JP2014239622A - Control device and control method, and power storage system comprising control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction in an operation rate of a power storage system even after a secondary battery deteriorates.SOLUTION: A battery control device 30 which is interconnected to a power system and controls charging/discharging of a secondary battery connected to a power generation device for generating power using natural energy comprises a command value adjustment unit 33 for multiplying a gain Kp by difference between a SOC current value, which is a current charging rate of the secondary battery, and a SOC target value of the secondary battery, controlling the SOC current value so as to be close to the SOC target value, and adjusting a charging/discharging command value of the secondary battery. The command value adjustment unit 33 adjusts the gain Kp depending on temperature of the secondary battery.

Description

  The present invention relates to a control device, a control method, and a power storage system including the control device.

  For example, a power generation facility using natural energy is provided with a power storage system having a plurality of batteries and battery modules, and the output fluctuation of the power generation facility is compensated by charging / discharging of the power storage system, and leveling or peak shifting is performed. . The power storage system used in such an environment is repeatedly charged and discharged. However, when the battery of the power storage system is a secondary battery such as a lithium ion battery, the internal resistance of the secondary battery is increased by repeatedly charging and discharging. Thus, the temperature of the battery itself is high. Therefore, it is known that when a secondary battery is used, it is necessary to operate the power generation equipment while monitoring the state of charge (SOC) and temperature state of the secondary battery.

In the following Patent Document 1, temperature control air is circulated through channels between secondary batteries of a battery assembly, and heat generated from each unit battery is cooled to control the temperature of the secondary battery. It is described.
In the following Patent Document 2, a technique for suppressing the self-heating amount of the secondary battery by reducing the secondary battery output based on the inverter output value is described.
Patent Document 3 listed below describes a technique for calculating the SOC compensation amount by multiplying a difference between the target SOC and the SOC of the battery equipment by a predetermined gain, and controlling the SOC so as to maintain 50%. .

JP 2007-042637 A Japanese Patent Laid-Open No. 1-206844 JP 2013-38960 A

  However, when priority is given to operation, charging / discharging is repeated according to a request from the power system or according to a request from a higher level than the power system even if the temperature of the battery is high. If it does so, the temperature upper limit of a battery or a battery module will be exceeded, and there existed a problem that an electrical storage system stopped as a result and led to the fall of the operation rate of power generation equipment. In the method described in Patent Document 3, the SOC is controlled to maintain the target value (50%), and when the secondary battery is deteriorated, the temperature of the secondary battery increases, and the power storage system It was not possible to suppress the decline in operating rate.

  The present invention has been made in view of such circumstances, and provides a control device and a control method for suppressing a reduction in operating rate of a power storage system even after a secondary battery has deteriorated, and a power storage system including the same. The purpose is to do.

In order to solve the above problems, the present invention employs the following means.
The present invention is a control device that controls charging and discharging of a secondary battery that is connected to a power system and connected to a power generator that generates power by natural energy, and is a current value that is a current charging rate of the secondary battery And a command value adjusting means for adjusting the charge / discharge command value of the secondary battery by multiplying the difference between the target charge rate of the secondary battery and a gain, controlling the current value so as to approach the target charge rate. And the said command value adjustment means provides the control apparatus which adjusts the said gain according to the temperature of the said secondary battery.

According to such a configuration, in the control device that controls charging / discharging of the secondary battery that is linked to the power system and connected to the power generation device that generates power by natural energy, it is adjusted according to the temperature of the secondary battery. The gain is multiplied by the difference between the current value, which is the current charging rate, and the target charging rate, and the current value is controlled to approach the target charging rate, thereby adjusting the charge / discharge command value of the secondary battery.
As described above, according to the present invention, since the gain multiplied by the difference between the current value and the target charging rate can be adjusted depending on whether the temperature of the secondary battery is high or low, the secondary battery is deteriorated. When the temperature of the secondary battery changes, the charge / discharge command value can be adjusted according to the temperature. Thereby, the charge / discharge amount is limited and the temperature rise of the secondary battery is suppressed, so that the charge / discharge operation of the secondary battery can be continued, leading to the suppression of the system operation rate decrease. When the secondary battery has deteriorated, it has been found that the temperature of the secondary battery changes as a means for easily monitoring the deterioration state. The value can be adjusted. Thereby, since the secondary battery is not stopped when the temperature of the secondary battery exceeds the upper limit value, the charge / discharge operation of the secondary battery can be continued.

  The control device compensates for the output fluctuation of the power generation device according to the output of the power generation device, and determines the charge / discharge command value so that the charging rate of the secondary battery is within a predetermined range. It is preferable that a determination unit is provided, and the command value determination unit determines the charge / discharge command value based on a control amount acquired from the command value adjustment unit.

