JP2007306669A - Power stabilization system employing power storage unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure efficient and effective compensation of power variation by shortening the time when the operating state sticks to the upper or lower limit of allowable operation range and power compensation becomes impossible, and suppressing abrupt variation in compensated effective power when power compensation is resumed. <P>SOLUTION: The power stabilization system 1 comprises a means for detecting effective power of an AC power system, a means for calculating a compensation target value by removing the effective power variation component from an effective power measurement, a means for calculating a compensation power by taking the difference between the compensation target value and the effective power measurement, a power converter control means originating a power converter output command depending on the compensation power, and a power converter 4 for delivering power stored in a power storage unit 3 to the AC power system and delivering power from the AC power system to the power storage unit 3. The compensation target value operating means has a low-pass filter having a function for limiting operation or an operation value by an upper limit threshold and a lower limit threshold wherein the upper limit threshold is the sum of the effective power measurement and a mechanical protection upper limit threshold, and the lower limit threshold is the sum of the effective power measurement and a mechanical protection lower limit threshold. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a system for stabilizing power applied to a power system from a generator such as a wind power generator, and more particularly to a power stabilization system using a power storage device.

  In recent years, interconnection of distributed power sources using natural energy such as wind power and sunlight has increased. However, since the output of a distributed power source that uses natural energy fluctuates from moment to moment depending on natural conditions such as wind speed, system frequency and voltage fluctuations occur especially in weak power systems such as remote areas and remote islands. It may become.

  In the future, it is possible to introduce microgrids. In the microgrid, output fluctuations of distributed power sources using natural energy and power demand fluctuations of demanding equipment cause supply and 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.

  Conventionally, a system has been developed that compensates for power fluctuations such as output fluctuations, load fluctuations, power flow fluctuations, etc. by absorbing or discharging power using a power storage device such as a flywheel or a secondary battery. . 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, the device capacity of the power converter and the stored power amount of the power storage device are finite, and there is an allowable operating range for the charge / discharge power in the power converter and the stored power amount in the power storage device. In case of deviation from the allowable operating range, for example, the power converter stops the equipment, the flywheel stops the equipment due to overspeed or the operation becomes unstable due to insufficient speed, and the secondary battery life due to overcharge / overdischarge Leading to a decline. Therefore, normally, a limiter for preventing deviation from the allowable operating range is provided at the output stage of the control device.

In Patent Literature 1, a charge / discharge power limiter is provided in the flywheel control device so that the charge / discharge power does not exceed the allowable operating range of the power converter, and the flywheel rotation speed (corresponding to the stored power amount) is the flywheel. A speed limiter is provided to protect the equipment so as not to exceed the allowable operating range of the wheel (power storage device).
Japanese Patent Laid-Open No. 11-262186

  In addition, since a loss occurs during charging and discharging in the power storage device and 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 from 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 for correcting the average bias of the charge / discharge amount of the power storage device and preventing the stored power amount from sticking to the upper and lower limit values in the long term.

As an example of using a flywheel as the power storage device, Patent Document 2 and as an example of using a secondary battery include Non-Patent Document 1 and the like.
In Patent Document 2, 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 obtained by removing the fluctuation component from the active power measurement value of the distributed power supply) Thus, 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 (February 2002)

  However, if the operating state reaches the upper and lower limits of the allowable operating range, the output of the compensating power can be limited by a limiter to prevent the deviation of the operating allowable range, but the preceding stage of the limiter, that is, the calculation of the compensating power that is the limiter input signal The value itself is still kept at a signal level that exceeds the allowable operating range. As a result, there has been a problem that further power compensation cannot be performed until the compensation power settles to a signal level that naturally falls within the allowable operating range.

  In addition, the direction of change in active power during the period when the operating state is stuck to the upper and lower limits of the allowable operating range and power compensation is not possible, and the power compensation direction when restarting power compensation is different. There was a problem that changed rapidly.

  The object of the present invention is to reduce the time during which power compensation cannot be performed when the operating state reaches the upper and lower limits of the allowable operating range, and after the compensation when the power compensation is resumed. A power stabilization system using a power storage device, its control device, etc. that can suppress sudden fluctuations in active power and can compensate for more efficient and effective power fluctuation within the allowable operating range of the power storage device Is to provide.

