JP6393242B2 - Power storage system, energy storage management system - Google Patents

Description

  The present invention relates to a power storage system and an energy storage management system.

  In recent years, from the viewpoint of global warming, the importance of introducing a power system that generates power using renewable energy such as sunlight and wind power has been increasing. However, in power generation using such renewable energy, there is a concern that power fluctuations in seconds to minutes due to changes in weather conditions will adversely affect the frequency and voltage stability of power flowing through the power grid. The

  With respect to the above, there is known a service provider that provides a power stabilization service for a power transmission network to an operation manager of the power transmission network for a fee. A service provider uses a power storage system (Battery Energy Storage System: BESS) that can store and release power using a battery, and performs charging / discharging with a power transmission network as necessary. This suppresses fluctuations in the frequency and voltage of power flowing through the power transmission network, provides a power stabilization service, and obtains a monetary profit.

  The battery used for BESS gradually decreases its capacity and gradually increases its internal resistance according to the operating conditions of BESS and the environmental conditions where BESS is placed. A decrease in battery capacity leads to a decrease in the amount of power that BESS can charge and discharge, and an increase in internal resistance leads to an increase in the amount of heat generated. As a result, the usefulness of BESS decreases year by year, and the operating cost of a cooling system that adjusts the temperature of the battery increases year by year. For this reason, service providers are demanding a technique that can maintain the usefulness of BESS throughout the lifetime of the battery and that can realize efficient temperature adjustment by the cooling system.

  Conventionally, in an output leveling system of a distributed power source that suppresses fluctuations in power supplied to a power system from a distributed power source that converts natural energy into electric power and outputs it, heat storage means for storing thermal energy by air conditioning equipment There has been proposed (see Patent Document 1). By temporarily storing excess heat energy in the heat storage means and releasing the heat energy from the heat storage means in the future, the heat energy released from the air conditioning equipment can be used effectively.

JP 2014-138546 A

  However, the apparatus described in Patent Document 1 can effectively use thermal energy by using the heat storage means, but cannot maintain the usefulness of BESS and reduce the operation cost.

The power storage system according to the present invention provides a power stabilization service for a power transmission network, and mutually converts a chargeable / dischargeable battery and power input / output between the battery and the power transmission network. A power conversion device, an air conditioning system that adjusts the temperature of the battery, and an energy management device that controls the operation of the power storage system, the air conditioning system including a thermal energy storage system capable of storing cold energy and a heat The energy management device controls operations of the air conditioning system and the thermal energy storage system based on a charge state of the battery and a cold energy storage state of the thermal energy storage system, and and controls charging and discharging of the battery, the thermal energy storage system includes a heat insulating tank water or ice is stored, A cooler that cools the water stored in the heat insulation tank and converts it into ice, a first refrigerant pipe for thermally coupling the heat insulation tank and the air conditioning system, and the first refrigerant pipe. A refrigerant pump for circulating the refrigerant, and the air conditioning system includes: a second refrigerant pipe; an evaporator that generates cold air by depressurizing and evaporating the refrigerant flowing through the second refrigerant pipe; and the evaporator A compressor that compresses the vaporized refrigerant; a radiator that radiates and liquefies the refrigerant compressed by the compressor; and a path of the refrigerant that flows through the second refrigerant pipe of the radiator or the first refrigerant pipe. A valve for switching to one of the above, and the energy management device is configured to operate the thermal energy in one of an ice storage mode and an ice cooling mode. When operating the storage system, operating the air conditioning system in either the normal mode or the heat storage mode, and operating in the ice storage mode, the thermal energy storage system operates the cooler. When the water stored in the heat insulation tank is cooled to change into ice and is operated in the ice cooling mode, the thermal energy storage system is stored in the heat insulation tank by operating the refrigerant pump. When the refrigerant cooled by ice flows to the air conditioning system through the first refrigerant pipe and operates in the normal mode, the air conditioning system causes the refrigerant to flow from the second refrigerant pipe to the radiator. Operate the valve to flow and operate the evaporator, compressor and radiator. When the cold air is generated and operated in the heat storage mode, the air conditioning system operates the valve so that the refrigerant flows from the second refrigerant pipe to the first refrigerant pipe, and the compressor In addition, by operating the evaporator without operating the radiator, the cold air is generated using the refrigerant cooled by the ice stored in the heat insulating tank .
An energy storage management system according to the present invention includes the above-described power storage system and a thermal energy storage system that can be thermally coupled to the air conditioning system and can store cold energy.