  In this way, by controlling the charging rate of the secondary battery to be within a predetermined range, the charging rate of the secondary battery is controlled to be leveled at the target value as in the conventional case. Thus, the charge / discharge control amount requirement of the secondary battery can be relaxed, and the temperature rise of the secondary battery can be suppressed. Here, the predetermined range is a range including a target value for leveling the secondary battery and a charging rate at which an output satisfying the demand from the power system side is obtained when combined with the output of the power generation device. is there.

  In the above control device, the command value adjusting means sets the gain larger as the temperature of the secondary battery becomes higher, and the larger the gain set by the command value adjusting means, It is preferable to control so that the absolute value of the charge / discharge command value of the secondary battery with respect to the amount becomes small.

  As the temperature of the secondary battery increases, the gain is increased and the charge / discharge amount of the secondary battery is limited, so that the temperature rise of the secondary battery is more reliably suppressed and the system operation rate is reduced.

  The control device includes a change rate determination unit that determines whether or not a change rate of the temperature of the secondary battery with respect to time is smaller than a first predetermined value, and the command value adjustment unit includes: When the change rate is determined by the change rate determination means to be greater than or equal to a first predetermined value, the gain is multiplied with respect to the temperature when the change rate is smaller than the first predetermined value. The gain may be set.

  When the rate of change of the temperature of the secondary battery with respect to time is equal to or higher than the first predetermined value, that is, in a situation where, for example, a sudden temperature change occurs, the gain is set larger than when the rate of change is smaller than the first predetermined value. And by controlling so that the charge / discharge control amount of a secondary battery may be made small, the temperature rise of a secondary battery can be suppressed more reliably and a secondary battery can be controlled to the safe side.

  The control device measures so that a difference between a combined output obtained by adding the power generation amount by the power generation device and the charge / discharge amount of the secondary battery and a target output that is the target combined output is within an allowable range. The combined output on the power system side may be feedback-controlled to adjust the gain.

  By adjusting the gain according to the temperature, the charge / discharge command value of the secondary battery varies, so that the combined output varies, and a case where the difference from the target output is outside the allowable range is also assumed. Therefore, according to the present invention, it is possible to adjust the gain so that the difference from the target output is within the allowable range by performing feedback control on the measured combined output on the power system side.

  When the control device according to any of the above is installed in a closed space where the indoor temperature is adjusted by an air conditioner, and the difference between the temperature of the closed space and the temperature of the secondary battery becomes large May determine that the air-conditioning apparatus is not in a desired operation and increase the adjustment amount of the charge / discharge command value by the command value adjusting means.

  When the air conditioner is not operating as desired and the room temperature cannot be adjusted, the adjustment amount of the charge / discharge command value is positively increased (that is, the gain set in the command value adjustment means is increased). To contribute to the suppression of the temperature rise of the secondary battery.

  The present invention provides a power storage system comprising any one of the above-described control devices and a secondary battery that is connected to a power system and that is connected to a power generation device that generates power using natural energy.

  The power storage system may include an air conditioner that adjusts the indoor temperature of a closed space in which the control device is disposed.

  The present invention is a control method for controlling charging and discharging of a secondary battery that is connected to a power system and connected to a power generation device that generates power by natural energy, and is a current value that is a current charging rate of the secondary battery And the target charging rate of the secondary battery is multiplied by a gain adjusted according to the temperature of the secondary battery to control the current value to be close to the target charging rate, A control method for adjusting a charge / discharge command value is provided.

  The present invention has an effect of suppressing a reduction in the operating rate of the power storage system even after the secondary battery has deteriorated.

1 is a schematic configuration diagram of a power storage system according to a first embodiment of the present invention. The functional block diagram of the battery control apparatus which concerns on 1st Embodiment is shown. It is the figure which showed the relationship between the output electric power with respect to time, and the charging rate in the case where the gain of the battery control apparatus which concerns on 1st Embodiment is adjusted according to temperature, and the case where it does not adjust according to temperature. The functional block diagram of the battery control apparatus which concerns on the 2nd Embodiment of this invention is shown. It is a schematic block diagram of the electrical storage system which concerns on the 3rd Embodiment of this invention. It is the figure which showed an example of the relationship between measured electric power value and an output target value in the electrical storage system which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram of the electrical storage system which concerns on the 4th Embodiment of this invention.

  Hereinafter, embodiments of a control device, a control method, and a power storage system including the control device according to the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 shows a schematic configuration of a power storage system 1 including a battery control device 30 (control device) according to the present embodiment. In the present embodiment, the case where the power generation device that generates power using natural energy is a wind power generation device will be described as an example. However, the power generation device generates power such as a solar power generation device and a wave power generation device in addition to the wind power generation device. A combination with a power storage device capable of quantity leveling is a preferred power generation device, and is not limited to a wind power generation device.
As shown in FIG. 1, a power storage system 1 according to the present embodiment includes a wind power generator (power generator) 2, a power storage device 3, and a natural energy power controller (hereinafter referred to as “power generator controller”) 10. Connected to the power system 6. The power generation controller 10 outputs the output of the wind power generation device acquired from the connection point to the power storage device 3.

