JP2017135865A - Power storage system - Google Patents

Abstract

An object of the present invention is to obtain power for monitoring control and protection control without charge / discharge loss of a power storage unit, and to reduce power consumption for monitoring control and system protection control of the power storage unit. A power supply device 13 supplies power for driving auxiliary devices 19a and 19b of the system and power for operating a monitoring control device 23 to the auxiliary devices 19a and 19b and the monitoring control device 23 for monitoring. The control device 23 is connected to the power storage unit 11 having the storage battery 18 and the power system 15 via the power conversion device 21 when the power used by the load 14 is small, when there is a charge command, or Depending on the operation mode of the operation schedule, the AC power of the power system 15 is converted to DC power and charged to the power storage unit 11, and when the load is large or when there is a discharge command, or depending on the operation mode of the operation schedule of the power storage unit 11 DC power is converted into AC power and discharged to the load 14, and monitoring control of the entire system including the power storage unit 11 is performed. [Selection] Figure 1

Description

  The present invention relates to a power storage system that is connected to and operated by an electric power system.

  Power storage systems are installed in power generation companies, renewable energy power generation companies, power transmission / distribution companies, customers, etc., to supply power in response to the peak demand that fluctuates over time in power generation companies. Used by renewable energy generators for smoothing of renewable energy generation, used by transmission / distribution operators for power quality improvement (frequency adjustment and voltage adjustment) in the power grid, etc. It is used for load leveling of electric power in customers.

  Lithium-ion rechargeable batteries have low internal resistance and low voltage fluctuation and temperature rise due to charging / discharging at large currents. Not only mobile objects such as EVs (Electric Vehicles) but also large power storage systems (Energy Storage System, ESS). A lithium ion secondary battery has a higher energy density than other secondary batteries, and uses an organic solvent as an electrolytic solution, so there is a risk of ignition at high temperatures. For this reason, in the power storage and storage system to which the lithium ion secondary battery is applied, monitoring control is performed to ensure the safety of the lithium ion secondary battery. The power consumption for the monitoring control of the lithium ion secondary battery is unexpectedly large, and is at a level that cannot be ignored by the power storage system.

  Here, to reduce the power consumption for monitoring and controlling the lithium ion secondary battery, when the storage cell is constantly monitored by the control circuit and the occurrence of the abnormality is detected, the irreversible display means is operated to make it irreversible and visually recognized. There is one that causes a possible state change and then continues to display the fact of occurrence of abnormality without accompanying power consumption of the storage cell (see, for example, Patent Document 1).

  The monitoring circuit is set to the sleep mode when the current of the secondary battery is below the specified value, the microcomputer operates at a low speed to reduce the internal power consumption, and the first when the battery pack is connected to the charger. When the sleep mode is set and the battery pack is not connected to the charger, the second sleep mode with the longest measurement interval is set to suppress internal power consumption (for example, see Patent Document 2).

JP 2009-199950 A JP-A-11-283777

  However, although the thing of patent document 1 does not consume electric power for the display of abnormality occurrence of an electrical storage cell, the calculation for the monitoring control of a lithium ion secondary battery is performed continuously, and a monitoring control apparatus monitors It requires power consumption for control.

  Patent Document 2 discloses a secondary battery for a portable electronic device, in which the microcomputer operates at a low speed when the current of the secondary battery is equal to or lower than a specified value to reduce internal power consumption. Since the device is always supplied with power from the secondary battery, and the power supplied to the monitoring and control device is through the secondary battery, there is a loss required to charge and discharge the secondary battery. doing.

  On the other hand, since the secondary battery of the power storage unit is large in the power storage system, in addition to the power consumption of the monitoring control device for monitoring control, system protection control such as cooling and heating of the secondary battery, cooling of the power conversion device, etc. Power consumption is also required. For example, most of the lithium-ion secondary battery has an endothermic characteristic during charging and a heat-generating characteristic at the time of discharging. Therefore, the secondary battery needs to be cooled or heated depending on the operation mode of the secondary battery. In addition, the power conversion device needs to be cooled, and a control power supply for the protection control device is also required.

  An object of the present invention is to obtain power for monitoring control and protection control without charge / discharge loss of the power storage unit, and to reduce power consumption for monitoring control and system protection control of the power storage unit It is to provide a storage system.

  The power storage system according to the invention of claim 1 includes a power storage unit having a storage battery in which a plurality of lithium ion battery cells are stacked, a load connected between a power system and the power storage unit, It has a determined operation schedule, inputs the power consumption of the load, a charge command or discharge command for the power storage unit from the outside, and based on the operation schedule, the charge command or discharge command, the power consumption of the load A monitoring control device that controls the power storage location and performs monitoring control of the entire system including the power storage unit, and operates according to a command from the monitoring control device, and there is a charge command when the power consumption of the load is small Or when the operation mode of the operation schedule of the power storage unit converts the AC power of the power system into DC power and charges the power storage unit, and uses the load A power conversion device that converts the DC power of the power storage unit into AC power and discharges it to the load according to the operation mode of the operation schedule of the power storage unit when the power is large or when there is a discharge command; And a power supply device that supplies power for driving the machine and power for operating the monitoring control device to the auxiliary device and the monitoring control device.