  The power stabilization system using the power storage device according to the first aspect of the present invention includes an active power detection means for detecting an active power of an AC power system as an active power measurement value, and an active power measurement detected by the active power detection means. A compensation target value calculation means for removing the active power fluctuation component from the value and calculating a compensation target value; a compensation target value calculated by the compensation target calculation means; and an active power measurement value detected by the active power detection means Compensation power calculation means for calculating the compensation power by taking the difference, power converter control means for transmitting a power converter output command according to the compensation power calculated by the compensation power calculation means, and the power conversion control means A power converter for inputting / outputting power stored in a power storage device to / from the AC power system in response to a power converter output command issued; A low-pass filter having a function to limit the calculation or the calculated value (hereinafter referred to as “internal limiter”), and the upper limit threshold is obtained by adding the machine protection upper limit threshold to the active power measurement value (internal limiter upper limit threshold The lower limit threshold value can be realized by adding the machine protection lower limit threshold value to the active power measurement value (internal limiter lower limit threshold value).

  According to the power stabilization system using the power storage device having the above configuration, when the operating state reaches the upper and lower limits of the allowable operating range, the internal limiter sets the signal level at which the calculated value of the compensation target value is within the allowable operating range. Limited. Therefore, at the stage where the increase / decrease in the active power measurement value is reversed, the operation state enters the operation allowable range, and the power compensation can be resumed. As a result, the time during which the operating state is stuck to the upper and lower limits of the allowable operating range and power compensation is not possible can be shortened. In addition, by resuming power compensation at the timing when the increase / decrease in active power is reversed, it is possible to perform power compensation in accordance with the tendency of power fluctuation before inversion. For example, when the active power measurement value that is an input signal to the compensation target value calculation means reaches the upper limit value of the internal limiter, the power compensation is resumed when the active power measurement value starts to decrease. Further, when the power compensation is resumed, the fluctuation of the active power after compensation when the power compensation is resumed can be suppressed by compensating for the fluctuation component that the active power measurement value decreases.

  The power stabilization system using the power storage device according to the second aspect of the present invention includes active power detection means for detecting active power of an AC power system as an active power measurement value, and active power measurement detected by the active power detection means. A compensation power calculation means for extracting an active power fluctuation component from the value and calculating compensation power; a power converter control means for transmitting a power converter output command in accordance with the compensation power calculated by the compensation power calculation means; In response to a power converter output command issued from the power conversion control means, a power converter that inputs and outputs power stored in a power storage device to the AC power system, the compensation target value calculation means, This is realized by having a high-pass filter with an internal limiter having a machine protection upper limit threshold as an internal limiter upper limit threshold and a machine protection lower limit threshold as an internal limiter lower limit threshold.

  According to the power stabilization system using the power storage device having the above configuration, when the operating state reaches the upper and lower limits of the allowable operating range, the internal limiter sets the signal level at which the calculated value of the compensation target value is within the allowable operating range. Limited. Therefore, at the stage where the increase / decrease in the active power measurement value is reversed, the operation state enters the operation allowable range, and the power compensation can be resumed. As a result, the time during which the operating state is stuck to the upper and lower limits of the allowable operating range and power compensation is not possible can be shortened. In addition, by resuming power compensation at the timing when the increase / decrease in active power is reversed, it is possible to perform power compensation in accordance with the tendency of power fluctuation before inversion. For example, when the active power measurement value that is an input signal to the compensation target value calculation means reaches the upper limit value of the internal limiter, the power compensation is resumed when the active power measurement value starts to decrease. Further, when the power compensation is resumed, the fluctuation of the active power after compensation when the power compensation is resumed can be suppressed by compensating for the fluctuation component that the active power measurement value decreases.

  According to the power stabilization system using the power storage device of the present invention, its control device, etc., even when the operating state reaches the upper and lower limits of the allowable operating range, the operating state sticks to the upper and lower limits of the allowable operating range. The time during which compensation is not possible can be shortened, and more efficient and effective compensation for power fluctuations can be achieved within the allowable operating range of the power storage device.

  Further, by resuming the power compensation at the stage where the increase / decrease in the active power is reversed, it becomes possible to perform the power compensation according to the power fluctuation tendency before the reversal. That is, even when the driving state reaches the upper and lower limits of the driving allowable range, resumption of power compensation while maintaining smoothness is realized.

  In addition, even when a correction signal for monitoring the power storage device is added, power fluctuation compensation that does not hinder the above effect is performed while preventing the deviation from the allowable operating range due to the addition of the correction signal.

Embodiments of the present invention will be described below 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 natural energy is connected is taken as an example. The present invention is not limited to this example. The power stabilization system of the present invention can be applied for the purpose of suppressing the active power of the AC power system, such as load fluctuations and fluctuations in the interconnection point 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.

  FIG. 1 is a configuration diagram of an entire power stabilization system using a power storage device in Embodiment 1 of the present invention. The power stabilization system 1 in FIG. 1 includes a power storage device 3, a power converter 4, and a control device 5, and is connected to the power system 2 via a transformer.