  The wind power generator 2 is an example of a power generator that generates power using natural energy, and is a power generator that generates power using wind power. For simplification, FIG. 1 will be described by taking an example in which there is one wind power generator 2, but the number of wind power generators 2 is not particularly limited. In the present embodiment, a wind power generator is taken as an example, but a plurality of different types of power generators may be provided.

The power storage device 3 includes a battery control device 30, a secondary battery 31, and a power converter 32. The power storage device 3 also includes a temperature measurement unit (not shown) that measures the cell temperature (module temperature) of the secondary battery 31, and the measurement result obtained by measuring the cell temperature of the secondary battery 31 is a battery control device. Output to 30. Here, in the following description, the cell temperature (module temperature) of the secondary battery 31 is simply referred to as the temperature of the secondary battery 31.
When the secondary battery 31 deteriorates, the temperature of the secondary battery 31 is a means for easily monitoring the deterioration state of the secondary battery 31, and the internal resistance increases and the temperature changes as the secondary battery 31 deteriorates. Then rise. The temperature change of the secondary battery 31 can be reduced by adjusting the charge / discharge amount with respect to the temperature indicating the deterioration state of the secondary battery 31. In addition, in this embodiment, the value measured as the temperature of the secondary battery 31 is the highest temperature among the temperatures of each cell, but is not limited to this. For example, the average value of each cell May be used.

The secondary battery 31 is not particularly limited, such as a lithium secondary battery, a lead secondary battery, or a nickel hydride secondary battery. However, the secondary battery 31 is preferably a lithium secondary battery because of good charge / discharge followability.
The battery control device 30 includes, for example, a CPU (Central Processing Unit) (not shown), a RAM (Random Access Memory), a computer-readable recording medium, and the like. A series of processing steps for realizing various functions to be described later are recorded in a recording medium or the like in the form of a program, and the CPU reads the program into a RAM or the like to execute information processing / arithmetic processing. Thus, various functions described later are realized.

  The battery control device 30 calculates or measures the charging rate (SOC) of the secondary battery 31, and is based on the charge / discharge command value determined based on the output information of the wind power generator acquired from the power generation controller 10. The power converter 32 is controlled to adjust the charging rate (SOC) of the secondary battery 31. Specifically, the battery control device 30 calculates the charge / discharge command value as a current value, and controls the inverter of the power converter 32 so as to be the calculated current value. The inverter of the power converter 32 includes a bidirectional inverter. When the power generation device generates alternating current, the alternating current input power is converted into direct current and the secondary battery 31 is charged. Further, when the secondary battery 31 discharges direct current, the direct current discharge power is converted into alternating current and output to the power system via a transformer.

Specifically, the battery control device 30 is shown in a functional block diagram as shown in FIG. As shown in FIG. 2, the battery control device 30 includes a command value adjusting unit (command value adjusting unit) 33 and a command value determining unit (command value determining unit) 34.
The command value adjustment unit 33 gains a difference between the SOC current value [%] that is the current charging rate (SOC) of the secondary battery 31 and the SOC target value [%] that is the target charging rate of the secondary battery 31. The charge rate (SOC) correction control is performed so that the SOC current value approaches the SOC target value by multiplying by Kp, and the charge / discharge command value of the secondary battery 31 is adjusted. The control amount of the charging rate (SOC) determined by the command value adjusting unit 33 is output to the command value determining unit 34 as a correction control amount of the charging rate (SOC).

  Note that the control so as to “close to” the SOC target value is not a goal that the SOC current value matches the SOC target value, but a predetermined range including the SOC target value is set as an allowable range and is within the allowable range. It means that the charging rate (SOC) is controlled. That is, paying attention to the fact that the secondary battery 31 is not required to strictly maintain the leveling (for example, the charging rate of 50 [%]), the leveling of the charging rate of the secondary battery 31 is somewhat sacrificed. Therefore, priority is given to the suppression of the temperature rise of the secondary battery 31. Note that the predetermined range is a range that includes a target value for leveling the secondary battery and has a charging rate that provides an output that satisfies the requirements from the power system when combined with the output of the power generation device. .