  The power storage system according to a second aspect of the present invention is the power storage system according to the first aspect, wherein the monitoring control unit is configured such that an operation mode of the power storage unit is a charge mode in which the power storage unit is charged with power from the power system, and the power storage unit Standby mode in which the calculation processing interval for the monitoring control is shortened and / or the number of monitoring control targets is increased and the charging / discharging operation of the power storage unit is awaited when the discharge mode is to discharge power to the load from When the charging / discharging operation of the power storage unit is stopped, the calculation processing interval for the monitoring control is increased and / or the number of monitoring control targets is reduced.

  The power storage system according to a third aspect of the present invention is the power storage system according to the first aspect, wherein the monitoring control unit is configured such that an operation mode of the power storage unit is a charge mode in which the power storage unit is charged with power from the power system or the power storage unit. When the battery voltage of the power storage unit, the battery current, or the battery temperature is large, the calculation processing interval for the monitoring control is shortened and / or monitored. The number of control objects is increased, and when the change in battery voltage or battery current of the power storage unit or the change in battery temperature is small, the calculation processing interval for the monitoring control is increased and / or the number of monitoring control objects is reduced. To do.

  The power storage system according to a fourth aspect of the present invention is the power storage system according to the first aspect, wherein the monitoring control unit is configured to wait for the operation mode of the power storage unit to wait for the start of charge / discharge operation of the power storage unit or the power storage system. When the charging / discharging operation of the unit is stopped, the calculation interval for the monitoring control is increased and / or the number of monitoring control objects is reduced after a certain time, and the standby mode or the stop mode When the operation mode of the predetermined operation schedule is in advance before the power storage unit is charged with power from the power system or the discharge mode is discharged from the power storage unit to the load. The calculation interval for the monitoring control is shortened and / or the number of monitoring control objects is increased.

  The power storage system according to a fifth aspect of the present invention is the power storage system according to any one of the first to fourth aspects, wherein the auxiliary device is an air conditioning facility that maintains a temperature of the power storage unit and the power conversion device at a predetermined temperature. The monitoring control unit precedes the operation mode of the operation schedule before becoming a discharge mode for discharging power from the power storage unit to the power system or a charge mode for charging power from the power system to the power storage unit. The air conditioner is driven, and the temperature of the power storage unit is controlled so that the temperature of the power storage unit becomes a predetermined temperature when the operation mode of the power storage unit becomes the discharge mode or the charge mode. .

  A power storage system according to a sixth aspect of the present invention is the air storage system according to any one of the first to fourth aspects, wherein the auxiliary device is an air conditioning facility that maintains the temperature of the power storage unit and the power converter at a predetermined temperature. The monitoring control unit drives the air conditioning equipment after completion of a discharge mode for discharging power from the power system to the power storage unit or after completion of a charge mode for charging power from the power system to the power storage unit, The temperature of the power storage unit is controlled so that the temperature of the power storage unit becomes a predetermined temperature.

  According to the first aspect of the present invention, the power for driving the auxiliary equipment of the system and the power for operating the monitoring control apparatus are supplied to the auxiliary equipment and the monitoring control apparatus from the power supply device provided independently from the power storage unit. Since power is supplied, power for monitoring control and protection control can be obtained without charge / discharge loss of the power storage unit.

  According to the invention of claim 2, in the charge / discharge mode in which the power storage unit requires highly reliable protection monitoring, the calculation processing interval for monitoring control is shortened and / or the number of monitoring control objects is increased, and the standby is not performed In the stop mode, the calculation processing interval for monitoring control is increased and / or the number of monitoring control objects is reduced, so that power consumption for monitoring control can be reduced.

  According to the invention of claim 3, in the charge / discharge mode in which highly reliable protection monitoring is required for the power storage unit, when the battery voltage change or battery current change or battery temperature change of the power storage unit is large, Since the arithmetic processing interval for monitoring control is shortened and / or the number of monitoring control objects is increased, and when not so, the arithmetic processing interval for monitoring control is increased and / or the number of monitoring control objects is decreased. Power consumption can be reduced.

  According to the fourth aspect of the present invention, when the standby mode is set, the operation interval for monitoring control is increased and / or the number of monitoring control objects is reduced after a certain period of time, so that the safety of monitoring control can be improved. Yes, because the operation interval for the monitoring control is shortened in advance and / or the number of monitoring control objects is increased before the operation mode of the predetermined operation schedule becomes the charge / discharge mode. Can be provided.

  According to the invention of claim 5, the monitoring control unit drives the air conditioning equipment that is an auxiliary machine before the operation mode of the operation schedule becomes the charge / discharge mode, and the operation mode of the power storage unit becomes the charge / discharge mode. Since the temperature of the power storage unit is controlled in advance so that the temperature of the power storage unit becomes a predetermined temperature at the time, the temperature change due to heat absorption or heat generation of the storage battery can be easily absorbed.