The power storage device 3 is, for example, a flywheel, a secondary battery, a capacitor, or the like.
The power converter 4 is based on the power converter output command value P _O from the control device 5 (here, the direction in which power is discharged from the power storage device is positive), and the power system 2, the power storage device 3, Give and receive power. When the power storage device 3 is a flywheel, the AC power on the flywheel side and the AC power on the power system side are converted bidirectionally, and when the power storage device 3 is a secondary battery, a capacitor, or the like, DC power on the secondary battery / capacitor side and AC power on the power system 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 is connected to the power system via a transformer. In addition, by detecting the effective power at the connection point of the microgrid, it can be applied to the suppression of fluctuations in the connection point power flow.
The control device 5 includes an active power detector 6, a compensation target calculation unit 7, a compensation power calculation unit 8, a power converter control unit 9, and the like.

  Although not shown in particular, the control device 5 is configured by a computer including a CPU and the like, and a storage device such as a memory and various storage media (hard disk, etc.). The above-described active power detection unit 6, compensation target value calculation The processing (to be described later) by the unit 7, the compensation power calculation unit 8, the power converter control unit 9, the stored power amount detection unit 11, the correction signal calculation unit 12, and the like is, for example, a predetermined value stored in the storage device by the CPU. This can be realized by reading and executing an application program (power stabilization control program).

  Alternatively, the processing by the active power detection unit 6, the compensation target value calculation unit 7, the compensation power calculation unit 8, the power converter control unit 9, the stored power amount detection unit 11, the correction signal calculation unit 12, etc. of the control device 5 is a dedicated circuit. It may be realized by hardware such as.

  Further, when realized by hardware, it may be controlled using a digital control device 5 (programmable controller), or may be realized by an analog control circuit such as an operational amplifier.

Active power detector 6 detects the effective power measured value P _G of the wind power generator on the basis of the voltage and current value of the output of the wind power generator.
Compensation target value computing unit 7, an arithmetic filter, or by smoothing the moving average or the like, the removal of the active power variation component from the effective power measured value P _G compensation target value P _A to remove variation such as a low-pass filter To do.

The compensation power calculation unit 8 calculates the compensation power ΔP _G (here, the direction in which power is discharged from the power storage device is positive) by subtracting the active power measurement value P _G from the compensation target value P _A. .
Power converter control section 9 generates a command value to the converter depending on the magnitude of the power converter output command value P _O of the compensation power [Delta] P _G.

FIG. 2 illustrates an internal configuration example of the compensation target value calculation unit. An active power fluctuation removal filter 10 (or smoothing process) is provided in the compensation target value calculation unit, and the active power fluctuation removal filter 10 is a limiter (hereinafter referred to as an internal limiter) that stops calculation at an upper / lower threshold value described later. To be referred). The internal limiter upper / lower threshold values (HL, LL) are set to a value obtained by adding the device protection upper / lower threshold values (HL _O , LL _O ) and the active power measurement value P _G. The device protection upper and lower thresholds (HL _O , LL _O ) may be fixed values (for example, upper and lower limit values that can be output from the power converter), or the state of the power stabilization system (for example, power It may be a variable value controlled according to the temperature of the storage device or the amount of stored power. In addition, the active power fluctuation component removal filter in the figure describes a first-order low-pass characteristic transfer function, but the present invention is not limited to this transfer function. Filter characteristics such as a transfer function are a design matter of the present inventor.

Here, the function of the above-described internal limiter will be described (Note that this limiter may be referred to as a dynamic limiter). In the prior art, the operating conditions such as the output P _O of the power converter (various detection signals) of the power converter, and so as not to deviate from the operation allowable range of the electric power storage device, the compensation power [Delta] P _G or the power converter output command value the upper and lower limit limiter (hereinafter this limiter is referred to as "external limiter") provided on the second half of the P _O of process, had set equipment protection over the lower threshold (HL _O, LL _O). The equipment protection over the lower threshold (HL _O, LL _O) set to a fixed value, or by variably controlling, was able to prevent a departure operation allowable range. For example, to prevent the operation allowable range deviation of the output P _O of the power converter, HL _O, it may be set the output upper and lower limits of the power converter LL _O.

However, when the operating condition reaches the upper and lower limits of the external limiter, the output value of the external limiter is limited by the upper and lower limits, but the compensation power ΔP _G that is the input value of the external limiter or the power converter output command value P _O Is still kept at a signal level exceeding the allowable operating range. Therefore, the deviation of the allowable operating range can be prevented, but more power compensation can be performed until the compensation power ΔP _G , which is the input / output value of the external limiter, or the power converter output command value _PO naturally falls within the allowable operating range. There wasn't.

  In addition, the active power change direction during the period when the operating state is stuck to the upper and lower limits of the allowable operating range and power compensation cannot be performed is different from the power compensation direction when resuming power compensation. There was a problem that changed greatly.