  ADVANTAGE OF THE INVENTION According to this invention, the usefulness maintenance of BESS and operation cost reduction can be aimed at using the thermal energy storage device which can store cold energy.

It is a schematic block diagram of the energy storage management system which concerns on one Embodiment of this invention. 1 is a schematic configuration diagram of a thermal energy storage system and an air conditioning system according to an embodiment of the present invention. It is a figure which shows the input / output signal and functional structure of an energy management apparatus. It is a time chart figure which shows the operation example of the electric power storage system which concerns on one Embodiment of this invention, and a thermal energy storage system.

  In the following embodiments, a power storage system called BESS will be described as described above.

  In countries and regions such as the United States, there are organizations called RTO (Regional Transmission Organization) and ISO (Independent Transmission Operator) as operation managers who operate and maintain the transmission network. The operation manager of such a power transmission network is responsible for maintaining the frequency and voltage of power supplied from the power transmission network to consumers within a certain range while using the power generated by various power generation facilities. In addition, there are service providers that provide auxiliary services such as frequency adjustment, reactive power supply and voltage control, system restart, etc. Are known. As mentioned above, these service providers use BESS to provide the power stabilization service as described above, and obtain revenue from the operation manager of the power grid by obtaining compensation according to the content and provision time. Raised.

  BESS used for providing power stabilization services to the power transmission network as described above is generally a plurality of batteries that can be charged and discharged, a power conversion device, an air conditioning system that adjusts the temperature in a facility where the BESS is installed, The battery management system is configured to control the entire operation of the BESS including charging and discharging of the battery. The characteristics of the battery are represented by capacity (Ah), internal resistance (Ω), state of charge (SOC) (%), and the like. As the battery deteriorates, its capacity decreases and the internal resistance increases. Factors that degrade the battery include the SOC range used for charging and discharging the battery, the number and period of charge and discharge cycles, the charge and discharge current, and the outside air temperature.

  FIG. 1 is a schematic configuration diagram of an energy storage management system according to an embodiment of the present invention. An energy storage management system 1 shown in FIG. 1 includes a BESS 2 and a thermal energy storage system (TESS) 3 connected to the BESS 2.

  The BESS 2 includes a battery 4, a power conversion device (PCS) 5, an air conditioning system 6, an energy management device 7, and a communication terminal 8.

  The battery 4 is a secondary battery that can be charged and discharged by mutually converting chemical energy and electrical energy using an electrochemical reaction, and is configured by one or a plurality of battery cells. The battery 4 is connected to the power transmission network 9 via the PCS 5. The PCS 5 converts DC power from the battery 4 into AC power and outputs it to the power transmission network 9, and conversely converts AC power from the power transmission network 9 into DC power and outputs it to the battery 4. The operations of the battery 4 and the PCS 5 are controlled by the energy management device 7.

  The air conditioning system 6 performs air conditioning control for maintaining the temperature in the facility where the BESS 2 is installed within an appropriate temperature range according to the operating conditions of the battery 4. Thereby, the temperature of the battery 4 is adjusted to be appropriate during the operation of the BESS 2. The operation of the air conditioning system 6 is controlled by the energy management device 7. Details of the air conditioning system 6 will be described later.

  The energy management device 7 receives the information transmitted from the management center 10 via the communication terminal 8. The management center 10 is installed in the aforementioned RTO or ISO, which is an organization that performs operation and maintenance of the power transmission network 9, and transmits information indicating the contents of services requested by these organizations to the BESS2 to the BESS2. To do. The energy management device 7 receives output signals from voltage, current, and temperature sensors (not shown). Based on the received information, the energy management device 7 performs charge / discharge control for the battery 4 and the PCS 5, control of the air conditioning system 6, and the like.

  The TESS 3 is a system capable of storing cold energy. The operation of the TESS 3 is controlled by the energy management device 7 so that it can be thermally coupled to the air conditioning system 6. Details of TESS3 will be described later.

  FIG. 2 is a schematic configuration diagram of a thermal energy storage system (TESS) 3 and an air conditioning system 6 according to an embodiment of the present invention.