  Further, the command value adjustment unit 33 adjusts the gain Kp according to the temperature of the secondary battery 31. Specifically, as shown in FIG. 2, the command value adjustment unit 33 has gain information 35 for setting a gain with respect to temperature. The gain information 35 provided in the command value adjustment unit 33 is set such that a large gain is set as the temperature of the secondary battery 31 increases. Information on the temperature of the secondary battery 31 acquired from the temperature measurement unit is input to the battery control device 30, and the command value adjustment unit 33 sets a gain set corresponding to the acquired temperature of the secondary battery 31. Read from the gain information 35 and set the read gain as the priority signal to the gain Kp.

  Here, in the present embodiment, the gain information 35 is described as being given in a table as shown in FIG. 2 in order to acquire the gain with respect to the temperature. For example, an arithmetic expression for calculating the gain according to the temperature is used. It may be obtained by linear interpolation, and is not particularly limited. In the present embodiment, the gain information 35 is a command value adjustment unit 33 in which an appropriate value for obtaining a charge / discharge command value within a range in which the temperature rise of the secondary battery 31 is suppressed is examined in advance by the measurement simulator. However, the present invention is not limited to this, and may be appropriately set by tuning during operation of the power storage system 1.

  In the present embodiment, the gain of the gain information 35 is adjusted according to the temperature. However, when the adjustment according to the temperature is not performed, a predetermined gain is set in the gain Kp of the functional block diagram shown in FIG. We will use it. When the predetermined gain Kp is used, the battery control device 30 outputs a charge / discharge command value that maintains the charge rate of the secondary battery 31 at a target charge rate (for example, 50 [%]). .

The command value determination unit 34 compensates for the output fluctuation of the wind power generator 2 according to the output power of the wind power generator 2 and charges / discharges so that the charging rate (SOC) of the secondary battery 31 is within a predetermined range. The command value is determined based on the control amount (correction control amount) acquired from the command value adjustment unit 33. Specifically, the command value determination unit 34 adds the output power [W] of the wind turbine generator 2 acquired from the power generation controller 10 and the correction control amount acquired from the command value adjustment unit 33 by the adder 37. The amount of power is limited by the limiter 38, and the output power of the wind power generator 2 is subtracted by the subtractor 40 from the amount of power smoothed by the smoothing filter 39. The value calculated in this way is limited to the value given to the power converter 32 by the inverter output limiter 41, and is a charge / discharge command for discharging if positive (+) and charging if negative (-). [W] is output as a control amount (charge / discharge command value).
The battery control device 30 outputs an output command value corresponding to the charge / discharge command value thus obtained to the power converter 32 and controls the power converter 32.

Further, the battery control device 30 is configured such that the larger the gain set by the command value adjustment unit 33, the smaller the absolute value of the charge / discharge command value of the secondary battery 31 with respect to the amount of power (output power) generated by the wind power generator 2. To control.
Specifically, the battery control device 30 increases the correction control amount for the command value determining unit 34 as the gain set by the command value adjusting unit 33 is increased, and the absolute value of the subtraction result in the subtractor 40 is increased. Becomes smaller. That is, reducing the output command value for the secondary battery 31 leads to suppression of the temperature rise of the secondary battery 31.

  The power converter 32 is a bidirectional inverter that converts alternating current and direct current, and for example, direct current power stored in the secondary battery 31 for alternating charge and discharge command values determined by the battery control device 30 is alternating current. It is converted into electric power and discharged from the secondary battery 31. Further, the power converter 32 converts AC power acquired from the wind power generator 2 or the power system 6 into DC power in order to obtain the charge / discharge command value determined by the battery control device 30, and converts the converted power into two. Output to the secondary battery 31 to charge the secondary battery 31.

Next, the operation of the battery control device 30 according to the present embodiment will be described.
When the power is generated by natural energy (the power is generated, the sign is +) and the output power information of the wind power generator 2 is obtained by the power generation controller 10, the output power information is output from the power generation controller 10 to the battery control device 30. Is done. In addition, information on the temperature of the secondary battery 31 and information on the charging rate (SOC) of the secondary battery 31 are input to the battery control device 30.

  The SOC target value is subtracted from the SOC current value of the secondary battery 31, and the subtraction result is multiplied by the gain read from the gain information 35 according to the acquired temperature of the secondary battery 31, and the charging rate (SOC) is calculated. A correction control amount is obtained. Further, the information on the output power generated by the wind power generator 2 and the correction control amount of the charging rate (SOC) are added, the power amount is limited by the limiter 38, and the smoothed power amount is obtained. The value of the output power obtained by the wind turbine generator 2 is subtracted from the smoothed power amount taking into account the correction control amount of the charging rate (SOC) determined according to the temperature, and the subtraction result is the inverter output limiter 41. Therefore, the charge / discharge command value [W] is determined. If the sign of the charge / discharge command value [W] is plus (+), control is performed in the direction in which the secondary battery 31 is discharged. If the sign is minus (−), control is performed in the direction in which the secondary battery 31 is charged. To do.