  In order to solve the above problem, in the present invention, a limiter is provided in the active power fluctuation elimination filter 10. This configuration differs greatly from the prior art in that the position of the limiter is arranged in the first half of the process. Furthermore, by providing a limiter in the filter, the calculation value itself is limited to a signal level that falls within an allowable range, so that excessive calculation that has been a problem in the prior art can be prevented.

  The mounting method in which the limiter is provided in the filter depends on the type of filter and the calculation method (digital filter, analog filter, transfer function, etc.). Moreover, the output finish when the upper and lower limit values are reached or when the separation is performed differs depending on how the calculation is suppressed. In other words, the configuration of the limiter in the filter according to the present invention is a design matter that the practitioner of the present invention performs according to the purpose.

This technical device, for example, when the effective power measured value P _G, which is an input signal to the filter has reached the upper limit value of the rapidly increasing internal limiter, calculation value itself of the compensation target value P _A is operation allowable by the internal limiter because it is limited to a signal level falls within the range, power compensation is resumed at the stage where active power measurement P _G began to decrease. That is, the time during which the operating state is stuck to the upper and lower limits within the allowable range and power compensation is not possible can be shortened.

Further, by resuming the power compensation at the timing when the increase / decrease in the active power is reversed, it becomes possible to perform the power compensation in accordance with the power fluctuation tendency before the reversal.
Also, the compensation target value P _A can be obtained by setting the internal limiter upper / lower limit threshold (HL, LL) to the value obtained by adding the active power measurement value P _G to the device protection upper / lower limit threshold (HL _O , LL _O ). the size of the upper limit value HL _O + P _G, is limited by the lower limit value HL _O + P _G. However, as shown in FIG. 3, since the later of the compensation power computing unit size for the compensation target value P _A is limited by the upper limit value HL _O + P _G, the lower limit HL _O + P _G, active power the size of the compensation power [Delta] P _G which is obtained by subtracting the measured value PG will be restricted upper limit value HL _O, at the lower limit HL _O. Thereby, the deviation | shift deviation of the driving | operation allowable range of a power converter and a power storage device can be prevented.

  FIG. 4 is a diagram of the overall configuration of the power stabilization system in the second embodiment of the present invention. The main point of the configuration of the present embodiment is that when the correction signal obtained by monitoring the stored electric energy is added, the correction state is added so that the operation state does not deviate from the operation allowable range. This is to prevent the features of the first embodiment of the present invention from being impaired.

The power stabilization system 1 in FIG. 1 includes a stored power amount detector 11 and a correction signal calculation unit 12 in addition to the components of the first embodiment.
Stored power amount detector 11, the stored power amount E _S of the electric power storage device, directly or indirectly detected / calculated. For example if the power storage device is a flywheel, to detect the flywheel speed when a secondary battery, capacitor or the like detects the terminal voltage, calculating a stored power amount E _S based on the detection result .

Correction signal calculating unit 12 receives the stored power amount E _S from a storage power amount detector 11 calculates a correction signal P _C, is added to the compensation target value P _A or compensation power [Delta] P _G. In this case, further also transfers the corrected signal P _C to the compensation target value computing unit 7.

FIG. 5 illustrates a configuration example of the compensation target value calculation unit 7 according to the second embodiment of the present invention. Incidentally, this configuration example is substantially the same even when adding the correction signal P _C to the compensation power [Delta] P _G.
As shown in the figure, the compensation target processing unit 7 has an effective power variation component removal filter with internal limiter, it calculates the compensation target value P _A from the active power measurements P _G. At this time, the internal limiter upper and lower thresholds (HL, LL) are determined as follows.

Internal limiter upper limit threshold HL =
Device protection upper threshold HLO + active power measurement value P _G -correction signal P _C
Internal limiter lower threshold LL =
Equipment protection lower limit threshold LLo + active power measurement value P _G -correction signal P _C
In other words, the magnitude of the compensation target value P _A is the upper limit value P _G + HLo-P _C, is limited by the lower limit value P _G + LLo-P _C.

The advantages determined in this way will be described with reference to FIG. Upper limit P _G + HLO-P _C, the lower limit value P _G + LLO-P _C in a restricted compensation target value P _A, the correction signal P _C at the subsequent stage is added, the compensation power calculating section 8 active power measurement P _G is subtracted. As a result, the size of the compensation power [Delta] P _G upper limit value _HLO, is limited by the lower limit value LLO. That is, while reflecting the correction signal P _C to the compensation power [Delta] P _G, change itself can be restricted upper limit _HLO, the lower limit value LLO. As a result, it is possible to reduce the time during which the power state cannot be compensated for when the operating state sticks to the upper and lower limits of the operation allowable range while preventing the deviation from the operation allowable range of the power converter and the power storage device.