  According to the invention of claim 6, the monitoring control unit drives the air conditioning equipment after the end of the charge / discharge mode and controls the temperature of the power storage unit so that the temperature of the power storage unit becomes a predetermined temperature. As a whole, power consumption for monitoring control can be reduced without consuming power from the power supply device during charging / discharging.

The block diagram of the electric power storage system which concerns on embodiment of this invention. The graph which shows an example of the operation mode of the electric power storage system which concerns on embodiment of this invention. The graph which shows an example of the voltage charge rate characteristic of the storage battery of the electrical storage part in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows Example 1 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows another example of Example 1 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows Example 2 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows another example of Example 2 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows Example 3 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows another example of Example 3 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows another another example of Example 3 of the arithmetic processing for the supervisory control in the supervisory control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows an example of Example 4 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention. The flowchart which shows an example of Example 5 of the arithmetic processing for the monitoring control in the monitoring control apparatus in the electric power storage system which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a power storage system according to an embodiment of the present invention. In FIG. 1, the case where it uses for the load leveling of the electric power in a consumer in the consumer is shown. The consumer has a power storage unit 11, a power storage unit operation device 12, and a power supply device 13, and attempts to level the power used by the customer load 14.

  The customer's load 14 is connected between the power system 15 and the power storage unit 11 through a circuit breaker 16, and power is supplied from the power system 15 through a power receiving transformer 17 in normal times. When the power supplied from the power system 15 to the load 14 exceeds a predetermined first predetermined power (discharge start power) (when the power used by the load 14 is large), the power stored in the power storage unit 11 To the load 14. The first predetermined power is a value in which the power used by the load is close to the contract power of the consumer, and is slightly smaller than the contract power. Further, when the power used by the load 14 is equal to or lower than a predetermined second predetermined power (power storage start power) (when the power used by the load 14 is small), the power from the power system 15 is stored in the power storage unit 11. . The second predetermined power is a value at which the power saving of the load is sufficiently smaller than the contract power of the consumer. For example, power from the power system 15 is stored in the power storage unit 11 at midnight. Thereby, leveling of the electric power which the load 14 of a consumer uses is aimed at.

  The power storage unit 11 has a storage battery 18 in which a plurality of lithium ion battery cells are stacked, and has an air conditioner for maintaining the temperature of the storage battery 18 at a predetermined temperature as an auxiliary machine 19a. Lithium-ion batteries have a heat generation characteristic during discharge and a high temperature, and during charging many endothermic characteristics and a low temperature keep the temperature of the storage battery 18 at a predetermined temperature to prevent the deterioration of the storage battery 18 from progressing. To do. The predetermined temperature is a temperature range having a width. This is to prevent frequent start and stop of the air conditioning equipment. The same applies to the following description.

  The power storage unit operating device 12 controls charging / discharging of the power storage unit 11. The power storage unit operation device 12 includes a protection device 20 that protects the system, a power conversion device 21 that performs AC / DC conversion of power, an interconnection transformer 22 that connects the power conversion device 21 to the power system 15 via the power receiving transformer 17, The monitoring control device 23 that performs monitoring control of the entire system including the unit 11 and an air conditioning facility as an auxiliary machine 19b for keeping the temperature of the power conversion device 21 at a predetermined temperature are provided.

  The protective device 20 inputs the voltage of the load 14 detected by the voltage detector 24 and the current of the load 14 detected by the current detector 25, and when an accident occurs in the system from the power receiving transformer 17 to the storage battery 18. Opens the circuit breaker 26.

  The power converter 21 is an AC / DC converter that converts AC power into DC power and DC power into AC power. When the power storage unit 11 is charged with power, the AC power of the power system 15 is converted into DC power and stored. The storage battery 18 of the unit 11 is charged. On the other hand, when electric power is discharged from the power storage unit 11, the DC power stored in the storage battery 18 of the power storage unit 11 is converted into AC power and discharged to the load 14.

  The monitoring control device 23 has a predetermined operation schedule of the power storage unit 11. In normal times, the battery 18 is controlled based on the operation schedule, but the battery 18 may be controlled based on the power used by the load 14. For example, when the power used by the load 14 becomes large, that is, when the power supplied from the power system 15 to the load 14 exceeds a predetermined first predetermined power, the power is stored in the power storage unit 11. Electric power is supplied to the load 14. Further, when the power used by the load 14 becomes small, that is, when the power used by the load 14 is equal to or lower than a predetermined second predetermined power, the power from the power system 15 is stored in the power storage unit 11.

  Further, the power storage location 18 may be controlled based on a charge command or a discharge command for the power storage unit 11 from the outside. External charge commands and discharge commands may be manually input by the operator of the power storage system, or other supervisory controls such as power load leveling and power quality improvement (frequency adjustment and voltage adjustment) It may be input from the device.

