discharging the stored power, and when the stored power amount approaches the lower limit value, the active power measurement value is corrected in the direction of charging the stored power. Correction signal calculation means for calculating a correction signal;
Means for adding the correction signal to the active power measurement value to calculate a corrected active power;
Compensation target value calculation means for removing the active power fluctuation component from the corrected active power and calculating a compensation target value;
Compensation power calculating means for subtracting the active power measurement value from the compensation target value to calculate compensation power;
Power converter control means for controlling the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power;
A power stabilization system comprising: A power storage device that stores power and absorbs or discharges power to or from the AC power system;
A power converter that mutually converts the power input and output between the AC power system and the power storage device;
A control device for controlling the conversion operation of the power converter so as to suppress fluctuations in the active power of the AC power system;
A power stabilization system including:
The controller is
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Compensation target value calculation means for removing the active power fluctuation component from the active power measurement value and calculating a compensation target value;
Compensation power calculation means for subtracting an active power measurement value from the compensation target value to calculate compensation power;
Power converter control means for controlling the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power;
When the stored power amount approaches the upper limit value, the stored power is discharged, and when the stored power amount approaches the lower limit value, the compensation target value or the compensated power is charged. Correction signal calculation means for calculating a correction signal for correcting
An addition means for adding the correction signal to the compensation target value or the compensation power after passing the correction signal through a filter for smoothing steep fluctuations;
A power stabilization system comprising: In the power stabilization system according to claim 1 or 2, in the correction signal calculation means,
Among the ranges of the stored power amount of the power storage device, a low storage power amount correction start threshold LS, a low storage power amount correction end threshold LE, a high storage power amount correction end threshold HE, The correction start threshold value HS at the time of high stored energy is set so that LS <LE <HE <HS,
When the stored power amount decreases and falls below the LS, the output of the correction signal is started in the direction in which the power storage device is charged, and then when the stored power amount rises and exceeds the LE, the correction is performed. Stop signal output,
When the stored power amount rises and exceeds the HS, the correction signal is output in the direction of discharging from the power storage device. After that, when the stored power amount decreases and falls below the HE, the correction signal A power stabilization system that operates to stop the output of the power. A power stabilization control program for controlling charging and discharging between the power storage device and the AC power system via the power converter so as to suppress fluctuations in the active power of the AC power system,
On the computer,
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
When the stored power amount approaches the upper limit value, the active power measurement value is corrected in the direction of discharging the stored power, and when the stored power amount approaches the lower limit value, the active power measurement value is corrected in the direction of charging the stored power. Correction signal calculation means for calculating a correction signal;
Means for adding the correction signal to the active power measurement value to calculate a corrected active power;
Compensation target value calculation means for removing the active power fluctuation component from the corrected active power and calculating a compensation target value;
Compensation power calculating means for subtracting the active power measurement value from the compensation target value to calculate compensation power;
Power converter control means for controlling the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power;
A power stabilization control program characterized by realizing the above. A power stabilization control program for controlling charging and discharging between the power storage device and the AC power system via the power converter so as to suppress fluctuations in the active power of the AC power system,
On the computer,
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Compensation target value calculation means for removing the active power fluctuation component from the active power measurement value and calculating a compensation target value;
Compensation power calculation means for subtracting an active power measurement value from the compensation target value to calculate compensation power;
Power converter control means for controlling the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power;
When the stored power amount approaches the upper limit value, the stored power is discharged, and when the stored power amount approaches the lower limit value, the compensation target value or the compensated power is charged in the direction of charging the stored power. Correction signal calculation means for calculating a correction signal for correcting
An addition means for adding the correction signal to the compensation target value or the compensation power after passing the correction signal through a filter for smoothing steep fluctuations;
A power stabilization control program characterized by realizing the above. In the power stabilization control program according to claim 4 or 5 , in the correction signal calculation means,
Among the ranges of the stored power amount of the power storage device, a low storage power amount correction start threshold LS, a low storage power amount correction end threshold LE, a high storage power amount correction end threshold HE, The correction start threshold value HS at the time of high stored energy is set so that LS <LE <HE <HS,
When the stored power amount decreases and falls below the LS, the output of the correction signal is started in the direction in which the power storage device is charged, and then when the stored power amount rises and exceeds the LE, the correction is performed. Stop signal output,
When the stored power amount rises and exceeds the HS, the correction signal is output in the direction of discharging from the power storage device. After that, when the stored power amount decreases and falls below the HE, the correction signal A power stabilization control program that operates to stop the output of the power. A power stabilization control method for controlling charging and discharging between a power storage device and an AC power system via a power converter so as to suppress fluctuations in active power of the AC power system,
Detecting the active power of the AC power system as an active power measurement value,
Detecting the stored power amount of the power storage device or a signal corresponding thereto,
When the stored power amount approaches the upper limit value, the active power measurement value is corrected in the direction of discharging the stored power, and when the stored power amount approaches the lower limit value, the active power measurement value is corrected in the direction of charging the stored power. Calculate the correction signal,
Add the correction signal to the active power measurement value to calculate the corrected active power,
The active power fluctuation component is removed from the corrected active power, the compensation target value is calculated,
Calculate the compensation power by subtracting the measured active power value from the compensation target value,
Control the conversion operation of the power converter by a power converter output command value corresponding to the magnitude of the compensation power,
The power stabilization control method characterized by the above-mentioned.   A power stabilization control method for controlling charging and discharging between a power storage device and an AC power system via a power converter so as to suppress variation in active power of the AC power system,
  Detecting the active power of the AC power system as an active power measurement value,
  Detecting the stored power amount of the power storage device or a signal corresponding thereto,
  The active power fluctuation component is removed from the active power measurement value, a compensation target value is calculated,
  Subtracting the active power measurement value from the compensation target value to calculate the compensation power,
  Control the conversion operation of the power converter by a power converter output command value according to the magnitude of the compensation power,
  When the stored power amount approaches the upper limit value, the stored power is discharged, and when the stored power amount approaches the lower limit value, the compensation target value or the compensated power is charged. Calculate the correction signal to correct
  After passing the correction signal through a filter that smooths steep fluctuations, the correction signal is added to the compensation target value or the compensation power.
The power stabilization control method characterized by the above-mentioned. 9. The power stabilization control method according to claim 7 , wherein a low storage power amount correction start threshold LS and a low storage power amount correction end are within the range of the stored power amount of the power storage device. Set threshold LE, correction end threshold HE for high stored energy, and correction start threshold HS for high stored energy so that LS <LE <HE <HS.
When the stored power amount decreases and falls below the LS, the correction of the charging power is started in the direction in which the power storage device is charged. After that, when the stored power amount rises and exceeds the LE, Stop the correction,
When the stored power amount rises and exceeds the HS, the correction of the discharge power is started in the direction of discharging from the power storage device. After that, when the stored power amount decreases and falls below the HE, the discharge power A power stabilization control method characterized by operating to stop correction.