FIG. 7 is a diagram showing the overall system configuration according to the third embodiment of the present invention.
The illustrated power stabilization system 1 includes a power storage device 3, a power converter 4, and a control device 5, and is connected to a power system via a transformer. Also in the present embodiment, it is assumed that a wind power generator is connected to the power system via a transformer, assuming a case where output fluctuation compensation of a distributed power source using natural energy is performed.

The control device 5 includes an active power detector 6, a compensation power calculation unit 8, a power converter control unit 9, and the like.
Active power detector 6 detects the effective power measured value P _G of the wind power generator on the basis of the voltage and current value of the output of the wind power generator.

The compensation power calculation unit 7 extracts the active power fluctuation component from the active power measurement value P _G by using a high-pass filter or the like, and calculates the compensation power ΔP _G (here, the direction in which the power is discharged from the power storage device is positive). .

Power converter control section 9 generates a command value to the converter depending on the magnitude of the power converter output command value P _O of the compensation power [Delta] P _G.
In the first and second embodiments, the compensation target value calculation unit 7 calculates the compensation target value PA by removing the active power fluctuation component from the active power measurement value PG, and the compensation power calculation unit calculates the compensation target value PA. While computing the active power measurement PG subtraction and compensated power [Delta] P _G, in the present embodiment 3, the compensation power calculating section 8 extracts the active power variation component from the active power measurement PG by the high-pass filter or the like compensation from Calculate power. That is, in the third embodiment, the same function is realized by different configurations.

FIG. 8 illustrates the configuration of the compensation power calculation unit in the third embodiment. A filter (high pass filter, etc.) 13 for extracting active power in the compensation power calculation unit 8 is provided with an internal limiter that stops the calculation at the upper and lower thresholds, and the internal limiter upper and lower thresholds (HL, LL) are used for device protection. Set the lower threshold (HL _O , LL _O ). The device protection upper and lower thresholds (HL _O , LL _O ) may be fixed values (for example, upper and lower limit values that can be output from the power converter), or the state of the power stabilization system (for example, power It may be a variable value controlled according to the temperature of the storage device or the amount of stored power. In addition, the active power fluctuation component extraction filter in the figure describes a transfer function having a first-order high-pass characteristic, but the present invention is not limited to this transfer function. Filter characteristics such as a transfer function are a matter of design for the practitioner of the present invention.

If a valid power measurements P _G is the input signal by the internal limiter to example filter has reached the upper limit value of the rapidly increasing internal limit, signal computation itself of the compensation power [Delta] P _G falls operation allowable range vision by the internal limiter Since the level is limited, the power compensation is resumed when the active power measurement value PG starts to decrease. That is, the time during which the operating state is stuck to the upper and lower limits within the allowable range and power compensation is not possible can be shortened.

Further, by resuming the power compensation at the timing when the increase / decrease in the active power is reversed, it becomes possible to perform the power compensation in accordance with the power fluctuation tendency before the reversal.
The internal limiter upper and lower limit threshold (HL, LL) the equipment protection over the lower threshold (HL _O, LL _O) by the magnitude of the compensation target value P _A is the upper limit value HL _O, the lower limit value Limited by HL _O. As a result, it is possible to prevent a deviation from the allowable operating range of the power converter and the power storage device.

  FIG. 9 is a diagram showing the overall configuration of the power stabilization system in Embodiment 4 of the present invention. The purpose of the configuration of this embodiment is to add the correction signal when the correction signal obtained by monitoring the power storage amount is added, while preventing the operation state from deviating from the allowable operating range. This is to avoid losing the characteristics of the third embodiment of the present invention.

The power stabilization system 1 in FIG. 1 includes a stored power detector 11 and a correction signal calculation unit 12 in addition to the components of the third embodiment.
Storage electric quantity detector 11, the stored power amount E _S of the electric power storage device, directly or indirectly detected / calculated. For example if the power storage device is a flywheel, to detect the flywheel speed when a secondary battery, capacitor or the like detects the terminal voltage, calculating a stored power amount E _S based on the detection result .

Correction signal calculating unit 12 receives the storage competence E _S from the reservoir competence detector 11, calculates a correction signal P _C, is added to the compensation power [Delta] P _G. In this case, further also transfers the compensation target value P _A in the compensation target value computing unit 7.

FIG. 10 illustrates a configuration example of the compensation power calculation unit 7 according to the fourth embodiment of the present invention. As shown in the figure, the compensation target processing unit 7 has an effective power variation component extraction filter with internal limiter, it calculates the compensation power [Delta] P _G from active power measurements P _G. At this time, the internal limiter upper and lower thresholds (HL, LL) are determined as follows.

