JP2011101553A - Energy storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To level off power load on a week-by-week basis. <P>SOLUTION: An energy storage system includes a heat-accumulating tank and a storage battery, and stores generated power from a photovoltaic power generator in the heat-accumulating tank or the storage battery to level off a power load. The energy storage system includes a database which associates past daily weather and temperature forecast data with past daily power load record data to store the associated data, a forecast data acquisition means which acquires data of weather and temperature forecast of one week since the current day, a similar data extraction means which extracts from the database the past daily weather and temperature forecast data similar to data of weather and temperature forecast of one week from the current day, and a control means which reads out the past daily power load record data associated with the extracted past daily weather and temperature forecast data to regard the past daily power load record data as data of power load estimation of one week from the current day, and based on the data of power load estimation, carries out control over charge and discharge of the storage battery and heat source operation control for accumulating heat in the heat-accumulating tank. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an energy storage system for leveling a power load.

  In Japan, the Cabinet decided in July 2008 the “Low Carbon Society Action Plan” that aims to introduce solar power generation 10 times that of FY2005 (13 million kW in FY2020) and 40 times (53 million kW in FY2030). It was. Furthermore, in April 2009, the target for introduction in 2020 was raised 20 times as a measure against the economic crisis. As a specific move, an action plan is being promoted in cooperation with nine ministries and agencies to expand the introduction of solar power generation to public facilities such as hospitals, welfare facilities, and police stations, in addition to roads and schools.

When the amount of photovoltaic power generation increases, the amount of power generation exceeds the demand during periods when demand is low (light load period), and there is a risk of surplus electricity. FIG. 3 is an explanatory diagram viewed from the standpoint of an electric power company published in the Agency for Natural Resources and Energy document “Effects of Mass Energy Introduction and Countermeasures” (September 8, 2008). With the reverse power flow to the electric power company, the voltage of the electric power company distribution network rises, and there is a risk of deviating from the suitability value (101 ± 6V) defined by the Enforcement Regulations of the Electricity Business Law. In order to maintain the voltage of other consumers appropriately, for example, a measure for suppressing the output of solar power generation may be taken. Suppressing electric power based on natural energy without CO ₂ emissions during power generation seems to be unacceptably emotionally acceptable.

  Looking at the situation of consumers such as individual buildings, surplus power will be generated on weekends and closed days on sunny days according to the installed output of solar power generation. On the other hand, one of the contract forms between electric power companies and customers is the “actual amount system” for the purpose of “load leveling + promotion of energy saving”. The contract contents of “actual amount system” are: (1) Contract power is less than 500 kW, (2) Contract power is the largest value among the maximum demand power of each month for the past one year including this month. (3) The maximum demand power refers to the largest monthly value among the power measured every 30 minutes (see FIG. 4). In other words, as a measure for reducing the electricity charge, consumers will be motivated to level the load and reduce the power demand peak.

  In addition, as a prior art, in order to smooth the photovoltaic power generation output and enable time shift, a storage battery module and a solar battery module are connected in parallel, and a solar battery string including a switch between the storage battery module and the solar battery module Is a photovoltaic power generation system connected to the system via a DC / AC converter. And a photovoltaic power generation system that smoothes the photovoltaic power generation output and enables time shift by switching and taking out the combined output of the solar cell module and the storage battery module or the output of the solar cell module by the switch is known. (For example, refer to Patent Document 1).

JP 2007-201257 A

  By the way, in the era of mass introduction of photovoltaic power generation, as one of the measures for solving the above-mentioned two situations, introduction of a power load leveling system in units of one week in a consumer can be considered. It is a system that saves energy by using power during holidays when power demand is small compared to contract power, cuts demand during the daytime on weekdays, and helps reduce power demand peak. The energy storage form may be electricity, heat, hydrogen, or the like. As a realistic method at the present time, a combination of heat storage and power storage can be considered. Thermal storage technology can be used to level out heat demand and save energy, such as expanding the availability of waste heat and natural energy by eliminating the time gap between the heat generation side and the heat demand side such as heating or cooling. A big contribution. Currently, most of the heat storage systems in practical use in Japan are intended to eliminate the gap between daytime and nighttime heat demand using limited space in buildings. In addition, although there are not many examples, a long-term heat storage system has been developed to eliminate the seasonal gap. Specifically, the underground ground heat storage system uses the heat capacity and heat insulation of unused underground aquifers and ground, and stores waste heat that has little utility value in the summer to serve as a heat source for heating and hot water supply in the winter. By using it, the purpose is to level out heat demand and save energy throughout the year.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an energy storage system capable of leveling a power load on a weekly basis.