  The air conditioning system 6 includes a radiator 61, a compressor 62, an evaporator 63, a refrigerant pipe 64, valves 65a, 65b, 65c and 65d, a blower 66, a fan 67, and a control unit 68. The TESS 3 includes a heat insulating tank 31, a refrigerant pipe 32, a refrigerant pump 33, a cooler 34, and a control unit 35.

  In the air conditioning system 6, the refrigerant pipe 64 is provided between the radiator 61, the compressor 62, and the evaporator 63. The refrigerant pipe 64 is connected to the refrigerant pipe 32 provided in the TESS 3. The path of the refrigerant flowing through the refrigerant pipe 64 is controlled by valves 65a to 65d.

  The evaporator 63 generates cold air by depressurizing and evaporating the refrigerant. The blower 66 and the fan 67 blow the cold air generated by the evaporator 63. Thereby, the facility in which BESS2 is installed is cooled. The compressor 62 compresses the refrigerant vaporized by the evaporator 63. The radiator 61 radiates and liquefies the refrigerant compressed by the compressor 62. The control unit 68 controls the operation of each component of the air conditioning system 6 in response to a command from the energy management device 7 of FIG.

  The air conditioning system 6 can operate in either the normal mode or the heat storage mode in accordance with a command from the energy management device 7. When operating in the normal mode, the control unit 68 controls the valves to close the valves 65a and 65b and open the valves 65c and 65d. Moreover, the heat radiator 61, the compressor 62, and the evaporator 63 are operated using the electric power supplied from the power transmission network 9 of FIG. Accordingly, the refrigerant is circulated through the refrigerant pipe 64 to the radiator 61, the compressor 62, and the evaporator 63 so that the facility is cooled.

  On the other hand, when operating in the heat storage mode, the control unit 68 controls the valves to open the valves 65a and 65b and close the valves 65c and 65d. Further, the operation of the radiator 61 and the compressor 62 is stopped, and only the evaporator 63 is operated. Thus, the refrigerant flows through the refrigerant pipe 64 of the air conditioning system 6 and the refrigerant pipe 32 of the TESS3.

  In the TESS 3, the heat insulating tank 31 stores a phase change material whose structure (form) changes according to temperature, for example, water (ice). The heat insulating tank 31 is connected to the refrigerant pipe 32 and a cooler 34 is attached. The refrigerant pipe 32 is provided with a refrigerant pump 33 for circulating the refrigerant in the refrigerant pipe 32. The control unit 35 controls the operation of each component of the TESS 3 in response to a command from the energy management device 7 of FIG.

  The TESS 3 can operate in either an ice storage mode or an ice cooling mode in accordance with a command from the energy management device 7. When operating in the ice storage mode, the control unit 35 operates the cooler 34 using the power supplied from the battery 4 of the BESS 2 via the PCS 5 or the power supplied from the power transmission network 9 of FIG. Thereby, the water in the heat insulation tank 31 is cooled by the cooler 34 and changed into ice.

  On the other hand, when operating in the ice cooling mode, the control unit 35 operates the refrigerant pump 33 using the power supplied from the battery 4 of the BESS 2 via the PCS 5 or the power supplied from the power transmission network 9 of FIG. Let At this time, by simultaneously operating the air conditioning system 6 in the heat storage mode, the refrigerant flows through the refrigerant pipe 64 of the air conditioning system 6 and the refrigerant pipe 32 of the TESS 3 as described above. Thereby, the refrigerant cooled by the ice stored in the heat insulation tank 31 flows into the evaporator 63 of the air conditioning system 6 through the refrigerant pipe 64 and the refrigerant pipe 32 to cool the facility. . In addition, the ice stored in the heat insulation tank 31 melts into water by absorbing heat from the refrigerant.

  FIG. 3 is a diagram showing input / output signals and a functional configuration of the energy management device 7.

  The energy management device 7 receives a charge / discharge request signal P_RTO representing the required value of power that the BESS 2 should charge / discharge to / from the power transmission network 9 from the management center 10 of FIG. Entered. Further, a battery current signal I_Battery representing the input / output current of the battery 4 and a battery voltage signal V_Battery representing the voltage of the battery 4 are input from a current sensor and a voltage sensor (not shown), respectively. Further, ambient temperature information T_ambient indicating the ambient temperature of the BESS 2 and battery temperature information T_cells indicating the temperature of the battery 4 are input from a temperature sensor (not shown). Further, a TESS state signal TESS_state representing the state of TESS3 is input from the control unit 35 of TESS3 illustrated in FIG.