Internal limiter upper limit threshold HL = Device protection upper limit threshold HLO-Correction signal P _C
Internal limiter lower threshold LL = Equipment protection lower threshold LLo-Correction signal P _C
In other words, the magnitude of the compensation target value P _A is the upper limit value HLO-P _C, it is limited by the lower limit value LLO-P _C.

The advantages determined in this way will be described with reference to FIG. Upper limit HLO-P _C, compensation power [Delta] P _G that is limited by the lower limit value LLO-P _C is the correction signal P _C at the subsequent stage is added, the compensation power calculating section 8 active power measurement P _G is subtracted . As a result, the size of the compensation power [Delta] P _G upper limit value _HLO, is limited by the lower limit value LLO. That is, while reflecting the correction signal P _C to the compensation power [Delta] P _G, change itself can be restricted upper limit _HLO, the lower limit value LLO. As a result, it is possible to reduce the time during which the power state cannot be compensated for when the operating state sticks to the upper and lower limits of the operation allowable range while preventing the deviation from the operation allowable range of the power converter and the power storage device.

About the effect of the electric power stabilization system using the electric power storage apparatus demonstrated above, the verification result by this inventor is shown below.
Here, in the power stabilization system using the power storage device according to the first embodiment of the present invention, when the internal limiter for preventing the deviation from the output range of the power converter is provided in the compensation target value calculation unit (hereinafter referred to as “internal limiter”). the measured waveform when ") provided with, a simulation result obtained when a external limiter for preventing the output range deviation of the power converter to compensate the power [Delta] P _G (hereinafter" when the external limiter provided ") FIG. 11, FIG. 12, and FIG.

In the following simulation, the upper / lower threshold value of the internal limiter is represented by the following equation.
Internal limiter upper / lower threshold (HL, LL)
= Device protection upper / lower threshold (HLo, LLo) + active power measurement value P _G
The external limiter upper and lower thresholds are as follows:

External limiter upper / lower threshold = device protection upper / lower threshold (HLo, LLo)
The device protection upper and lower thresholds (HLo, LLo) are fixed to the power converter output upper and lower limits ± 0.2 [pu].

11, the measured waveforms for the compensation target value P _A of the case in which the internal limiter, and simulation compensation target value P _A 'results obtained when a external limiter, internal limiter upper limit in the case of providing the internal limiter The measured waveforms of the threshold value HL and the internal limiter lower threshold LL are shown.

From the waveform of FIG. 11, when an external limiter is provided for the decrease in active power from around 47500 seconds, the compensation target value P _A ′ exceeds the internal limiter upper limit threshold HL from around 47600 seconds to around 47900 seconds. Yes. This indicates that when an external limiter is provided, even if the compensation target value P _A ′ reaches a level that deviates from the allowable operating range, the compensation target value P _A ′ itself is not limited in size. It shows that the signal level at which the compensation target value P _A ′ exceeds the threshold value of the external limiter is maintained until the power is increased and the compensation target value P _A ′ naturally falls within the range of the external limiter.

In addition, the compensation target value P _A ′ and the internal limiter upper limit threshold HL intersect at around 47900 seconds. This indicates that the direction of change in active power differs from the direction of power compensation when power compensation is resumed, and this becomes a variation factor of post-compensation active power when power compensation is resumed.

On the other hand, the case of providing an internal limiter, follows the same value as the compensation target value P _A is the internal limiter upper threshold to around 47,800 seconds around 47600 seconds since been increasing active power again at around 47,800 seconds, compensation target value P _a is below the internal limiter upper threshold HL. If this is provided with internal limiter, the compensation target value P _A itself shows to be limited within the limiter upper and lower limit threshold, a result, the compensation target value P _A at the stage of active power is reversed the internal limiter Is within the upper and lower thresholds.

Also a compensation target value P _A in the vicinity 47,800 seconds and an internal limiter upper threshold HL is separated. This indicates that power compensation is performed along the direction of change of the active power up to that time when the power compensation is resumed, whereby the fluctuation of the compensated active power when the power compensation is resumed can be suppressed.
Figure 12 shows the measured waveform of the compensation power [Delta] P _G obtained when a internal limiter, the simulation results of compensated power [Delta] P _G 'obtained when a external limiter.

From the waveform of FIG. 12, when an external limiter is provided, the compensation power ΔP _G ′ is limited to the device protection upper limit threshold value HLo (0.2 [pu]) by the external limiter from around 47600 seconds to around 47900 seconds. On the other hand, the case of providing an internal limiter, compensation power [Delta] P _G to around 47,800 seconds around 47600 seconds is limited by equipment protection upper threshold HLo (0.2 [pu]).