  Here, an example of the result obtained when the gain Kp of the battery control device 30 according to the present embodiment is adjusted according to the temperature and when the gain Kp is not adjusted according to the temperature will be described with reference to FIG. In FIG. 3, the horizontal axis represents time, the left vertical axis represents output power [%], and the right vertical axis represents charge rate (SOC) [%]. Here, the mark ◆ in FIG. 3 represents the input power from the wind power generator 2, the mark x represents the charge / discharge amount of the secondary battery 31 obtained when the gain is not adjusted according to the temperature, and the mark * represents the temperature. The charging rate (SOC) obtained when the gain is not adjusted, and the ● mark is the combined output of the wind power generator 2 and the secondary battery 31 obtained when the gain is not adjusted according to the temperature. The charge / discharge amount of the secondary battery 31 obtained when the gain is adjusted according to the temperature, the mark ◇ is the charge rate (SOC) obtained when the gain is adjusted according to the temperature, and the mark ■ is the temperature The combined output of the wind power generator 2 and the secondary battery 31 obtained when the gain is adjusted.

  When the gain corresponding to the temperature of the secondary battery 31 is not set, when the input power of the wind turbine generator 2 fluctuates, the charge rate (SOC) is leveled to the SOC target value (for example, 50 [%]). Control that satisfies the requirements of the power system 6 is performed. That is, by setting the gain Kp for maintaining the SOC target value in the command value adjustment unit 33, the charge / discharge amount for obtaining an output as indicated by x is determined, and the charging rate of the secondary battery 31 ( SOC) is maintained at the target charging rate of 50%. Thereby, the combined output of the wind power generator 2 and the secondary battery 31 is stabilized.

  On the other hand, when the gain adjusted according to the temperature is set in the command value adjustment unit 33 as in the present embodiment, even if the input power of the wind turbine generator 2 fluctuates, the temperature The higher the value is, the larger the gain is set, which limits the amount of charge / discharge of the secondary battery 31 (as indicated by the asterisk) as compared with the case where the temperature is not adjusted. As a result, the gain is controlled to be close to the SOC target value although the value may slightly deviate from the charging rate (SOC) when the temperature is not adjusted. In addition, the combined output of the wind power generator 2 and the secondary battery 31 fluctuates due to the effect of limiting the charge / discharge amount of the secondary battery 31 (marked with ■), but the request from the power system 6 side is allowed. It is controlled to be within the range. Although there is a fluctuation in the combined output of the wind power generator 2 and the secondary battery 31, the fluctuation is not a problem because it is controlled so as to be within the allowable range required by the power system 6. Rather, since the gain adjusted according to the temperature of the secondary battery 31 is set, the temperature rise of the secondary battery 31 can be suppressed, so that the temperature of the secondary battery 31 exceeds the upper limit value. Since the secondary battery 31 is not stopped, the effect that the charge / discharge operation of the secondary battery 31 can be continued is obtained.

As described above, according to the battery control device 30 and the control method and the power storage system 1 including the battery control device 30 according to the present embodiment, the gain Kp adjusted according to the temperature of the secondary battery 31 is the SOC current value. The charge / discharge command value of the secondary battery 31 is adjusted by multiplying the difference from the SOC target value and controlling the SOC current value to approach the SOC target value. Moreover, the gain set by the gain information 35 of the command value adjustment unit 33 is set to an appropriate gain so as to obtain a charge / discharge command value that suppresses the temperature rise of the secondary battery 31, and the temperature of the secondary battery 31 is set. The higher the value, the larger the value. Thereby, even when the secondary battery 31 is deteriorated and the temperature of the secondary battery 31 is changed, the secondary battery 31 is controlled so as to limit the charge / discharge amount and reduce the control amount. The charging / discharging requirement can be relaxed, and the temperature rise can be suppressed so as to prevent the secondary battery 31 from reaching an upper limit value that cannot be used due to temperature conditions. Thereby, the charging / discharging operation of the secondary battery 31 can be continued, which leads to suppression of a reduction in the operating rate of the power storage system 1.
Further, the present invention pays attention to the fact that the secondary battery 31 is not required to be strictly leveled (for example, the charge rate 50 [%]), and the charge rate of the secondary battery 31 is somewhat leveled. Even if lost, priority is given to suppressing the temperature rise of the secondary battery 31 while keeping the output fluctuation within an allowable range.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. The battery control device 30 of the present embodiment is different from the above-described embodiment in that it further includes a change rate determination unit (change rate determination means) 42 that determines the magnitude of the change rate with respect to time of the temperature of the secondary battery 31. . Hereinafter, with respect to the battery control device 30 of the present embodiment, description of points that are common to the first embodiment will be omitted, and differences will be mainly described.