  The energy management device 7 includes functional modules of a battery capacity calculation unit 71, an SOC calculation unit 72, a power distribution calculation unit 73, an operation mode setting unit 74, and a storage unit 75. The energy management device 7 can realize these functional modules by executing a predetermined program on a computer.

  The battery capacity calculation unit 71 calculates the current charge capacity of the battery 4 based on the battery current signal I_Battery, the battery voltage signal V_Battery, and the battery temperature information T_cells. The SOC calculation unit 72 calculates the SOC of the battery 4 based on the current charging capacity of the battery 4 calculated by the battery capacity calculation unit 71, the battery current signal I_Battery, the battery voltage signal V_Battery, and the battery temperature information T_cells. The power distribution calculation unit 73 consumes the TESS 3 for operating the refrigerant pump 33 and the cooler 34 based on the SOC of the battery 4 calculated by the SOC calculation unit 72 and the charge / discharge request signal P_RTO and the TESS state signal TESS_state. The power distribution between the power and the charge / discharge power of the battery 4 is calculated. The calculation result of the power distribution by the power distribution calculation unit 73 is output as the TESS power signal P_TESS and the battery power signal P_Battery to the control unit 35 of TESS3, the battery 4 and PCS5 of BESS2, respectively. The operation mode setting unit 74 sets the operation mode of the air conditioning system 6 and the operation mode of the TESS 3 based on the power distribution calculated by the power distribution calculation unit 73. The setting results of these operation modes by the operation mode setting unit 74 are output to the control unit 68 of the air conditioning system 6 and the control unit 35 of the TESS3, respectively. The storage unit 75 stores various data used in the battery capacity calculation unit 71, the SOC calculation unit 72, the power distribution calculation unit 73, and the operation mode setting unit 74, respectively.

The energy management device 7 controls the battery 4 and the PCS 5 so that the SOC of the battery 4 is maintained within a predetermined SOC range. When the minimum value and maximum value of the SOC range at this time are expressed as SOC_min (%) and SOC_max (%), these values are expressed by the following formula (1) in consideration of deterioration characteristics and safety of the battery 4. Is set to satisfy the relationship.
0 ≦ SOC_min <SOC_max ≦ 100 (1)

  When the battery 4 is charged, the SOC of the battery 4 gradually increases and approaches SOC_max. When the SOC reaches the maximum value SOC_max, the energy management device 7 instructs the PCS 5 to stop charging until the battery 4 can be discharged. On the other hand, when the battery 4 is discharged, the SOC of the battery 4 gradually decreases and approaches SOC_min. When the SOC reaches the minimum value SOC_min, the energy management device 7 instructs the PCS 5 to stop discharging until the battery 4 can be charged. At this time, if the charge capacity of the battery 4 is reduced due to deterioration, the SOC of the battery 4 is likely to reach SOC_max or SOC_min as compared with a new product.

  When the input / output power of the entire energy storage management system 1 for the power transmission network 9 is expressed as P_sys, if the value of the input / output power P_sys matches the charge / discharge request signal P_RTO, the energy storage for the request from the management center 10 is performed. The operating rate of the management system 1 is 100%. However, if the value of the input / output power P_sys does not coincide with the charge / discharge request signal P_RTO, the operation rate is 0% or more and less than 100%, and the operation rate decreases as the difference increases.

  In general, the profit obtained by the power stabilization service provided by the BESS varies in proportion to the value of the operation rate of the BESS. For this reason, it is preferable to maintain the operating rate as high as possible. However, if the battery charge capacity decreases due to deterioration as described above, the SOC range that can be charged and discharged becomes narrow, and it becomes difficult to maintain the operating rate. Therefore, in the energy storage management system 1 according to the present embodiment, by using BESS2 and TESS3 in combination, the operating rate of the entire system is maintained and the operation cost is reduced.