  The present invention is an energy storage system comprising a heat storage tank and a storage battery, and leveling the power load by storing the generated power of the photovoltaic power generation device in the heat storage tank or storage battery, and the past daily weather / temperature forecast data And a database for storing past power load performance data for each day, forecast data acquisition means for acquiring weather / temperature forecast data one week after the day, and weather / temperature one week after the day Similar data extracting means for extracting past daily weather / temperature forecast data similar to the forecast data from the database, and the past daily power related to the extracted past daily weather / temperature forecast data Load actual load data is read, and the past power load actual data for each day is used as power load predicted data one week after the current day. Based on, characterized by comprising a charging and discharging control of the battery, and control means for heat source operation control for heat storage in the heat storage tank.

  According to the present invention, it is possible to obtain an effect that the power load can be leveled on a weekly basis.

It is a block diagram which shows the structure of one Embodiment of this invention. It is explanatory drawing which shows an electric power load prediction method. It is explanatory drawing which shows generation | occurrence | production of the surplus electric power accompanying solar power generation mass introduction. It is explanatory drawing which shows how to determine contract electric power by a real quantity system. It is explanatory drawing which shows the electric power load leveling image per week.

  Hereinafter, an energy storage system according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 1 is a control device configured by a computer and controlling the operation of the energy storage system. Reference numeral 2 denotes a supply source of electric power supplied from the electric power company. Reference numeral 3 denotes a solar power generation device. Reference numeral 4 denotes a storage battery subject to charge / discharge control. Reference numeral 5 denotes a heat source device subject to operation control. Reference numeral 6 denotes a heat storage tank. Reference numeral 11 denotes an acquisition information database that stores input photovoltaic power generation output information, heat demand information, and weather / temperature forecast information. Reference numeral 12 denotes a monitoring unit that monitors purchased power information and solar power generation output information from the power company 11. Reference numeral 13 denotes a holiday day output predicting unit for predicting an output on the holiday day. Reference numeral 14 denotes a weekly heat demand prediction unit that predicts a heat demand for each week. Reference numeral 15 denotes a storage battery charge / discharge control unit that manages the SOC (State Of Charge) of the storage battery 4 and controls charge / discharge. The code | symbol 16 is a heat source operation control part which performs operation control of the heat source apparatus 5 based on the prediction result of a heat demand and photovoltaic power generation output.

  Next, with reference to FIG. 2, the operation | movement in which the weekly heat demand prediction part 14 shown in FIG. 1 estimates the heat demand (electric power load) for one week is demonstrated. First, in the acquisition information database 11, past daily weather / temperature forecast data and daily power load data are stored in association with each other, and weather / temperature forecast data for one week from the current day. Is accumulated. Accumulation of this acquired information is performed every day, and the weather / temperature forecast data one week after the current day is related to the power load data of this week, and the weather / temperature forecast for the past day. It is accumulated as data and data on the load of power every day.

  The weekly heat demand forecasting unit 14 uses a neural network to obtain past weather / temperature forecast data similar to the weather / temperature forecast data one week after the current date stored in the acquisition information database 11. 11 to extract. When there is no similar past weather / temperature forecast data, the most similar past weather / temperature forecast data is extracted. Then, the weekly heat demand prediction unit 14 reads out the data of the load load of the electric power for one week related to the extracted weather / temperature forecast data for the past one week from the acquired information database 11, and Output as power load prediction result information. This weekly power load prediction result information becomes a prediction result of heat demand one week after the current day.

  In this way, past weather / temperature forecast data and power load record data are stored in association with each other, and past weather / temperature forecast data similar to the one-week weather / temperature forecast data for which power load should be predicted are stored. Since the load of power related to the temperature forecast data is set as the power load to be predicted, it is possible to perform highly accurate power load prediction.

  Next, the operation of the control device 1 shown in FIG. 1 will be described with reference to FIG. First, the monitoring unit 12 inputs the purchased power information from the electric power company 2 and the photovoltaic power generation output information of the photovoltaic power generation device 3, and charges and discharges the input purchased power information and the photovoltaic power generation output information. Output to the control unit 15. The storage battery charge / discharge control unit 15 performs storage battery SOC management for storing the power generated by the solar power generation device 3 in the storage battery 4 based on the purchased power information and the photovoltaic power generation output information. Thereby, surplus electric power among the electric power generated by the solar power generation device 3 is stored in the storage battery 4.