FIG. 4 is a functional block diagram of the battery control device 30 according to the present embodiment.
The battery control device 30 includes a command value adjustment unit 33 and a command value determination unit 34.
The command value adjustment unit 33 includes a change rate determination unit 42.
The change rate determination unit 42 determines whether or not the change rate of the temperature of the secondary battery 31 with respect to time is smaller than the first predetermined value, and outputs the determination result to the command value adjustment unit 33.
When the change rate determination unit 42 determines that the change rate is equal to or higher than the first predetermined value, the command value adjustment unit 33 is multiplied by the gain when the change rate is smaller than the first predetermined value. Set a larger gain.

Specifically, the command value adjustment unit 33 includes other gain information 43 in addition to the gain information 35 described in the first embodiment.
For example, as shown in FIG. 4, when the rate of change of the temperature with respect to time is smaller than the first predetermined value, the gain is 1 when the temperature is 35 ° C., the gain is 1.5 when the temperature is 38 ° C. The gain is read from the gain information 35 set as described above. When the rate of change of temperature with respect to time is equal to or greater than the first predetermined value, the gain is 1.5 when the rate of change of temperature is 2.0, and the gain is 2.0 when the rate of change of temperature is 2.5. The gain is read from the other gain information 43 set as follows. The gain read in this way is set to the gain Kp as a priority signal.

In this way, the gain information 43 is associated with the rate of change of temperature and the gain, and is a gain greater than the gain set when the rate of change of temperature is smaller than the first predetermined value. The larger the change rate, the larger the gain.
The gain information 43 will be described as being preliminarily examined by the measurement simulator and stored in the storage unit (not shown) of the command value adjustment unit 33. However, the present invention is not limited to this, and the power storage system 1 is in operation. It is good also as tuning and setting suitably.
The command value determination unit 34 determines the charge / discharge command value based on the correction control amount output from the command value adjustment unit 33.

  Thus, when the rate of change of the temperature of the secondary battery 31 is equal to or higher than the first predetermined value, the charge rate correction control amount is multiplied by a larger gain than when the rate of change is smaller than the first predetermined value. Therefore, the battery control device 30 can reduce the charge / discharge control amount of the secondary battery 31 (compared to the case where the temperature change rate is smaller than the first predetermined value). Thereby, in the situation where the rapid temperature change of the secondary battery 31 is assumed, since the charge / discharge amount of the secondary battery 31 is more limited, the temperature rise of the secondary battery 31 can be reliably suppressed. .

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. The battery control device 30 of the present embodiment is different from the above-described embodiment in that the control result based on the determined charge / discharge command value is fed back. Hereinafter, with respect to the battery control device 30 of the present embodiment, description of points that are common to the first embodiment and the second embodiment will be omitted, and different points will be mainly described.

  As described above, when the correction control amount of the charging rate (SOC) is calculated, the gain Kp is adjusted according to the temperature, so that the secondary battery 31 is affected by the adjustment corresponding to the temperature. As a result, the output fluctuates, and as a result, the combined output (measured combined output) of the wind power generator 2 and the secondary battery 31 slightly deviates from the target output (target combined output) that is the target combined output. (See the graph with ■ in Fig. 3). Further, the charging rate (SOC) may slightly deviate from the target charging rate (for example, 50 [%]). In the present embodiment, control is performed so that such combined output (measured combined output) approaches the target output (target combined output).

FIG. 5 shows a schematic configuration diagram of the power storage system 1 according to the present embodiment.
As shown in FIG. 5, the power storage system 1 according to this embodiment includes a wind power generation device (power generation device) 2, a power storage device 3, and a power generation controller 10, and is connected to the power system 6. Yes. The power generation controller 10 outputs the output of the wind power generation device acquired from the connection point to the power storage device 3. In addition, information on the actually measured power value (P_mes) measured from the power system 6 side is input to the battery control device 30 of the power storage device 3.

The battery control device 30 is measured such that the difference between the target output and the combined output obtained by adding the power generation amount (output power) by the wind power generation device 2 and the charge / discharge amount of the secondary battery 31 is within the allowable range. The combined output on the power system 6 side is feedback-controlled to the command value adjustment unit 33 to adjust the gain Kp.
Specifically, the integrated value of the difference between the combined output (measured combined output) and the target output (target combined output) for a predetermined period is ΔW_mes, and the difference between ΔW_mes and the allowable integrated value for a predetermined period is ΔW_accept. The target output is defined as P_target and is defined as the following equation (1).

ΔW_mes = ∫ (P_mes−P_target) dt (1)
Here, the predetermined period (integration interval) is t1 to t2, and ΔW_accept and P_target are predetermined values.
When ΔW_accept− | ΔW_mes |> 0, the gain Kp is maintained as it is.
When ΔW_accept− | ΔW_mes | <0, the gain Kp is changed.