  FIG. 4 is a time chart showing an operation example of the power storage system (BESS) 2 and the thermal energy storage system (TESS) 3 according to the embodiment of the present invention. In FIG. 4, the solid line 101 and the broken line 102 represent the charge / discharge power of the battery 4 and the power consumption of the TESS 3 on a certain control target day (referred to as the d-th day). A solid line 103 represents the SOC of the battery 4 on the d-th day. Moreover, the figures 104 and 105 represent the operation modes of the air conditioning system 6 and the TESS 3 on the d-th day, respectively. Solid lines 106 and 107 represent the operation cost and the operation rate of the energy storage management system 1 on the d-th day, respectively. On the other hand, the solid line 201 and the broken line 202 represent the charge / discharge power of the battery 4 and the power consumption of the TESS 3 on the next day (d + 1 day), respectively. A solid line 203 represents the SOC of the battery 4 on d + 1 day. Moreover, the figures 204 and 205 represent the operation modes of the air conditioning system 6 and the TESS 3 on the d + 1 day, respectively. Solid lines 206 and 207 respectively represent the operation cost and the operation rate of the energy storage management system 1 on the d + 1 day.

  When the charge / discharge request signal P_RTO for requesting charging from the power transmission network 9 is input from the management center 10 on the d-th day, the energy management device 7 commands to charge the battery 4 by absorbing power from the power transmission network 9. Is output to PCS5. At this time, the charging / discharging power of the battery 4 is on the charging side as indicated by the solid line 101, and the power consumption of the TESS 3 is 0 as indicated by the broken line 102. Further, as indicated by the solid line 103, the SOC of the battery 4 gradually increases. Like the figures 104 and 105, the air conditioning system 6 is operating in the normal mode, and the TESS 3 is stopped. As a result, the operation cost of the energy storage management system 1 becomes an amount corresponding to the power consumption in the air conditioning system 6 as indicated by the solid line 106. Further, as indicated by the solid line 107, the operating rate of the energy storage management system 1 becomes 100% when the battery 4 is charged.

When the SOC of the battery 4 reaches the maximum value SOC_max as indicated by the solid line 103 at time t1, the energy management device 7 outputs a command to stop charging the battery 4 to the PCS 5. Thereby, the charging / discharging power of the battery 4 becomes 0 as indicated by the solid line 101. At this time, it is assumed that water remains in the heat insulation tank 31 in the TESS 3 and the TESS 3 can be operated in the ice storage mode. In this case, the energy management device 7 outputs a command to operate the cooler 34 using the power from the power transmission network 9 to the control unit 35 of the TESS 3. As a result, the TESS 3 operates in the ice storage mode as shown in the figure 105. When the power consumption of the cooler 34 at this time is expressed as P_compressor, the relationship of the following formula (2) is established.
P_TESS = P_compressor = P_RTO (2)

  As described above, even when charging of the battery 4 is stopped, power absorption from the power transmission network 9 can be continued. Therefore, as indicated by the solid line 107, the operating rate of the energy storage management system 1 can be maintained at 100%.

  Thereafter, it is assumed that a charge / discharge request signal P_RTO for requesting discharge to the power transmission network 9 is input from the management center 10 at time t2. In this case, the energy management device 7 outputs to the PCS 5 a command to discharge the battery 4 and release power to the power transmission network 9. As a result, the charge / discharge power of the battery 4 becomes the discharge side as indicated by the solid line 101, and the SOC of the battery 4 gradually decreases as indicated by the solid line 103. In addition, the energy management device 7 outputs a command to stop the operation in the ice storage mode to the control unit 35 of the TESS 3. As a result, the operation of TESS3 is stopped as in the case of the graphic 105.

  As described above, even when the charge / discharge request signal P_RTO is switched from the charge side to the discharge side, the operating rate of the energy storage management system 1 can be maintained at 100% as indicated by the solid line 107.

  Thereafter, after maintaining the above state until the next day, it is assumed that a charge / discharge request signal P_RTO for requesting charging from the power transmission network 9 is input from the management center 10 at time t3 on the (d + 1) th day. In this case, the energy management apparatus 7 outputs a command for charging the battery 4 by absorbing power from the power transmission network 9 to the PCS 5. As a result, the charging / discharging power of the battery 4 becomes the charging side as indicated by the solid line 201, and the SOC of the battery 4 gradually increases as indicated by the solid line 203. In addition, the energy management device 7 outputs a command to stop the operation of the TESS 3 to the control unit 35 of the TESS 3. As a result, the power consumption of the TESS 3 becomes 0 as indicated by the broken line 202, and the TESS 3 maintains the stopped state as indicated by the graphic 205. As a result, the operating cost of the energy storage management system 1 is an amount corresponding to the power consumption in the air conditioning system 6, as indicated by the solid line 206, as in the period up to the time t1 of the previous day. Further, as indicated by the solid line 207, the operating rate of the energy storage management system 1 becomes 100% when the battery 4 is charged.