This indicates that the compensation operation can be resumed earlier when the internal limiter is provided, as compared with the case where the external limiter is provided, as described with reference to FIG.
13, the measurement result after compensation active power P _G + [Delta] P _G obtained when a internal limiter, simulation results after compensation active power P _G + ΔP _G 'obtained when a external limiter, and (before compensation of) shows the active power measurement P _G. This amount is a measure of how much power supplied to the compensated power system is smoothed compared to before compensation.

From the waveform in FIG. 13, when an external limiter is provided, the active power fluctuation component that could not be compensated from around 47600 seconds to around 47900 seconds appears in the compensated active power P _G + ΔP _G ′. It can be seen that the power change is also large. The reason why the power change at the time of resuming the compensation operation is abrupt is that the change direction of the active power during the period in which the power state cannot be compensated for the operation state sticks to the upper and lower limits of the operation allowable range and the power compensation direction when the power compensation is resumed Because.

On the other hand, the case of providing an internal limiter, but the active power variation component which could not be compensated to around 47,800 seconds around 47600 seconds is appeared after compensation active power P _G + [Delta] P _G, and resumed compensation operation early It can also be seen that the power fluctuation when the compensation operation is resumed is small. Compensating power [Delta] P _G is limited by equipment protection upper threshold HLo (0.2 [pu]). When the internal limiter is provided, the power fluctuation when resuming the compensation operation is small because the compensation operation is resumed at the timing when the increase / decrease in the active power is reversed, thereby compensating for the power fluctuation along the power fluctuation trend before the reversal. This is because it becomes possible.

  As described above, according to the power stabilization system using the power storage device of this example, the power storage device capable of efficient and effective power fluctuation compensation within the allowable operating range of the power storage device. The power fluctuation compensation system used can be provided.

It is a block diagram of the whole system in Example 1 of this invention. It is a block diagram of the compensation target value calculating part in Example 1. It is a figure explaining the calculation method of the compensation electric power in Example 1. FIG. It is a block diagram of the whole system in Example 2 of this invention. It is a block diagram of the compensation target value calculating part in Example 2 of this invention. It is a figure explaining the calculation method of the compensation electric power in Example 2 of this invention. It is a block diagram of the whole system in Example 3 of this invention. It is a block diagram of the compensation electric power calculating part in Example 3 of this invention. It is a block diagram of the whole system in Example 4 of this invention. It is a block diagram of the compensation electric power calculating part in Example 4 of this invention. It is a graph which shows a compensation target value and an internal limiter upper / lower limit threshold value. It is a graph which shows compensation electric power. It is a graph which shows the distributed power supply active power before and behind compensation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power stabilization system 2 Electric power system 3 Power storage apparatus 4 Power converter 5 Control apparatus 6 Active power detection part 7 Compensation target value calculation part 8 Compensation power calculation part 9 Power converter control part 10 Low pass filter 11 with an internal limiter Storage power Quantity detector 12 Correction signal calculator 13 High-pass filter with internal limiter

Claims (18)