  The monitoring control device 23 inputs the open / close state of the circuit breakers 14, 26, the input / output value of power to the power storage unit 11, the voltage, current, and temperature that are the state quantities of the storage battery 18 of the power storage unit 11. 11 performs the monitoring control of the entire system including 11. For example, the monitoring control device 23 confirms that the circuit breaker 26 is closed when the operation mode of the predetermined operation schedule becomes the charging mode, and issues a command to the power conversion device 21 to start charging. When the storage battery 18 of the power storage unit 11 is fully charged (charging rate upper limit threshold in the vicinity of full charging) or when the charging mode is ended in the operation schedule, the power conversion device 21 is instructed to be charged. Exit. On the other hand, when the operation mode of the predetermined operation schedule becomes the discharge mode, it is confirmed that the circuit breaker 16 is closed, a command is issued to the power converter 21 to start charging, and the storage battery of the power storage unit 11 When 18 is completely discharged (charge rate lower limit threshold in the vicinity of complete discharge) or when the discharge mode is ended in the operation schedule, a command is issued to the power converter 21 to complete the discharge.

  Furthermore, when the power used by the load 14 is zero or when there is a charge command to the power storage unit 11 from the outside, the monitoring control device 23 issues a command to the power conversion device 21 to convert the AC power of the power system 15 to DC power. And the power storage unit 11 is charged. On the other hand, when the amount of power used by the load 14 increases, that is, when the power used by the load 14 exceeds the discharge start power of the power storage unit 11 or when there is a discharge command to the power storage unit 11 from the outside, A command is issued to the power converter 21 to convert the DC power of the power storage unit 11 into AC power and discharge the load 14.

  Furthermore, the monitoring control device 23 drives the auxiliary machine 19a that is an air conditioning facility to control the storage battery 18 of the power storage unit 11 to maintain a predetermined temperature, and also drives the auxiliary machine 19b that is an air conditioning facility to drive the power storage unit operating device. The twelve power converters 21 are controlled to maintain a predetermined temperature.

  The power supply device 13 is an uninterruptible power supply (USP), and even when power from the power system 15 is cut off, the power supply device 13 continues to supply power to the connected devices without power failure for a certain period of time. Yes, the power supply 13 supplies power for driving the auxiliary machines 19a and 19b of the system and power for operating the protection device 20 and the monitoring control device 23. That is, in the embodiment of the present invention, the power to the auxiliary machines 19a and 19b, the protection device 20, and the monitoring control device 23 is supplied from the power supply device 13 instead of the storage battery 18 of the power storage unit 11. The power for monitoring control and protection control can be stably obtained by eliminating 11 charge / discharge losses.

  FIG. 2 is a graph showing an example of an operation mode of the power storage system according to the embodiment of the present invention. The operation mode of the power storage system includes a charge mode, a discharge mode, a standby mode, and a stop mode. The storage battery 18 of the power storage unit 11 of the power storage system is charged with power when in the charge mode, and when in the discharge mode. Discharge power. The standby mode is a state in which the apparatus is waiting in a state where it can immediately shift to the charge / discharge mode, and the stop mode is a state in which the operation is stopped.

  In FIG. 2, the charging mode is from 0 o'clock to 7 o'clock, the stop mode is from 7 o'clock to 10 o'clock, the discharge mode is from 10 o'clock to 18 o'clock, the standby mode is from 18 o'clock to 20 o'clock, and the charging mode is from 20 o'clock to 24 o'clock Shows the case.

  In the charge mode and the discharge mode, the storage battery 18 of the power storage unit 11 is in an operating state, and thus monitoring control is necessary. In the charging mode, the storage battery 18 of the power storage unit 11 has an endothermic characteristic and the temperature is lowered. Therefore, the air conditioning equipment as the auxiliary machine 19a is driven as necessary to hold the storage battery 18 of the power storage unit 11 at a predetermined temperature. In the case of a lithium ion battery, when the voltage is not controlled with high accuracy, the battery is likely to deteriorate, and when it is overcharged, it generates heat or ignites, so that highly reliable protection monitoring is required. Therefore, the monitoring control device 23 measures the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 and monitors and controls the storage battery 18 of the power storage unit 11.

  In the discharge mode, the storage battery 18 of the power storage unit 11 has a heat generation characteristic and the temperature becomes high. Therefore, the air conditioning equipment as the auxiliary machine 19a is driven as necessary to hold the storage battery 18 of the power storage unit 11 at a predetermined temperature. Even in the discharge mode, overdischarge leads to abnormal heat generation and high-reliability protection monitoring is required. Therefore, the monitoring control device 23 measures the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 to check the charge mode. Similarly to the case, the voltage of the storage battery 18 of the power storage unit 11 is monitored and controlled with high accuracy.

  On the other hand, in the standby mode and the stop mode, since the storage battery 18 of the power storage unit 11 is in an inoperative state, it is not always necessary to monitor and control the voltage with high accuracy as in the charge mode or the discharge mode. Abnormal heat generation due to deterioration of the 11 storage batteries 18 must be monitored.