  When the SOC of the battery 4 reaches the maximum value SOC_max as indicated by the solid line 203 at time t4, the energy management device 7 outputs a command to stop the charging of the battery 4 to the PCS 5. As a result, the charge / discharge power of the battery 4 becomes zero as indicated by the solid line 201. At this time, it is assumed that the ice stored in the previous day remains in the heat insulating tank 31 in the TESS 3 and the TESS 3 can be operated in the ice cooling mode. In this case, the energy management device 7 outputs a command to operate the refrigerant pump 33 using the power from the power transmission network 9 to the control unit 35 of the TESS 3. In addition, the controller 68 of the air conditioning system 6 outputs a command for controlling the valves to stop the operations of the radiator 61 and the compressor 62, open the valves 65a and 65b, and close the valves 65c and 65d. To do. Thereby, like the figures 204 and 205, the air conditioning system 6 operates in the heat storage mode, and the TESS 3 operates in the ice cooling mode.

  As described above, even when charging of the battery 4 is stopped, power absorption from the power transmission network 9 can be continued. Therefore, as indicated by the solid line 207, the operating rate of the energy storage management system 1 can be maintained at 100%. Furthermore, the power consumption of the air conditioning system 6 can be reduced by stopping the operation of the radiator 61 and the compressor 62 in the air conditioning system 6. Therefore, as indicated by the solid line 206, the operation cost of the energy storage management system 1 can be significantly reduced.

  The energy storage management system 1 continues the operation state of the air conditioning system 6 and the TESS 3 as described above until the time t5 when the ice stored in the heat insulating tank 31 of the TESS 3 is completely melted to become water. Can do.

  Even when the charge / discharge request signal P_RTO for requesting discharge to the power grid 9 is input from the management center 10, if the importance is low and the SOC of the battery 4 is close to the maximum value SOC_max, The energy management device 7 may perform control different from the above. Specifically, the energy management device 7 discharges the battery 4 with a discharge power larger than the requested value, thereby releasing a power to the power transmission network 9 and a command to supply power to the TESS 3 to the PCS 5. Output. At the same time, the energy management device 7 outputs a command to operate the cooler 34 or the refrigerant pump 33 to the control unit 35 of the TESS 3 using the power supplied from the battery 4 via the PCS 5. At this time, which of the cooler 34 and the refrigerant pump 33 is to be operated may be determined based on the TESS state signal TESS_state. Furthermore, when operating the refrigerant pump 33, the operation of the radiator 61 and the compressor 62 is stopped with respect to the control unit 68 of the air conditioning system 6, and the valves 65a and 65b are opened and the valves 65c and 65d are closed. A command for controlling each valve is output as follows. As a result, the operating rate of the energy storage management system 1 can be maintained at a high value while decreasing the SOC of the battery 4 and increasing the amount of power that can be charged. Furthermore, when the air conditioning system 6 can be operated in the heat storage mode, the power consumption of the air conditioning system 6 can be reduced to reduce the operation cost. The same control may be performed when discharge to the power transmission network 9 is not requested.

  As described above, according to the energy storage management system 1 of the present embodiment, even when the SOC of the battery 4 reaches the maximum value SOC_max, the operating rate of the entire system can be maintained to the maximum. Furthermore, when ice is stored in the heat insulating tank 31 of the TESS 3, the operation cost can be reduced. Therefore, even if the charge capacity of the battery 4 is reduced due to deterioration, a high operating rate can be maintained throughout the system operation period, and the system operation cost can be reduced.

  According to one embodiment of the present invention described above, the following operational effects are obtained.

(1) The BESS 2 provides a power stabilization service for the power transmission network 9, and the battery 4 that can be charged and discharged, and the PCS 5 that mutually converts power input and output between the battery 4 and the power transmission network 9. And an air conditioning system 6 that adjusts the temperature of the battery 4 and an energy management device 7 that controls the operation of the BESS 2. The air conditioning system 6 can be thermally coupled to the TESS 3 capable of storing cold energy. The energy management device 7 controls the operation of the air conditioning system 6 and the TESS 3 and the charge / discharge of the battery 4 based on the state of charge of the battery 4 and the cold energy storage state of the TESS 3. Since it did in this way, the usefulness maintenance of BESS2 and operation cost reduction can be aimed at using TESS3 which is a thermal energy storage device which can store cold energy.