In a power stabilization system that suppresses fluctuations in the active power of the AC power system,
A power storage device for storing and releasing power to the AC power system;
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
Compensation target value calculation means for removing the active power fluctuation component from the active power measurement value detected by the active power detection means and calculating a compensation target value;
Compensation power calculation means for calculating the compensation power by taking the difference between the compensation target value calculated by the compensation target calculation means and the active power measurement value detected by the active power detection means;
Power converter control means for transmitting a power converter output command according to the compensation power calculated by the compensation power calculation means;
In response to a power converter output command issued from the power converter control means, a power converter that inputs and outputs power stored in the power storage device to the AC power system,
The compensation target value calculation means includes a low pass filter having a function of calculating or limiting a calculation value with an upper limit threshold and a lower limit threshold, and a power stabilization system using a power storage device. The power stabilization system according to claim 1,
The low-pass filter is characterized in that the upper threshold value is obtained by adding the measured active power value and the machine protection upper threshold value, and the lower threshold value is obtained by adding the measured active power value and the machine protection lower threshold value. A power stabilization system using a power storage device. The power stabilization system according to claim 1,
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Correction signal calculation means for calculating a correction signal for correcting the compensation target value or the compensation power from the stored power quantity detected by the stored power quantity detection means;
An electric power stabilization system using an electric power storage device. The power stabilization system according to claim 3,
In the low-pass filter, the upper threshold is a value obtained by adding a machine protection upper threshold to the active power measurement value and subtracting the correction signal, and the lower threshold is obtained by adding a machine protection lower threshold to the active power measurement value. A power stabilization system using a power storage device, wherein a correction signal is subtracted. In a power stabilization system that suppresses fluctuations in the active power of the AC power system,
A power storage device for storing and releasing power to the AC power system;
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
Compensation power calculation means for extracting active power fluctuation components from the active power measurement value detected by the active power detection means and calculating compensation power;
Power converter control means for transmitting a power converter output command according to the compensation power calculated by the compensation power calculation means;
In accordance with a power converter output command issued from the power conversion control means, a power converter that inputs and outputs power stored in the power storage device to the AC power system,
The compensation power calculating means includes a high-pass filter having a function of limiting an operation value or an operation value with an upper limit threshold and a lower limit threshold. The power stabilization system according to claim 5,
The power stabilization system using a power storage device, wherein the upper threshold of the high-pass filter is a machine protection upper threshold and the lower threshold is a machine protection lower threshold. The power stabilization system according to claim 5,
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Correction signal calculation means for calculating a correction signal for correcting the compensation power from the stored power quantity detected by the stored power quantity detection means;
An electric power stabilization system using an electric power storage device. The power stabilization system according to claim 7,
In the high-pass filter, the upper limit threshold value is obtained by subtracting the correction signal from a machine protection upper limit threshold value, and the lower limit threshold value is obtained by subtracting the correction signal from a machine protection lower limit threshold value. Power stabilization system using The power stabilization system according to any one of claims 1 to 8,
The machine protection upper limit threshold and the machine protection lower limit threshold are variably controlled according to the state of the power stabilization system (output of the power converter, stored power amount of the power storage device, temperature of the power storage device, etc.). A power stabilization system using the featured power storage device. In the control device of the power stabilization system using the power storage device controlled by the power converter, which suppresses the active power fluctuation of the AC power system,
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
Compensation target value calculation means for removing the active power fluctuation component from the active power measurement value detected by the active power detection means and calculating a compensation target value;
Compensation power calculation means for calculating the compensation power by taking the difference between the compensation target value calculated by the compensation target calculation means and the active power measurement value detected by the active power detection means;
Power converter control means for transmitting a power converter output command according to the compensation power calculated by the compensation power calculation means,
The compensation target value calculation means includes a low-pass filter having a function of calculating or limiting a calculation value with an upper limit threshold and a lower limit threshold, and a control device for a power stabilization system using a power storage device. A control device for a power stabilization system according to claim 10,
The low-pass filter is characterized in that the upper threshold value is obtained by adding the measured active power value and the machine protection upper threshold value, and the lower threshold value is obtained by adding the measured active power value and the machine protection lower threshold value. Control device for power stabilization system using power storage device. A control device for a power stabilization system according to claim 10,
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Correction signal calculation means for calculating a correction signal for correcting the compensation target value or the compensation power from the stored power quantity detected by the stored power quantity detection means;
A control device for a power stabilization system using the power storage device. A control device for a power stabilization system according to claim 12,
In the low-pass filter, the upper threshold is a value obtained by adding a machine protection upper threshold to the active power measurement value and subtracting the correction signal, and the lower threshold is obtained by adding a machine protection lower threshold to the active power measurement value. A control device for a power stabilization system using a power storage device, wherein a correction signal is subtracted. In the control device of the power stabilization system using the power storage device controlled by the power converter, which suppresses the active power fluctuation of the AC power system,
Active power detection means for detecting the active power of the AC power system as an active power measurement value;
Compensation power calculation means for extracting active power fluctuation components from the active power measurement value detected by the active power detection means and calculating compensation power;
Power converter control means for transmitting a power converter output command according to the compensation power calculated by the compensation power calculation means,
The compensation power calculation means includes a high-pass filter having a function of limiting the calculation value or a calculation value with an upper limit threshold value and a lower limit threshold value. A control device for a power stabilization system according to claim 14,
The control device of the power stabilization system using the power storage device, wherein the upper threshold of the high pass filter is a machine protection upper threshold and the lower threshold is a machine protection lower threshold. A control device for a power stabilization system according to claim 14,
A stored power amount detecting means for detecting a stored power amount of the power storage device or a signal corresponding thereto; and
Control of a power stabilization system using a power storage device, comprising correction signal calculation means for calculating a correction signal for correcting the compensation power from the stored power quantity detected by the stored power quantity detection means apparatus. A control device for a power stabilization system according to claim 16,
In the high-pass filter, the upper limit threshold value is obtained by subtracting the correction signal from a machine protection upper limit threshold value, and the lower limit threshold value is obtained by subtracting the correction signal from a machine protection lower limit threshold value. Control device of power stabilization system using A control device for a power stabilization system according to any one of claims 10 to 17,
The machine protection upper limit threshold and the machine protection lower limit threshold are variably controlled according to the state of the power stabilization system (output of the power converter, stored power amount of the power storage device, temperature of the power storage device, etc.). The control apparatus of the power stabilization system using the electric power storage apparatus characterized by the above.