  On the other hand, in the acquired information database 11, the actual power output information and the heat demand actual information are accumulated one by one. The holiday day output prediction unit 13 refers to the photovoltaic power output information and weather forecast data stored in the acquisition information database 11 to predict the solar power output on the holiday day, and sets the predicted photovoltaic power output value. Output to the heat source operation control unit 16. Further, the weekly heat demand prediction unit 14 performs one-week heat demand (electric power load) prediction by the above-described processing operation, and outputs the predicted electric power load value to the heat source operation control unit 16. The heat source operation control unit 16 is based on the one-week power load prediction value (heat demand) output by the weekly heat demand prediction unit 14 and the photovoltaic power generation output prediction value output by the holiday day output prediction unit 13. An operation plan for the heat source device 5 is created, and an operation command for the heat source device 5 is output based on the operation plan. At this time, the heat source operation control unit 16 inputs information on the charge / discharge control status of the storage battery charge / discharge control unit 15 and creates an operation plan of the heat source device 5 according to the charge / discharge control status. Further, the storage battery charge / discharge control unit 15 inputs information on the heat source operation command of the heat source operation control unit 16 and performs charge / discharge control according to the information on the heat source operation command.

  As described above, the control device 1 shown in FIG. 1 operates the heat source device 5 using the surplus power of the solar power generation introduced by the consumer (does not cause the power company to reverse flow) on weekends and stores heat. . Also, if the day of the holiday is rainy, or if the solar power generation output forecast on the day of the holiday is out of the range, the heat source equipment is purchased from the power company within the range of the difference between the contract power and the actual load. To store heat. Furthermore, according to the storage loss performance of the heat storage tank 6 and the storage battery 4 to be installed, for example, the heat energy stored in the heat storage tank 6 is used for peak cuts in the power demand peak hours for three days on Monday, Tuesday, and Wednesday, It is also possible to use the electrical energy stored in the storage battery for two-day peak cuts on Thursday and Friday.

  Although the storage battery 4 is easy to use because of its excellent charge / discharge speed, the construction cost of the storage battery 4 is about 1.5 times the construction cost of the heat storage tank 6. The combined use of the heat storage tank 6 can reduce the cost of the storage battery. Moreover, what is necessary is just to equip the storage battery 4 only for the part limited to the load which needs quick energy discharge | release in the case of peak cut.

  As explained above, in the era of large-scale introduction of solar power generation, it becomes a power supply destination when surplus power is generated on weekends and closed days on sunny days, preventing reverse power flow to the power company and burdening the power company Power management can be reduced. In addition, customers can effectively use green power from solar power generation and contribute to load leveling on a weekly basis. Reduction is possible, which in turn has the advantage of reducing electricity charges. In addition, the electric power company sets the unit price of electric power on holidays less than the weekday in the contract, and there is an economic advantage based on the difference.

  It is noted that a program for realizing the function of the control device 1 shown in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by a computer system and executed to store energy. Management processing may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  By storing surplus power by the generator, it can be applied to applications where it is essential to level the power load.

  DESCRIPTION OF SYMBOLS 1 ... Control apparatus, 11 ... Acquisition information database, 12 ... Monitoring part, 13 ... Holiday day output prediction part, 14 ... Weekly heat demand prediction part, 15 ... Storage battery charge / discharge control , 16 ... Heat source operation control unit, 2 ... Power supply source (electric power company), 3 ... Solar power generation device, 4 ... Storage battery, 5 ... Heat source device, 6 ... Heat storage Tank

Claims (1)

An energy storage system comprising a heat storage tank and a storage battery, and leveling the power load by storing the generated power of the solar power generation device in the heat storage tank or storage battery,
A database for storing past weather / temperature forecast data for each past day and past power load record data for each past day;
Forecast data acquisition means for acquiring weather / temperature forecast data one week after the day,
Similar data extraction means for extracting past daily weather / temperature forecast data similar to the weather / temperature forecast data one week after the day from the database;
Read the past daily power load actual data related to the extracted past daily weather / temperature forecast data, and use the past daily power load actual data for one week from the current day. An energy storage system comprising: charge / discharge control of the storage battery based on the power load prediction data; and control means for performing heat source operation control for storing heat in the heat storage tank.

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