  FIG. 3 is a graph showing an example of voltage charge rate characteristics of the storage battery of the power storage unit in the power storage system according to the embodiment of the present invention. FIG. 3 shows a characteristic curve C of voltage charge rate characteristics when the storage battery 18 of the power storage unit 11 is at a constant temperature. As shown in FIG. 3, the charging rate is 100% when fully charged, and the charging rate is 0% when fully discharged. From the charging rate 100% (full charge) to the charging rate A1%, the change rate of the characteristic curve C is large, and the change of the battery voltage with respect to the charging rate of the storage battery 18 of the power storage unit 11 is large. Hereinafter, this region is referred to as a large change rate region T1. On the other hand, from the charging rate A1% to the charging rate A2%, the change rate of the characteristic curve C is small, and the change of the battery voltage with respect to the charging rate is small. Hereinafter, this region is referred to as a small change rate region T2.

  The heat generation amount of the storage battery 18 of the power storage unit 11 is large in the large change rate region T1, and the heat generation amount is small in the small change rate region T2. In addition, as described above, if overcharge occurs, it generates heat or ignites, so charging is stopped at the charge rate upper limit threshold AU before full charge, and overdischarge leads to abnormal heat generation. It is desirable to stop discharging at the charging rate lower limit threshold AL.

  In the above description, the change rate large region T1 and the change rate small region T2 are determined by the change in the battery voltage with respect to the charging rate of the power storage unit, but the change rate large region T1 and the change rate small region are determined by the change in the battery current. T2 may be determined, or the change rate large region T1 and the change rate small region T2 may be determined by a change in battery temperature.

  FIG. 4 is a flowchart illustrating the first embodiment of the arithmetic processing for the supervisory control in the supervisory control device 23. As described above, in the case of a lithium ion battery, a highly reliable protection monitoring is required in the charge mode and the discharge mode, and the voltage must be controlled with high accuracy. As described above, the monitoring control device 23 determines whether or not the storage battery 18 of the power storage unit 11 of the power storage system is in the charge / discharge mode (S1). The interval is shortened (S2). In monitoring control of the storage battery 18 of the power storage unit 11, the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 are read in a short cycle as the state quantity to be monitored and controlled, and the charge rate and temperature of the storage battery 18 of the power storage unit 11 are read. Monitoring is performed, and charging is stopped when the charging rate reaches the charging rate upper limit threshold AU so as not to cause overcharging or overdischarging, and discharging is stopped when the charging rate reaches the charging rate lower limit threshold AL. Thereby, the safety | security of the storage battery 18 of the electrical storage part 11 is ensured.

  On the other hand, when the charging / discharging mode is not determined in the determination of step S1, the calculation processing interval for supervisory control is lengthened because it is the standby mode or the stop mode (standby stop mode) (S3). This is because the storage battery 18 of the power storage unit 11 is in an inoperative state when in the standby stop mode, and the voltage of the storage battery 18 of the power storage unit 11 is not controlled with high accuracy, and highly reliable protection monitoring is not required. Thereby, the power consumed by the monitoring control device 23 for monitoring control can be reduced.

  Further, instead of shortening the calculation processing interval for monitoring control in the charge / discharge mode and increasing the calculation processing interval for monitoring control in the standby stop mode, FIG. As shown, it is possible to increase the number of monitoring control targets in the charge / discharge mode and decrease the number of monitoring control targets in the standby stop mode. That is, when the charging / discharging mode is determined in step S1, the number of monitoring control targets is increased (S4), and when the standby stop mode is set, the number of monitoring control targets is decreased while leaving the important monitoring control targets (S5). For example, when the monitoring control target is voltage, current, and temperature, when in charge / discharge mode, all of these voltage, current, and temperature are monitored and controlled, and when in standby stop mode, for example, only temperature is monitored. It can be considered as a control target. This is because the temperature of the storage battery 18 is an important monitoring control target even in the standby stop mode.

  Further, as shown in FIG. 5, when the charging / discharging mode is determined in step S1, the calculation processing interval for monitoring control is shortened (S2), the number of monitoring control targets is increased (S4), and the standby stop mode is set. In such a case, the calculation processing interval for monitoring control may be increased (S3) and the number of monitoring control objects may be decreased (S5).

  FIG. 6 is a flowchart illustrating the second embodiment of the arithmetic processing for the supervisory control in the supervisory control device 23. The second embodiment is different from the first embodiment shown in FIG. 4 in the step S1 in which the voltage, current, and temperature of the storage battery 18 are acquired when the charge / discharge mode is determined in step S1, and the voltage of the storage battery 18; Step S7 for determining whether the current and temperature are in the large change rate region is additionally provided.