(2) The TESS 3 thermally controls the heat insulation tank 31 in which water or ice is stored, the cooler 34 that cools the water stored in the heat insulation tank 31 and converts it into ice, and the heat insulation tank 31 and the air conditioning system 6. A refrigerant pipe 32 for coupling and a refrigerant pump 33 for circulating the refrigerant in the refrigerant pipe 32 are provided. The energy management device 7 operates the TESS 3 in either the ice storage mode or the ice cooling mode. When operating in the ice storage mode, the TESS 3 operates the cooler 34 to cool the water stored in the heat insulation tank 31 and change it into ice. On the other hand, when operating in the ice cooling mode, the TESS 3 operates the refrigerant pump 33 so that the refrigerant cooled by the ice stored in the heat insulation tank 31 flows to the air conditioning system 6 through the refrigerant pipe 32. . Since it did in this way, according to a condition, cold energy can be accumulate | stored in TESS3, or the cold energy accumulated in TESS3 can be utilized with the air conditioning system 6. FIG.

(3) The air conditioning system 6 includes a refrigerant pipe 64, an evaporator 63 that generates cold air by depressurizing and evaporating the refrigerant flowing through the refrigerant pipe 64, a compressor 62 that compresses the refrigerant vaporized by the evaporator 63, and a compressor A heat radiator 61 that radiates and liquefies the refrigerant compressed in 62 and valves 65 a to 65 d for switching a refrigerant path flowing through the refrigerant pipe 64 to either the heat radiator 61 or the refrigerant pipe 32 are provided. The energy management device 7 operates the air conditioning system 6 in either the normal mode or the heat storage mode. When operating in the normal mode, the air conditioning system 6 operates the valves 65 a to 65 d so that the refrigerant flows from the refrigerant pipe 64 to the radiator 61, and operates the evaporator 63, the compressor 62, and the radiator 61, Is generated. On the other hand, when operating in the heat storage mode, the air conditioning system 6 operates the valves 65a to 65d so that the refrigerant flows from the refrigerant pipe 64 to the refrigerant pipe 32, and operates the evaporator 63 without operating the compressor 62 and the radiator 61. By operating, cold air is generated using the refrigerant cooled by the ice stored in the heat insulation tank 31. Since it did in this way, the air conditioning system 6 can be operated using either the refrigerating cycle in the air conditioning system 6 or the cold energy accumulated in the TESS 3.

(4) Requesting charging from the power transmission network 9 when water is stored in the heat insulation tank 31 and the SOC of the battery 4 is a predetermined maximum value SOC_max as in the period from time t1 to time t2 in FIG. In the case where the energy management device 7 is operated, the power from the power transmission network 9 is used to operate the TESS 3 in the ice storage mode and the air conditioning system in the normal mode. Further, as in the period from time t4 to t5 in FIG. 4, when the ice is stored in the heat insulation tank 31 and the state of charge of the battery 4 is the maximum value SOC_max, charging from the power transmission network 9 is requested. In this case, the energy management device 7 operates the TESS 3 in the ice cooling mode and operates the air conditioning system 6 in the heat storage mode. Since it did in this way, also when the battery 4 cannot be charged any more, the power absorption from the power transmission network 9 can be continued and the operation rate of the energy storage management system 1 can be maintained. In addition, the operation cost of the energy storage management system 1 can be reduced.

(5) The energy management device 7 can also operate the TESS 3 in the ice storage mode or the ice cooling mode using the power from the battery 4. Even in this case, it is possible to maintain the operation rate of the energy storage management system 1 and reduce the operation cost.

(6) The energy management device 7 includes a battery capacity calculation unit 71 that calculates the charge capacity of the battery 4, an SOC calculation unit 72 that calculates the SOC of the battery 4, and the power consumption of the TESS 3 and the charge / discharge power of the battery 4. The power distribution calculating unit 73 for calculating the power distribution in the above and the operation mode setting unit 74 for setting the operation mode of the air conditioning system 6 and the operation mode of the TESS 3 are provided. Since it did in this way, the function required for control of the energy storage management system 1 is realizable in the energy management apparatus 7. FIG.

  The embodiment and various examples described above are merely examples, and the present invention is not limited to these contents as long as the features of the invention are not impaired. The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the present invention.