  In FIG. 6, the horizontal axis represents time [second], and the vertical axis represents output power [PU]. The horizontal line at the position where the output is 50 [PU] indicates the target output value, the ■ mark in FIG. 6 indicates the actually measured power value (synthesized output), and the difference is indicated as the integrated value ΔW_mes. Yes.

In the present embodiment, the gain is set as follows. For example, when the gain Kp before the change is set to 1.0 when the gain Kp is 35 ° C. and 1.5 when the gain Kp is 38 ° C., the gain Kp after the change is set to 0.5 when the temperature is 35 ° C. The gain is set to 1.0. In other words, when the gain Kp is changed, the output command value (charge / discharge command value) is adjusted with the previously set gain Kp, so that the measured power value deviates from the output target value beyond the allowable range. Therefore, by changing the gain to a value that is smaller than the currently set gain Kp, the actually measured power value is brought closer to the output target value.
Thus, according to the present embodiment, it is determined that the combined output deviates from the target output based on the charge / discharge command value of the secondary battery 31 adjusted to suppress the temperature increase of the secondary battery 31. In this case, since the degree of suppression of the temperature rise of the secondary battery 31 can be relaxed by feedback control of the actually measured power value, the temperature rise of the secondary battery 31 can also be suppressed while approaching the target output. .

[Fourth Embodiment]
Next, the 4th Embodiment of this invention is described using FIG.1 and FIG.7. The control device of this embodiment is different from the above-described embodiment in that it includes a temperature determination unit. Hereinafter, with respect to the battery control device 30 of the present embodiment, description of points that are common to the first embodiment, the second embodiment, and the third embodiment will be omitted, and different points will be mainly described.

FIG. 7 is a schematic configuration diagram of the power storage system 1 according to the present embodiment.
In the present embodiment, the case where the battery control device 30 is applied to a power storage system provided in a container will be described as an example, but the present invention is not limited to this. In the following description, the front / rear, upper / lower / left / right directions are based on the front / rear, upper / lower / left / right directions shown in FIG.
FIG. 7 is a perspective view of a schematic configuration of a container to which the control device according to the present embodiment is applied. As shown in FIG. 7, the power storage system 11 includes a control device 10, a plurality of storage battery modules 20, an air conditioning unit (air conditioner) 13, and an air supply duct 14 in a container (closed space) 10. ing. The storage battery module 20 includes one or more secondary batteries 31 so as to satisfy a predetermined voltage and a storage capacity. Moreover, the heat by charging / discharging of the storage battery module 20 is cooled by the air conditioning unit 13 and the air supply duct 14.

Inside the container 12, a plurality of storage battery modules 20 are arranged side by side on a vertical and horizontal matrix. The number of storage battery modules 20 varies depending on the required voltage, such as several tens to several hundreds, and the rows and columns of the matrix also differ. An aggregate of a plurality of storage battery modules 20 is defined as a storage battery module group. In addition, the number of storage battery modules 20, an arrangement position, etc. are not specifically limited.
The air supply duct 14 is a header that distributes cold air to the storage battery module group, and a plurality of slits 15 (blowing ports) are opened downward so that the cold air is uniformly supplied. Each storage battery module 20 is cooled by supplying cold air from the slit 15. A part of the cold air supplied from the air supply duct 14 is moved in the direction of the air flow R by the fan of each storage battery module 20 (passing through each storage battery module 20 from the rear to the front), and the inside of the storage battery module 20 is To be cooled.

Further, a part of the cold air supplied from the slit 15 of the air supply duct 14 flows out into the container 12 without passing through each storage battery module 20, and each part in the container 12 is cooled. The air that has passed through each storage battery module 20 and has increased in temperature, and the air that has increased in temperature by passing through the inside of the container 12 returns to the air conditioning unit 13 through the exhaust port 23, and is cooled again. Air is circulated so as to be supplied to each storage battery module 20 and the container 12.
The air conditioning unit 13 adjusts the indoor temperature of the container, and may be installed inside the container 12 as shown in FIG. 7 or installed outside the container 12 (not shown). Good. In FIG. 7, the air conditioning unit 13 is installed above the storage battery module 20. However, the air conditioning unit 13 may be installed on the side surface or below the storage battery module 20 regardless of the inside or outside of the container 12. The air conditioning unit 13 can use a commercially available air conditioning unit.