  6A, it is determined whether or not the storage battery 18 of the power storage unit 11 of the power storage system is in the charge / discharge mode (S1). When the storage battery 18 is in the charge / discharge mode, the voltage, current, and temperature of the storage battery 18 are determined. It is acquired (S6), and it is determined whether the voltage, current, and temperature of the storage battery 18 are in the large change rate region (S7). When the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 are in the large change rate region in the determination in step S7, the calculation processing interval for monitoring control is shortened (S2). That is, in the monitoring control of the storage battery 18 of the power storage unit 11, the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 are read in a short cycle as the state quantity to be monitored and controlled, and the storage battery 18 of the power storage unit 11 is monitored and controlled. . This is because the heat generation amount of the storage battery 18 of the power storage unit 11 is large in the large change rate region, and highly reliable protection monitoring of the voltage, current, and temperature of the storage battery 18 of the power storage unit 11 is required. Further, the charging is stopped when the charging rate reaches the charging rate upper limit threshold AU so as not to overcharge or over discharge, and the discharging is stopped when the charging rate becomes the charging rate lower limit threshold AL.

  On the other hand, when the charge / discharge mode is not determined in step S1 and when the change rate is not large in the determination in step S7, the calculation processing interval for monitoring control is lengthened (S3). When it is not the charge / discharge mode, it is the standby stop mode, and when it is not the large change rate region, it is the small change rate region, and the amount of heat generated by the storage battery 18 of the power storage unit 11 is small. This is because highly reliable protection monitoring of current and temperature is not required. Thereby, the power consumed by the monitoring control device 23 for monitoring control can be reduced.

  Further, instead of shortening the calculation processing interval for monitoring control in the charge / discharge mode and increasing the calculation processing interval for monitoring control in the standby stop mode, FIG. As shown, it is possible to increase the number of monitoring control targets in the charge / discharge mode (S4) and decrease the number of monitoring control targets in the standby stop mode (S5). Also by this, the power consumed by the monitoring control device 23 can be reduced.

  Also, as shown in FIG. 7, when the change rate is large in the determination in step S7, the calculation processing interval for monitoring control is shortened (S2), the number of monitoring control targets is increased (S4), and standby stop is performed. When in the mode, the calculation processing interval for monitoring control may be increased (S3) and the number of monitoring control targets may be decreased (S5).

  Next, FIG. 8 is a flowchart showing a third embodiment of arithmetic processing for supervisory control in the supervisory control device 23. Compared with the first embodiment shown in FIG. When a certain period of time elapses, the calculation interval for monitoring control is lengthened, and the calculation interval for monitoring control is set in advance before the operation mode of the storage battery 18 of the power storage unit 11 becomes the charge / discharge mode. It was designed to be shorter.

  Normally, the power storage system is operated according to a predetermined operation schedule as described above. Now, assuming that the operation schedule of the operation mode shown in FIG. 2 is determined in advance, the operation mode of the storage battery 18 of the power storage unit 11 is known in advance. For example, the monitoring control device 23 sets the operation mode to the charge / discharge mode. It is possible to shorten the calculation interval for supervisory control in advance before becoming.

  In FIG. 8, Step S8, Step S9, and Step S10 are added to Example 1 shown in FIG. First, it is determined whether or not the storage battery 18 of the power storage unit 11 of the power storage system is in the charge / discharge mode (S1). If the storage battery 18 is in the charge / discharge mode, the calculation processing interval for monitoring control is shortened (S2). . If the charge / discharge mode is not determined in step S1, it is determined in step S3 whether or not a predetermined time has elapsed since the standby stop mode was set before increasing the calculation processing interval for monitoring control (S8). When a predetermined time has elapsed, the calculation processing interval for monitoring control is lengthened (S3). This is to ensure the safety of the monitoring control when the operation mode is switched from the charge / discharge mode to the standby stop mode. This is because, for the sake of safety, the calculation processing interval for monitoring control is shortened so that monitoring control can be performed with high accuracy for a certain period of time after entering the standby stop mode.

  Next, the time when it becomes charge / discharge mode is acquired from the operation schedule of the power storage unit 11 (S9). Then, it is determined whether or not the predetermined time before the charging / discharging mode is reached (S10). When the predetermined time before the charging / discharging mode is reached, the monitoring is performed even if the standby stop mode is set. The calculation processing interval for control is shortened (S2). Thereby, before it becomes charge / discharge mode, it can prepare for the supervisory control of a high system | strain in advance.

  Further, instead of shortening the calculation processing interval for monitoring control in the charge / discharge mode and increasing the calculation processing interval for monitoring control in the standby stop mode, as shown in FIG. It is also possible to increase the number of monitoring control targets in the charge / discharge mode and to decrease the number of monitoring control targets in the standby stop mode. That is, when the charging / discharging mode is determined in step S1, the number of monitoring control targets is increased (S4), and when the standby stop mode is set, the number of monitoring control targets is decreased while leaving the important monitoring control targets (S5). For example, when the monitoring control target is voltage, current, and temperature, when in charge / discharge mode, all of these voltage, current, and temperature are monitored and controlled, and when in standby stop mode, for example, only temperature is monitored. It can be considered as a control target. This is because the temperature of the storage battery 18 is an important monitoring control target even in the standby stop mode.