1 Energy storage management system 2 Power storage system (BESS)
3 Thermal energy storage system (TESS)
4 Battery 5 Power converter (PCS)
6 Air conditioning system 7 Energy management device 8 Communication terminal 9 Power transmission network 10 Management center 31 Heat insulation tank 32 Refrigerant pipe 33 Refrigerant pump 34 Cooler 35 Control unit 61 Radiator 62 Compressor 63 Evaporator 64 Refrigerant pipes 65a, 65b, 65c, 65d Valve 66 Blower 67 Fan 68 Control unit 71 Battery capacity calculation unit 72 SOC calculation unit 73 Power distribution calculation unit 74 Operation mode setting unit 75 Storage unit

Claims (5)

A power storage system that provides a power stabilization service for a power grid,
A chargeable / dischargeable battery;
A power converter that mutually converts power input and output between the battery and the power grid, and
An air conditioning system for adjusting the temperature of the battery;
An energy management device for controlling the operation of the power storage system,
The air conditioning system can be thermally coupled to a thermal energy storage system capable of storing cold energy,
The energy management device, based on the cooling energy storage state of the charge state and the thermal energy storage system of the battery, controls the operation of the air conditioning system and the thermal energy storage system to control the charging and discharging of the battery ,
The thermal energy storage system includes a heat insulating tank in which water or ice is stored, a cooler that cools the water stored in the heat insulating tank into ice, and the heat insulating tank and the air conditioning system are thermally coupled. A first refrigerant pipe for circulating the refrigerant and a refrigerant pump for circulating the refrigerant in the first refrigerant pipe,
The air conditioning system includes: a second refrigerant pipe; an evaporator that generates cold air by depressurizing and evaporating the refrigerant flowing through the second refrigerant pipe; a compressor that compresses the refrigerant vaporized by the evaporator; A radiator that radiates and liquefies the refrigerant compressed by the compressor; and a valve that switches a path of the refrigerant flowing through the second refrigerant pipe to either the radiator or the first refrigerant pipe. ,
The energy management device operates the thermal energy storage system in an operation mode of either an ice storage mode or an ice cooling mode, and operates the air conditioning system in an operation mode of a normal mode or a heat storage mode,
When operating in the ice storage mode, the thermal energy storage system operates the cooler to cool the water stored in the heat insulation tank and convert it into ice,
When operating in the ice cooling mode, the thermal energy storage system operates the refrigerant pump so that the refrigerant cooled by the ice stored in the heat insulation tank passes through the first refrigerant pipe. Flow to the system,
When operating in the normal mode, the air conditioning system operates the valve so that the refrigerant flows from the second refrigerant pipe to the radiator, and operates the evaporator, the compressor, and the radiator. Produce the cold,
When operating in the heat storage mode, the air conditioning system operates the valve so that the refrigerant flows from the second refrigerant pipe to the first refrigerant pipe, and without operating the compressor and the radiator. The electric power storage system which produces | generates the said cold using the refrigerant | coolant cooled with the ice stored in the said heat insulation tank by operating the said evaporator . The power storage system according to claim 1 ,
When water is stored in the heat insulation tank and the state of charge of the battery is a predetermined maximum value, when the charging from the power transmission network is requested, the energy management device And operating the thermal energy storage system in the ice storage mode and operating the air conditioning system in the normal mode,
When the ice is stored in the heat insulation tank and when the charging state of the battery is the maximum value, when the charging from the power grid is requested, the energy management device sets the thermal energy storage system to the thermal energy storage system. An electric power storage system that operates in an ice cooling mode and operates the air conditioning system in the heat storage mode. The power storage system according to claim 1 or 2 ,
The energy management device uses the power from the battery to operate the thermal energy storage system in the ice storage mode or the ice cooling mode. In the electric power storage system according to any one of claims 1 to 3 ,
The energy management device includes a battery capacity calculation unit that calculates a charge capacity of the battery, an SOC calculation unit that calculates a charge state of the battery, a power consumption of the thermal energy storage system, and a charge / discharge power of the battery. An electric power storage system comprising: an electric power distribution calculation unit that calculates electric power distribution in the unit; and an operation mode setting unit that sets an operation mode of the air conditioning system and an operation mode of the thermal energy storage system. The power storage system according to any one of claims 1 to 4 ,
An energy storage management system comprising: a thermal energy storage system capable of being thermally coupled to the air conditioning system and capable of storing cold energy.

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