When the storage battery module 20 is installed in the container 12, the room temperature is adjusted by the air conditioning unit 13. In this case, the temperature of the storage battery module 20 is affected by the room temperature in the closed space. That is, when the room temperature changes due to the malfunction of the air conditioning unit 13 or the like, the temperature of the secondary battery 31 constituting the storage battery module 20 may also change, and the two prepared in the first embodiment described above. It is assumed that appropriate control cannot be performed with the gain Kp of the gain information 35 set corresponding to the temperature of the secondary battery 31.
In the present embodiment, the battery control device 30 is provided with a temperature determination unit that determines a temperature difference between the room temperature of the container 12 and the temperature of the secondary battery 31.
When it is determined by the temperature determination unit that the temperature difference between the room temperature of the container 12 and the temperature of the secondary battery 31 is equal to or greater than the second predetermined value, the battery control device 30 performs a desired operation by the air conditioning unit 13. Therefore, the adjustment amount of the charge / discharge command value by the command value adjustment unit 33 is increased.

Specifically, the command value adjustment unit 33 sets the value of the gain Kp to be larger as the temperature difference between the room temperature of the container 12 and the temperature of the secondary battery 31 increases.
As described above, the temperature determination unit is provided, and the adjustment amount of the charge / discharge command value is increased when it is determined that the temperature difference between the room temperature of the container 12 and the temperature of the secondary battery 31 is equal to or greater than the second predetermined value. By setting the value of the gain Kp as large as possible, the influence of the room temperature is reduced with respect to the combined target output and the target temperature of the secondary battery 31, the temperature rise of the secondary battery 31 is suppressed, and the charging rate ( Control is performed so that (SOC) falls within a predetermined range.

  Note that the first embodiment to the fourth embodiment may be combined as appropriate. For example, the configuration of the third embodiment may be combined with the configuration of the first embodiment, or the configuration of the second embodiment and the configuration of the fourth embodiment may be combined with the configuration of the first embodiment. Also good.

1 Power Storage System 6 Power System 12 Container (Closed Space)
13 Air conditioning unit (air conditioner)
20 Battery module 30 Battery control device 31 Secondary battery 33 Command value adjustment unit 34 Command value determination unit 35 Gain information 42 Change rate determination unit 43 Gain information

Claims (9)

A control device that controls charging and discharging of a secondary battery connected to a power generation device that is connected to an electric power system and generates power by natural energy,
The difference between the current value that is the current charging rate of the secondary battery and the target charging rate of the secondary battery is multiplied by a gain, and the current value is controlled so as to approach the target charging rate, and the secondary battery Comprising command value adjusting means for adjusting the charge / discharge command value;
The command value adjusting means adjusts the gain according to the temperature of the secondary battery. In accordance with the output of the power generation device, there is provided command value determination means for compensating the output fluctuation of the power generation device and determining the charge / discharge command value so that the charging rate of the secondary battery is within a predetermined range. ,
The control device according to claim 1, wherein the command value determining unit determines the charge / discharge command value based on a control amount acquired from the command value adjusting unit.   The command value adjusting means sets a larger gain as the temperature of the secondary battery becomes higher. The larger the gain set by the command value adjusting means, the larger the secondary power with respect to the amount of power generated by the power generator. The control device according to claim 1, wherein control is performed so that an absolute value of the charge / discharge command value of the battery is reduced. The command value adjustment means comprises a change rate determination means for determining whether a change rate of the temperature of the secondary battery with respect to time is smaller than a first predetermined value,
The command value adjusting means, when the change rate determining means determines that the change rate is greater than or equal to a first predetermined value, when the change rate is smaller than the first predetermined value with respect to temperature. The control device according to claim 1, further comprising setting the gain larger than the gain to be multiplied.   The measured power so that a difference between a combined output obtained by adding the amount of power generated by the power generation device and the charge / discharge amount of the secondary battery and a target output that is the target combined output is within an allowable range. The control apparatus according to claim 1, wherein feedback control is performed on a combined output on a system side to adjust the gain.   The control device according to any one of claims 1 to 5 is installed in a closed space in which a room temperature is adjusted by an air conditioner, and the temperature of the closed space and the temperature of the secondary battery are When the difference is equal to or greater than a second predetermined value, the control device determines that the air conditioner is not performing a desired operation and increases the adjustment amount of the charge / discharge command value by the command value adjusting means. A control device according to any one of claims 1 to 6;
A power storage system including a secondary battery that is connected to a power system and connected to a power generation device that generates power using natural energy.   The power storage system according to claim 7, further comprising an air conditioner that adjusts an indoor temperature of a closed space in which the control device is disposed. A control method for controlling charging and discharging of a secondary battery that is connected to a power system and connected to a power generator that generates power by natural energy,
The difference between the current value that is the current charging rate of the secondary battery and the target charging rate of the secondary battery is multiplied by a gain that is adjusted according to the temperature of the secondary battery, and the current value is calculated as the target charging value. The control method which adjusts the charging / discharging command value of the said secondary battery by controlling so that it may approximate to a rate.

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