  As shown in FIG. 10, when the charging / discharging mode is determined in step S1, the calculation processing interval for monitoring control is shortened (S2), the number of monitoring control targets is increased (S4), and the standby stop mode is set. In such a case, the calculation processing interval for monitoring control may be increased (S3) and the number of monitoring control objects may be decreased (S5).

  FIG. 11 is a flowchart illustrating the fourth embodiment of the arithmetic processing for monitoring control in the monitoring control device 23. Before the operation mode of the storage battery 18 of the power storage unit 11 becomes the charge / discharge mode, the power storage unit 11 It is a flowchart which shows the arithmetic processing in the monitoring control apparatus 23 for controlling the temperature of the storage battery 18.

  In FIG. 11, first, it is determined whether or not the storage battery 18 of the power storage unit 11 of the power storage system is in the charge / discharge mode (S1). This is because the storage battery 18 of the power storage unit 11 is temperature-controlled in advance before the operation mode of the storage battery 18 of the power storage unit 11 is changed to the charge / discharge mode. It is because it does not.

  When it is not charging / discharging mode by determination of step S1, the time of becoming discharge mode and the temperature of the storage battery 18 are acquired from the driving schedule of the electrical storage part 11 (S11). Then, it is determined whether or not the temperature of the power storage unit 11 has deviated from the predetermined temperature (S12). When the temperature deviates from the predetermined temperature at which high efficiency operation can be performed, the temperature of the power storage unit 11 in the charge / discharge mode is The temperature of the power storage unit 11 is controlled in advance so as to reach a predetermined temperature (S13).

  For example, before the operation mode is changed to the discharge mode, it has heat generation characteristics at the time of discharge, so when the temperature of the storage battery 18 is high, it is cooled to a predetermined temperature. At that time, in consideration of the temperature of the storage battery 18 and the ambient temperature, the cooling start time is determined so that the temperature of the power storage unit 11 becomes a predetermined temperature at the start of discharge. On the other hand, before the operation mode becomes the charging mode, the heat absorption characteristic is obtained at the time of charging. Therefore, when the temperature of the storage battery 18 is low, the battery 18 is heated to a predetermined temperature. At that time, in consideration of the temperature of the storage battery 18 and the ambient temperature, the heating start time is determined so that the temperature of the power storage unit 11 becomes a predetermined temperature at the start of charging. Many of the lithium-ion secondary batteries have endothermic characteristics as described above, but they may exhibit exothermic characteristics in the later stages of charging. The heating start time is determined so as to reach a predetermined temperature.

  FIG. 12 is a flowchart showing the fifth embodiment of the arithmetic processing for monitoring control in the monitoring control device 23. The air conditioning equipment is driven after the end of the charge / discharge mode so that the temperature of the power storage unit becomes a predetermined temperature. The temperature of the power storage unit is controlled.

  In FIG. 12, first, it is determined whether or not the storage battery 18 of the power storage unit 11 of the power storage system has ended the charge / discharge mode (S1). When the charge / discharge mode has not ended, the process ends. This is because the air conditioning equipment is driven after the end of the charge / discharge mode of the storage battery 18 of the power storage unit 11 and the temperature of the power storage unit is controlled so that the temperature of the power storage unit becomes a predetermined temperature. This is because this processing is not required.

  When the charge / discharge mode is terminated in the determination in step S1, the temperature of the storage battery 18 is acquired (S11). Then, it is determined whether or not the temperature of the power storage unit 11 deviates from the predetermined temperature (S12). When the temperature deviates from the predetermined temperature, the power storage unit 11 is set so that the temperature of the power storage unit 11 becomes the predetermined temperature. The temperature is controlled (S15).

  That is, the monitoring control unit 23 allows heat generation of the storage battery 18 in the discharge mode, drives the air conditioning equipment after the end of the discharge mode, and controls the temperature of the power storage unit so that the temperature of the power storage unit 11 becomes a predetermined temperature. . That is, the power storage unit 11 is cooled by an amount corresponding to the temperature rise due to the heat dissipation of the storage battery 18 due to the discharge. When the power storage unit 11 is in the discharge mode, power is supplied from the power storage unit 11 to the load 14, and power supply from the power system 15 to the load 14 is restricted. Therefore, stopping power supply to the air conditioning facility for temperature adjustment of the power storage unit 11 leads to load leveling of power in the consumer, and therefore air conditioning is performed when power is not supplied from the power storage unit 11 to the load 14. The equipment is driven to cool the power storage unit 11.

  On the other hand, in the charge mode, the heat absorption of the storage battery 18 is allowed, the air conditioning equipment is driven after the end of the charge mode, and the temperature of the power storage unit is controlled so that the temperature of the power storage unit 11 becomes a predetermined temperature. That is, the power storage unit 11 is heated by the amount of heat that the storage battery 18 has absorbed by charging and the temperature has dropped. When the power storage unit 11 is in the charging mode, power is being supplied from the power system 15 to the power storage unit 11, and the power supply to the air conditioning equipment for adjusting the temperature of the power storage unit 11 should be stopped. Since this leads to load leveling of the power in the house, the air conditioner is driven to heat the power storage unit 11 when power is not supplied from the power system 15 to the power storage unit 11.

  As a result, the monitoring control unit 23 does not consume power from the power supply device 13 during charging / discharging of the power storage unit 11 and can reduce power consumption for monitoring control as a whole.

  The fourth embodiment shown in FIG. 11 and the fifth embodiment shown in FIG. 12 can be applied to the first embodiment, the second embodiment, and the third embodiment.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Power storage part, 12 ... Power storage part operation device, 13 ... Power supply device, 14 ... Load, 15 ... Electric power system, 16 ... Circuit breaker, 17 ... Power receiving transformer, 18 ... Storage battery, 19 ... Auxiliary machine, 20 ... Protection device , 21 ... Power conversion device, 22 ... Interconnection transformer, 23 ... Monitoring and control device, 24 ... Voltage detector, 25 ... Current detector, 26 ... Circuit breaker

Claims (6)

A power storage unit having a storage battery in which a plurality of lithium ion battery cells are stacked;
A load connected between a power system and the power storage unit;
The power storage unit has a predetermined operation schedule, the power consumption of the load, a charge command or discharge command for the power storage unit from the outside is input, the operation schedule, the charge command or discharge command, the load A monitoring control device that controls the power storage location based on electric power used, and performs monitoring control of the entire system including the power storage unit;
Operates according to a command from the supervisory control device, and converts AC power of the power system into DC power when the power consumption of the load is small or when there is a charge command or according to the operation mode of the operation schedule of the power storage unit. The power storage unit is charged, and when the load uses a large amount of power or when there is a discharge command, or the operation mode of the operation schedule of the power storage unit converts the DC power of the power storage unit into AC power, the load A power converter that discharges into
A power storage system comprising: a power supply device that supplies power for driving an auxiliary machine of the system and power for operating the monitoring control device to the auxiliary device and the monitoring control device.   The monitoring control unit is configured to perform the monitoring control when the operation mode of the power storage unit is a charging mode in which the power storage unit is charged with power from the power system, or a discharge mode in which power is discharged from the power storage unit to the load. When the calculation processing interval is shortened and / or the number of monitoring control targets is increased, the standby mode waiting for the start of the charge / discharge operation of the power storage unit, and the stop mode in which the charge / discharge operation of the power storage unit is stopped The power storage system according to claim 1, wherein an arithmetic processing interval for the monitoring control is increased and / or a monitoring control target is decreased.   In the monitoring control unit, the operation mode of the power storage unit is a charge mode in which the power storage unit is charged with power from the power system or a discharge mode in which power is discharged from the power storage unit to the load, and the battery voltage of the power storage unit Change, battery current change, or battery temperature change is large, the calculation processing interval for the monitoring control is shortened and / or the number of monitoring control targets is increased, and the battery voltage or battery current change or battery of the power storage unit is increased. 2. The power storage system according to claim 1, wherein when the temperature change is small, the calculation processing interval for the monitoring control is increased and / or the number of monitoring control targets is decreased.   The monitoring control unit is fixed when the operation mode of the power storage unit is in a standby mode waiting for the start of charge / discharge operation of the power storage unit or a stop mode in which the charge / discharge operation of the power storage unit is stopped. When the operation interval for the monitoring control is increased and / or the number of monitoring control targets is reduced after a lapse of time, and the standby mode or the stop mode is in progress, the operation mode of a predetermined operation schedule is stored in the power storage unit. Prior to the charging mode for charging power from the power system or the discharging mode for discharging power from the power storage unit to the load, the calculation interval for the monitoring control is shortened in advance and / or the number of monitoring control targets is increased. The power storage system according to claim 1.   The auxiliary machine is an air conditioning facility that maintains a temperature of the power storage unit and the power conversion device at a predetermined temperature, and the monitoring control unit discharges power from the power storage unit to the power system in an operation mode of the operation schedule. Prior to the discharge mode or the charging mode for charging power from the power system to the power storage unit, the air conditioning equipment is driven in advance, and the operation mode of the power storage unit becomes the discharge mode or the charging mode. The power storage system according to any one of claims 1 to 4, wherein the temperature of the power storage unit is controlled so that the temperature of the power storage unit becomes a predetermined temperature.   The auxiliary machine is an air conditioner that keeps the temperature of the power storage unit and the power conversion device at a predetermined temperature, and the monitoring control unit is configured to discharge the power from the power system to the power storage unit after the end of the discharge mode or the The power storage unit is driven after the end of a charging mode for charging power from the power system to the power storage unit, and the temperature of the power storage unit is controlled so that the temperature of the power storage unit becomes a predetermined temperature. The electric power storage system of any one of thru | or 4.

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